Question: A 23-year-old woman presents to labor and delivery at 40 weeks gestation with abdominal contractions and leakage of fluid from her vagina. She subsequently undergoes an uncomplicated vaginal delivery. The child is healthy and is heated, suctioned, and stimulated. While holding her newborn, the mother endorses a headache, blurry vision, and abdominal pain. Her temperature is 98.0°F (36.7°C), blood pressure is 194/104 mmHg, pulse is 100/min, respirations are 18/min, and oxygen saturation is 98% on room air. Physical exam reveals an uncomfortable woman. There is blood in her vagina and her uterus is contracted. Her cranial nerve exam is unremarkable and she has normal strength and sensation. Laboratory studies and a urinalysis are pending. Which of the following is the most appropriate next step in management?

Answer: Magnesium

Explanation:
This postpartum patient is presenting with hypertension, headache, blurry vision, and abdominal pain, which are concerning for a diagnosis of preeclampsia. The most appropriate initial intervention is magnesium.

Preeclampsia classically presents after 20 weeks gestation (or earlier in the setting of a molar pregnancy) with hypertension and proteinuria. Other symptoms that may be indicative of preeclampsia with severe features include headaches, visual changes, and abdominal pain. Other features consistent with preeclampsia include thrombocytopenia, kidney insufficiency, impaired liver function, and pulmonary edema. The diagnosis can be supported when a pregnant patient is both hypertensive and demonstrates an elevated protein in her urine. It is possible for postpartum patients to experience preeclampsia. Though the fetus and placenta have been delivered, which is the definitive treatment of preeclampsia, further medical management is still needed. The most important initial step in management is to administer magnesium which is neuroprotective and also modestly lowers blood pressure. Further care involves blood pressure control and benzodiazepines as needed to abort seizure episodes (though note that if a patient with preeclampsia is having seizures, by definition, they have eclampsia).

Al-Safi et al. discuss preeclampsia and eclampsia. They note that postpartum preeclampsia and eclampsia can occur within the first week after delivery. They recommend that mothers should be educated on what symptoms to look for.

Incorrect Answers:
Answer A: CT head may be indicated, in particular, if an intracranial hemorrhage was thought to be the cause of this patient’s headache and vision changes. A subarachnoid hemorrhage would present with the classic “thunderclap” headache with blood in the subarachnoid space on head CT. A CTA may localize a bleeding aneurysm and a lumbar puncture would show an elevated red blood cell count in the CSF. It would not explain this patient’s hypertension and abdominal pain. Note that a CT head is not a CTV which is specific venous imaging.

Answer B: Labetalol is an appropriate blood pressure medication to give in pregnancy; however, it is more appropriate to first give magnesium as this agent is neuroprotective and is the first-line agent of choice in preeclampsia.

Answer D: MRV head or a CTV head would be appropriate in the workup of cerebral venous thrombosis which is common in the setting of hypercoagulability (such as in the postpartum period) and presents with headache, blurry vision, and seizures. Note that it would not explain this patient’s profound hypertension. It would be more reasonable to first empirically treat this patient's possible preeclampsia.

Answer E: Ondansetron and morphine would be appropriate symptomatic management of this patient but would not treat her underlying preeclampsia. It is more appropriate to first treat the life-threatening diagnosis before symptom management. If this patient’s hypertension was thought to be due to pain, then morphine could be helpful.

Bullet Summary:
Preeclampsia can occur in the postpartum period and should be managed with magnesium sulfate.


Question: A 57-year-old man is brought to the emergency department by his wife with confusion. He was seen in the emergency department 2 days ago for profuse epistaxis. His primary care provider was concerned and had advised him to go to the hospital, as the patient is on warfarin for atrial fibrillation. However, his bleeding resolved with pressure and nasal packing. Upon presentation to the ED today, his temperature is 97.6°F (36.4°C), blood pressure is 64/33 mmHg, pulse is 160/min, respirations are 32/min, and oxygen saturation is 100% on room air. Physical exam reveals an obtunded man who cannot answer questions. A dark, purpuric rash is noted on his torso and extremities. The patient’s nasal packing is removed with no further bleeding. The patient is given IV fluids and blood cultures are drawn. Which of the following should be administered first?

Answer: Clindamycin

Explanation:
This patient is presenting with nasal packing, hypotension, tachycardia, a dark, purpuric rash, and confusion, which are concerning for toxic shock syndrome. The most important initial step in management is to administer clindamycin.

Toxic shock syndrome is a life-threatening diagnosis caused by Streptococcus pyogenes or Staphylococcus aureus and occurs commonly secondary to retained tampons or nasal packing. Patients are critically ill and require immediate management with fluids, vasopressors, and blood cultures. Source control is imperative, and the foreign body causing the infection must be removed. Next, broad-spectrum antibiotics should be started immediately. Clindamycin is often preferred as the first agent as this lincosamide antibiotic not only covers Staphylococcus aureus and Streptococcus pyogenes, but also has the theoretical benefit of suppressing toxin production. Further management is centered on fluid administration, vasopressors, and monitoring and care in an ICU setting as these patients are typically critically ill.

Russell and Pachorek review the treatments for toxic shock syndrome. They note that clindamycin is particularly important in toxic shock syndrome that is complicated by toxin production. They recommend that administration may reduce toxin production and could improve outcomes.

Incorrect Answers:
Answer B: Meropenem is a broad-spectrum antibiotic that covers most organisms except for MRSA. It is generally not used as a first-line agent unless the patient has allergies to other antibiotics or the infectious organism is only sensitive to this agent. Even in toxic shock syndrome, it would not be used as a first-line agent.

Answer C: Penicillin may be used for infections such as streptococcal pharyngitis, which presents with a sore throat, fever, and tonsillar exudates. It is a relatively weaker antibiotic and would not be used in a critically ill patient with toxic shock syndrome.

Answers 4 & 5: Piperacillin-tazobactam and vancomycin represent a powerful broad-spectrum regimen of antibiotics that covers gram-positives, gram-negatives, Pseudomonas aeruginosa, and anaerobes (piperacillin-tazobactam) as well as further gram-positive coverage and MRSA (vancomycin). Though this is a potent antibiotic combination, neither of these takes priority over clindamycin given the possible benefit of toxin suppression from clindamycin. In this patient, clindamycin and piperacillin-tazobactam would be an appropriate antibiotic regimen.

Bullet Summary:
Clindamycin may suppress toxin production and should be given early in toxic shock syndrome.


Question: A 69-year-old woman presents with pain in her hip and groin. The pain is present in the morning but is nearly unbearable by the end of the day. Her medical history is notable for a treated episode of acute renal failure, diabetes mellitus, obesity, and hypertension. Her current medications include losartan, metformin, insulin, and ibuprofen. The patient recently started taking high doses of vitamin D as she believes that it could help her symptoms. She also recently fell off the treadmill while exercising at the gym. Her temperature is 98.6°F (37°C), blood pressure is 135/91 mmHg, pulse is 72/min, and respirations are 12/min. On exam, an obese woman in no distress is noted. There is pain, decreased range of motion, and crepitus on exam of her right hip. The patient points to the areas that cause her pain stating that it is mostly over the groin. Which of the following is most likely to be found on plain radiographic imaging of this patient?

Answer: Loss of joint space and osteophytes

Explanation:
This patient is presenting with pain worse on exertion, decreased range of motion, and crepitus in her hip, suggesting a diagnosis of osteoarthritis. A loss of joint space and osteophytes (reactive bone formation) would be seen on radiography.

Osteoarthritis occurs due to wear and tear of the joint typically from repeat trauma in the setting of risk factors such as obesity. Pain can be located in the hip, and can be referred to the groin or knee. The classic presentation is pain that worsens with activity. Crepitus and decreased range of motion can be found on physical exam. Common radiological findings include a loss of joint space and osteophytes. Treatment should start with conservative measures such as activity modification, weight loss, and an unloading brace. A corticosteroid injection may be appropriate as a second-line measure. Refractory cases can be treated with a total joint replacement.

Glyn-Jones et al. review the evidence regarding the diagnosis and treatment of osteoarthritis. They discuss how total joint arthroplasty operations can be limited by the lifestyle of the prosthesis and other complications. They recommend considering joint preserving options such as lifestyle modification.

Incorrect Answers:
Answer A: Femoral neck fracture would present acutely with pain in the hip and a shortened and externally rotated leg. This diagnosis is possible given the patient's recent fall; however, her other symptoms and less acute presentation suggest a diagnosis of osteoarthritis. Treatment is with a hemiarthroplasty.

Answer B: Hyperdense foci in the ureters suggest a diagnosis of renal calculi. Though this patient's referred pain to the groin, history of renal failure, and possible hypercalcemia (due to increased vitamin D intake) could suggest this diagnosis, her other symptoms are more suggestive of osteoarthritis. Treatment is lithotripsy or stone removal for larger kidney stones.

Answer D: Normal radiography would be found with a minor sprain/muscular injury which presents with a self-limited course of pain and tenderness over the affected muscle. Treatment is with rest, ice, compression, and elevation.

Answer E: Posterior displacement of the femoral head suggests a diagnosis of posterior hip dislocation. Posterior hip dislocation would present with a shortened and internally rotated leg and a more acute presentation. Treatment is with closed reduction of the hip under sedation.

Bullet Summary:
Osteoarthritis presents with joint pain that is worse with exertion and radiographical findings of decreased joint space and osteophytes.


Question: A 7-year-old adopted boy presents to the emergency department after fainting. He just switched from being home-schooled to public school and joined the basketball team. He has fainted several times during basketball practices. He did not sustain any injuries or have any prodromes prior to these episodes. He is usually unconscious for less than a minute. He is otherwise healthy and has met all developmental milestones. He does not currently take any medications. His temperature is 97.6°F (36.4°C), blood pressure is 104/54 mmHg, pulse is 100/min, respirations are 19/min, and oxygen saturation is 98% on room air. Physical exam reveals a well-appearing and playful boy. An ECG is performed as seen in Figure A. An echocardiogram is ordered and pending. Which of the following is the most likely diagnosis?

Answer: Arrhythmogenic right ventricular dysplasia

Explanation:
This adopted pediatric patient is presenting with recurrent syncope and an ECG demonstrating an epsilon wave and T wave inversions, which are concerning for arrhythmogenic right ventricular dysplasia.

An epsilon wave is a small positive deflection at the end of the QRS complex. This is an ominous finding and suggests a diagnosis of arrhythmogenic right ventricular dysplasia (ARVD) though it may also be seen in other infiltrative diseases such as sarcoidosis or after ischemic events. ARVD is an autosomal dominant condition where there is fatty infiltration of the right ventricular wall predisposing the patient (classically younger patients) to sudden cardiac death from lethal ventricular dysrhythmias. The epsilon wave is the most specific finding; however, other findings include T wave inversion in V1-V3 or a left bundle branch appearance with frequent premature ventricular complexes among other possibilities. This is a potentially lethal diagnosis and requires management with antiarrhythmics (such as beta-blockers or amiodarone) and the placement of an implantable cardioverter-defibrillator.

Kayser et al. review AVRD. They note the presentation and management of ARVD and how it may present initially only with syncope. Cardiac arrest is a possible presentation as well. They recommend early detection and treatment with an implantable cardioverter-defibrillator to prevent death in this population.

Figure/Illustration A is an ECG with an epsilon wave (red arrow) and inverted T waves in V1/V2 (blue arrows) concerning for ARVD.

Incorrect Answers:
Answer B: Brugada syndrome is an autosomal dominant mutation in cardiac ion channels that presents with a possible right bundle branch pattern with ST segment elevation in V1-V3 or ST coving in these same leads. It may present with syncope.

Answer C: Hypertrophic obstructive cardiomyopathy presents with syncope, sudden death, or cardiac arrest in a young patient associated with exertion or dehydration. It can cause obstruction of the left ventricular outflow tract. A systolic murmur can be heard on cardiac auscultation and echocardiography can confirm the diagnosis. ECG will demonstrate large voltages in V1-V5.

Answer D: QT prolongation can lead to torsades des pointes which presents with twisting of the QRS complexes around an isoelectric baseline. It may present with syncope, hemodynamic instability, or cardiac arrest. Medications, infection, and congenital conditions may prolong the QT interval.

Answer E: Wolff Parkinson White syndrome presents with a delta wave on ECG or a slurred upstroke of the QRS complex. It may cause syncope and evolve into other dysrhythmias including supraventricular tachycardia and ventricular tachycardia.

Bullet Summary:
Arrhythmogenic right ventricular dysplasia (ARVD) may cause syncope or cardiac arrest, and presents on ECG with an epsilon wave.


Question: A 48-year-old woman, gravida 3 para 3, presents to the clinic with a 5-month history of intermittent loss of urine. Her urinary leaking occurs throughout the day and night, and she often has to get up to use the bathroom while asleep. Exercising does not affect the loss of urine. She states that she often cannot make it to the bathroom in time once she senses a need to void. Her last menstrual period was 2 weeks ago. Her urinalysis is unremarkable, and her postvoid residual volume is 40 mL. On pelvic examination, there is no dribbling of urine when the patient coughs. Physical exam is otherwise unremarkable. Which of the following is the most likely diagnosis?

Answer: Urge incontinence

Explanation:
This patient with a sudden need to void followed by loss of urine with urgency (unable to make it to the bathroom in time) most likely has urinary urge incontinence.

Urge incontinence is a form of urinary incontinence characterized by a sudden urge to urinate, resulting in the involuntary leakage of urine. Normally, bladder contraction occurs due to the stimulation of muscarinic receptors in the detrusor muscle. Urinary urge incontinence is due to detrusor overactivity, leading to a sudden and frequently overwhelming need to void that occurs throughout the day and night. The most common cause is idiopathic, though it may be secondary to neurologic disorders (e.g., spinal cord injury or multiple sclerosis), bladder abnormalities, or chronic bladder inflammation. Workup is first centered on ruling out a urinary tract infection with a urinalysis. The diagnosis is made with urodynamic studies, and first-line treatment involves bladder training and pelvic floor exercises. Should first-line treatment of urge incontinence fail, antimuscarinic medications (such as oxybutynin) which reduce acetylcholine activity on muscarinic receptors can decrease detrusor contraction and thus the sense of urgency.

Nandy and Ranganathan review urge incontinence. They note that it presents with leakage of urine associated with a sudden urge to urinate. They recommend an appropriate history and workup to first rule out other causes.

Incorrect Answers
Answer A: Genitourinary syndrome of menopause represents urinary symptoms (stress and/or urge incontinence) due to vaginal dryness and atrophy from menopause. This patient still has menstrual cycles and no symptoms of ovarian follicle depletion (narrowed introitus, vulvovaginal dryness and irritation, irregular vaginal bleeding), making this an unlikely diagnosis.

Answer B: Mixed urinary incontinence presents with features of both stress and urge incontinence. This patient lacks symptoms of stress incontinence given a lack of incontinence with increases in intrabdominal pressure (such as exercise, coughing, laughing, or sneezing).

Answer C: Overflow incontinence is caused by impaired detrusor muscle activity or bladder outlet obstruction. It presents with constant involuntary dribbling or urine and incomplete bladder emptying. Post-void residual volume is increased in patients with overflow incontinence.

Answer D: Stress incontinence is caused by urethral hypermobility and otherwise insufficient urethral support. It presents with urinary leakage with activities that increase intraabdominal pressure (such as coughing, sneezing, laughing, and exercising). This patient’s symptoms are unrelated to exercise.

Bullet Summary:
Urge incontinence presents with sudden urinary urgency with a normal post-void residual volume and absence of findings consistent with urinary tract infection.


Question: A 51-year-old man presents for his annual wellness visit with his primary care physician. His wife has noticed a tremor while he is working on his car and knows that his father died of Parkinson disease. He says that the tremor is nothing to worry about and only occurs during a few activities such as pouring drinks, pointing the remote at the television, or fixing his car. The patient states his wife is just overreacting. His medical problems include hypertension, diabetes, and hyperlipidemia for which he takes lisinopril, metformin, and atorvastatin. He has 3-5 drinks of scotch per night before working on his car. On physical exam, the tremor is replicated during finger to nose testing. Romberg sign is negative. Cranial nerves II-XII are intact. The rest of the exam is benign. Which of the following is the most appropriate treatment for this patient's tremor?

Answer: Propranolol

Explanation:
This patient who presents with a tremor that only occurs during terminal activity and is likely improved by alcohol (hence why he drinks prior to working on the car) has benign essential tremor. This is best treated with propranolol.

Benign essential tremor is a type of rhythmic oscillatory movement that occurs with posturing and action. The pathophysiology of this disorder is unclear; however, it classically gets worse with actions that require terminal positioning of the extremities such as pouring a drink or pointing a television remote. The tremor improves with alcohol consumption so patients will often self-medicate with alcoholic drinks. There is a strong genetic component, with an autosomal dominant pattern of inheritance with incomplete penetrance. The best method of replicating the tremor is with the finger-nose-finger test because this requires the patient to perform a precise activity at a terminal distance. The diagnosis is made clinically. Treatment is with propranolol or primidone, which are both considered first-line agents although the latter has less evidence for its efficacy.

Paparella et al. studied the effects of propranolol on head and upper extremity movements in patients with benign essential tremors. They found that this medication has no effect on head movements but reduces the number of upper extremity tremors in these patients. They recommended that agents other than propranolol should be used for the treatment of head tremors in these patients.

Incorrect Answers:
Answer A: Alcoholics anonymous is the first-line treatment for patients with alcohol use disorder; however, the tremors that occur during alcohol withdrawal are not isolated to movements during terminal activities. Alcohol withdrawal also presents with other signs including restlessness, diaphoresis, and insomnia. More severe cases can present with hallucinations and seizures. The response of this patient's tremor to alcohol consumption is typical of patients with benign essential tremor.

Answer B: Aripiprazole and other atypical antipsychotic medications can be used in patients with Tourette syndrome; however, these patients will present with involuntary tics rather than a tremor that only occurs during a voluntary activity at the terminal range of motion. Moreover, for the diagnosis of Tourette syndrome, both motor and phonic tics must be present.

Answer C: Carbidopa can be used in the treatment of Parkinson disease; however, the tremor associated with this disease classically occurs at rest and is described in character as a "pill-rolling" tremor. The other features of Parkinson disease include bradykinesia or akinesia, rigidity, and postural instability.

Answer D: Phenobarbital can be used in the treatment of Huntington disease; however, the involuntary movements seen in this disease are classically choreiform rather than intention tremor. Huntington disease presents with chorea, psychiatric illness, and depression. There is commonly a strong genetic predisposition, as it is a trinucleotide repeat disorder that exhibits anticipation.

Bullet Summary:
Propranolol can be used in the treatment of patients with benign essential tremor, which presents with an action tremor that is alleviated by alcohol use.


Question:
A 26-year-old woman presents to the clinic with diarrhea, bloating, flatulence, and abdominal cramps. These symptoms have been going on for 2 months. She has lost 6 pounds (2.7 kg) over these 2 months. Her medical history is significant for mild intermittent asthma for which she uses an albuterol inhaler as needed. She is sexually active with 1 male partner. She recently returned from South India following a mission trip for 6 weeks. Her temperature is 98.6°F (37.0°C), blood pressure is 105/70 mmHg, pulse is 95/min, and respirations are 14/min. On examination, the patient’s skin is pale. Labs are obtained and show the following results:

Leukocyte count: 4,500/mm^3
Hemoglobin: 10.5 g/dL
Platelets: 110,000/mm^3
Mean corpuscular volume (MCV): 116 µm^3
Reticulocyte count: 0.5%

A biopsy of the small bowel reveals blunting of villi and a mixed infiltration of lymphocytes, plasma cells, and eosinophils. Which of the following is the most likely diagnosis?

Answer: Tropical sprue

Explanation:
The patient is presenting with chronic diarrhea, weight loss, megaloblastic anemia (low hemoglobin and elevated MCV), and a biopsy showing blunted villi and mixed infiltrate following significant travel to South India. This is consistent with tropical sprue.

Tropical sprue is characterized by chronic diarrhea that occurs after travel to an endemic area. It is thought to be due to a bacterial overgrowth/infection that then damages the intestinal mucosa. Endemic areas include the Caribbean, Southeast Asia, and South India. Patients present with chronic diarrhea, abdominal discomfort/cramps, progressive weight loss, and clinical features of malabsorption. Patients with tropical sprue can develop megaloblastic anemia (low hemoglobin and elevated MCV) from a deficiency in folate and vitamin B12 absorption. A small bowel biopsy would show blunting of the villi and infiltration of lymphocytes, plasma cells, and eosinophils. Microorganisms may also be seen. Treatment is an oral tetracycline and folic acid for 3-6 months.

McCarroll et al. study the relationship between infectious gastroenteritis and tropical sprue. In a case-control study, the authors found that prior infectious gastroenteritis increased the risk of tropical sprue. The authors recommend treatment of suspected tropical sprue with oral folic acid replacement.

Incorrect Answers:
Answer A: Celiac disease can present similarly to tropical sprue with chronic diarrhea, abdominal pain, and weight loss. A small intestine biopsy can similarly show villous atrophy and a lymphocytic infiltrate, as well as crypt hyperplasia. Celiac disease is an immune response to gluten, while symptoms of tropical sprue are not diet-associated. The development of symptoms following significant travel (lasting at least several weeks) to an endemic country should raise suspicion for tropical sprue.

Answer B: Crohn disease presents with chronic diarrhea, abdominal pain, weight loss, skip lesions anywhere from mouth to anus, extraintestinal manifestations, and signs of malabsorption. A biopsy will show transmural inflammation with noncaseating granulomas, giant cells, and aggregates of lymphocytes in the lamina propria.

Answer C: Giardia is a parasite that is endemic in the tropics and North American mountain regions. Patients present with foul-smelling diarrhea, excessive gas, and nausea. Diagnosis can be confirmed with a stool analysis or immunoassay. Though a biopsy is normally not indicated, it would show mild lymphocytic infiltration and Giardia trophozoites on the intestinal surface.

Answer E: Whipple disease is caused by the bacteria Tropheryma whipplei. Patients present with diarrhea, abdominal pain, and signs of malabsorption. Extraintestinal symptoms such as arthritis are common. A biopsy of the small intestine would show Periodic acid-Schiff (PAS)-positive foamy macrophages in the lamina propria.

Bullet Summary:
Tropical sprue presents with diarrhea, abdominal cramping, weight loss, megaloblastic anemia due to malabsorption, and a small bowel biopsy showing villi blunting following travel to an endemic area such as South Asia or the Caribbean.


Question: A 33-year-old woman presents to the emergency department with muscle spasms. She has noticed "twitching" in both her upper and lower extremities over the past 3 days that have interfered with her training for a marathon. She has felt more fatigued over the past month. She has no significant medical history. She takes no medication other than whey protein supplements, a multivitamin, and fish oil. Her temperature is 98.5°F (36.9°C), blood pressure is 103/71 mmHg, pulse is 105/min, respirations are 11/min, and oxygen saturation is 100% on room air. Physical exam reveals a thin woman with thinning hair. She appears pale and her mucous membranes are dry. Her neurological and cardiac exams are unremarkable. Laboratory studies are ordered as seen below. Hemoglobin: 10 g/dL Hematocrit: 30% Leukocyte count: 6,100/mm^3 with normal differential Platelet count: 187,500/mm^3 Serum: Na+: 130 mEq/L Cl-: 100 mEq/L K+: 2.3 mEq/L HCO3-: 28 mEq/L BUN: 40 mg/dL Glucose: 79 mg/dL Creatinine: 0.9 mg/dL Ca2+: 8.2 mg/dL Mg2+: 1.8 mg/dL Thyroid stimulating hormone (TSH): 4.0 mIU/L Free T4: 0.4 ng/dL (normal: 0.7-1.53 ng/dL) The patient is given 4 liters of lactated ringer solution and 40 mEq of potassium. Her repeat whole blood potassium 3 hours later is 2.4 mEq/L, and her repeat BUN is 20 mEq/L. Another 40 mEq of potassium is administered. Another repeat whole blood potassium is 2.5 mEq/L. The patient’s muscle spasms persist. Which of the following is the most likely underlying etiology for this patient’s chief concern?

Answer: Hypomagnesemia

Explanation:
This patient is presenting with what appears to be anorexia nervosa (thin habitus, possible excessive exercise in the setting of marathon running, thinning hair, dry mucous membranes, decreased free T4 level, and multiple electrolyte derangements). The lack of improvement in either her muscle spasms with fluid repletion or her hypokalemia with adequate repletion, even in the setting of normal serum magnesium, suggests depleted magnesium stores are the underlying etiology of her symptoms.

Hypomagnesemia typically occurs in alcoholics, malnourished patients, and patients with eating disorders such as anorexia or bulimia nervosa. Patients may present with a wide array of symptoms including weakness, confusion, dysrhythmias, hypotension, and overall malaise. Hypomagnesemia can cause hypocalcemia as magnesium is needed for proper parathyroid hormone secretion. Another pathognomonic finding associated with hypomagnesemia is hypokalemia which is refractory to repletion. The pathophysiology is thought to be due to increased potassium wasting in the kidney due to increased activity of renal outer medullary potassium (ROMK) channels. The serum magnesium level should be checked and repletion should occur accordingly. Serum magnesium levels represent 1% or less of total body magnesium stores and do not reflect if a patient truly has hypomagnesemia, particularly if there is intracellular depletion (such as in chronically malnourished patients). Thus, any patient with findings consistent with hypomagnesemia with normal serum magnesium should have their other electrolytes repleted and be given magnesium. Magnesium repletion is a safe intervention with a wide therapeutic index, and the serum level often does not correlate with total body stores.

Razzaque discusses the relationship between serum magnesium levels and total body magnesium status. The author finds that inadequate magnesium balance is associated with myriad disorders including skeletal deformities, cardiovascular diseases, and metabolic syndrome. The author recommends the use of the magnesium loading test to provide more accurate reflections of total body magnesium status.

Incorrect Answers:
Answer A: Hypocalcemia may present with perioral numbness, paresthesias, and muscle spasms. It can occur secondary to poor nutrition, vitamin D deficiency, and hypoparathyroidism. Low serum calcium may also be seen in patients with low albumin and in states of hyperventilation (which lowers the free calcium but not the total calcium due to a respiratory alkalosis that causes albumin to bind free calcium and release protons). Hypomagnesemia can also cause hypocalcemia as magnesium is needed for proper parathyroid hormone release.

Answer C: Hyponatremia may present with malaise, nausea, vomiting, headache, and confusion. Patients may also be asymptomatic in mild cases. Asymptomatic patients with hyponatremia and functioning kidneys require only fluid restriction. On the other hand, severe hyponatremia presents with very low sodium (often < 120 mEq/L) and neurological symptoms such as profound confusion or seizures. Treatment with hypertonic saline would be indicated in this situation.

Answer D: Hypothyroidism presents with fatigue, malaise, weight gain, bradycardia, scarce lanugo, and depression. This patient’s TSH is on the high end of normal and her T4 is lower than the cutoff value. However, this is likely a compensatory response to her low BMI and excessive exercise in order to slow down her metabolism to conserve energy.

Answer E: Hypovolemia was certainly present in this patient given her dry mucous membranes and prerenal pattern of labs (BUN:Cr ratio > 20:1). After receiving 4L of fluids, it is clear that dehydration is not the cause of her symptoms as her BUN corrects and her symptoms persist. In general, hypovolemia should be treated with oral rehydration, if possible.

Bullet Summary:
Hypomagnesemia can cause hypocalcemia and hypokalemia refractory to repletion (a normal serum level does not indicate normal intracellular levels of magnesium).


Question: A 70-year-old woman is brought to the emergency department by ambulance. She was found on the floor of her apartment after her neighbor called 911. She is confused and is unable to provide any history, but complains of generalized pain. Her temperature is 99.2°F (37.3°C), blood pressure is 129/64 mmHg, pulse is 63/min, respirations are 13/min, and oxygen saturation is 99% on room air. Physical exam reveals, a confused, ill-appearing woman. Lungs are clear to auscultation bilaterally. An electrocardiogram is obtained as shown in Figure A. Dipstick urinalysis is notable for 4+ blood and dark colored urine. Which of the following is the most appropriate next step in management?

Answer: Calcium gluconate

Explanation:
This patient with confusion, dark urine, and peaked T waves on electrocardiogram in the setting of a prolonged time spent down likely has developed rhabdomyolysis with associated hyperkalemia. For patients with suspected hyperkalemia and electrocardiogram changes, the most appropriate next step in management is treatment with calcium gluconate

Rhabdomyolysis occurs when muscle cells lyse and release their intracellular contents. This can occur secondary to intense athletics, seizures, stimulant drug use, or a prolonged period of immobility. Lysis of muscle cells leads to release of potassium, myoglobin, purines, and other intracellular contents. Release of large amounts of myoglobin can result in renal impairment and myoglobinuria. On dipstick urinalysis, myoglobin causes a positive result for blood. Renal impairment further increases the risk for development of hyperkalemia. On ECG, hyperkalemia manifests with a "peaked" appearance of T waves, especially in the precordial leads. As hyperkalemia worsens, electrocardiogram changes progress to loss of P waves, QRS complex widening, and eventual sine wave rhythm. For patients with suspected hyperkalemia and characteristic changes noted on the electrocardiogram, the most appropriate immediate step in management is treatment with intravenous calcium gluconate. Calcium gluconate acts to stabilize cardiac myocyte membranes and prevent development of life-threatening arrhythmias.

Gupta et. al review rhabdomyolysis. They discuss the pathophysiology, clinical manifestations and diagnosis. They further detail complications that may arise such as hyperkalemia, and discuss respective management strategies.

Figure A demonstrates an electrocardiogram with features characteristic of hyperkalemia. Note the peaked appearance of the T waves in the precordial leads.

Incorrect Answers:
Answer A: Albuterol and IV fluid resuscitation may eventually be appropriate. Albuterol (a beta agonist) will act to shift potassium to the intracellular compartment. This patient's electrocardiogram changes warrant immediate treatment with calcium gluconate in order to stabilize cardiac myocyte membranes.

Answer C: Insulin, glucose, and IV fluid resuscitation are indicated in this patient. Insulin acts to shift potassium to the intracellular compartment, and fluid resuscitation is warranted for the patient's likely renal impairment. Calcium gluconate is the more immediate priority to prevent development of arrhythmia.

Answer D: IV fluid resuscitation is indicated for this patient with likely renal impairment. However, calcium gluconate is the more immediate priority to address this patient's hyperkalemia and prevent development of arrhythmia.

Answer E: Sodium polystyrene is an oral potassium binder that increases GI excretion of potassium. It may be appropriate to treat mild hyperkalemia in some patients. It takes a prolonged amount of time to have any significant effect.

Bullet Summary:
For patients with suspected hyperkalemia and characteristic changes noted on ECG, the most appropriate immediate step in management is treatment with intravenous calcium gluconate.


Question: A 3-week-old girl presents with her parents to her pediatrician for a routine visit. The child is sleeping at regular 2-hour intervals and feeding and stooling well. The parents have noticed a “swelling of the belly button.” Cord separation occurred at 7 days of age. The swelling seems to come and go but is never larger than the size of a blueberry. They deny any drainage from the swelling. Her temperature is 98.6°F (37°C), blood pressure is 68/43 mmHg, pulse is 128/min, and respirations are 32/min. On physical exam, the child is in no acute distress and appears developmentally appropriate for her age. Her abdomen is soft and non-tender with a soft, 1 cm bulge at the umbilicus. The bulge increases in size when the child cries and can be easily reduced inside the umbilical ring without apparent pain. Which of the following is the most appropriate next step in management?

Answer: Expectant management

Explanation:
This infant presents with a soft, 1 cm bulge at the umbilicus that is easily reducible inside the umbilical ring, which suggests a diagnosis of an umbilical hernia. Most umbilical hernias in children resolve spontaneously and can be managed expectantly.

An umbilical hernia is a protrusion of bowel, omentum, or preperitoneal fat through the umbilical ring that can change in size with increases in intra-abdominal pressure (e.g., crying). The majority of umbilical hernias in patients under 5 years of age resolve spontaneously. The indications for surgery on umbilical hernias in that age group are limited to incarcerated hernias or hernias > 1.5 cm in diameter. Incarcerated hernias present with an irreducible mass that is associated with pain and erythema. Surgical closure may be considered in patients whose defects fail to close by the age of 5.

Chirdan et al. review the evidence regarding the diagnosis and treatment of pediatric patients with an incarcerated umbilical hernia. They discuss how most patients with hernias resolve spontaneously before 5 years of age but a small number will have incarcerated hernias that require surgery earlier. They recommend active observation of patients to diagnose incarceration earlier.

Incorrect Answers:
Answer A: Elective surgical management later on in childhood is usually not required to manage umbilical hernias as most umbilical hernias in patients less than 5 years of age close spontaneously. Hernias that persist past age 5 can be closed surgically in an elective fashion.

Answer C: Histopathologic evaluation would be the most appropriate next step in management if the patient had an unknown umbilical mass, such as an umbilical granuloma or polyp. Umbilical granulomas form shortly after birth from excess tissue at the base of the umbilicus and can be treated topically, whereas umbilical polyps are firm masses of omphalomesenteric duct or urachal embryologic remnants and require surgical excision.

Answer D: Immediate surgical management is required in patients with incarcerated hernias, but this patient’s hernia is easily reducible and < 1.5 cm. Incarcerated hernias present with an irreducible mass that is associated with pain and erythema.

Answer E: Thyroid hormone replacement would be indicated in newborns that suffer from hypothyroidism which could present with an umbilical hernia. This patient has no other symptoms of hypothyroidism such as dry skin, hypoactive reflexes, constipation, poor muscle tone, and coarse facial features.

Bullet Summary:
Umbilical hernias are common in children and usually resolve spontaneously in children under 5 years of age.


Question: A 72-year-old man presents to his primary care physician for a general checkup. The patient works as a farmer and has no concerns about his health. He has a medical history of hypertension and obesity. His current medications include lisinopril and metoprolol. His temperature is 99.5°F (37.5°C), blood pressure is 177/108 mmHg, pulse is 90/min, respirations are 17/min, and oxygen saturation is 98% on room air. Physical exam is notable for a murmur after S2 over the left sternal border. The patient demonstrates a stable gait and 5/5 strength in his upper and lower extremities. Which of the following is another possible finding in this patient?

Murmur that radiates to the carotids during systole

Answer: Femoral artery murmur

Explanation:
This patient is presenting with aortic regurgitation which could be associated with Duroziez sign (femoral artery murmur).

Aortic regurgitation occurs when the aortic valve closes improperly resulting in retrograde flow during diastole. This is auscultated as a diastolic murmur heard best over the left upper sternal border and the left lower sternal border. This murmur typically occurs in elderly patients and the retrograde flow through the aorta cause a number of physical exam findings. These include a wide pulse pressure, fingernail pulsations, head bobbing, and femoral artery murmur. Treatment is with surgical valve replacement.

Sapira reviews the evidence regarding the physical exam findings in aortic regurgitation. He discusses how Duroziez sign can often be seen in patients with this disease. He recommends using these signs to properly identify patients.

Incorrect Answers:
Answer A: An audible click heard at the cardiac apex describes mitral valve prolapse which typically is asymptomatic and presents in younger women. Treatment is with surgical valve replacement in symptomatic patients.

Answer C: A murmur that radiates to the carotids during systole describes aortic stenosis which is possible in this patient except for the fact that his murmur is diastolic. Treatment is with valvuloplasty or with surgical valve replacement.

Answer D: A rumbling heard at the cardiac apex describes mitral valve stenosis which presents with a diastolic murmur best heard at the cardiac apex. Treatment is with valvuloplasty or with surgical valve replacement.

Answer E: A wedge pressure lower than expected would be seen in tricuspid regurgitation. In tricuspid stenosis, less blood flows to the lungs and thus the left heart, resulting in a low wedge pressure. Treatment is with identification of the underlying cause and valve replacement.

Bullet Summary:
Aortic regurgitation is associated with a wide pulse pressure, fingernail pulsations, head bobbing, and a femoral artery murmur.


Question: A 69-year-old man presents to clinic due to shortness of breath, worsening pain in his right shoulder, and episodes of hemoptysis. His symptoms began 3 months ago. He has also lost 18 pounds. He has a history of coronary artery disease and underwent an uncomplicated coronary angioplasty with stent placement 2 years ago. He routinely travels both domestically and internationally as a senior shipyard worker and has a 30-pack-year smoking history. He used to drink 4 cocktails a week. He has not smoke or drank alcohol in over 7 years. His temperature is 99.5°F (37.7°C), blood pressure is 140/60 mmHg, pulse is 97/min, and respirations are 13/min. Physical exam is notable for right pupillary constriction as well as paresthesias in his right fourth and fifth digits. There is no pain with active shoulder rotation. His chest imaging is shown in Figure A. Which of the following is most likely responsible for the patient’s symptoms?

Answer: Lung adenocarcinoma

Explanation:
This elderly patient with an extensive smoking history is presenting with hemoptysis, weight loss, and shortness of breath. Combined with neurological findings in the ulnar nerve distribution (paresthesias in fourth and fifth digits) and imaging evidence of a superior right lung mass, the most likely diagnosis is a Pancoast tumor, which is most commonly a lung adenocarcinoma.

A Pancoast tumor is a peripheral lung cancer often caused by lung adenocarcinoma or squamous cell carcinoma and is often located in the superior sulcus of the lung. The most important risk factor is smoking. This tumor causes compression of adjacent structures. Patients can present with severe, localized axilla pain (due to invasion of the brachial plexus), weakness of intrinsic hand muscles with radicular pain and paresthesias in the fourth and fifth digits (due to invasion of the C8-T1 portion of the brachial plexus), Horner syndrome (miosis, ptosis, and facial anhidrosis due to invasion of the cervical sympathetic nerves), hoarseness (due to invasion of the recurrent laryngeal nerve), and edema of the arm with facial swelling (due to compression of the superior vena cava). Treatment is varied and involves a combination of radiation, chemotherapy, and surgery.

Wu et al. studied the role of the tyrosine-kinase inhibitor, osimertinib, in the treatment of completed resected epidermal growth factor receptor (EGFR)-mutated non-small cell lung cancer (NCSLC). The authors find that 89% of patients in the osimertinib group and 52% of the placebo groups were alive and disease free at 24 months. The authors recommend the use of osimertinib in patients with stage IB to IIIA EGFR-mutated NSCLC.

Figure/Illustration A demonstrates a right apical lung mass found on computed tomography (CT) scan (green arrow).

Incorrect Answers:
Answer B: Mesothelioma is a neoplasm of the pleura found in people with occupational exposures to asbestos, such as shipyard workers. While this neoplasm can present with hemoptysis and dyspnea, chest imaging of mesothelioma reveals pleural plaques and thickening, not an isolated apical lung lesion.

Answer C: Rotator cuff tendinopathy presents with pain with abduction and external rotation of the arm. This patient has no pain with active shoulder rotation.

Answer D: Syringomyelia is a cyst or cavity in the spinal column that can cause Horner syndrome and fluctuating radicular pain. It is unlikely to cause hemoptysis, weight loss, and the chest imaging findings in this patient.

Answer E: Tuberculosis is a possible diagnosis in this patient with hemoptysis, weight loss, and extensive travel history. Tuberculosis often presents with a fever and does not usually cause shoulder pain.

Bullet Summary:
Pancoast tumor presents with shoulder pain, cervical radiculopathy, Horner syndrome, and hoarseness and should be suspected in a patient with a smoking history and an apical lung mass on imaging.


Question: A 36-year-old woman, G1P1001, presents to her gynecologist for an annual visit. She has a medical history of hypertension for which she takes hydrochlorothiazide. The patient’s mother had breast cancer at age 68, and her sister has endometriosis. She states that she feels well and has no complaints. Her temperature is 98.6°F (37.0°C), blood pressure is 138/74 mmHg, pulse is 80/min, and respirations are 13/min. Her BMI is 32.4 kg/m^2. A pelvic exam reveals a non-tender, 12-week-size uterus with an irregular contour. A transvaginal ultrasound is performed and demonstrates two intramural leiomyomas. Which of the following is a likely complication of this patient’s condition?

Answer: Iron deficiency anemia

Explanation:
This patient presents with an irregularly enlarged uterus on examination consistent with the intramural leiomyomas (fibroids) seen on ultrasound. Leiomyomas increase the risk of iron deficiency anemia due to heavy menstrual bleeding.

Leiomyoma are benign overgrowths of myometrial tissue. The most common presentation is heavy or prolonged menstrual bleeding or symptoms related to mass effect such as pelvic pressure or pain.. Affected women often develop these symptoms in their 30s or 40s, though they may occur at any age, and many are asymptomatic. Risk factors include early menarche, obesity, family history, and African American race. Submucosal fibroids that disrupt the endometrium may cause heavy menstrual bleeding. Intramural fibroids also commonly cause heavy bleeding despite the fact that they do not disrupt the endometrium due to alterations in the uterine vasculature. Patients may be managed medically with a wide range of options including oral contraceptive pills, tranexamic acid, and GnRH agonists. Definitive management is with surgical intervention. Myomectomy is preferred for patients that desire child bearing in the future. For those that do not have plans for pregnancy in the future, hysterectomy is recommended.

Yang et. al review the diagnosis and management of uterine fibroids. They note the range of clinical presentations to include heavy menstrual bleeding. They discuss management to include surgical intervention with myomectomy or hysterectomy.

Incorrect Answers:
Answer A: Amenorrhea, or the absence of menstrual bleeding, is often due to anovulation or uterine adhesions. Uterine fibroids are not associated with amenorrhea.

Answer B: Endometrial cancer is a known cause of heavy menstrual bleeding. However, this patient’s ultrasound notes the presence of intramural leiomyomas. Her age, history, and ultrasound findings are not suggestive of endometrial cancer.

Answer D: Uterine prolapse is associated with multiparity, chronically increased intra-abdominal pressure (from chronic obstructive pulmonary disease, obesity, etc.), and connective tissue diseases. While fibroids rarely may prolapse, they typically do not cause the entire uterus to prolapse.

Answer E: Uterine sarcoma may very rarely result from uterine fibroids, as both arise from the uterine smooth muscle. However, this patient’s history and ultrasound findings are more suggestive of uterine leiomyoma.

Bullet Summary:
Patients with uterine leiomyomata (fibroids) are at risk for iron deficiency anemia due to heavy bleeding.


Question: A 77-year-old man presents to the emergency department acutely obtunded. The patient lives alone and was found unresponsive by his son. Generally, the patient manages his own finances, medications, and works part-time. He has not been responding to phone calls for the past 3 days. The patient is unable to offer a history. He has a past medical history of hypothyroidism, depression, and diabetes. His temperature is 88.0°F (31.1°C), blood pressure is 92/62 mmHg, pulse is 35/min, respirations are 9/min, and oxygen saturation is 92% on room air. The patient is cold to the touch and moves all extremities to painful stimuli. His pupils are reactive and sluggish, and he does not follow commands. There are no signs of trauma or skin infections. The patient is started on IV fluids and hydrocortisone, is externally warmed, and is started on a norepinephrine drip. An ECG is performed as seen in Figure A. Which of the following is the most appropriate next step in management?

Answer: Levothyroxine administration

Explanation:
This elderly patient with a past medical history of hypothyroidism is presenting with altered mental status, hypotension, hypothermia, and bradycardia, which are concerning for myxedema coma. Empiric and immediate treatment with levothyroxine is the appropriate management of this condition prior to confirming the diagnosis with lab studies.

Myxedema coma is a life-threatening complication of hypothyroidism. It presents with stupor/obtundation, bradycardia, hemodynamic instability, and hypothermia. With a high clinical suspicion, appropriate history, physical exam, and vitals, it is appropriate to first treat the patient with IV hydrocortisone (or another highly potent steroid) and levothyroxine prior to confirming the diagnosis given the high morbidity and mortality associated with this condition. Triiodothyronine is given in some circumstances as well (in more ill patients) but is less dire than first giving levothyroxine. Subsequently, the diagnosis can be confirmed with a serum thyroid stimulating hormone (TSH) and free T4 level. Patients are critically ill and typically require further care in an ICU.

Wall discusses the management of myxedema coma. He notes this is a potentially lethal condition. He recommends immediate administration of IV levothyroxine.

Figure A is an ECG with sinus bradycardia.

Incorrect Answers:
Answers 1, 3, & 4: Thyroid stimulating hormone and free T4 levels should certainly be obtained; however, the mortality for myxedema coma is so high that empiric treatment with levothyroxine should be started with clinical suspicion alone prior to confirming the diagnosis with laboratory studies, as a delay in therapy could increase morbidity and mortality. After administration of levothyroxine and initial supportive therapy, the diagnosis can be supported with laboratory studies.

Answer E: Triiodothyronine or T3 could be appropriate in patients with myxedema coma in severe scenarios where patients do not respond to levothyroxine. In some cases, it may also be given empirically but does not take priority over T4 administration.

Bullet Summary:
In myxedema coma, empiric treatment with levothyroxine is appropriate with a high clinical suspicion for the diagnosis prior to laboratory confirmation.


Question: A 39-year-old man presents to his doctor for a wellness checkup. He is concerned about a rash that does not seem to be improving. He was recently exposed to his grandfather who has vesicular lesions on his skin and is being treated. He has a family history of skin cancer, colon cancer, and ovarian cancer. The patient has a medical history of asthma and seasonal allergies. His temperature is 98.6°F (37.0°C), blood pressure is 137/98 mmHg, pulse is 90/min, respirations are 14/min, and oxygen saturation is 98% on room air. Physical exam reveals the finding in Figure A. Which of the following describes this patient's most likely diagnosis?

Answer: Benign capillary proliferation

Explanation:
This patient who presents with red raised papules is presenting with a cherry angioma. These lesions are composed of benign capillary proliferations.

Cherry angiomas present with cherry red macules/papules that occur secondary to benign capillary and venule proliferation. The lesions are entirely benign and are cosmetic. These lesions are common in middle-aged adults. As the patient ages, more lesions will appear. In the absence of symptoms, observation and reassurance can be used for conservative management. They can be removed surgically if the patient desires.

Nazer et al. study the risk factors associated with the development of cherry angioma. They found that the use of clopidogrel and tamsulosin is associated with these lesions. They recommend ruling out underlying conditions.

Figure/Illustration A demonstrates cherry red macules/papules classically seen in patients with cherry angioma.

Incorrect Answers:
Answer B: Edema of the epidermis describes eczema or atopic dermatitis. This disease would present with pruritic, erythematous, and vesicular lesions. Topical creams and hygiene can be used for symptomatic management of these lesions.

Answer C: Healthy dermatologic development misses the diagnosis of a cherry angioma, which although benign, is a more accurate diagnosis for this case.

Answer D: Malignant blood vessel proliferation does not describe a cherry angioma which is benign and purely cosmetic. An angiosarcoma usually occurs in deep tissues and requires surgical excision.

Answer E: Viral infection describes herpes simplex virus which would present with vesicular lesions and neurogenic pain. These patients can be treated with valacyclovir as well as gabapentin for neuropathic pain.

Bullet Summary:
Cherry angiomas are benign capillary proliferations that appear as cherry red macules/papules.


Question: A newborn boy is evaluated 30 minutes after birth. He was born at 39 weeks gestation to a 27-year-old primigravid mother via cesarean section for cervical insufficiency. The pregnancy was complicated by gestational diabetes and the amniotic fluid was clear. Upon delivery, the patient had strong respiratory effort and a strong cry. His Apgar scores at 1 and 5 minutes were 7 and 8, respectively. The patient now is exhibiting increased work of breathing and is progressively more tachypneic. His birth weight is 3,568 g (7 lb 14 oz). His temperature is 99.0°F (37.2°C), blood pressure is 60/44 mmHg, pulse is 146/min, and respirations are 72/min. On physical exam, the patient is grunting with nasal flaring and subcostal retractions. Breath sounds are decreased at the bases bilaterally. The patient has central cyanosis. His chest radiograph can be seen in Figure A. Which of the following is the most likely etiology of this patient’s presentation?

Answer: Transient tachypnea of the newborn

Explanation:
This newborn is presenting with increased work of breathing and progressive tachypnea in the 1st hour of life, which is consistent with a diagnosis of transient tachypnea of the newborn.

Transient tachypnea of the newborn presents with respiratory distress and marked tachypnea within 2 hours of delivery. Transient tachypnea of the newborn is caused by delayed resorption and clearance of alveolar fluid, which results in mild pulmonary edema. Chest radiography typically demonstrates bilateral perihilar streaking and hyperinflation of the lungs. Transient tachypnea of the newborn is benign and usually resolves by day 2 of life. The management of this condition is supportive.

Alhassen et al. review the evidence regarding the diagnosis and treatment of TTN. They discuss how this condition sometimes requires extended hospitalization and is associated with wheezing in childhood. They recommend using ultrasound to help make this diagnosis.

Figure/Illustration A demonstrates prominent vascular markings around the hilum (yellow arrows), and increased lung volumes on chest radiograph, which is consistent with transient tachypnea of the newborn.

Incorrect Answers:
Answer A: Meconium aspiration syndrome can cause respiratory distress in the immediate newborn period, but it would be unlikely in a patient with a history of clear amniotic fluid, and a more mild clinical picture. Meconium aspiration syndrome would be seen on chest radiograph as coarse, irregular infiltrates and hyper expansion. Treatment is with antibiotics and airway clearance.

Answer B: Neonatal respiratory distress syndrome is a disease of prematurity and does not often occur in infants born at term to healthy mothers. The chest radiograph in neonatal respiratory distress syndrome is also more likely to demonstrate low lung volumes. Treatment is with surfactant administration.

Answer C: Persistent pulmonary hypertension is a cause of respiratory distress in the newborn period, but a chest radiograph typically shows clear lungs. Treatment is with respiratory support as well as inhaled nitric oxide.

Answer E: Viral pneumonia is uncommon in the immediate newborn period. Bacterial pneumonia is more common but usually presents with signs of infection in the mother, which are not present in this case. Treatment is with broad-spectrum antibiotics.

Bullet Summary:
Transient tachypnea of the newborn presents with worsening tachypnea within 2 hours of delivery and is caused by pulmonary edema resulting from inadequate clearance of alveolar fluid.


Question: A 55-year-old man presents to the emergency department after fainting while moving furniture. He states that he has been working in a hot, humid attic all day and forgot his water bottle. He felt dizzy when standing up and then fainted and was unconscious for roughly 1 minute. He awoke at his neurologic baseline afterwards. The patient has a history of hypertension being managed by his primary care doctor. His temperature is 98.7°F (37.1°C), blood pressure is 149/82 mmHg, pulse is 86/min, respirations are 15/min, and oxygen saturation is 99% on room air. Physical exam reveals a diaphoretic man. He demonstrates an unremarkable cardiopulmonary exam. The patient walks with a steady gait and his neurologic exam is non-focal. An ECG is performed as seen in Figure A. The patient is given 2 liters of oral fluids and feels back to his baseline. Which of the following conditions is most likely to occur in this patient based on his current history and ECG?

Answer: Complete heart block

Explanation:
This patient is presenting with dizziness and syncope in the setting of likely dehydration (working in a hot/humid environment without water) and feels better after rehydration, suggesting a diagnosis of orthostatic hypotension. An ECG is performed and incidentally demonstrates a bifascicular block, which is at high risk of progressing to a complete heart block.

Bifascular block is a conduction abnormality in 2 of the 3 fascicles that conduct electricity from atria to ventricles. This leaves conduction to the ventricles via the single remaining fascicle. There are different possibilities that may present on ECG. One possibility is a right bundle branch block with a left anterior fascicular block; the other is a right bundle branch block with a left posterior fascicular block. Note that the pathophysiology of complete heart block is an inability to conduct electricity from the atria to the ventricles. If there is only 1 fascicle left to conduct electricity, the patient would be in complete heart block if this fascicle were to no longer work, which is a common outcome in patients with bifascicular block. Treatment of complete heart block involves the placement of a pacemaker.

Wiberg et al. discuss bifascicular block. They note the possible outcome of a complete heart block. It is recommended to look for this finding on ECG and appropriately workup patients to prevent progression of disease.

Figure/Illustration A is an ECG demonstrating bifascicular block. Note the left axis deviation as suggested by the net upward deflection of the QRS in lead I and net downward deflection in lead II (blue arrows). Then, note the appearance of a right bundle branch block with the RSR pattern in aVR (black arrow) and upward R’ in lead V1 (green arrow). This is a classic pattern for bifascicular block. Contrast this to the other pattern of bifascicular block which would present with a right bundle branch block and right axis deviation (upward QRS in lead II and downward in lead I), which was not seen in this case.

Incorrect Answers:
Answer A: Atrial fibrillation may occur secondary to aging, hypertension, or ischemia and presents with an irregularly irregular rate and rhythm with an absence of P waves. It may cause complications such as stroke. Management typically involves rate control agents such as beta-blockers or calcium channel blockers.

Answer C: Myocardial infarction is a likely outcome in individuals with risk factors such as obesity, hypertension, smoking, and dyslipidemia, in particular, without proper preventive measures and medical therapy including statins, beta blockers, and ACE inhibitors. This patient may be at risk of a myocardial infarction with his hypertension, and his underlying bifascicular block could suggest undiagnosed cardiac ischemia; however, it is more likely this patient progresses to complete heart block in the setting of his bifascicular block.

Answer D: Stroke is a possible complication of atrial fibrillation. For this reason, most patients with atrial fibrillation are on blood thinners to prevent this complication. It occurs secondary to stasis of blood in the fibrillating left atrium. Patients are often risk stratified prior to starting blood thinners with tools such as CHADS2VASC and HASBLED. Isolated syncope is a rare manifestation of stroke.

Answer E: Torsades des pointes is a progression from QT prolongation which may occur secondary to genetic conditions, medications, and/or infection. It presents on ECG with QRS complexes that twist in amplitude around the electrical baseline. Treatment involves the administration of magnesium sulfate and, if needed, electrical cardioversion.

Bullet Summary:
A bifascicular block can progress to complete heart block.


Question: A 68-year-old man presents to the emergency department with right ear pain that he developed 4 days prior, and it has progressively worsened. The pain is worse at night. He has associated fever and chills. This morning, he awoke with purulent, foul-smelling discharge on his pillow. He has a history of type II diabetes mellitus and hypertension. He takes metformin, insulin, and lisinopril. His temperature is 102.2°F (39.0°C), blood pressure is 130/87 mmHg, pulse is 110/min, and respirations are 16/min. The patient is toxic in appearance and in mild distress due to pain. Examination of the external ear reveals findings shown in Figure A. Granulation tissue and purulent drainage are noted in the external auditory canal. Physical exam is otherwise unremarkable. Which of the following is the most appropriate therapy for this patient?

Answer: Vancomycin and piperacillin-tazobactam

Explanation:
The patient in this vignette most likely has malignant otitis externa (also referred to as necrotizing otitis externa), which is a life-threatening infection requiring therapy with intravenous anti-pseudomonal and broad-spectrum antibiotics. Piperacillin-tazobactam and vancomycin is an appropriate initial regimen.

Malignant otitis externa is an invasive infection of the external auditory canal and skull base, and is seen almost exclusively in immunocompromised patients. Patients with poorly controlled type II diabetes mellitus are at particularly increased risk. The infection spreads from the floor of the ear canal to the nearby tissues including the bones at the base of the skull and the temporomandibular joint. The resulting skull base osteomyelitis distinguishes the "necrotizing" or "malignant" presentation of otitis externa. Patients often present with severe otalgia and purulent drainage from the external auditory canal. Granulation tissue in the external auditory canal is a characteristic exam finding. Pseudomonas aeruginosa is the causative organism in most cases of necrotizing otitis externa. Therefore, intravenous antibiotics with sufficient coverage of Pseudomonas are the therapy of choice. As infection progresses, involvement of cranial nerves with resultant palsy may be observed.

Aaraj et. al review the clinical manifestations, diagnosis and management of malignant otitis externa. They note the risk for this disease among patients with diabetes or other etiologies of an immunocompromised state. They recommend management with intravenous ciprofloxacin.

Figure A shows the external ear of a patient with malignant otitis externa. Note the classic granulation tissue at the cartilage-bone junction and crusted, purulent discharge.

Incorrect Answers:
Answer A: Intravenous acyclovir would be appropriate for suspected herpes zoster, which may present with ear pain and a vesicular rash in the external auditory canal. This patient's granulation tissue in the external auditory canal and purulent drainage make malignant otitis externa more likely.

Answer B: Oral amoxicillin may be appropriate for management of acute otitis media which presents with ear pain and a distended tympanic membrane that is immobile.

Answer C: Ceftriaxone is appropriate coverage for cellulitis which presents with warmth, erythema, and tenderness of the skin. It would be too narrow of spectrum to treat malignant otitis externa.

Answer E: Topical ofloxacin may be appropriate for some cases of simple otitis externa ("swimmer's ear") which presents with ear pain and drainage in young, healthy patients who swim regularly. Patients are well-appearing.

Bullet Summary:
Malignant otitis externa is an invasive infection of the external auditory canal and skull base that requires management with broad-spectrum intravenous antibiotics that cover Pseudomonas aeruginosa.


Question: A 54-year-old man is brought to the emergency department following a skiing accident. The patient lost control of his skis and collided with a tree. He lost consciousness for about 30 seconds. When he woke up, he was mildly confused but able to ski down the rest of the mountain. The patient initially denied medical treatment but his wife convinced him to be taken by ambulance to the emergency department for evaluation. The paramedics report that at the scene the patient had a Glasgow Coma Score (GCS) of 15. During the ride, he became gradually more somnolent. His medical history is significant for hypertension, hyperlipidemia, coronary artery disease, and a prior transient ischemic attack. His medications include atorvastatin and lisinopril. In the emergency department, his temperature is 97.8°F (36.6°C), blood pressure is 141/84 mmHg, pulse is 71/min, and respirations are 16/min. He is difficult to arouse with a GCS of 7. A head CT is performed and can be seen in Figure A. Which of the following is the most likely cause of this patient’s presentation?

Secondary hemorrhage into prior area of infarction

Answer: Damage to the sphenoid bone

Explanation:
This patient presents with a lucid interval followed by worsening somnolence and a biconvex lesion on head CT, which suggests a diagnosis of acute epidural hematoma. Acute epidural hematomas are most commonly caused by damage to the middle meningeal artery from trauma to the sphenoid bone.

Patients with an epidural hematoma typically have an initial loss of consciousness followed by a lucid interval, during which their mental status returns to baseline or near baseline. As the hematoma expands, patients display increasing somnolence from the increase in intracranial pressure. For that reason, epidural hematomas are sometimes referred to as the “talk and die” syndrome. If not relieved, this increase in intracranial pressure can lead to uncal herniation or death. Patients with neurologic findings or those with expanding bleeds require urgent surgical decompression.

Dadashi et al. present cases of patients with epidural hematoma from acute trauma. They discuss how patients often sustain these injuries from extreme sports. They recommend being aware of this syndrome so that acute interventions can be taken.

Figure/Illustration A demonstrates a biconvex hyperdensity that is limited by suture lines (red circle). This is the typical appearance of an epidural hematoma on head CT.

Incorrect Answers:
Answer A: Damage to the cerebral bridging veins results in a subdural hematoma (SDH). An acute SDH more commonly presents with a gradual increase in headache and confusion rather than the “talk and die” syndrome presented in this vignette. However, a minority of patients with acute SDH may have a lucid interval followed by progressive neurological decline. SDH would have a crescent-shaped appearance on head CT rather than the biconvex appearance of an epidural hematoma.

Answer C: Occlusion of cerebral small penetrating arteries describes a lacunar stroke. Although this patient has 2 risk factors for lacunar stroke (hypertension and smoking), this patient’s head CT demonstrates an epidural hematoma.

Answer D: A ruptured cerebral aneurysm would most likely lead to a subarachnoid hemorrhage. A subarachnoid hemorrhage presents as a sudden, severe headache (“thunderclap headache”), confusion or somnolence, nausea and vomiting, and meningismus. Surgical clipping or embolization of the bleeding vessel may be required.

Answer E: Secondary hemorrhage into a prior area of infarction usually occurs in the setting of a recent embolic stroke. Although this patient has a history of TIA and other risk factors for stroke, his head CT demonstrates an epidural hematoma. Treatment is supportive with the control of underlying risk factors such as hypertension.

Bullet Summary:
Epidural hematomas are caused by damage to the middle meningeal artery as it passes through the foramen spinosum of the sphenoid bone.


Question: A 2-day-old boy has an episode of vomiting in the hospital nursery. The vomitus was described as “bright green” without any traces of blood. The patient has urinated several times since he was born but has not passed any stool. He was born at 37 weeks of gestation to a 38-year-old G3P3 woman. The pregnancy was uncomplicated and the patient’s mother refused all prenatal testing. The patient’s 2 older siblings are both healthy. His temperature is 98.6°F (37°C), blood pressure is 67/43 mmHg, pulse is 135/min, and respirations are 34/min. On physical exam, the patient has upslanting palpebral fissures, epicanthal folds, and a single transverse palmar crease. His abdomen is non-tender, firm, and distended. Bowel sounds are hypoactive. Digital rectal exam evacuates a small amount of stool and flatulence. A nasogastric tube is placed to decompress the stomach. The patient’s abdominal radiograph can be seen in Figure A. Which of the following is the most likely diagnosis?

Answer: Hirschsprung disease

Explanation:
This pediatric patient presents with features of Down syndrome (trisomy 21), bilious vomiting, and colonic distention on an abdominal radiograph, which suggests a diagnosis of Hirschsprung disease.

Hirschsprung disease is associated with Down syndrome and presents with bilious vomiting, failure to pass meconium in the first 48 hours of life, and abdominal distension. A digital rectal exam may temporarily relieve the obstruction and lead to the expulsion of gas and stool (the “squirt sign”). Abdominal radiography typically demonstrates signs of distal intestinal obstruction such as proximal dilation and an absence of air in the rectum. Contrast enema may reveal a transition zone between the dilated proximal megacolon and the narrow rectosigmoid colon. A biopsy can confirm the diagnosis. Treatment is with surgical removal of the defective segment of the bowel.

Kessman reviews the evidence regarding the diagnosis and treatment of Hirschsprung disease. She discusses how the diagnosis can be made using a rectal suction biopsy. She recommends monitoring patients closely for enterocolitis for years after surgical treatment.

Figure/Illustration A is an abdominal radiograph that demonstrates colonic distension (red circle). This finding is consistent with a diagnosis of Hirschsprung disease.

Incorrect Answers:
Answer A: Duodenal atresia is associated with Down syndrome (trisomy 21) and may also present in the first 48 hours of life with bilious vomiting. The abdominal radiograph will demonstrate the “double bubble” sign, which reflects air trapping in the stomach and first portion of the duodenum. Treatment is with the surgical opening of the atretic segment.

Answer C: Intestinal malrotation may preset with bilious vomiting in a neonate due to the development of a midgut volvulus. An abdominal radiograph may show the extension of the nasogastric tube into an abnormally positioned duodenum and would not show diffuse colonic distension. Treatment is with surgical derotation of the volvulus.

Answer D: Meconium ileus is associated with cystic fibrosis and also presents with delayed (> 48 hours) passing of meconium. The distal obstruction in these patients will not be temporarily relieved by a digital rectal exam. Contrast enema will demonstrate microcolon involving the entire large bowel. Treatment is with irrigation and removal of the meconium.

Answer E: Pyloric stenosis usually presents in the first 3-6 weeks of life with post-prandial, nonbilious, projectile vomiting and a palpable olive-shaped mass in the epigastrium. This patient is presenting at just 2 days of life and has bilious vomiting. Treatment is with surgical release of the stenosis.

Bullet Summary:
Hirschsprung disease is associated with Down syndrome (trisomy 21) and presents with retention of stool that can be relieved by digital disimpaction, bilious vomiting, and colonic distention on abdominal radiography.


Question: A 15-year-old girl is brought to the clinic because her mother is worried the patient has not yet had her period. The patient’s older sister had her first period at age 14. The mother had her first period at age 13. The patient reports she is doing well in school and is on the varsity basketball team. Her medical history is significant for asthma and atopic dermatitis. Her medications include albuterol and topical triamcinolone. Her temperature is 98°F (36.7°C), blood pressure is 111/72 mmHg, pulse is 65/min, and respirations are 14/min with an oxygen saturation of 99% on room air. Her body mass index (BMI) is 19 kg/m^2. Physical exam shows absent breast development and external genitalia at Tanner stage 1. Serum follicle-stimulating hormone (FSH) level is measured to be 38 mIU/mL. Which of the following is the most appropriate next diagnostic step?

Gonadotrophin-releasing hormone stimulation test

Answer: Karotype

Explanation:
The patient is presenting with primary amenorrhea and an increased follicle-stimulating hormone (FSH) level, suggesting a gonadal abnormality and making karyotyping the most appropriate next step in management.

Primary amenorrhea can be diagnosed if a patient has normal secondary sex characteristics but no menarche by age 16, or if she has no secondary sex characteristics and no menarche as early as age 14. Primary amenorrhea is caused by either hypothalamic/pituitary (central) or gonadal (peripheral) abnormalities. Increased FSH indicates a peripheral cause or hypergonadotropic hypogonadism. Karyotyping would be the most appropriate next diagnostic step because these disorders can include Turner syndrome and androgen insensitivity syndrome.

Gravholt et al. review the evidence regarding the diagnosis and treatment of Turner syndrome. They discuss how this disease presents with hypergonadotropic hypogonadism. They recommend growth hormone therapy and hormone replacement therapy in these patients.

Incorrect Answers:
Answer A: CYP17 gene work-up should be done in patients with primary amenorrhea, an absence of secondary sex characteristics, elevated FSH, and hypertension. Alterations in the CYP17 gene can cause congenital adrenal hyperplasia due to 17-hydroxylase deficiency. The resulting excess of deoxycorticosterone is associated with hypertension and hypokalemia. Treatment is with hormone repletion therapy.

Answer B: Estrogen levels would be low in this patient as evidenced by her absence of breast development. Therefore, measuring estrogen levels would provide no additional diagnostic information. Estrogen levels may be useful in cases of peripheral gonadotropin resistance but these are rare.

Answer C: Gonadotropin-releasing hormone (GnRH) stimulation test would be the next diagnostic step if FSH were decreased. A decrease in FSH indicates a central cause or hypogonadotropic hypogonadism. A GnRH stimulation test is used to assess whether the central abnormality is due to the hypothalamus or the pituitary.

Answer E: Luteinizing hormone (LH) levels with a repeat FSH level may be helpful if FSH is low or normal. Low or normal FSH levels indicate hypogonadotropic hypogonadism as caused by hypothalamic-pituitary axis abnormalities. Cases of high FSH represent a different diagnostic entity as adequate gonadotropins are produced.

Bullet Summary:
In a patient with primary amenorrhea and an increased FSH, the next step in management is karyotyping.


Question: A 36-year-old G3P2002 woman presents to her obstetrician’s office for her 1st prenatal visit at 10 weeks and 2 days gestation. She has felt nauseous the last several mornings and has been tired for a few weeks. The patient has had 2 uncomplicated spontaneous vaginal deliveries at full term with her last child born 6 years ago. She is concerned about the risk of Down syndrome in this fetus, as her sister gave birth to an affected child at age 43. She has a history of generalized anxiety disorder, atopic dermatitis, and she is currently on escitalopram. Her temperature is 98.6°F (37.0°C), pulse is 70/min, blood pressure is 121/67 mmHg, and respirations are 13/min. The patient appears anxious, but overall comfortable, and cardiopulmonary and abdominal exams are unremarkable. Pelvic exam reveals normal external genitalia, a closed and soft cervix, a 10-week-sized uterus, and no adnexal masses. Which of the following is the most appropriate next step for definitively determining whether this patient’s fetus has Down syndrome?

Answer: Chorionic villus sampling

Explanation:
This patient is over 35 years of age and concerned about the risk of Down syndrome (trisomy 21) in her fetus at just over 10 weeks gestation. At this gestational age, the most definitive method for determining whether such an aneuploidy is present is chorionic villus sampling (CVS).

CVS, or sampling of the placental tissue, can be performed as early as 10 weeks gestation. This is in contrast to amniocentesis, which should be avoided prior to 14 weeks. There are other screening tests for a patient concerned about aneuploidy; however, only CVS and amniocentesis offer definitive diagnoses. Complications of this procedure include pregnancy loss (at a rate of 1-2%), transverse limb abnormality, rupture of membranes, and chorioamnionitis. Patients should also have counseling if genetic abnormalities are detected using this procedure.

Farina reviews the evidence regarding the complications associated with CVS. He discusses how this procedure is becoming more common as the definitive method of providing an early diagnosis. He recommends being aware of complications such as possible pregnancy loss.

Incorrect Answers:
Answer A: Amniocentesis is a useful tool for the definitive diagnosis of aneuploidy and other genetic conditions. Due to the higher rate of fetal loss at younger gestational ages, it is reserved for those above 14 weeks.

Answer B: The anatomy ultrasound can be helpful in identifying morphologic features that are concerning for Down syndrome, such as a flat nasal bridge or an echogenic cardiac focus. This screening tool is most accurate after 18 weeks gestation.

Answer D: Genetic testing of the patient’s sister may be able to help identify if there is a parental translocation or aneuploidy that led to the child’s Down syndrome. This is much less likely than meiotic nondisjunction due to advanced maternal age, and this would not help diagnose Down syndrome in the patient’s fetus.

Answer E: The nuchal translucency test examines the thickness of the nuchal fold. When the thickness exceeds normal measurements, there is an increased risk of aneuploidy such as Down syndrome, but this is a screening result that would not provide a definitive diagnosis.

Bullet Summary:
Chorionic villus sampling is a definitive method of identifying aneuploidy in fetuses starting at 10 weeks of gestational age.


Question: A 9-hour-old newborn girl is found in the newborn nursery with diffuse swelling of the scalp not present at birth. The child was born at 38 weeks of gestation to a 28-year-old G3P3 mother. The mother went into spontaneous labor but the delivery was complicated by a prolonged 2nd stage of labor. A vacuum-assisted vaginal delivery was eventually performed. The child’s Apgar scores were 8 and 9 at 1 and 5 minutes, respectively. The pregnancy was complicated by preeclampsia in the mother which was well-controlled throughout the pregnancy. Her temperature is 98.6°F (37°C), blood pressure is 67/43 mmHg, pulse is 135/min, and respirations are 34/min. On physical exam, she appears to be in mild distress and has a 4x5 cm ecchymotic area of swelling over the bilateral parietal bones. Serial assessments of the child’s head circumference over the next 12 hours show no change in the size of the swelling. This patient’s condition most likely affects which of the following spaces or potential spaces?

Between periosteum and galea aponeurosis

Answer: Between scalp and galea aponeurosis

Explanation:
This patient presents following a vacuum-assisted vaginal delivery with an ecchymotic swelling of the scalp that crosses the midline, which suggests a diagnosis of caput succedaneum. Caput succedaneum is caused by bleeding between the skin and the galea aponeurosis.

Caput succedaneum is an uncommon extracranial injury that occurs during a traumatic birth, particularly in deliveries in which a vacuum-assist device is used. It involves bleeding between the skin of the scalp and the galea aponeurosis. Unlike a cephalohematoma, caput succedaneum lesions may cross the suture lines of the cranial bones. Caput succedaneum is typically described as fluctuant and ecchymotic, and the swelling usually self-resolves within a few days. Treatment is supportive though patients may occasionally require phototherapy if they develop high levels of bilirubin. Transfusion is indicated if there is significant anemia present (though this is uncommon).

Jacob and Hoerter present evidence regarding the diagnosis and treatment of patients with caput succedaneum. They discuss how this lesion commonly crosses cranial suture lines as well as the midline. They recommend differentiating this disease from more malignant etiologies such as intracranial hemorrhage.

Incorrect Answers:
Answer A: Bleeding between the dura and arachnoid mater describes a subdural hematoma. Subdural hematomas are the most common type of intracranial hemorrhage found in neonates, but they usually present with more serious signs of respiratory depression, apnea, or seizures. Patients with a subdural hematoma should be evaluated for non-accidental trauma. Treatment of expanding lesions may require surgical decompression.

Answer B: Bleeding between the periosteum and galea aponeurosis describes a subgaleal hemorrhage, an uncommon but serious complication of traumatic birth. Like caput succedaneum, subgaleal hemorrhages occur most commonly in newborns delivered via vacuum-assisted delivery, but the swelling in a subgaleal hemorrhage involves the entire scalp. Patients may also present with signs of extensive blood loss and neurological disturbances. Treatment involves resuscitation with fluids or blood and possibly neurosurgical intervention.

Answer C: Bleeding between the periosteum and skull describes a cephalohematoma. Cephalohematoma occurs in newborns and is caused by the rupture of the blood vessels crossing the periosteum. They are usually secondary to a prolonged second stage of labor and, unlike caput succedaneum, do not cross suture lines. The treatment for these lesions is supportive as most of these lesions resolve spontaneously.

Answer E: Bleeding into the lateral ventricles describes an intraventricular hemorrhage. Intraventricular hemorrhage is associated with premature delivery and usually presents with neurological symptoms. Neurologic findings include seizures, apnea, respiratory depression, or asymmetric reflexes. Treatment may involve urgent surgical decompression to prevent herniation.

Bullet Summary:
Caput succedaneum is an extracranial injury caused by bleeding between the skin of the scalp and the galea aponeurotica in neonates.


Question: At a local community hospital staffed only by attending physicians, it is noted that the time to tissue plasminogen activator administration in suspected stroke patients is roughly 10 minutes from presentation. At a teaching hospital with residents, the time to tissue plasminogen activator administration is roughly 2 hours. This has led to many adverse outcomes and increased morbidity at the teaching hospital. Which of the following is the most appropriate next step in further elucidating the problem?

Automatically consult neurology for patients with concerning neurologic symptoms

Empirically scan patients with concerning neurologic symptoms

Perform a root cause analysis of the process

Perform a systems-based approach implementation

Answer: Perform a root cause analysis of the process

Explanation:
This case outlines a delay in treating strokes at a teaching hospital. To determine the underlying cause, a root cause analysis to determine the underlying issue is the most appropriate way to begin to address this issue.

When a problem is found in healthcare, it is important to elucidate the underlying cause. A root cause analysis is the current preferred method of determining the underlying cause of a problem. A root cause analysis outlines all the people, materials, equipment, and processes in place and outlines them. It then locates the problem and attempts to find the breakdown or issue in all these inputs that lead to the problem. Once the problem is identified, then a strategy or intervention can be implemented to fix the underlying problem.

Percarpio et al. review root cause analysis. They note the ubiquity of root cause analysis. They call into question its cost and efficacy despite it being such a widespread practice and recommend a careful assessment of the costs and benefits.

Incorrect Answers:
Answer A: Automatically consulting neurology for patients with concerning neurologic symptoms may be appropriate if the issue was lack of access to timely neurologist assessment in the workup of stroke. While may hospitals have this as a default for patients with stroke-like symptoms, it would be premature to implement this as a solution without a root cause analysis to first determine what the problem is.

Answer B: Empirically scanning patients with concerning neurologic symptoms would be wasteful and not plausible in a healthcare system. There are many concerning neurologic chief complaints including those that originate in the brain, the spine, or the peripheral nerves; thus, merely CT scanning everyone with a neurological chief complaint is an inefficient use of resources.

Answer C: Improving resident education is assuming that the problem is a lack of knowledge based on the residents. Before proposing a solution, it is important to first find the underlying cause and address said cause as the delayed intervention may not be the fault of the residents.

Answer E: A systems-based approach is the best solution when fixing a medical error. However, a root cause analysis is first needed to determine which solution is needed. If an error in the process is noted, a systems-based approach would be the best method to address it.

Bullet Summary:
When an error is noted in patient care, the most appropriate initial step in fixing the issue is conducting a root cause analysis.


Question: A 55-year-old man presents to the emergency department with worsening dyspnea over the past 48 hours. He recently had a cold that kept him home from work for the past week. He has a past medical history of diabetes, obesity, and hypertension. He had his Achilles tendon repaired 4 weeks ago and he has been less mobile. His temperature is 99.2°F (37.3°C), blood pressure is 150/85 mmHg, pulse is 82/min, respirations are 16/min, and oxygen saturation is 100% on room air. Physical exam is notable for dyspnea provoked by walking short distances. Jugular venous distension is noted on exam. The patient’s blood pressure is 130/70 mmHg during inspiration. A bedside echocardiogram demonstrates impaired diastolic filling with normal ventricular contractility. An ECG is performed as seen in Figure A. Which of the following is the most likely diagnosis?

Answer: Constrictive pericarditis

Explanation:
This patient is presenting with a preceding viral illness, dyspnea, jugular venous distension, pulsus paradoxus (blood pressure drop from 150/85 to 130/70 mmHg during inspiration), an echocardiogram with impaired diastolic filling, and diffuse ST elevation with PR depression on ECG. This constellation of symptoms is concerning for constrictive pericarditis.

Constrictive pericarditis occurs when the pericardium becomes thickened and fibrotic. In contrast to other types of pericarditis, in constrictive pericarditis, there is impaired diastolic filling and thus impaired cardiac function. There are many possible etiologies of constrictive pericarditis including infection, inflammatory conditions, or idiopathic. Patients will present with dyspnea, hypotension, tachycardia, a pericardial friction rub, and positional chest pain (usually worsened by laying back and relieved by leaning forward). Patients may also demonstrate jugular venous distension, lower extremity edema, worsening dyspnea, and congestive hepatopathy. ECG may demonstrate diffuse ST elevation with PR depression, and an echocardiogram will demonstrate impaired diastolic filling and may demonstrate a thickened pericardium. The diagnosis can be supported with pulsus paradoxus (a drop of blood pressure by > 10 mmHg during inspiration).

Welch reviews constrictive pericarditis. He discusses constrictive pericarditis and how the inelastic pericardium inhibits cardiac filling possibly causing unexplained heart failure. Welch notes making the diagnosis is very challenging and requires meticulous echocardiograph assessment.

Figure/Illustration A demonstrates diffuse ST elevation (blue arrows) with PR depression (black arrows). This is consistent with pericarditis.

Incorrect Answers:
Answer A: Cardiac tamponade can occur after trauma, in the setting of infection, or in the setting of autoimmune disease and is more likely to occur with a rapid accumulation of pericardial fluid. While pulsus paradoxus would be present in this condition, muffled heart sounds and electrical alternans would be more likely to be seen on ECG. Echocardiography would demonstrate an echogenic rim of fluid around the heart.

Answer C: Myocardial infarction presents with chest pain, dyspnea, hypotension, tachycardia, and ST elevation in a vascular distribution. Note that this patient’s ST elevation is diffuse and there is no reciprocal ST depression. Moreover, the pattern of chest pain in myocardial infarction is typically exertional and not positional.

Answer D: Pulmonary embolism may present with pleuritic chest pain, shortness of breath, tachycardia, hypoxia, hemoptysis, a history of hypercoagulability, and recent stasis or surgery (such as this patient’s recent Achilles tendon surgery). It can cause obstructive shock leading to hypotension and tachycardia. Note that right heart strain and sinus tachycardia would be seen on ECG.

Answer E: Restrictive cardiomyopathy presents very similarly to restrictive pericarditis. Note that in restrictive cardiomyopathy, patients will also have impaired diastolic filling; however, it is due to a myocardium that will not expand rather than the pericardium impairing filling. It can occur secondary to conditions such as amyloidosis or hemochromatosis as well as other chronic inflammatory states. The ECG findings are nonspecific but may include low voltage QRS complexes, ST segment changes, T wave changes, bundle branch blocks, and pathologic Q waves (abnormally deep and wide Q waves). The diagnosis can be supported with an ultrasound demonstrating impaired diastolic filling and possible myocardial speckling if a protein (amyloid) is present and deposited in the myocardial wall. The diagnosis can only definitively be confirmed with a biopsy which is highly invasive.

Bullet Summary:
Restrictive pericarditis presents with chest pain that is positional, pulsus paradoxus, a friction rub, and diffuse ST elevation with PR depression on ECG.


Question: A 4-day-old neonate is brought to the pediatrician with vaginal discharge for the last 2 days. Her daughter has been feeding and voiding well. The neonate was delivered at 39 weeks gestation via an uncomplicated vaginal delivery and was discharged home after 2 days. The prenatal course was complicated by chlamydia in the mother during the first trimester, for which she and the partner were both treated with a confirmatory test of cure. The biological father is no longer involved in the patient's life, but her mother’s boyfriend has been caring for the baby whenever the mother rests. The neonate’s temperature is 98.5°F (36.9°C), blood pressure is 56/35 mmHg, pulse is 138/min, and respirations are 51/min. She appears comfortable, and cardiopulmonary and abdominal exams are unremarkable. There are no bruises or marks on her skin. Examination of the genitals reveals no vulvar irritation or skin changes but there is scant pink mucoid discharge at the introitus. Which of the following is the most appropriate next step in management?

Answer: Reassurance

Explanation:
This neonate presents with bloody vaginal discharge soon after birth without vulvar irritation, which is most consistent with physiologic neonatal vaginal discharge. Reassurance is the most appropriate next step in management.

Vaginal discharge in a neonate that is bloody and/or mucoid is most commonly due to the rapid withdrawal of maternal hormones that cross the placenta. This results in a pink discharge that may be observed as “menses” in the perinatal period. This most commonly presents several days to 1 week after birth and will self-resolve. Without concerning red flags such as genital trauma, mucopurulent discharge, or surrounding skin changes, there is no need for work-up or treatment. Additional concerning findings should prompt a work-up for child abuse.

Guritzky and Rudnitsky review the evidence regarding the work-up of a bloody neonatal diaper. They discuss how using an Apt test can be helpful in distinguishing between maternal and fetal blood. They recommend being aware of neonatal conditions that can cause bleeding to avoid missing pathologies.

Incorrect Answers:
Answer B: Reporting the case to child protective services would be necessary if child abuse were suspected. Although having an unrelated adult as a caregiver is traditionally a risk factor, there is no evidence that this neonate is being abused. Risk factors include vaginal trauma and bruising.

Answer C: Vaginal culture may be indicated if an infectious etiology such as chlamydia or group A streptococcus is suspected; however, this would more commonly present with bloody and mucopurulent discharge with or without surrounding skin inflammation. Furthermore, the patient’s mother was successfully treated for chlamydia during pregnancy, making chlamydial infection unlikely.

Answer D: Vaginal exam under anesthesia would be appropriate if a foreign body or trauma is suspected because prepubescent children should not undergo exams while awake. In a neonate with physiologic discharge, an exam is unnecessary. Foreign bodies would present with bloody discharge, pain, and potential purulence.

Answer E: Warm water irrigation of the vagina may be helpful in locating a foreign body, which is the most common cause of vaginal bleeding and discharge in a prepubertal girl. This is unlikely in a neonate and there is no evidence of trauma or irritation in the perineum.

Bullet Summary:
Vaginal discharge in a neonate is most commonly due to the withdrawal of maternal hormones and will self-resolve.