Question: A 65-year-old man presents to the emergency department with anxiety and intermittent palpitations. He began feeling the palpitations 3 days ago while eating dinner. He denies chest pain, shortness of breath, or loss of consciousness. He has a history of hypertension, major depressive disorder, Raynaud disease, and chronic obstructive pulmonary disease (COPD) on 2 liters of oxygen at home. Current medications include lisinopril, inhaled umeclidinium-vilanterol, and as-needed albuterol. He drinks 4 beers a day and has smoked 1 pack of cigarettes a day for 40 years. His temperature is 98.9° F (37.2° C), blood pressure is 130/85 mmHg, pulse is 125/min, and respirations are 16/min. Physical exam is notable for an irregular pulse and scattered end-expiratory wheezes. An echocardiogram performed 1 month ago showed a left ventricular ejection fraction of 60-65%. The patient requires 3 liters of oxygen today. An ECG is performed as seen in Figure A. Which of the following is the most appropriate treatment for the patient’s tachycardia?

Answer: Verapamil

Explanation:
This patient’s new-onset palpitations, irregularly irregular pulse, and absent p-waves on ECG are consistent with atrial fibrillation. In hemodynamically stable patients with a relative contraindication to β-blockers (COPD on home oxygen with increasing oxygen need), rate control with a non-dihydropyridine calcium channel blocker such as verapamil is preferred.

Atrial fibrillation can present with palpitations, lightheadedness, or shortness of breath. ECG findings will be an irregularly irregular rhythm and absent P waves with an erratic baseline as shown in Illustration A. Treatment is centered on rate control. First-line agents for rate control include β1 selective blockers (metoprolol and esmolol) and non-dihydropyridine calcium channel blockers (verapamil and diltiazem). In patients with COPD, non-selective β-blockers (propranolol, timolol, and sotalol) can worsen bronchoconstriction by activating β2-adrenoreceptors. Other relative contraindications to β-blockers include Raynaud disease and depression (increased risk of fatigue and sexual dysfunction). In patients with relative contraindications to β-blockers, non-dihydropyridine calcium channel blockers are the preferred initial treatment option.

Van Gelder et al. studied lenient (resting heart rate < 110 beats per minute) versus strict rate control (resting heart rate < 80 beats per minute) in patients with atrial fibrillation in a randomized control trial. The authors found that there was no difference in the primary composite outcome of death from cardiovascular causes, hospitalization for heart failure, stroke, bleeding, and life-threatening arrhythmias between the 2 groups. The authors recommend a lenient rate control strategy in patients with atrial fibrillation.

Figure/Illustration A is an ECG lacking P waves (red arrows) and irregularly irregular RR intervals (red/blue lines), which are classic findings in atrial fibrillation.

Incorrect Answers:
Answer A: Amiodarone is an antiarrhythmic that can be used in patients to convert atrial fibrillation to sinus rhythm. It is often suitable to use in patients with depressed left ventricular function. Amiodarone has multiple multi-system adverse effects including pulmonary toxicity, and it is not used as a first-line agent.

Answer B: Clopidogrel is an antiplatelet agent that can be used to reduce the risk of thrombosis. Although patients with atrial fibrillation are at increased risk of stroke, the preferred anticoagulation agents are warfarin or direct oral anticoagulants (apixaban).

Answer C: Digoxin can be used as a rate control agent in atrial fibrillation as it directly suppresses atrioventricular nodal conduction. Due to its narrow therapeutic window and risk of toxicity, it is used as second-line therapy when first-line agents fail.

Answer D: Metoprolol is a β-blocker that is a first-line agent for rate control in atrial fibrillation. In patients with contraindications to β-blockers, non-dihydropyridine calcium channel blockers are the treatment of choice. This patient has COPD with increasing oxygen needs making calcium channel blockers possibly a better choice.

Bullet Summary:
In hemodynamically stable patients with atrial fibrillation and relative contraindications to β-blockers, non-dihydropyridine calcium channel blockers are the treatment of choice.


Question: A 65-year-old man presents to the emergency department with sudden-onset altered mental status. He was last seen normal 1 hour ago. His wife noticed that he was confused, slurring his speech, and had notable weakness that caused him to drop his cup of coffee. The patient is confused and not able to answer any questions. Facial drooping of the left lower face is noted, and the patient cannot follow any commands. He has a past medical history of diabetes and atrial fibrillation and is currently taking warfarin. His other medications are not known. His temperature is 98.0°F (36.7°C), blood pressure is 150/90 mmHg, pulse is 115/min, and respirations are 17/min. The patient is not able to follow any commands for further neurologic evaluation but does not appear to be moving his right upper extremity. In addition to further physical exam, which of the following is the most appropriate next step in management?

Answer: Fingerstick blood glucose

Explanation:
This patient is presenting with sudden onset confusion, slurred speech, asymmetric smile, and weakness in the setting of risk factors for stroke (atrial fibrillation, diabetes, and hypertension). The most important initial step in management in a patient with altered mental status and neurological deficits is to obtain a fingerstick blood glucose.

The workup of stroke is first centered on a thorough history and physical and immediately calculating an NIH stroke scale (11-domain assessment of stroke severity involving patient consciousness level, orientation, ability to follow commands, degree of gaze palsy, degree of vision loss, ataxia, motor drift, sensation, inattention, language/speech) as well as ascertaining when the patient was last known to be neurologically normal. While performing the exam and NIH stroke scale, a fingerstick blood glucose should be performed in all patients as hypoglycemia may present identically to a stroke. Severe hypoglycemia may present with lethargy, confusion, focal or global weakness, nausea, vomiting, agitation, and even seizures. If the patient is hypoglycemic, dextrose can be given which will rapidly correct the patient's underlying deficits.

Ohshita et al. review other possible causes of stroke-like symptoms. They note that hypoglycemia may mimic stroke and cause focal neurological signs with common findings being unilateral motor weakness with mild or moderate alteration of consciousness. They noted that all patients improved within 1 hour of glucose injection in this study, thus the recommendation to check a fingerstick blood glucose in all stroke patients.

Incorrect Answers:
Answer A: Alteplase would be indicated if a patient presented with disabling neurologic deficits from an ischemic stroke within 4.5 hours of symptom onset only after a CT scan of the head has ruled out an intracranial bleed. The patient must have no other contraindications to thrombolytics including but not limited to recent trauma, known intracranial hemorrhage, rapidly improving neurologic deficits (spontaneously), and no other clear reversible cause (among many other contraindications).

Answer B: CT head is the most appropriate initial step in the management of an acute stroke; however, a rapid fingerstick blood glucose takes precedence as hypoglycemia can mimic a stroke and be immediately addressed thus removing the need for further workup if there is a complete resolution of symptoms with normoglycemia. While an exam is ongoing, a fingerstick blood glucose is being obtained, and neuroimaging is also often ordered to be performed immediately after.

Answer D: Fresh frozen plasma and vitamin K would be indicated in this patient if he had a hemorrhagic stroke (a CT of the head would need to confirm this) to reverse his anticoagulation with warfarin. Factor concentrate can also be used to rapidly reverse anticoagulation with warfarin.

Answer E: MRI brain would be indicated in the workup of a stroke or transient ischemic attack after all emergency interventions and labs including CT head, serum chemistries, CBC, and ECG. It delineates the extent of the stroke and gives useful prognostic and diagnostic information. It also may elucidate strokes missed on other forms of neuroimaging such as CT perfusion.

Bullet Summary:
A fingerstick blood glucose should be obtained immediately in all patients with stroke-like symptoms or altered mental status.


Question: A 35-year-old man presents to his primary care physician with pain along the bottom of his foot. The patient is a long-time runner but states that the pain has been getting worse recently. When running and at rest he has a burning and aching pain along the bottom of his foot that sometimes turns to numbness. Taking time off from training does not improve his symptoms. The patient has a medical history of surgical repair of his Achilles tendon, ACL, and medial meniscus. He is currently not taking any medications. The patient lives with his wife and they both practice a vegan lifestyle. His temperature is 98.6°F (37°C), blood pressure is 114/72 mmHg, pulse is 81/min, and respirations are 12/min. On physical exam, the patient states that he is currently not experiencing any pain in his foot but rather is experiencing numbness/tingling along the plantar surface of his foot. Strength is 5/5 and reflexes are 2+ in the lower extremities. Which of the following is the most likely diagnosis?

Answer: Tarsal tunnel syndrome

Explanation:
This patient is presenting with pain, tingling, and numbness on the plantar surface of his foot that is not associated with exertion or rest suggesting a diagnosis of tarsal tunnel syndrome.

Tarsal tunnel syndrome occurs due to compression of the tibial nerve as it travels through the tarsal tunnel. Compression of the nerve leads to symptoms along the plantar surface of the foot which can include pain, tingling, or numbness. These symptoms can be exacerbated/triggered by tapping on the tunnel, which lies posterior to the medial malleolus. In addition, the symptoms can occur at rest or during activity and are not improved with rest. Treatment is rest, NSAIDs, properly fitted shoes/orthotics, and in refractory cases, surgical release of the tarsal tunnel.

Gould reviews the evidence regarding the diagnosis and treatment of tarsal tunnel syndrome. He discusses how this syndrome represents a collection of different entities including space-filling lesions and local inflammation. He recommends definitive diagnosis prior to surgical treatment given that the syndrome is often misdiagnosed.

Incorrect Answers:
Answer A: Common fibular nerve compression typically occurs when there is trauma/compression just inferior to the head of the fibula. This can occur when an individual wears work boots and after fractures of the fibular neck. Symptoms of common fibular nerve compression include foot drop and numbness on the dorsum of the foot. Treatment is with activity modification and a foot orthosis to prevent an equinus contracture.

Answer B: Herniated disc presents with symptoms of radiculopathy including pain that travels down the leg through the toes. Symptoms are worsened with flexion of the leg such as during the straight leg raise test. Treatment is with NSAIDs and corticosteroid injections with surgical decompression of the disc in refractory cases.

Answer C: Plantar fasciitis can present very similarly to tarsal tunnel syndrome with pain along the plantar surface of the foot. The pain is typically exacerbated by activity and improves with rest in contrast to this patient. In addition, there is an absence of burning, pain, and numbness that occur in tarsal tunnel syndrome. Tenderness will be at the medial insertion of the plantar fascia into the calcaneal tuberosity. Treatment is conservative with NSAIDs and activity modification.

Answer E: Vitamin B12 deficiency could present with symptoms of peripheral neuropathy. This is possible given this patient's vegan diet. This patient has pain only in one of his feet and he does not have symptoms of anemia such as fatigue or pallor. Treatment is with the repletion of vitamin B12.

Bullet Summary:
Tarsal tunnel syndrome presents with pain, numbness, tingling, and aching along the plantar surface of the foot that is not associated with activity.


Question: A 25-year-old woman presents to her primary care physician complaining of recent hair growth along her jawline, now requiring her to shave every 2 days. She has not shaved in about a week. She has also gained about 10 pounds in the last several months, and her periods have become irregular over the last year. Her last menstrual period was 3 months ago. Her temperature is 98.6°F (37.0°C), pulse is 72/min, blood pressure is 136/86 mmHg, and respirations are 13/min. Her BMI is 26 kg/m^2. Her skin exam reveals hirsutism along the jawline and acanthosis nigricans in the axillary folds. Cardiopulmonary and abdominal exams are unremarkable. A pelvic exam reveals normal external genitalia, a mobile and non-tender 6-week-sized uterus, and no adnexal masses or tenderness. Transvaginal ultrasound is performed and shown in Figure A. This patient is at increased future risk of which of the following?

Answer: Endometrial carcinoma

Explanation:
This patient presents with hirsutism, oligomenorrhea, and multiple follicles on pelvic ultrasound, which is most consistent with polycystic ovarian syndrome (PCOS). PCOS is associated with an increased risk of endometrial carcinoma.

PCOS is an acquired endocrinopathy characterized by ovarian dysfunction and high rates of amenorrhea. Patients with PCOS are at risk for endometrial carcinoma due to unopposed estrogen exposure. Anovulation results in decreased progesterone, which prevents excessive endometrial build-up and thus increases the risk of endometrial hyperplasia and subsequent carcinoma. Increased adiposity in PCOS also increases estrogen, which is aromatized from testosterone in adipose cells, and further raises the risk for endometrial carcinoma. Treatment is with weight loss, metformin, and hormonal contraceptives.

Khan et al. review the genetic basis underlying PCOS. They discuss how this disease is the most common endocrinopathy in reproductive-age women resulting in anovulatory infertility. They recommend using multimodal methods to treat this disease.

Figure/Illustration A shows a transvaginal ultrasound of the ovary with many peripheral follicles (red circle). These findings are characteristic of PCOS.

Incorrect Answers:
Answer B: Ovarian cancer does not occur with increased incidence in patients with PCOS. They are at baseline risk and do not require additional screening. The rates of ovarian cancer increase with hereditary cancer syndromes such as BRCA mutation.

Answer C: Ovarian cyst rupture is not a complication of PCOS, as PCOS does not actually cause cysts (despite the name). The cystic spaces seen on ultrasound are immature follicles rather than cysts. Recurrent infections can lead to cysts and rupture.

Answer D: Type 1 diabetes mellitus is not associated with PCOS, but type 2 diabetes mellitus is. Type 2 diabetes can cause acanthosis nigricans via insulin resistance. Patients with recurrent bouts of pancreatitis are predisposed to diabetes mellitus.

Answer E: Virilization is not seen in PCOS, as the testosterone levels are elevated but not to the degree necessary to produce frank masculinization. If there is evidence of virilization, such as voice deepening or clitoromegaly the differential should be broadened to other diagnoses.

Bullet Summary:
Patients with PCOS are at increased risk of endometrial carcinoma as a result of unopposed estrogen from anovulation as well as aromatization in adipose tissue.


Question: A 35-year-old man is brought into the emergency department by ambulance for a stab wound to the left leg near the inguinal ligament. The patient has no significant medical history, and takes no other medication. He was not stabbed or otherwise injured elsewhere. His temperature is 98.6°F (37.0°C), pulse is 130, blood pressure is 85/50, and respirations are 22. Primary and secondary survey and FAST exam are unremarkable for other associated injuries. Pressure is removed from the wound, and pulsatile bleeding from the wound is noted. Which of the following is the most appropriate next step in management?

Answer: Emergent surgical intervention

Explanation:
This patient with pulsatile bleeding from a wound to the left thigh and hemodynamic instability has hard signs of vascular injury. Patients with penetrating wounds and hard signs of vascular injury should be managed with emergent surgical intervention.

Vascular injury commonly occurs as a result of penetrating trauma, such as a stab wound as in this patient. Evaluation begins with a primary and secondary trauma survey to assess for other injuries. Hard signs of vascular injury include pulsatile bleeding, expanding hematoma, and absent pulses distal to the wound. For patients with suspected vascular injury that display either hard signs or hemodynamic instability, emergent surgical intervention is the most appropriate next step in management. For those with soft signs of vascular injury such as non-pulsatile bleeding or associated bony injury, the most appropriate next step in management is CT angiography of the affected limb.

Ball et al. discuss penetrating trauma to the extremities. They state that extremity trauma is the most common source of vascular injury (51%), with femoral artery as the most frequently injured vessel (35%). They also state that though obtaining pulses is important, distal pulses can continue to be present in many limbs with arterial injuries and therefore may require confirmatory evaluation via doppler, CT scan, or even angiography.

Incorrect Answers:
Answer A: Angiography of the left lower extremity may be utilized if this patient did not present with hard signs of vascular injury. However, this patient's presentation warrants emergent surgical intervention.

Answer B: CT scan of the left lower extremity may be utilized if this patient did not present with hard signs of vascular injury. This patient's presentation warrants emergent surgical intervention.

Answer D: Observation may be appropriate if this patient was hemodynamically stable, and showed no hard or soft signs of vascular injury.

Answer E: Wound closure may eventually be appropriate if this patient was hemodynamically stable, and showed no hard or soft signs of vascular injury.

Bullet Summary:
For patients with suspected vascular injury with hard signs of vascular injury the first step in management is emergent surgical intervention.


Question: A 67-year-old man presents to the emergency room with difficulty speaking for the past 1 hour. He was having dinner at home with his wife when he suddenly noticed he had difficulty eating and speaking. He also noticed a new-onset weakness on his left side. His medical history is significant for type 2 diabetes mellitus, hypertension, and hyperlipidemia. His current medications include metformin, atorvastatin, and lisinopril. His temperature is 98.6°F (37°C), blood pressure is 130/80 mmHg, pulse is 70/min, and respirations are 15/min. On examination, strength is 5/5 in the right upper and lower extremities and 3/5 in the left upper and lower extremities. On cranial nerve examination, his tongue deviates to the right side. There is also decreased sensation to light touch and vibration on the left side of his body. Which of the following arteries is most likely involved in this patient’s presentation?

Answer: Anterior spinal artery

Explanation:
This patient with hypertension, diabetes, hyperlipidemia, deviation of the tongue to the right, left-sided hemiparesis, and decreased sensation to light touch and vibration on the left side of his body most likely has a stroke of the right medial medulla. The medial medulla is supplied by paramedian branches of the vertebral arteries and the anterior spinal artery.

Medial medullary syndrome (Dejerine syndrome) is usually caused by atherosclerotic occlusion of paramedian branches of the anterior spinal artery, vertebral arteries, or basilar artery which supply the medial medulla. Medial medullary structures include the lateral corticospinal tract, the medial lemniscus, and the hypoglossal nerve. Lesions to the lateral corticospinal tract lead to contralateral paresis of the upper and lower extremities. Lesions to the medial lemniscus lead to decreased vibration, proprioception, and light touch on the contralateral body. Ipsilateral hypoglossal nerve dysfunction leads to ipsilateral loss of function of the intrinsic and extrinsic muscles of the tongue including the genioglossus muscle, which protrudes the tongue forward from the root and is unopposed on the contralateral side. This pushes the tongue towards the side of the lesion, leading to ipsilateral tongue deviation. Treatment includes reperfusion via thrombolytics if the patient presents within 4.5 hours of the time last known well.

Kim and Han present clinical findings, radiographic findings, angiographic data, and long-term outcomes from a case series of 86 patients with medial medullary infarction. The authors found that old age and severe motor dysfunction at admission were predictive factors portending poor prognosis. The authors recommend close follow-up of these patients for the development of central post-stroke pain.

Incorrect Answers:
Answer A: Anterior inferior cerebellar artery infarction leads to a lesion of the lateral pons, with damage to the facial nucleus, vestibular nuclei, spinothalamic tract, spinal trigeminal nucleus, sympathetic fibers, labyrinthine artery, and middle and inferior cerebellar peduncles. This presents with complete facial hemiparesis, vomiting, decreased pain and temperature sensation on the contralateral body and ipsilateral face, ipsilateral Horner syndrome, ipsilateral ataxia and dysmetria, and ipsilateral sensorineural deafness and vertigo.

Answer C: Lenticulostriate branches of the middle cerebral artery supply the internal capsule. Strokes of the posterior limb of the internal capsule lead to contralateral hemiparesis. The findings of ipsilateral tongue deviation and sensory changes are not consistent with a lesion to the internal capsule.

Answer D: Pontine perforators of the basilar artery supply the medial pons. Strokes of the medial pons lead to quadriplegia and loss of facial, mouth, and tongue movements with preserved sensorium. This patient’s findings of hemiparesis, ipsilateral tongue deviation, and changes in sensorium are more suggestive of a lesion to the medial medulla, not the medial pons.

Answer E: Posterior inferior cerebellar artery infarction leads to a stroke of the lateral medulla (Wallenberg syndrome). This leads to lesions to the nucleus ambiguus, vestibular nuclei, lateral spinothalamic tract, spinal trigeminal nucleus, sympathetic fibers, and inferior cerebellar peduncle. Clinically this presents with dysphagia, hoarseness, decreased gag reflex, vomiting, vertigo, decreased pain and temperature sensation from the contralateral body and ipsilateral face, ipsilateral Horner syndrome, and ipsilateral ataxia.

Bullet Summary:
Occlusion of the anterior spinal artery can lead to medial medullary syndrome, which presents with ipsilateral deviation of the tongue, contralateral paresis of the upper and lower extremities, and contralateral loss of light touch and vibration sensation.


Question:
A 26-year-old man presents to his primary care physician with a 6-month history of increasing lower back pain. He first felt the pain while lifting boxes at work but thought that he had just strained a muscle. The pain appears to be worse in the mornings and after rest. Exercise and physical activity appear to temporarily make the pain better. He has taken acetaminophen and ibuprofen for the pain. He has no significant medical history and takes no medications. His temperature is 98.6°F (37.0°C), blood pressure is 115/70 mmHg, pulse is 70/min, and respirations are 12/min. On physical exam, he is found to have limited flexion and extension of his spine as well as tenderness to palpation over the insertion of his patellar tendons bilaterally. Results from laboratory tests are shown below:

Serum:
Erythrocyte sedimentation rate (ESR): 61 mm/hr
C-reactive protein (CRP): 36 mg/L (normal <10 mg/L)

Which of the following is the most accurate test for this patient's condition?

Answer: Magnetic resonance imaging

Explanation:
This young man presents with low back pain that is relieved by physical activity, decreased spinal mobility, enthesitis of his patellar tendons, and elevated ESR/CRP values most likely has ankylosing spondylitis (AS). The most accurate diagnostic test for early ankylosing spondylitis is MRI.

Multiple imaging tests can diagnose ankylosing spondylitis. Radiographs of the spine will show squaring of vertebrae with vertical or marginal syndesmophytes resulting in a "bamboo spine" appearance. The earliest radiographic sign is the erosion of the iliac side of the sacroiliac joint, but this finding is not sensitive in the early stages of the disease. MRI is sensitive in detecting sacroiliac inflammation, which makes this the best modality for early detection of ankylosing spondylitis in young patients. Initial therapy for ankylosing spondylitis includes lifestyle modifications (exercise, smoking cessation, physical therapy) and non-steroidal anti-inflammatory drugs (NSAIDs). Therapy for patients with inadequate response to NSAIDs includes tumor necrosis factor inhibitors (etanercept, infliximab, adalimumab) and interleukin 17 inhibitors (secukinumab, ixekizumab).

Jung et al. studied whether signs of inflammation on MRI are correlated with bone quality in patients with ankylosing spondylitis. The authors find that bone marrow edema is negatively correlated with the trabecular bone score. The authors recommend control of active bone inflammation to prevent osteoporosis in patients with ankylosing spondylitis.

Incorrect Answers:
Answer A: Bone scan will show inflammation in the sacroiliac joints, but this study lacks specificity for this disease compared with other inflammatory forms of arthritis.

Answer B: CT will show bony changes but not active inflammation, so it is most commonly used to diagnose cervical fractures in patients with ankylosing spondylitis. While it can support the diagnosis, it is less accurate than an MRI.

Answer D: Radiographs will show erosion of the iliac side of the sacroiliac joint, but this finding is not sensitive in the early stages of the disease when bony ankylosis has not yet occurred. Radiographs may be an appropriate initial test.

Answer E: Ultrasound is useful in evaluating muscle strains or tendon tears; however, it is not able to detect bony abnormalities and is therefore of limited use in ankylosing spondylitis.

Bullet Summary:
MRI is the most sensitive and accurate test for the early detection of ankylosing spondylitis.


Question: A 3-day-old boy is evaluated in the neonatal intensive care unit for failure to pass meconium. The patient is otherwise doing well and feeding every 2 hours. He is urinating 8-10 times per day. The patient has had 2 episodes of vomiting that were described as green in color. He was born at 39 weeks gestation to a 38-year-old G3P3 mother. The pregnancy was uncomplicated, and the patient’s mother received routine prenatal care. She declined prenatal testing. One of the patient’s older siblings has Down syndrome. The patient's temperature is 98.2°F (36.8°C), blood pressure is 48/32 mmHg, pulse is 164/min, and respirations are 48/min. On physical exam, the patient is in no acute distress. His abdomen is firm, non-tender, and distended with hypoactive bowel sounds. A digital rectal exam fails to relieve the obstruction. An abdominal radiograph is performed and the result can be seen in Figure A. Which of the following is the most appropriate next step in management?

Answer: Contrast enema

Explanation:
This patient presents with delayed passage of meconium, bilious emesis, unsuccessful disimpaction on digital rectal exam, and dilated loops of bowel on abdominal radiograph which suggests a diagnosis of meconium ileus. The most appropriate next step in management is an enema with water-soluble contrast which may be both diagnostic and therapeutic.

Meconium ileus presents with bilious emesis and failure to pass meconium in the first 48 hours of life. Abdominal radiography typically shows dilated loops of the small intestine proximal to the obstruction. Enema with water-soluble contrast (Gastrografin) is both diagnostic and therapeutic, as the contrast not only visualizes a microcolon but also relieves the obstruction via the osmotic pull of water into the lumen of the colon. Surgery may be necessary if the contrast enema fails. Patients should also be evaluated for underlying conditions such as cystic fibrosis.

Adams and Stanton review the evidence regarding the diagnosis and treatment of neonatal bowel obstruction. They discuss how malrotation, jejunoileal atresia, duodenal atresia, and colonic atresia are common causes of this finding. They recommend surgical management of these conditions.

Figure/Illustration A is an abdominal radiograph demonstrating dilated loops of bowel and a “soap bubble” appearance of meconium mixed with bowel gas in the right lower quadrant (red circle). These findings are classically seen in patients with meconium ileus.

Incorrect Answers:
Answer A: An abdominal radiograph would be faster but less accurate than an abdominal CT. The use of CT should also be restricted in the pediatric population due to the radiation exposure involved.

Answer C: Rectal suction biopsy is the most accurate test to diagnose Hirschsprung disease, which may present like meconium ileus with bilious vomiting, delayed passage of meconium, and dilated loops of bowel on an abdominal radiograph. A digital rectal exam typically temporarily relieves the intestinal obstruction in Hirschsprung disease and produces an expulsion of gas and stool called the “squirt sign.”

Answer D: Sweat testing is used to diagnose cystic fibrosis, which is strongly associated with meconium ileus. An enema with water-soluble contrast would be the best next step to both confirm the diagnosis and relieve the obstruction. The patient should subsequently undergo sweat testing.

Answer E: Upper gastrointestinal series is the diagnostic test of choice for intestinal malrotation which may also present with bilious vomiting. Malrotation is less likely to present with delayed passage of meconium, and an abdominal radiograph would more likely demonstrate a midgut volvulus. Treatment is with surgical derotation.

Bullet Summary:
Patients with meconium ileus should undergo an enema with water-soluble contrast (Gastrografin) to both confirm the diagnosis and relieve the obstruction.


Question: A 50-year-old man presents to the emergency department with chest pain. He states that the pain is dull in quality, started 30 minutes ago, has been gradually worsening, and is worse with exertion. He also endorses some shortness of breath. He also believes the pain is worse when leaning back and improved when leaning forward. His wife noticed he fainted after the pain started but regained consciousness shortly after. He has a medical history of diabetes and hypertension for which he is on metformin and losartan. His temperature is 99.2°F (37.3°C), blood pressure is 130/87 mmHg, pulse is 99/min, respirations are 22/min, and oxygen saturation is 100% on room air. Physical exam reveals an overweight man. A normal S1 and S2 are auscultated with clear breath sounds. An ECG is performed as seen in Figure A. Which of the following is the most likely diagnosis?

Answer: Myocardial infarction

Explanation:
This patient is presenting with chest pain and an ECG demonstrating hyperacute T waves (leads V2-V6) which is an early finding concerning for a myocardial infarction.

A myocardial infarction occurs when an atherosclerotic plaque ruptures causing occlusion of a coronary artery. Patients classically present with chest pain, dyspnea, and diaphoresis. Atypical manifestations of an acute myocardial infarction may include abdominal pain, nausea, reflux symptoms, and dizziness. The most important initial step in management is to administer aspirin as it lowers mortality and carries minimal risk. An ECG should then be performed. Classically, an ST-elevation myocardial infarction (STEMI) will demonstrate ST elevations in a vascular distribution. However, the progression to a STEMI is usually stepwise and may present with ST depressions, hyperacute T waves, pseudonormalization of the ST segment (a normal ST segment after a depression as it elevates), ST elevations, and finally tombstoning (a concave down wave that looks like a tombstone). If a STEMI is suspected after an ECG is performed, the patient should be started on a second antiplatelet agent (e.g., ticagrelor), heparin, and sent immediately to the cardiac catheterization laboratory.

Nable et al. review the typical electrophysiologic changes found in STEMI. The authors note that T-wave inversions and ST-segment depression can before, during, or after the STEMI event. The authors recommend obtaining serial ECGs in patients with suspected STEMI.

Figure/Illustration A demonstrates hyperacute T waves (blue arrows) that are only occurring in a vascular distribution (V2-V6).

Incorrect Answers:
Answer A: Hyperkalemia can present with peaked T waves; however, peaked T waves would be demonstrated in all leads. Other findings of hyperkalemia can include QRS widening. Immediate management of hyperkalemia with ECG changes should include calcium administration followed by drugs that shift potassium intracellularly such as insulin, albuterol, or sodium bicarbonate. Further management may include diuresis and/or dialysis.

Answer B: Hypertrophic obstructive cardiomyopathy may demonstrate increased voltages throughout the ECG, in particular, in leads V2-V6 with deep Q waves in the septal leads. It may present with syncope upon exertion in a young patient (and in rare cases, sudden cardiac death). Ultrasound would show hypertrophy and left ventricular outflow tract obstruction. Management involves staying hydrated, avoiding strenuous activities, and beta blockers.

Answer C: Hypokalemia can present initially on ECG with U waves and may progress to cardiac dysrhythmias. Repletion with potassium is the preferred treatment, and the magnesium level should be checked as low magnesium can lead to potassium wasting in the kidneys.

Answer E: Pericarditis presents with chest pain worse by laying back and relieved by leaning forward. ECG may demonstrate diffuse ST elevations with PR depressions, and echocardiography may demonstrate a pericardial effusion. Management involves the administration of ibuprofen or colchicine and steroids in refractory cases. However, these therapies should not be used after myocardial infarction.

Bullet Summary:
Hyperacute T waves are an early finding that is concerning for myocardial infarction.


Question:
A 31-year-old man presents to clinic for evaluation of a 3-year history of infertility. He has no significant medical history and takes no medications. He exercises twice a day, often with heavy weightlifting, and eats a high-protein diet. He reports occasional alcohol use and remote marijuana use. His temperature is 99.5°F (37.5°C), blood pressure is 148/90 mmHg, pulse is 84/min, and respirations are 15/min. He is sexually active with his wife and has no history of sexually transmitted infections. Physical exam reveals small testes and a receding hairline. He also has palpable tissue underneath his nipples bilaterally. His muscle tone is normal in his upper and lower extremities bilaterally. His laboratory values are below:

Serum:
Creatinine: 1.3 mg/dL
Glucose: 110 mg/dL
Total bilirubin: 0.8 mg/dL
Aspartate aminotransferase (AST, GOT): 410 U/L
Alanine aminotransferase (ALT, GPT): 275 U/L

Hemoglobin: 12 g/dL
Leukocyte count: 5,300/mm^3
Platelet count: 250,000/mm^3

Which of the following is the most likely cause of this patient’s infertility?

Answer: Anabolic steroid use

Explanation:
This patient with infertility is presenting with decreased testicular size, receding hairline, gynecomastia (palpable breast tissue), and transaminitis. This is most likely due to exogenous testosterone from anabolic (androgenic) steroid use.

Young people (especially athletes and heavy weightlifters) looking to improve their physical performance may rely on the use of anabolic steroids (testosterone, boldenone, and stanozolol). These steroids adversely impair endogenous testicular function, causing infertility secondary to decreased testicular size and sperm count. Furthermore, hepatic dysfunction and cardiac dysfunction can occur at high doses. Excess testosterone is converted to estradiol, leading to breast enlargement and signs of gynecomastia. Aggression and mood disturbances may also occur in patients with excessive anabolic steroid use. Finally, skin findings of anabolic steroid use include accelerated male pattern baldness and acne. Patients should be counseled on avoiding these agents.

Van Wagoner et al. study the chemical composition of products marketed as selective androgen receptor modulators (SARMs). The authors find that less than half of the analyzed products contained compounds in the amount listed on the label. The authors recommend that clinicians counsel athletes and bodybuilders that these products are often mislabeled, are not regulated, and have not been shown to be safe or effective.

Incorrect Answers:
Answer B: Cryptorchidism is the failure of testicular descent into the scrotum and typically manifests in infancy. While uncorrected cryptorchidism can be a cause of infertility, this is an unlikely diagnosis in a man with palpable testes. Furthermore, cryptorchidism would not explain this patient’s receding hairline or gynecomastia.

Answer C: Excess growth hormone use should be suspected because growth hormone can be taken exogenously to improve athletic performance and can present with hypertension. This typically also presents with hyperglycemia and enlarged hands and feet.

Answer D: Klinefelter syndrome is an inherited disorder that also presents with infertility, gynecomastia, and decreased testicular size. This disorder also causes mental impairment and would not explain the patient’s elevated aminotransferases.

Answer E: Myotonic dystrophy is a multi-system disorder that can also present with testicular atrophy, reduced fertility, and hair loss. Patients with myotonic dystrophy also have widespread muscular atrophy and weakness, as well as clinical features of myotonia (e.g., difficulty releasing a handshake).

Bullet Summary:
Anabolic steroid use in men can cause reduced fertility by suppressing endogenous testosterone activity, and presents with gynecomastia, testicular atrophy, accelerated male balding patterns, and hepatotoxicity.


Question: A 4-day-old girl is brought in by her mother for bilateral purulent eye discharge. Pregnancy and delivery were uncomplicated. The newborn had been sleeping regularly and feeding well. Then 1 day ago, the patient developed eyelid edema and eye redness. This morning, the newborn developed a thick yellow-white eye discharge. The mother denies that anyone in the house smokes. The family has a cat at home. The patient’s rectal temperature is 99°F (37.2°C), blood pressure is 80/50 mmHg, pulse is 134/min, and respirations are 34/min with an oxygen saturation of 98% O2 on room air. Figure A shows a photograph of one of the patient's eyes. The patient's physical exam is otherwise unrevealing. Which of the following most appropriately would have prevented this infant's condition?

Answer: Topical erythromycin

Explanation:
This patient is presenting with bilateral purulent eye discharge 4 days post-birth, suggesting the diagnosis of gonococcal conjunctivitis. Standard prophylaxis for this condition is topical erythromycin ointment.

Neonatal gonococcal conjunctivitis is caused by Neisseria gonorrhea and presents in newborns that are 0-5 days old. Symptoms include purulent discharge and eye swelling. Standard prophylaxis for gonococcal conjunctivitis is erythromycin ointment. Silver nitrate drops can also be used as prophylaxis, but this treatment has been abandoned in most practices as it can cause chemical conjunctivitis. Treatment for gonococcal conjunctivitis includes intravenous or intramuscular ceftriaxone. All neonates with gonococcal conjunctivitis should also be treated for chlamydia.

Franco and Hammerschlag prevent the current methods of providing prophylaxis against gonococcal conjunctivitis. They discuss how the development of macrolide resistance may make erythromycin ointment ineffective. They recommend screening and treatment of pregnant women to prevent the development of this disease.

Figure/Illustration A shows a newborn's eye that is exhibiting eyelid swelling, redness, and purulent discharge (red circle). These findings are consistent with gonococcal conjunctivitis.

Incorrect Answers:
Answer A: Artificial tears can be used in the management of chemical conjunctivitis. The most common cause of neonatal chemical conjunctivitis is post-delivery use of silver nitrate drops. Symptoms usually present within the first 24 hours following birth/exposure as mild conjunctival injection and tearing without purulent discharge.

Answer B: Intramuscular ceftriaxone is used as treatment, not prophylaxis, of neonatal gonococcal conjunctivitis. This disease would present with purulent discharge and eye swelling. The goal of prophylaxis is to prevent the development of this condition.

Answer C: Oral erythromycin is used to treat neonatal chlamydial conjunctivitis. Symptoms of chlamydial conjunctivitis usually present 5-14 days post-birth with mild hyperemia and scant mucoid or watery discharge. Patients who are diagnosed with gonorrhea should also be treated empirically for chlamydia.

Answer D: Topical bacitracin can be used as a treatment for gram-positive neonatal bacterial conjunctivitis. It would not be used as a prophylaxis. These patients would present with rapidly progressive infection associated with surrounding soft tissue cellulitis or abscess formation.

Bullet Summary:
Neonatal gonococcal conjunctivitis is treated with an intramuscular shot of ceftriaxone and standard prophylaxis to prevent this condition is with erythromycin ointment.


Question: A 69-year-old man presents to his primary care physician with hip and back pain. He states this weekend he had a barbecue. When he was lifting a heavy object, he suddenly felt pain in his lower back. He describes the pain as in his buttocks but states that at times it travels down his leg. He states that it feels electrical and burning in nature. The patient has a medical history of obesity, diabetes, depression, anxiety, diverticulosis, constipation, and a surgical repair of his anterior cruciate ligament. His current medications include metformin, insulin, lisinopril, fluoxetine, and sodium docusate. His temperature is 98.6°F (37°C), blood pressure is 131/82 mmHg, pulse is 82/min, and respirations are 14/min. On physical exam, he is found to have an intact motor and sensory function in his lower extremities bilaterally. No clonus or Babinski sign is appreciated. An exam of the cranial nerves is intact bilaterally. Which of the following is most likely to help confirm the diagnosis?

Answer: Straight leg raise

Explanation:
This patient is presenting with lower back pain that is electrical and travels down his legs after lifting an object suggesting a diagnosis of a herniated disc. The straight leg test can help confirm the diagnosis.

A herniated disc classically presents in a middle-aged or older individual who was lifting a heavy object with improper form. They will typically experience lower back pain that can be described as radicular. The pain will typically travel down the legs or "shoot down" the legs and is typically described as feeling electrical. The straight leg test on physical exam supports the diagnosis without an MRI. When the individual raises their leg, this causes compression of the spinal nerve roots leading to an exacerbation of symptoms. The most appropriate initial step in management for these patients is limiting strenuous activity, physical therapy, and NSAIDs. Patients who have chronic symptoms that have failed conservative management can undergo surgical laminectomy.

Camino and Piuzzi present the data regarding the diagnostic value of the straight leg raise test. They discuss how this test can exacerbate patients with radicular symptoms. They recommend all practitioners learn how to perform and interpret this test.

Incorrect Answers:
Answer A: Flexion, abduction, and external rotation of the thigh is referred to as the FABER test and is used to evaluate for sacroiliitis which can present with lower back pain and pain in the buttocks. This exam maneuver will cause intense pain in patients who have inflammation of the joint. Treatment is with physical therapy and NSAIDs.

Answer B: Internal rotation of the extended hip is the Freiberg test which evaluates for piriformis syndrome. Piriformis syndrome presents with lower back pain similar to a herniated disc; however, is less likely to have occurred after a single lifting episode and does not typically present with electrical pain that originates in the buttocks.

Answer C: Palpating the paraspinal muscles is a non-specific test that could further support a diagnosis of a muscle strain. It will likely not provide much information in the diagnosis of a herniated disc. Patients with muscle strain can be treated conservatively with relative rest and NSAIDs.

Answer D: Radiography is unlikely to offer information regarding this patient's herniated disc. While it can detect bony abnormalities, the detail of this imaging modality will not depict a herniated disc. An MRI is required to offer the detail necessary to make the diagnosis and is the most accurate test for a herniated disc.

Bullet Summary:
A herniated disc typically presents with pain in the lower back that radiates down the legs and is exacerbated by the straight leg raise test.


Question:
A 5-year-old boy presents to his primary care physician for recurrent colds, fatigue, and fussiness. Over the past several weeks, the child has been more fatigued and his parents state that “he always seems to be sick.” They state that sometimes he complains about his bones hurting and they note that he is less playful. He is up to date on his vaccinations. His temperature is 102°F (38.9°C), blood pressure is 92/60 mmHg, pulse is 115/min, respirations are 23/min, and oxygen saturation is 99% on room air. Physical exam is notable for diffuse non-tender lymphadenopathy. Abdominal exam reveals hepatosplenomegaly. Laboratory studies are ordered as seen below.

Hemoglobin: 8.0 g/dL
Hematocrit: 23%
Leukocyte count: 27,500/mm^3 with 35% lymphoblasts
Platelet count: 49,000/mm^3

Serum:
Na+: 139 mEq/L
Cl-: 101 mEq/L
K+: 4.0 Eq/L
HCO3-: 24 mEq/L
BUN: 16 mg/dL
Glucose: 100 mg/dL
Creatinine: 0.7 mg/dL

Which of the following is the most likely diagnosis?

Answer: Acute lymphoblastic leukemia

Explanation:
This pediatric patient is presenting with recurrent colds, fatigue, non-tender lymphadenopathy, hepatosplenomegaly, and leukocytosis with increased lymphoblasts, which are concerning for acute lymphoblastic leukemia (ALL).

ALL is the most common hematologic cancer in pediatric patients. It initially presents with a vague constellation of symptoms including fatigue, fevers, easy bleeding/bruising, bone pain, lymphadenopathy, hepatosplenomegaly, and possibly testicular enlargement. The diagnosis is supported when the white blood cell count (which can be low, normal, or high) demonstrates increased lymphoblasts. Further confirmatory testing may include testing for the 12:21 translocation, which is more common with a better prognosis, or the 9:22 translocation (the Philadelphia chromosome), which is less common and denotes a poor prognosis.

Onciu reviews ALL. He notes that ALL has a high cure rate with intensive chemotherapeutic regimens and that new research is improving outcomes in this very common condition. He recommends early treatment with these regimens for an improved prognosis.

Incorrect Answers:
Answer B: Acute myelogenous leukemia is a malignancy of myeloblasts and is more common in the elderly. Patients will present with systemic symptoms, weight loss, anorexia, leukocytosis, anemia (causing fatigue), thrombocytopenia (causing bleeding including gingival bleeding and bleeding from the gastrointestinal tract), and neutropenia (predisposing patients to life-threatening infection). Myeloblasts produce increased amounts of myeloperoxidase which can lead to the formation of Auer rods that can be seen on peripheral smear.

Answer C: Chronic myelogenous leukemia is a neoplastic proliferation of myeloid stem cells and presents with a leukocyte count > 50,000/mm3. There are different presentations for this condition. Most patients present in the chronic phase with minimal symptoms (and a low blast count); however, they can also present with an accelerated phase and a blast phase which can lead to a hematologic emergency termed a blast crisis which may cause a hyperviscosity syndrome.

Answer D: Leukemoid reaction is an overly robust immune reaction (often to infection) that resembles chronic myelogenous leukemia. However, the leukocyte alkaline phosphatase level is elevated. This elevated level indicates it is a robust immune response rather than increased cell levels from malignancy.

Answer E: Parvovirus B19 infection presents with erythema infectiosum (fifth disease) which may include "slapped cheek" rash, fever, malaise, and possibly respiratory symptoms. In healthy patients, symptoms are usually minimal and self-limited. However, in patients with hemoglobinopathies (such as sickle cell disease), the transient halt in erythropoiesis that occurs in addition to hemolysis may lead to significant anemia requiring transfusion.

Bullet Summary:
Acute lymphoblastic leukemia presents in pediatric patients with pancytopenia, fatigue, repeat infections, easy bleeding, bone pain, lymphadenopathy, hepatosplenomegaly, and increased blast cells on peripheral smear.


Question: A 15-year-old boy presents to his pediatrician after an appendectomy 1 week ago. The patient denies any abdominal pain, fevers, chills, nausea, vomiting, diarrhea, or constipation. He eats solids and drinks liquids without difficulty. He is back to playing basketball for his school team without any difficulty. His urine appears more amber than usual but he suspects dehydration. His temperature is 98.6°F (37°C), blood pressure is 110/70 mmHg, pulse is 76/min, and respirations are 15/min. His physical exam is unremarkable. The laparoscopic incision sites are all clean without erythema. The pediatrician orders a urinalysis, which is notable for the following. Urine: Epithelial cells: Scant Glucose: Negative Protein: 3+ WBC: 3/hpf Bacteria: None Leukocyte esterase: Negative Nitrites: Negative The patient is told to return in 3 days for a follow-up appointment; however, his urinalysis at that time is similar. Which of the following is the most appropriate next step in management?

CT scan abdomen and pelvis with contrast

Urine dipstick in the morning and in the afternoon

Answer: Urine dipstick in the morning and in the afternoon

Explanation:
This patient is found to have proteinuria on urinalysis in the absence of clinical symptoms or signs of nephrotic syndrome. Given the likely diagnosis of transient proteinuria, the most appropriate next step is to repeat the urine dipstick in the morning and in the afternoon.

Transient proteinuria can be due to febrile illnesses, seizures, strenuous exercise, emotional stress, serious illnesses like heart failure, and abdominal surgery. A detailed workup is not needed if the clinical story is clear, but an orthostatic test can be completed. One way to do this is to assess the urine dipstick in the morning and in the afternoon. Another way requires the patient to collect urine at multiple times throughout the day. A diagnosis is confirmed if the morning sample is protein-free but the evening sample contains protein. In general, pediatric patients with orthostatic proteinuria should have under 1 gram of protein in a full 24 hours. Treatment is with reassurance because this condition usually resolves by itself.

Ingold and Bhatt review the evidence regarding the diagnosis and treatment of orthostatic proteinuria in patients. They discuss how this condition is benign and typically occurs in adolescents. They recommend reassurance and supportive treatment.

Incorrect Answers:
Answer A: A CT scan of the abdomen and pelvis with contrast could assess for any anatomic obstruction and a possible post-renal cause of kidney dysfunction. It would be more prudent to obtain basic labs and a timed urinalysis before exposing a pediatric patient to radiation.

Answer B: Renal biopsy is indicated if the patient's clinical presentation is concerning for a glomerular or tubulointerstitial etiology for proteinuria. Patients will have edema, hematuria, or dysuria.

Answer C: Repeat urinalysis will not change the presence of proteinuria. Generally, a patient who has proteinuria should have a repeat urinalysis performed to rule out transient proteinuria. If the repeat urinalysis demonstrates proteinuria (as in this patient), then the diagnosis is unlikely to be transient proteinuria, and further workup is needed.

Answer E: Urine electrolytes and creatinine will assess the kidney's ability to concentrate urine and assess the etiology of acute kidney injury. Patients will present with oliguria or anuria.

Bullet Summary:
Consistent proteinuria in a child should by evaluated by performing a urinalysis in the morning and in the afternoon to see if proteinuria comes on toward the end of the day.


Question:
A 24-year-old woman with no significant medical history presents to the emergency department for progressive shortness of breath. She endorses decreased exercise tolerance as well as intermittent palpitations. She returned from a recent missionary trip to South America 12 months prior where she endorsed eating a local delicacy as well as a period of fevers and eyelid swelling during her stay. Her temperature is 99.1°F (37.3°C), pulse is 95/min, blood pressure is 130/85 mmHg, respirations are 15/min, and oxygen saturation is 97% on room air. Physical exam is notable for a laterally displaced point of maximal impulse as well as a 2/6 diastolic murmur radiating to the axilla. A blood smear is shown in Figure A. Her laboratory results are:

Leukocyte count and differential:
Leukocyte count: 10,000/mm^3
Neutrophils: 57%
Lymphocytes: 30%
Monocytes: 3%
Eosinophils: 9%
Basophils: 1%
Hemoglobin: 13.1 g/dL
Platelet count: 420,000/mm^3

Which of the following is the most appropriate treatment?

Answer: Benznidazole

Explanation:
This patient presents with symptoms of heart failure, eosinophilia, trypanosomes on peripheral smear, and a history of recent travel to South America consistent with the diagnosis of Chagas disease. Treatment options for Chagas disease include benznidazole and nifurtimox.

Chagas disease is caused by the parasite Trypanosoma cruzi and is most commonly transmitted by the reduvvid (kissing) bug. The disease is endemic to South America and presents in an acute and chronic phase. The acute phase is characterized by fever, headaches, myalgias, and unilateral eyelid swelling (Romaña’ sign) where the infectious agent has been rubbed into the eye. The chronic phase of the disease is characterized by dilated apical cardiomyopathy leading to conduction abnormalities and valvular dysfunction, megacolon, and megaesophagus. Laboratory testing reveals a peripheral eosinophilia and a peripheral blood smear may reveal the infectious trypanosomes. Treatment is with benznidazole and/or nifurtimox.

Perez-Molina and Molina present the data surrounding the diagnosis and treatment of Chagas disease. They discuss how many cases progress to a chronic state characterized by cardiomyopathy, arrhythmias, and organomegaly. They recommend prompt treatment of the disease to avoid end organ damage.

Figure/Illustration A shows a peripheral blood smear with the trypomastigote form of Trypanosoma cruzi (red circle). Note the anterior location of the dense basophilic nucleus.

Incorrect Answers:
Answer A: Amphotericin B is a potent antifungal that has application in the treatment of multiple fungal infections. It is used as a first-line agent for mucormycosis and cryptococcal meningitis (in addition to flucytosine). Amphotericin B with sodium stibogluconate is used to treat visceral leishmaniasis, a protozoal infection most commonly caused by Leishmania donovani. Side effects can include nausea, vomiting, rigors, fever, hypertension or hypotension, renal dysfunction, and hypoxia.

Answer C: Erythromycin is a macrolide antibiotic that is used in the treatment of bacterial infections. It has a pro-motility effect and can also be used as a gastric pro-motility agent. Potential side effects include gastrointestinal upset, prolonged QT interval, inhibition of the P450 system, and pyloric stenosis in infants.

Answer D: Ganciclovir is a synthetic nucleoside analogue that is mainly used in the treatment of cytomegalovirus (CMV) infections. The most common side effects are bone marrow suppression (granulocytopenia, thrombocytopenia, and anemia) and gastrointestinal upset.

Answer E: Praziquantel is an anti-helminthic used in the treatment of tapeworms and flukes including Echinococcus, Taenia solium (cysticerosis), Schistosoma sp., Clonorchis sinensis (liver fluke), and Paragonimus westermani (lung fluke). Side effects of praziquantel develop due to release of contents from dead parasites and can include gastrointestinal upset, elevated liver enzymes, and dizziness.

Bullet Summary:
Treatment of Chagas disease is with benznidazole or nifurtimox.


Question: A 27-year-old man presents for an appointment to establish care. He recently was released from prison. He has felt very fatigued and has had a cough. He has lost roughly 15 pounds over the past 3 weeks. He attributes this to intravenous drug use in prison. His temperature is 99.5°F (37.5°C), blood pressure is 127/68 mmHg, pulse is 100/min, respirations are 18/min, and oxygen saturation is 98% on room air. QuantiFERON gold testing is positive. The patient is started on appropriate treatment. Which of the following is the most likely indication to discontinue this patient's treatment?

Answer: Elevated liver enzymes

Explanation:
This patient is presenting with weight loss and cough with a positive quantiFERON gold test suggestive of tuberculosis and has been started on treatment. The most likely indication to discontinue tuberculosis therapy is elevation of liver enzymes.

Tuberculosis typically presents with weight loss, cough, and night sweats usually in high-risk patients (prisoners or the immunosuppressed). It can be diagnosed using sputum samples as these organisms will be positive on an acid-fast test. These bacteria are slow to grow so cultures need to be held for an extended period of time. QuantiFERON gold testing can be used to make the diagnosis as well. Treatment for tuberculosis is RIPE therapy: Rifampin, Isoniazid, Pyrazinamide, and Ethambutol. The most common indication to alter or discontinue therapy is an elevation of liver enzymes 5 times greater than baseline.

Tweed et al. review the evidence regarding liver injury in patients with RIPE therapy. They discuss how patients on HIV therapy are at higher risk. They recommend measuring liver enzymes to detect this potential side effect.

Incorrect Answers:
Answer B: Hyperuricemia is a side-effect of pyrazinamide; however, this is not the most common indication for discontinuing RIPE therapy. Patients can be treated with supportive therapy or with uric acid lowering agents in those with arthralgias.

Answer C: Optic neuritis is a side-effect of ethambutol; however, it is not the most common indication for discontinuing RIPE therapy. Treatment is with discontinuation of ethambutol.

Answer D: Peripheral neuropathy is a side-effect of isoniazid; however, it is typically not an indication to discontinue RIPE therapy. Treatment is with supplementation of vitamin B6.

Answer E: Red body excretions are a side-effect of rifampin; however, this is a cosmetic concern rather than an indication to discontinue RIPE therapy. Patients should be counseled regarding this side effect prior to initiation of treatment.

Bullet Summary:
Elevation of liver enzymes 5 times above normal is the most common indication to alter or discontinue RIPE therapy when treating tuberculosis.


Question: A 37-year-old man presents to the emergency department for a persistent fever. The patient has felt unwell for the past week and has felt subjectively febrile. The patient has a medical history of a suicide attempt and alcohol abuse. He is not currently taking any medications. The patient admits to using heroin and cocaine and drinking 5-8 alcoholic drinks per day. His temperature is 103°F (39.4°C), blood pressure is 92/59 mmHg, pulse is 110/min, respirations are 20/min, and oxygen saturation is 96% on room air. Cardiopulmonary exam is notable for a systolic murmur heard best along the left sternal border. Dermatologic exam reveals scarring in the antecubital fossa. IV fluids are administered and the blood pressure is subsequently 120/70 mmHg. Which of the following is the most appropriate next step in management for the most likely underlying diagnosis?

Answer: Blood cultures

Explanation:
This patient is presenting with fever and a systolic murmur suggestive of bacterial endocarditis. The most appropriate initial step in management is to draw blood cultures.

Bacterial endocarditis presents with fever, systemic symptoms (aches, myalgias, and fatigue), and a new murmur typically in a patient with intravenous drug use. These patients introduce bacteria intravenously which then flows to the right side of the heart and can cause right-sided endocarditis. The most appropriate initial step in management is to draw blood cultures. Once blood cultures have been drawn, broad-spectrum antibiotics can be started (vancomycin and gentamicin), and an ultrasound can be performed to further support the diagnosis (or rule out vegetations) and plan operative interventions if necessary.

Wang et al. review the evidence regarding the diagnosis and treatment of infectious endocarditis. They discuss how echocardiogram and blood cultures are the mainstay of diagnosis. They recommend broad spectrum antibiotics.

Incorrect Answers:
Answer B: A chest radiograph may be performed in the workup for bacterial endocarditis; however, it is not the most appropriate initial step in management and is neither sensitive nor specific.

Answer C: A CT scan would not be a very helpful confirmatory test in the diagnosis of bacterial endocarditis. A better confirmatory test would be an ultrasound. It may workup alternative causes of fever such as pneumonia.

Answer D: Ultrasound (echocardiography) would be the imaging test of choice for bacterial endocarditis. It would be performed after blood cultures have been drawn and antibiotics had been started.

Answer E: Vancomycin and gentamicin are the broad-spectrum antibiotics of choice for bacterial endocarditis. They would be started after blood cultures have been drawn and reduce mortality when given early in sepsis.

Bullet Summary:
The most appropriate initial step in the management of bacterial endocarditis after initial stabilization is to draw blood cultures.


Question: A 32-year-old woman presents to her primary care provider with pelvic pain. She reports that for the last several years, she has had chronic pain that is worse just before her menstrual period. Over the past 2 months, she has also had worsening pain during intercourse. She denies dysuria, vaginal discharge, or vaginal pruritus. The patient has never been pregnant and previously used a copper intrauterine device (IUD) for contraception, but she had the IUD removed 1 year ago because it worsened her menorrhagia. She has now been using combined oral contraceptive pills (OCPs) for nearly 1 year. The patient reports improvement in her menorrhagia on the OCPs but denies any improvement in her pain. Her medical history is otherwise unremarkable. Her temperature is 98.0°F (36.7°C), blood pressure is 124/73 mmHg, pulse is 68/min, and respirations are 12/min. The patient has pain with lateral displacement of the cervix on pelvic exam. A pelvic ultrasound shows no abnormalities, and a urine pregnancy test is negative. Which of the following is most likely to confirm the diagnosis?

Answer: Laparoscopy

Explanation:
This patient presents with chronic pelvic pain that is worse before her menstrual period, vaginal tenderness on physical exam, and lateral displacement of the cervix, which is consistent with a diagnosis of endometriosis. Since this patient has failed therapy with oral contraceptive pills (OCPs), she should undergo laparoscopy.

Endometriosis classically presents with chronic pelvic pain and the “3 D symptoms” of dysmenorrhea, dyspareunia, and dyschezia. Since laparoscopy with biopsy is required for definitive diagnosis, patients with suspected endometriosis may be empirically managed with OCPs and NSAIDs. Most patients achieve symptom control on this regimen. If patients fail empiric therapy, have contraindications to hormonal therapy, or have severe symptoms they should undergo laparoscopy for both definitive diagnosis and treatment of the disease.

Vercellini et al. review the evidence regarding the diagnosis and treatment of endometriosis. They discuss how the diagnosis of this disorder is carried out by direct visualization and histologic examination of lesions. They recommend medical treatment for symptomatic relief and surgical excision in refractory patients.

Incorrect Answers:
Answer A: Abdominal ultrasound is less accurate than a transvaginal ultrasound which has already been performed. Since there were no findings on transvaginal ultrasound, it is unlikely that abdominal ultrasound would reveal pathology. This modality would be effective for intra-abdominal disorders such as cholelithiasis or appendicitis (in pediatric and pregnant patients to avoid radiation exposure).

Answer B: Hysterosalpingogram is more useful in the workup of infertility, particularly for patients with a history of pelvic inflammatory disease. It is not routinely used to diagnose endometriosis. Patients with pelvic inflammatory disease present with fever, purulent discharge, and cervical motion tenderness. Treatment is with antibiotics.

Answer C: Hysteroscopy is used in the workup of abnormal uterine bleeding, fibroids, and endometrial thickening or polyps. Since endometriosis is defined as endometrial glands and stroma outside of the uterine cavity, a hysteroscopy is not particularly helpful in making the diagnosis. Treatment for polyps or fibroids is with surgical excision.

Answer E: Pelvic MRI can be used to better characterize an abnormality seen on pelvic ultrasound or CT or to diagnose adenomyosis. It can aid in making the diagnosis of endometriosis but is not the most accurate/confirmatory test. A laparoscopy would both be diagnostic and therapeutic for this disorder.

Bullet Summary:
Patients with suspected endometriosis may be managed empirically with oral contraceptive pills and NSAIDs, but laparoscopy with biopsy is necessary for definitive diagnosis and management.


Question: A 27-year-old man presents to his primary care physician for a checkup. He has no health concerns and has not seen a physician in years. The patient has a medical history of depression treated with fluoxetine and lithium. His temperature is 99.5°F (37.5°C), blood pressure is 122/78 mmHg, pulse is 90/min, respirations are 13/min, and oxygen saturation is 98% on room air. Physical exam is notable for the finding in Figure A. Which of the following represents the most likely risk factor for this patient's presenting condition?

Answer: Alcohol consumption

Explanation:
This patient is presenting with adherent white plaques on the inside of the cheek consistent with oral leukoplakia. Alcohol consumption is a risk factor for this disease.

Oral leukoplakia presents with a white patch/plaque that occurs over the oral mucosa that is adherent and non-scrapable. Risk factors for this condition include the risk factors for squamous cell carcinoma such as consumption of alcohol and smoking. Though the cause of this lesion is largely idiopathic, any irritating substance can induce it. Other potential risk factors include candidiasis, vitamin deficiency, endocrine disturbances, and viral infections. A diagnosis can be made using a biopsy showing the degree of dysplasia. Treatment is with smoking and alcohol cessation as well as surgical removal for suspicious lesions.

Mohammed and Fairozekhan review the evidence regarding the diagnosis and risk factors for leukoplakia. They discuss how this disease is associated with smoking and alcohol use. They recommend screening patients for these modifiable risk factors.

Figure/Illustration A is a clinical photograph demonstrating adherent white plaques on the inside of the cheek (red circle). These findings are consistent with oral leukoplakia.

Incorrect Answers:
Answer B: Antibiotic use is a risk factor for candidiasis; however, this patient is not presenting with symptoms of candidiasis which is itself a risk factor for oral leukoplakia. Candidiasis presents with opaque white lesions that can be scraped off.

Answer C: Intravenous drug use does make this patient riskier overall for many conditions; however, alcohol is a more direct risk factor for oral leukoplakia. Immunodeficiency conditions can cause widespread fungal and viral infections on the mucosal surfaces.

Answer D: Poor dental hygiene may be found more often in patients with oral leukoplakia; however, it is not itself a direct cause.

Answer E: Sexual intercourse would predispose this patient to infections and viruses (such as Epstein-Barr virus); however, it is a less likely risk factor than is alcohol consumption or smoking. These infections tend to present with ulcers more commonly than leukoplakia.

Bullet Summary:
Risk factors for oral leukoplakia and squamous cell carcinoma include alcohol consumption and smoking.


Question: A 32-year-old man presents to the emergency department for evaluation of headache. His symptoms started last night and have persisted. He occasionally has migraine headaches, but he has not had a headache like this in the past. He reports associated nausea, vomiting, fevers, and neck pain. He has a medical history of asthma. His temperature is 100.4°F (38.0°C), blood pressure is 110/60 mmHg, pulse is 95/min, respirations are 17/min, and oxygen saturation is 98% on room air. On physical exam, he appears uncomfortable. Neurologic exam reveals no focal deficits. There is pain with passive neck flexion. No edema or rashes are noted. Lungs are clear to auscultation bilaterally. Lumbar puncture is performed and CSF results are obtained as shown below. Cerebrospinal fluid (CSF): Cell count: 175/mm^3 RBCs: 0/mm^3 Cl-: 119 mEq/L Glucose: 49 mg/dL Pressure: 150 mmH2O Total protein: 55 mg/dL Based on these results, which of the following is the most appropriate treatment regimen for this patient?

Answer: Supportive care and monitoring

Explanation:
This patient with headache, fever, and neck stiffness has a presentation and CSF studies consistent with a diagnosis of viral or aseptic meningitis. Supportive care is the most appropriate management strategy for patients with viral meningitis.

Aseptic (viral) meningitis presents similarly to bacterial meningitis with neck stiffness, photophobia, fever, malaise, and flu-like symptoms. Patients should be worked up and treated as if they have bacterial meningitis until proven otherwise. CSF findings in aseptic meningitis show an elevated cell count (though typically < 300/mm^3 in contrast to bacterial meningitis), a normal or elevated protein, and a normal glucose. CSF should be sent for Gram stain and culture to confirm the diagnosis and rule out bacterial meningitis. Once the diagnosis has been confirmed, management of viral meningitis consists of supportive care and monitoring for complications such as seizures, cerebral edema, or SIADH.

Kohil et. al review viral meningitis. They discuss the pathophysiology, clinical manifestation and diagnosis. They recommend that most patients with viral meningitis be treated with supportive care.

Incorrect Answers:
Answer A: Acyclovir would be appropriate for suspected HSV or varicella encephalitis or meningitis. This patient with no RBCs in the CSF and no changes in mental status is not likely to have infection with HSV or varicella.

Answer B: Amphotericin and 5-flucytosine followed by long-term fluconazole is the appropriate management of cryptococcal meningitis. Cryptococcal meningitis presents similarly to bacterial and viral meningitis, almost exclusively in immunocompromised patients.

Answer C: Ceftriaxone and vancomycin would be appropriate if bacterial meningitis was suspected. Steroids are generally added if a bacterial source is likely. However, this patient has a presentation that is less concerning for bacterial meningitis, and CSF studies that are more consistent with aseptic meningitis.

Answer D: Ceftriaxone, vancomycin and steroids are an appropriate initial regimen for bacterial meningitis. Dexamethasone reduces inflammatory injury while patients are being treated with antibiotics.

Bullet Summary:
Viral or aseptic meningitis is managed with supportive care and monitoring.


Question: A 23-year-old woman presents with a 7-day history of abdominal pain, and now bloody diarrhea that brings her to her primary care physician. Review of systems is notable for a 12-pound unintentional weight loss and intermittent loose stools. She has a family history notable for a father with coronary artery disease and a mother with primary sclerosing cholangitis. Her temperature is 37.2°C (98.9°F), blood pressure is 100/72 mmHg, pulse is 72/min, respirations are 12/min, and oxygen saturation is 100% on room air. Her abdomen is soft, mildly diffusely tender to deep palpation, and non-distended. She is found to have the finding on colonoscopy in Figure A. Serum perinuclear antineutrophil cytoplasmic antibodies (p-ANCA) are positive. Which of the following is most likely to be present in this patient?

Continuous lesion beginning in the rectum

Answer: Continuous lesion beginning in the rectum

Explanation:
This patient presents with features suggestive of inflammatory bowel disease (IBD), and her colonoscopic and serologic studies suggest ulcerative colitis (UC). UC typically begins in the rectum and progresses proximally towards the ileocecal valve in a continuous fashion.

The diagnosis of IBD should always prompt further investigation to better delineate between UC, Crohn disease, or indeterminate colitis. Further delineation guides treatment and informs prognosis. UC has a peak incidence in the second and third decades of life. It is characterized by disease extending from the rectum proximally towards the ileocecal valve in a continuous fashion. UC presents as mucosal and submucosal inflammation, with characteristic crypt distortion and presence of crypt abscesses. P-ANCA is positive in most individuals with UC. Repeated mucosal injury can induce pseudopolyp formation, and pancolitis or disease in the descending colon warrants screening colonoscopy due to increased risk of colon cancer. On imaging, the colon can be dilated by edema, losing its haustral markings and giving it a "lead pipe" appearance.

Gajendran et al. review the pathophysiology, diagnosis, and treatment of UC. They found that colonoscopy with biopsy is the best way to make a definitive diagnosis of UC. They recommend the Mayo scoring system as a commonly used method of assessing disease severity, guiding treatment options, and monitoring patients during therapy.

Figure A is a colonoscopy image showing continuous colonic mucosal inflammation typical of ulcerative colitis.

Incorrect Answer:
Answer A: Cobblestoning and skip lesions refer to the patchy areas of inflammation noted in Crohn disease. In contrast, the inflammation seen in UC involves continuous stretches of colon mucosa.

Answer C: Fistulae and stricture formation are features of Crohn disease, not UC. Fistulizing and stricture formation can affect the entire gastrointestinal tract in Crohn disease.

Answer D: Perianal disease is a feature of Crohn disease. Although UC commonly affects the rectum, it tends to spare the anus.

Answer E: Worse disease severity near the ileocecal valve is a feature of Crohn disease and not UC. UC tends to be characterized by more uniform disease severity spanning in continuous fashion from rectum towards the cecum.

Bullet Summary:
Ulcerative colitis is characterized by disease extending from the rectum proximally towards the ileocecal valve in a continuous fashion.


Question: A 71-year-old woman arrives to clinic with sudden vision loss. She was in her usual state of health until waking up this morning unable to see out of her right eye. She denies pain, but reports her right eye “feels funny.” The patient’s medical history is significant for a previous myocardial infarction, hypertension, and osteoporosis. Her current medications include aspirin, metoprolol, rosuvastatin, lisinopril, and alendronate. Her temperature is 98°F (36.7°C), blood pressure is 145/86 mmHg, pulse is 62/min, and respirations are 12/min with an oxygen saturation of 98% on room air. The patient's pupils are symmetric in size and equally reactive to light with accommodation. A fundoscopic exam of the right eye is shown in Figure A. The left optic fundus is unremarkable. Which of the following is the most likely diagnosis?

Answer: Retinal vein occlusion

Explanation:
This patient is presenting with sudden, painless, unilateral vision loss with a fundoscopic exam positive for venous dilation and retinal hemorrhage. These findings are consistent with the diagnosis of retinal vein occlusion.

Retinal vein occlusion can occur in either central or branch retinal veins and is often caused by compression from nearby arterial atherosclerosis. It presents as acute onset, painless vision loss, normally in one eye. On fundoscopic exam, classic findings of this disease include venous engorgement, retinal hemorrhage, cotton wool exudates, and edema/swelling of the optic disk can be seen. There is no definitive treatment for this disorder but symptomatic treatment includes intravitreal glucocorticoid injections and retinal laser photocoagulation. Retinal vein occlusion may resolve spontaneously or progress to permanent vision loss.

Robinson and Halpern present evidence regarding the treatment of retinal vein occlusion. They discuss how the treatments for the acute phase of this disease have been disappointing. They recommend managing long-term complications such as neovascularization with phototherapy.

Figure/Illustration A is a fundoscopic exam showing engorged retinal veins, optic disk swelling, and widespread retinal hemorrhages (red circle). These findings are characteristic of central retinal vein occlusion.

Incorrect Answers:
Answer A: Central retinal artery occlusion can present as sudden onset, unilateral vision loss. Fundoscopic exam will show a “cherry-red” spot at the fovea and a “fuzzy” retina with attenuated vessels. Embolic sources may include carotid artery atherosclerosis or cardiac vegetation. Treatment is with risk factor control.

Answer B: Closed-angle glaucoma presents as sudden, painful, vision loss caused by increased intraocular pressure. The eye will appear red and often feel “hard.” The optic disc will show characteristic cupping. Intraocular pressure will be levated and treatment is with acetazolamide, steroids, timolol, bromidine, and pilocarpine. Irodotomy is reserved for refractory cases.

Answer C: Papilledema may present as an enlargement in the blind spot and is usually bilateral, as it is caused by increased intracranial pressure. On fundoscopic exam, there will be bilateral optic disk swelling, seen as an elevated optic disk and blurred margins. Patients should undergo a neurologic evaluation to determine the etiology of the papilledema.

Answer D: Retinal detachment presents as monocular loss of vision, often described as a “curtain pulled down,” and preceded by “flashers” and “floaters.” On fundoscopic exam, crinkling of the retinal tissue and abrupt changes in vessel direction can be seen. Surgical reattachment of the retina is required to prevent loss of vision.

Bullet Summary:
Retinal vein occlusion presents with a sudden, monocular, painless loss of vision with optic disk swelling, dilated veins, cotton wool spots, and retinal hemorrhages.


Question: A 23-year-old woman presents to her psychiatrist concerned about her mood. She has felt tired and unwilling to engage in any activities lately. She states that her limbs feel heavy all the time and that completing any activity takes tremendous effort. She no longer finds any happiness in activities that she previously enjoyed. She struggles to sleep and at times can't sleep for several days. The patient is started on appropriate first-line therapy and sent home. She returns 1 week later stating that her symptoms have not improved. She is requesting help as her performance at work and school is suffering. Her temperature is 99.5°F (37.5°C), blood pressure is 115/72 mmHg, pulse is 60/min, respirations are 13/min, and oxygen saturation is 98% on room air. Which of the following is the most appropriate next step in management?

Answer: Continue current therapy

Explanation:
This patient is presenting with depression and should be treated with a selective serotonin reuptake inhibitor (SSRI) for at least 4 weeks. Patients who have tried the therapy for a shorter duration of time may not yet have experienced the benefit of the medication.

Depression presents with SIGE CAPS (Sleeplessness, Interest loss, Guilt, Energy decreased, Concentration abnormalities, Appetite changes, Psychomotor retardation, and Suicidal ideation). The most appropriate initial step in management is to treat the patient with an SSRI for at least 4 weeks since SSRI's take several weeks to reach their potential. If the treatment has failed after 4 weeks of use, altering the patient's medications could be appropriate. Treatment and side effects should be monitored by a physician.

Kato et al. review the evidence regarding the treatment of depression with SSRI medications. They discuss how medications should be used for at least 4 weeks to determine treatment response. They recommend not allowing patients to switch between drug classes too early.

Incorrect Answers:
Answer A: Adding lithium to the treatment regimen could be an appropriate treatment if this patient had failed to respond to therapy after 4 weeks of using the drug. Lithium is an augmenting agent that could potentiate the effect of an SSRI.

Answer B: Changing the treatment to duloxetine would be inappropriate as this patient has not taken the first-line SSRI for at least 4 weeks. Patients should try a full treatment course in order to determine if they may derive some benefit.

Answer C: Changing the treatment to lithium would be appropriate if this patient's diagnosis was bipolar disorder, which would present with episodes of depression and mania. Altered sleep alone does not indicate mania.

Answer E: Electroconvulsive therapy is the most effective treatment for depression; however, it is typically a last-line treatment. This therapy can be useful in refractory cases.

Bullet Summary:
SSRI medications are the most appropriate first-line agent for depression and should be tried for at least 4 weeks before changing therapy.


Question: A 72-year-old man presents to the clinic for his annual exam. For the past few months, he has pain in his chest with physical activity. The pain goes away after he takes a break. He reports no chest pain while he is resting, and the pain is not worsening. His past medical history is notable for hypertension, type 2 diabetes mellitus, and hyperlipidemia. His medications include amlodipine, atorvastatin, and metformin. His temperature is 36.5°C (97.7°F), blood pressure is 132/80 mmHg, pulse is 74/min, respirations are 14/min, and oxygen saturation is 98% on room air. He has a regular rate and rhythm, normal S1 and S2, and no murmurs, rubs, or gallops. His anterior, lateral, and posterior chest are non-tender to palpation. His electrocardiogram is shown in Figure A. Troponin I level is < 0.017 ng/mL. Which of the following is the most likely diagnosis?

Answer: Stable angina

Explanation:
This patient who presents with exertional chest pain that is relieved with rest without increasing frequency or intensity of chest pain, a normal electrocardiogram (ECG), and normal troponin level most likely has stable angina.

Angina pectoris is chest pain secondary to myocardial ischemia and is most commonly caused by atherosclerosis, though it can be caused by any etiology leading to narrowing of the coronary arteries. The pain tends to be substernal, dull, squeezing, or pressure-like and can also radiate to the neck or arm. It may also be associated with shortness of breath, dizziness, lightheadedness, nausea/vomiting, or diaphoresis. In stable angina, the chest pain is precipitated by exertion or stress and is consistently relieved with rest or nitroglycerin. ECG tends to be normal, and troponin I levels are not elevated. Treatment of stable angina includes beta blockers and nitrates (for episodes of pain), as well as therapy to prevent disease progression disease progression which may include antiplatelet therapy (aspirin), lipid-lowering medications, and glycemic control. Lifestyle measures are also the mainstay of therapy and may include smoking cessation, exercise, and dietary modification.

Joshi and de Lemos review stable angina. They note the optimal management of this condition. They recommend lifestyle interventions, lipid-lowering therapy, and antiplatelets to reduce morbidity and mortality.

Figure A shows an electrocardiogram with regular rate and rhythm. Every P wave is followed by a narrow QRS complex, which is consistent with normal sinus rhythm.

Incorrect Answers:
Answer A: Costochondritis presents with pain of the chest wall that can be sharp, aching, or pressure-like and typically worsens with cough or deep breathing. It is typically caused by injury to the chest, physical strain, or can be associated with inflammatory conditions such as arthritis. On exam, the pain can be reproduced with palpation of the chest wall, in particular, the costochondral junction. This patient's chest pain is associated with exertion and relieved with rest, and his pain is not reproduced upon palpation of the chest wall. Thus, he is unlikely to have costochondritis.

Answer B: Non-ST elevation myocardial infarction presents similarly to unstable angina with substernal chest pain that is new-onset, accelerating, or occurring at rest, without ST elevations on ECG. However, ST depressions or T wave inversions may be present on ECG, and troponin I and creatine kinase-MB isoenzyme (CK-MB) would be elevated, indicating myocardial injury.

Answer C: ST-elevation myocardial infarction presents with acute onset substernal chest pain that can radiate to the neck, arm, shoulders, or jaw and is sometimes associated with diaphoresis, nausea/vomiting, shortness of breath, lightheadedness, or anxiety. ECG shows ST elevations in a vascular distribution, and troponin I and CK-MB levels are elevated. This patient's ECG does not show ST elevations, and his symptoms are more consistent with stable angina.

Answer E: Unstable angina is characterized by substernal chest pain occurring at rest or occurring with more severity, longer duration, or increasing frequency. ECG may be normal or show ST depression or T wave inversion, and the troponin level is not elevated. It is caused by incomplete coronary artery occlusion by a thrombus or atherosclerosis, commonly due to a ruptured plaque with subsequent clot formation. This patient's chest pain is exertional, does not occur at rest, and is consistently relieved with rest, and thus would be consistent with stable angina.

Bullet Summary:
Stable angina is characterized by exertional chest pain that is not changing in quality or quantity and is relieved with rest.


Question:
A 49-year-old man presents with 3 months of generalized weakness. He has had a chronic cough and a 20 pound unintentional weight loss over the past 6 months. He has a medical history significant for high blood pressure, hyperlipidemia, and seasonal allergies with no prior surgical history. He has no history of tobacco use. He moved from India 7 years prior to presentation. He currently lives in Oregon and has not left the west coast since moving. His temperature is 99°F (37.2°C), blood pressure is 100/70 mmHg, pulse is 76/min, and respirations are 16/min. His physical exam is significant for hyperpigmentation of the oral mucosa and temporal muscle wasting. Radiography of the abdomen demonstrates bilateral adrenal calcifications. Laboratory values are as follows:

Serum:
Na+: 130 mEq/L
Cl-: 96 mEq/L
K+: 5.2 mEq/L
HCO3-: 24 mEq/L
Morning cortisol: 2 ug/dL
30-minute cortisol during cosyntropin test: 8 ug/dL (normal > 18 ug/dL)
Morning adrenocorticotropic hormone (ACTH) concentration (serum): 80 pg/mL (normal 10-60 pg/mL)

Which of the following is the most appropriate next step in management?

Bilateral adrenalectomy, prednisone, and fludrocortisone

Hydrocortisone and immunoglobulin therapy

Rifamycin, isoniazid, pyrazinamide, ethambutol, and hydrocortisone therapy

Answer: Rifamycin, isoniazid, pyrazinamide, ethambutol, and hydrocortisone therapy

Explanation:
This man from India presents with generalized weakness, chronic cough, unintentional weight loss, skin hyperpigmentation, hyponatremia, hyperkalemia, hypocortisolism, cosyntropin stimulation test failure, elevated ACTH, and bilateral adrenal calcifications on radiography. These symptoms and signs in this patient are most consistent with adrenal tuberculosis requiring RIPE therapy (rifamycin, isoniazid, pyrazinamide, ethambutol) as well as glucocorticoid and mineralocorticoid therapy.

Adrenal insufficiency occurs when the adrenal glands do not produce enough cortisol and aldosterone. Primary adrenal insufficiency is due to dysfunction at the level of the adrenal glands themselves, as opposed to upstream factors such as the pituitary gland. Primary adrenal insufficiency in developed nations is most often caused by autoimmune disease. In developing nations, adrenal tuberculosis is a significant cause of primary adrenal insufficiency. Adrenal tuberculosis often presents with a history of tuberculosis or tuberculosis symptoms, as well as symptoms of adrenal insufficiency such as fatigue, unintentional weight loss, and hyperpigmentation. Patients often have hyponatremia, hyperkalemia, low morning cortisol, a failed cosyntropin test, and high ACTH concentrations. Radiography may demonstrate bilateral adrenal calcifications, and/or adrenal enlargement. Tuberculosis can infect all cortices of the adrenal glands bilaterally, and therefore treatment requires eradicating the infection with multi-drug therapy (RIPE therapy) as well as replacement of glucocorticoids and mineralocorticoids, which may be achieved by high-dose hydrocortisone or other combinations of steroids that together provide glucocorticoid and mineralocorticoid replacement.

Vinnard and Blumberg outline the signs and symptoms, histopathology, lab results, imaging, differential diagnosis, and treatments associated with adrenal tuberculosis. They recommend early recognition and treatment.

Incorrect Answers:
Answer A: Bilateral adrenalectomy, prednisone therapy, and fludrocortisone therapy are incorrect because medical therapy should first be attempted to eradicate the infection before undergoing surgery. Bilateral adrenalectomy may be considered if there is suspicion of lung cancer with metastasis to the bilateral adrenal glands. Patients will require lifelong replacement therapy.

Answer B: Dexamethasone alone is incorrect because this patient likely has tuberculosis and should be treated for it. Additionally, this patient has signs of mineralocorticoid deficiency (hyponatremia, hyperkalemia), and patients often require mineralocorticoid therapy or a high dose of a glucocorticoid with mineralocorticoid activity (e.g., hydrocortisone). Dexamethasone has minimal to absent mineralocorticoid activity.

Answer C: Hydrocortisone therapy and immunoglobulin therapy are incorrect because this patient has adrenal tuberculosis. Although autoimmune adrenalitis can cause primary adrenal insufficiency, immunoglobulins are not used to treat this condition.

Answer D: Prednisone taper would be appropriate for acute conditions such as an asthma or COPD exacerbation. While prednisone will treat the symptoms of primary adrenal insufficiency, it will not treat active tuberculosis infection. Primary adrenal insufficiency in developed nations is most often caused by autoimmune adrenalitis (Addison disease) and presents with fatigue, unintentional weight loss, abdominal pain, hyperpigmentation, and muscle weakness. In this condition, long-term steroid therapy is indicated.

Bullet Summary:
Patients with adrenal tuberculosis should be treated with rifamycin, isoniazid, pyrazinamide, ethambutol, as well as glucocorticoid and mineralocorticoid replacement.


Question: A 23-year-old man presents to the emergency department for altered mental status after a finishing a marathon. He has a medical history of obesity and anxiety and is not currently taking any medications. His temperature is 104°F (40°C), blood pressure is 147/88 mmHg, pulse is 200/min, respirations are 33/min, and oxygen saturation is 99% on room air. Physical exam reveals dry mucous membranes, hot flushed skin, and inappropriate responses to the physician's questions. Laboratory values are ordered as seen below. Hemoglobin: 15 g/dL Hematocrit: 44% Leukocyte count: 8,500/mm^3 with normal differential Platelet count: 199,000/mm^3 Serum: Na+: 165 mEq/L Cl-: 110 mEq/L K+: 4.0 mEq/L HCO3-: 20 mEq/L BUN: 30 mg/dL Glucose: 133 mg/dL Creatinine: 1.5 mg/dL Ca2+: 10.2 mg/dL AST: 12 U/L ALT: 10 U/L Which of the following is the most appropriate next step in management?

Answer: Lactated ringer

Explanation:
This patient is presenting with hypernatremia and heat stroke for which the most appropriate next step in management is the administration of lactated ringer solution.

Heat stroke presents with hot/flushed skin, fever, altered mental status, and hypernatremia secondary to loss of free water. Patients should immediately be cooled with external measures and started on fluids. Minor cases where the patient is cognitively intact can be treated with oral replacement with an electrolyte balanced solution (though this would be heat exhaustion and not heat stroke). Patients with altered mental status should be started on normal saline or lactated ringer, and sodium levels should be corrected slowly. Rapid correction of serum sodium or administration of hypotonic fluids can cause cerebral edema and seizures; however, this is more common in hypernatremia that has persisted for days as it has led to cerebral adaptations.

Tinawi reviewed the evidence regarding the use of intravenous fluids in the hospital setting. He discusses how a large volume of normal saline can result in hypernatremia and hyperchloremia. He recommends considering the risks and benefits of colloid versus crystalloid usage.

Incorrect Answers:
Answers 1-3: 50% normal saline 50% dextrose, dextrose solution, and hypotonic saline are hypotonic solutions and would treat the hypernatremia too rapidly predisposing the patient to seizures.

Answer E: Normal saline would be a reasonable option for this patient; however, it is less desirable given that this patient is suffering from hypernatremia, hyperchloremia, and a metabolic acidosis which could be worsened by normal saline given the large sodium and chloride load of this solution.

Bullet Summary:
Hypernatremia and dehydration should be treated with lactated ringer and sodium levels should be corrected no more rapidly than 1 mEq/L/hour.