USMLE CK - Medicine

3. A 64-year-old female with a history of HTN, CAD, and CHF presents to the ED with a chief complaint of leftsided chest pain that began 4 to 5 hours ago. She has a history of periodic episodes of chest pain for which she takes sublingual nitroglycerin, but today's episode has been more severe, has lasted longer, and is not relieved by nitroglycerin. She denies nausea/vomiting, any radiation of the pain, or diaphoresis. Temperature = 97.8°F, BP = 136/76 mm Hg, HR = 105, RR = 20. Physical examination includes clear lungs on auscultation, no JVP elevation, and no LE swelling. EKG shows Q waves in lateral leads and no ST elevation. Troponin is 0.50 ng/mL. Aspirin is given. What is the most important intervention indicated at this time? A. Alteplase B. Heparin C. Hydralazine D. Furosemide E. Digoxin

3. Answer: B. Heparin. IV UFH (unfractionated heparin) and subq LMWH are shown to decrease mortality in UA/NSTEMI. In addition, statins, ASA, β-blockers are shown to do so as well. ACE inhibitors have evidence of benefit and are recommended in the acute setting after an MI as well. Alteplase is NOT indicated for UA/NSTEMI but ONLY for STEMI when PCI is not available. Hydralazine, furosemide, and digoxin offer no mortality benefit in this setting either.

1. A 61-year-old male presents to your office with the chief complaint of "coughing up blood and weakness" for the past 3 weeks. He reports at least five to six episodes every 2 to 3 days of coughing of bright red blood, approximately one to two tablespoons each time. The patient denies any chest pain, fevers, chills, or recent travel. He has mild dyspnea at baseline. He has recently developed lower extremity muscle cramps and he has difficulty rising from a chair. Past medical history is significant for COPD diagnosed 5 years ago and HTN. He has a 40-pack-year smoking history and currently smokes 1 pack per day. Examination is notable for end-expiratory wheezing and a prolonged expiratory phase on lung auscultation. He has 3/5 hip flexion and decreased deep tendon reflexes bilaterally in lower extremities. Laboratory tests are normal including electrolytes. CXR reveals typical changes seen in COPD (flattened diaphragms, hyperinflation) and a perihilar mass. What is the most likely diagnosis? A. Bronchial carcinoid B. Adenocarcinoma C. Large cell carcinoma D. Squamous cell carcinoma E. Small cell carcinoma

1. Answer: E. Small cell carcinoma. The patient most likely has small cell carcinoma given the main risk factor of a strong smoking history, a mass located in the central/proximal airways and the weakness suggestive of paraneoplastic Lambert-Eaton syndrome. Other associated paraneoplastic syndromes with small cell include Cushing and SIADH. Bronchial carcinoid is not clearly associated with smoking or Lambert-Eaton, although usually presents as a central/proximal lesion. Large cell carcinoma is not associated with Lambert-Eaton. Squamous cell carcinoma is not associated with Lambert-Eaton but is typically a central lesion; this lung malignancy is also the most likely lung cancer associated with paraneoplastic hypercalcemia.

10. A 55-year-old male presents to the ED with epigastric abdominal pain. He denies nausea/vomiting/diarrhea. His PMH is significant for stroke HTN and osteoarthritis of his knees. Medications include enalapril and a daily aspirin tablet. Vital signs are as follows: RR = 20, BP = 155/90 mm Hg, pulse = 70. His physical examination reveals epigastric tenderness, no abdominal distention, and rectal examination is positive for dark stool that is guaiac positive. Laboratory tests reveal hemoglobin of 10.2 g/dL, hematocrit of 30.0%, platelets 190 × 103/μL. LFT results are normal. Na 135 mEq/L, K 4.5 mEq/L, Cl 105 mEq/L, HCO3 22 mEq/L, BUN 30 mg/dL, Cr 1.2 mg/dL. What is the next recommended step in managing this patient? A. IV omeprazole B. IV octreotide C. Platelet transfusion D. RBC transfusion E. Normal saline

10. Answer: A. IV omeprazole. The patient likely has an upper GI bleed as evidenced by epigastric abdominal pain, melena, and labs showing an elevated BUN:Cr ratio of 25 in the setting of ASA use. Acid suppression and upper endoscopy (EGD) are the indicated interventions. IV octreotide is not indicated as the patient has no signs of liver disease to suggest esophageal varices as the cause of bleeding. Platelet transfusion will not reverse the effect aspirin has had on platelets and the platelet level presented is not low enough to lead to bleeding. RBC transfusion is not necessary as the patient is hemodynamically stable and the Hgb is not low enough that the patient is symptomatic. Normal saline is not necessary as the patient is already hypertensive and does not have hypovolemia.

11. A 45-year-old female is admitted to the hospital with abdominal swelling. She has not previously sought medical care and had been well until 3 months ago when swelling began. Swelling gradually began and has worsened to the point that she is now short of breath and has difficulty mobilizing. She was born in Mexico but has been living in the United States for the past 20 years. She denies any use of medications. She admits to social drinking but denies daily use. Lung examination reveals decreased breath sounds at the bases. Cardiac examination reveals no murmurs, JVP 2 cm above sternal angle. Abdomen is moderately distended with a positive fluid wave; liver is unable to be palpated. Skin examination does not reveal telangiectasias. A diagnostic/ therapeutic paracentesis is performed which reveals the following: serum albumin 2.5 g/dL, serum total protein 5.0 g/dL, ascites total protein 2.3 g/dL, ascites albumin 1.6 g/dL. What test is the most likely to reveal the cause of her ascites? A. Echocardiogram B. Pelvic ultrasound C. Liver biopsy D. PPD E. 24-hour urine protein

11. Answer: E. 24-hour urine protein. The patient has ascites in the setting of a low SAAG (<1.1 g/dL) indicating a lack of portal hypertension, and low ascitic protein (<2.5 g/dL) indicating low protein overall. The expected diagnoses would be severe malnutrition or protein-losing disorder such as nephrotic syndrome; thus, 24-hour urine protein is the most appropriate test. Echocardiogram would be helpful if the patient had hepatic congestion in the setting of elevated SAAG and elevated ascitic protein. Pelvic ultrasound to assess for potential ovarian malignancy would be indicated if patient had low SAAG and elevated ascitic protein. Liver biopsy would be helpful to assess for causes of cirrhosis if patient had elevated SAAG and low ascitic protein. PPD would be indicated if patient had low SAAG and elevated ascitic protein.

12. A 65-year-old man presents to the ED with lower extremity weakness. His symptoms started 1 week prior when he noticed difficulty walking and he tripped once. He now has difficulty raising his legs off the floor and is now using a wheelchair. He denies any pain in his lower extremities but does have paresthesias in both legs. He denies weakness elsewhere. He denies dyspnea or any other associated symptoms. Prior to this he had an episode of nonbloody diarrhea a few weeks prior but that is now resolved. His only past medical history is hypertension for which he takes hydrochlorothiazide. Cardiac examination is normal. Pulmonary examination reveals nonlabored breathing, clear lung fields, and O2 saturation 98% on room air. Neurologic examination reveals normal speech without dysarthria and cranial nerves without deficits. Strength is 5/5 in bilateral upper extremities in shoulder/elbow/wrist flexion and extension, 1/5 dorsiflexion/plantar flexion bilateral ankles, 1/5 flexion/extension knees, 2/5 hip flexion. Achilles and patellar reflexes are absent bilaterally. Sensory examination is normal. Labs including electrolytes, renal function, and blood counts are normal. CT head is negative for stroke and shows no acute findings. Lumbar puncture is performed and analysis reveals 3 WBC/mm3, protein 100 mg/dL (normal range <50 mg/dL), Gram stain negative. What is the most appropriate therapy? A. Prednisone B. IVIG C. Ciprofloxacin D. Pyridostigmine E. Botulism antitoxin

12. Answer: B. IVIG. The patient is presenting with an ascending paralysis, absent reflexes, and albuminocytologic dissociation consistent with a diagnosis of Guillain-Barré syndrome in the setting of a preceding diarrheal illness. IVIG and plasmapheresis are the recommended treatments. Prednisone is not recommended as steroids have not shown benefit. Ciprofloxacin is not indicated as there are no signs of infection; there are many precipitating illnesses that can trigger this disorder. Pyridostigmine would be indicated in myasthenia gravis. Botulism antitoxin would be beneficial if the patient has symptoms suggestive of botulism, a DESCENDING paralysis.

2. A 67-year-old male presents to the ED with LLQ pain that began a few hours ago. His PMH is significant for hypertension, CHF, and renal calculi. He reports one episode of blood in his stools a few months ago. Vital signs are as follows: Temperature = 101.1°F, BP = 130/76 mm Hg, pulse = 70. On physical examination, he has guarding and tenderness to palpation in the LLQ but no epigastric tenderness or flank tenderness. His examination is otherwise unremarkable. His stool is negative for occult blood. Urinalysis reveals no leukocytes or RBCs and Gram stain is negative. Laboratory tests reveal a leukocyte count of 16,000 cells/μL and normal electrolytes and renal function. What is the next step in managing this patient? A. Check a serum lactate B. Obtain a retroperitoneal ultrasound C. Prepare the patient for colonoscopy D. Obtain contrast enhanced CT of the abdomen E. Proceed to the operating room

2. Answer: D. Obtain contrast enhanced CT of the abdomen. The patient is presenting with typical signs/ symptoms of acute diverticulitis—fever, leukocytosis, LLQ location of pain. Further suggestion is made by the fact that the patient had a prior episode of rectal bleeding, likely from underlying diverticulosis. CT scan will help not only confirm the diagnosis but also to rule out other processes and assess for any complications of diverticulitis. Checking the serum lactate will help assess for ischemia but will not help you confirm the diagnosis of diverticulitis. Retroperitoneal ultrasound will assess for hydronephrosis and pyelonephritis but urinalysis/chemistry are normal and there is no suggestion of obstruction/infection regardless of his history of renal stones. Colonoscopy would be contraindicated in a patient with acute diverticulitis because of the risk of perforation. Proceeding to the operating room would be premature unless the patient had surgical indications such as fistula, stricture, large abscess, or perforation related to the diverticulitis.

4. A 64-year-old male presents to the ED with symptoms of RUE weakness and slurred speech. His symptoms started 5 hours ago and have not improved. He has a medical history significant for hypertension and diabetes. Neurologic examination confirms RUE paresis and dysarthria. Rest of examination is normal. Vitals: BP 190/100 mm Hg, HR 75. Labs are notable for glucose of 135 mg/dL, A1c 7.3%. CT head shows an area of ischemia without associated hemorrhage. Home medications include metformin and lisinopril. What is the most important intervention at this point? A. Insulin B. Heparin C. Aspirin D. Alteplase E. Labetalol

4. Answer: C. Aspirin. Aspirin is shown to reduce recurrent stroke and to decrease mortality and should be administered within 48 hours. Insulin is not necessary as the level of glucose elevation is not contributing to the current presentation; in fact, aggressive glycemic control is associated with worse outcomes. Heparin has not been shown to improve outcomes and is not recommended as an acute treatment for ischemic stroke. Alteplase can be considered but only for significant deficits when the patient presents within 3 hours of symptom onset and has no contraindications; this patient presented too late for this to be a treatment option. Labetalol would not be used despite the elevated BP as permissive hypertension is allowed in the setting of an acute ischemic stroke; BP up to 220/120 mm Hg is generally tolerated initially.

5. A 58-year-old male presents to your office with weakness in his legs and a history of frequent falls over the past few months. He also complains of fatigue at the end of the day. He denies any back pain. He does not drink alcohol or smoke. His medical history is significant for gastric carcinoma for which he underwent total gastrectomy 2 years ago and there are no signs of recurrence. On physical examination, he is found to have conjunctival pallor, increased deep tendon reflexes, and mild weakness of his lower extremities, along with diminished vibratory sense in his toes. Cerebellar testing is normal. His examination is otherwise unremarkable. What would be the best test in confirming the cause of his symptoms? A. Folate B. CBC with mean corpuscular volume C. Intrinsic factor Ab D. MRI lumbar spine E. Methylmalonic acid

5. Answer: E. Methylmalonic acid. The other answers will help narrow down your differential but will not definitely give your diagnosis. The patient has a gastrectomy and thus loss of intrinsic factor leading to impaired absorption of B12. The neurologic symptoms are a result of this deficiency and the fatigue/pallor are related to macrocytic anemia. Laboratory assessment of B12, methylmalonic acid, or homocysteine would all be useful to confirm deficiency; however, homocysteine is also elevated in folate deficiency and thus not as specific. Folate level could help confirm a deficiency in this vitamin which does cause a macrocytic anemia but this deficiency is not associated with neurologic deficits; in addition, folic acid is absorbed in the small intestine not the stomach. CBC with mean corpuscular volume may help confirm macrocytic anemia but this is not always present with B12 deficiency; in addition, there are multiple causes of macrocytosis and anemia and this will not confirm his diagnosis. Intrinsic factor Ab is present in pernicious anemia; it is not a sensitive test but regardless, a positive test would not confirm the cause of his symptoms. MRI lumbar spine has nonspecific findings in B12 deficiency; it may help assess for central/foraminal stenosis but without back pain this is unlikely and would this test would not assess his pallor/anemia.

6. A 37-year-old nulliparous female presents to your office complaining of weakness, especially with activities that require muscular force, such as climbing stairs. Her symptoms have developed gradually over the past year and she has largely ignored them. She reports a recent weight gain of 25 lb over the past year and has been feeling melancholy for the past few months. She has also had back pain for the past several months. Her medical history is significant for mild HTN, for which she takes metoprolol, and DM that requires insulin therapy. She takes no other medications. Physical examination reveals mild obesity, with fat deposition mainly around the trunk and the posterior neck. You note some facial hair and scattered purple striae on the abdomen. Radiographs reveal a compressed fracture at the level of T11. Vital signs are as follows: BP = 140/85 mm Hg, pulse = 70. What would be the most appropriate next test in this patient? A. Serum ACTH B. MRI brain C. CT abdomen D. 24-hour urine-free cortisol E. CRH stimulation test

6. Answer: D. 24-hour urine-free cortisol. The patient likely has Cushing syndrome given the constellation of weight gain, striae (without prior history of pregnancy), new onset diabetes, hypertension, and vertebral compression fracture indicative of osteoporosis. 24-hour urine-free cortisol, dexamethasone suppression test, and late night salivary cortisol are the screening tests that are indicated at this point. Serum ACTH is not used for screening and is only helpful in determining the etiology once the diagnosis of Cushing syndrome has been made. MRI brain and CT abdomen may help identify pituitary adenoma and adrenal adenoma respectively but this test is premature at this point as the diagnosis of Cushing has not yet been confirmed. CRH stimulation test is only used once hypercortisolism has been established and ACTH is elevated as it helps distinguish Cushing disease versus ectopic ACTH production.

7. A 56-year-old male with a history of cigarette smoking and hypercholesterolemia is brought to the ED with severe, crushing chest pain that has lasted for 90 minutes. He states that he felt ill all day and then started experiencing pain in his jaw, which progressed to chest pain with radiation to the left arm associated with nausea. Vital signs are as follows: Temperature = 97.4°F, HR = 50, BP = 85/45 mm Hg, RR = 22, pulse oximetry = 98% on room air. Examination reveals JVP without elevation, normal lung examination, and no peripheral edema. An ECG reveals significant ST elevations in leads II, III, and aVF. What is the next step in managing this patient? A. Nitroglycerin B. Normal saline C. Furosemide D. Metoprolol E. Morphine

7. Answer: B. Normal saline. The patient is presenting with an inferior MI as evidenced by the location of the ST elevations on ECG. Because the patient also has bradycardia and hypotension he also has evidence of an associated right ventricular MI, which is strongly associated with inferior wall MIs and importantly is treated much differently than L-sided MI. It is important to remember that hemodynamic instability can result from increased vagal tone and sinus node dysfunction. The patient is preload dependent and IV fluids are indicated and will increase the patient's systemic blood pressure. Treatment with ASA, fibrinolysis versus PCI, heparin are all indicated as well. Nitroglycerin will decrease preload and worsen the patient's hemodynamics. Furosemide is not indicated as the patient has no signs of fluid overload and diuresis will decrease preload. Patient is already showing signs of hemodynamic instability and metoprolol will cause further bradycardia and hypotension. Morphine may cause vasodilation and further hypotension.

8. A 45-year-old female with history of DM, alcohol abuse, and COPD is evaluated for confusion in the ED. She lives with a roommate who states the patient was acting differently from baseline. The patient is agitated, not oriented, and not responding to questions appropriately. Vitals T 37.5°C, P 110, RR 30. Physical examination reveals lungs with minimal end-expiratory wheezing. Physical examination is otherwise normal. UA is within normal limits. Labs: Na 140 mEq/L, Cl 105 mEq/L, K 5 mEq/L, HCO3 15 mEq/L, BUN 20 mg/dL, Cr 1 mg/dL. ABG: pH 7.30, PCO2 25 mm Hg, PO2 85 mm Hg. What is the next appropriate medical intervention? A. Fomepizole B. Acetylcysteine C. Albuterol D. Sodium bicarbonate E. Insulin

8. Answer: D. Sodium bicarbonate. The patient has evidence of an anion gap metabolic acidosis (HCO3 is decreased and AG is 15) as well as a respiratory alkalosis (CO2 is decreased) consistent with salicylate toxicity. This involves using Winter's formula and the expected PCO2 in this example is 31 ± 2; however, the actual PCO2 is 25 confirming there is a respiratory alkalosis as well. Treatment options include alkalinization of urine and hemodialysis. Fomepizole is indicated for methanol or ethylene glycol toxicity; however neither of these would also cause respiratory alkalosis. Albuterol will treat a COPD exacerbation although this usually leads to retention of CO2 from inability to expire sufficiently and respiratory acidosis would be the dominant finding in that scenario. Insulin will help treat DKA if that was the underlying diagnosis but ketones are not mentioned thus assumed to be negative and not treating salicylate toxicity in a timely fashion will be detrimental.

9. A 64-year-old male presents to your office for a physical examination. His PMH is significant for HTN, for which he takes metoprolol. He has never had screening for colorectal cancer previously. On examination, there are no palpable masses in the abdomen, no tenderness, and bowel sounds are normal. He denies any change in bowel habits. The remainder of his physical examination is unremarkable. He is given fecal occult blood testing and two of three samples are positive. What is the appropriate next step in managing this patient? A. Flexible sigmoidoscopy B. Digital rectal examination C. Video capsule endoscopy D. CT colonography E. Colonoscopy

9. Answer: E. Colonoscopy. The patient has not had colorectal cancer screening and this would certainly be indicated at this time given his age (>50). Initial choices for screening include FOBT, flexible sigmoidoscopy, or colonoscopy. In this example, the patient had a positive screening test and requires a colonoscopy as it will allow full visualization of the entire colon for diagnostic and therapeutic (biopsy if needed) purposes. Flexible sigmoidoscopy will miss more than half of the colon and therefore is not the best answer. Digital rectal examination has no role as it will not be sensitive enough to check anything but the rectum. Video capsule endoscopy is not the best next step; it will allow visualization of the entire GI tract but will not allow for biopsy if needed. CT colonography will not be sensitive enough to detect small lesions and again will not allow for intervention of necessary.