SeanWu25/NEJM-AI_Benchmarking_Medical_Language_Models huggingface dataset:
Subject: Electrolyte Acid-Base Disorders
A 75-year-old man with recently diagnosed pancreatic cancer and hypertension is seen in consultation for hyponatremia. According to family members, he was in his usual state of health until the day before admission, when he developed progressive confusion and agitation. His medications are lisinopril and chlorthalidone. Review of his medical record shows that his serum sodium level was 134 mEq/L 6 weeks ago. On physical examination, he is intermittently agitated and disoriented. The BP is 140/85 mmHg, and the pulse rate is 85/min. There are no postural changes in BP or pulse. The neurologic examination shows no focal deﬁcits. The remainder of examination is unremarkable. Laboratory results show sodium of 115 mEq/L, potassium of 3.9 mEq/L, chloride of 80 mEq/L, total CO2 of 25 mmol/L, BUN of 6 mg/dl, creatinine of 0.8 mg/dl, glucose of 106 mg/dl, calcium of 9.0 mg/dl, and serum osmolality of 236 mOsm/kg. The urine osmolality is 380 mOsm/kg, the urine sodium is 40 mEq/L, and the urine potassium is 30 mEq/L..
Question: In addition to ﬂuid restriction and discontinuing chlorthalidone, which ONE of the following is the MOST appropriate next step in management?
A. No additional interventions
B. 3% saline to increase serum sodium concentration  4–6 mEq/L
C. Tolvaptan
D. Furosemide plus intravenous isotonic saline with potassium chloride at 40 mEq/L
Answer: B
Subject: Electrolyte Acid-Base Disorders
Question: Question 2616:
Which ONE of the following is MOST likely to be associated with the development of hyponatremia in individuals involved in heavy exercise?
A. Urine sodium plus urine potassium equal to 36 mEq/L
B. Urine osmolality of 200 mOsm/kg after exercise
C. Weight gain .3 kg after exercise
D. An increase in urinary osmolality during exercise
Answer: C
Subject: Electrolyte Acid-Base Disorders
A 70-year-old man with refractory nocturnal polyuria is evaluated 1 week after starting desmopressin for enuresis. He has heart failure with a preserved ejection fraction that has been well compensated. Optimization of treatment for lower urinary tract symptoms stemming from benign prostatic hypertrophy has failed to control his nocturia. Before starting desmopressin, the ﬁrst morning void urine osmolality was 286 mOsm/kg. After starting desmopressin, the frequency of nocturia decreased from ﬁve to two times per night. On physical examination, he is alert and oriented. The BP is 130/78 mmHg, and the pulse rate is 72/min. An S4 gallop is present. There is trace pretibial edema. The remainder of the examination is normal. Laboratory studies show that the serum sodium level has decreased to 133 mEq/L from a baseline level of 138 mEq/L. The urine osmolality is 526 mOsm/kg..
Question: In addition to close follow-up of the serum sodium level, which ONE of the following is the MOST appropriate management for this man’s enuresis, hyponatremia, and heart failure?
A. Discontinue desmopressin
B. Discontinue desmopressin plus a 100-ml bolus of 3% saline
C. Continue desmopressin, decreasing ﬂuid in-take in response to thirst only
D. Continue desmopressin and increase dietary sodium
Answer: C
Subject: Electrolyte Acid-Base Disorders
A 46-year-old man with central diabetes insipidus (DI) is evaluated in the emergency department for a 1-day history of generalized fatigue. Over the past 2 weeks, he increased his ﬂuid intake because of an upper respiratory tract infection. His only medication is intranasal desmopressin at 10 mg twice daily. On physical examination, he is alert and oriented. The remainder of the examination is normal. Laboratory studies show serum sodium of 116 mEq/L, potassium of 3.8 mEq/L, chloride of 82 mEq/L, total CO2 of 24 mmol/L, BUN of 5 mg/dl, creatinine of 0.7 mg/dl, and glucose of 120 mg/dl. The urine osmolality is 826 mOsm/kg. He is admitted, and desmopressin therapy is withheld. The urine volume subsequently rises to 500 ml/h. A repeat serum sodium level obtained 4 hours after the initial laboratory studies is 124 mEq/L, and the urine osmolality is now 36 mOsm/kg..
Question: In addition to ongoing monitoring of the serum sodium level and neurologic status, which ONE of the following is the MOST appropriate treatment for this patient?
A. Restart intranasal desmopressin at 10 mg twice daily
B. Desmopressin at 4 mg subcutaneously plus intravenous 5% dextrose in water (D5W) to achieve a serum sodium of 118–122 mEq/L
C. Restart intranasal desmopressin at 10 mg twice daily plus a 100-ml bolus of 3% saline intravenously
D. Start intravenous D5W at 250 ml/h
Answer: B
Subject: Electrolyte Acid-Base Disorders
You are asked to see a 65-year-old woman with stage 3b:A3 CKD from diabetic kidney disease and chronic systolic heart failure in consultation 1 week in advance of elective coronary angiography (CA). Medications are metformin, simvastatin, lisinopril, chlorthalidone, and aspirin. A physical examination shows a BP of 132/80 mmHg. There is trace ankle edema. The remainder of the examination is normal. Laboratory studies show sodium of 138 mEq/L, potassium of 5.2 mEq/L, chloride of 104 mEq/L, total CO2 of 23 mmol/L, BUN of 32 mg/dl, creatinine of 1.9 mg/dl, and eGFR of 32 ml/min per 1.73 m2..
Question: Which ONE of the following is the BEST management recommendation?
A. Discontinue metformin 2–3 days before CA
B. Discontinue lisinopril 1 day before CA
C. Make no changes to the current medication regimen
D. Discontinue chlorthalidone
Answer: A
Subject: Electrolyte Acid-Base Disorders
A 78-year-old-man with advanced chronic obstructive lung disease, congestive heart failure, and stage G3b CKD is admitted for treatment of pneumonia. Over the past 3 days, his oral intake has been minimal. His home medications include inhaled ﬂuticasone-salmeterol and furosemide. On physical examination, his breathing is labored, with use of accessory respiratory muscles. The BP is 96/60 mmHg, the pulse rate is 120/min, and the temperature is 38.1C. The oxygen saturation is 98% on 2 L/min supplemental oxygen via nasal cannula. The jugular venous pressure is 5 cm H2O. The lung examination shows scattered wheezes and poor air movement. There is no peripheral edema. Laboratory studies show se-rum sodium of 145 mEq/L, potassium of 3.0 mEq/L, chloride of 100 mEq/L, total CO2 of 40 mmol/L, BUN of 45 mg/dl, and creatinine of 2.5 mg/dl (increased from a recent baseline level of 1.8 mg/dl). An arterial blood gas on 2 L/min of supplemental oxygen shows pH 7.47, PaCO2 of 55 mmHg, bicarbonate of 38 mEq/L, and PaO2 of 65 mmHg. The patient is treated with antibiotics, bronchodilators, and systemic corticosteroids. You are asked to help manage his acid-base disorder..
Question: In addition to potassium supplementation and continuous monitoring of the volume status, which ONE of the following is the MOST appropriate management strategy for this man’s acid-base disorder?
A. Discontinue furosemide and begin intravenous 0.9% saline at 125 ml/h
B. Replace furosemide with acetazolamide at 500 mg daily
C. Add spironolactone at 50 mg twice daily
D. Ammonium chloride at 20 mEq in 1 L 0.9% saline intravenously over 24 hours
Answer: A
Subject: Electrolyte Acid-Base Disorders
A 50-year-old man with bipolar disorder is referred for persistent polyuria. He had previously been maintained on lithium for 15 years, but it was discontinued 6 months ago because of a progressive rise in the serum creatinine level from 0.8 to 1.4 mg/dl. A water deprivation test 2 months ago was consistent with nephrogenic DI. He is now maintained on hydrochlorothiazide at 25 mg daily. Laboratory studies show serum osmolality of 298 mOsm/kg, sodium of 141 mEq/L, potassium of 3.9 mEq/L, chloride of 102 mEq/L, total CO2 of 24 mmol/L, BUN of 28 mg/dl, creatinine of 1.4 mg/dl, and glucose of 90 mg/dl. A 24-hour urine collection shows a volume of 4.0 L, a sodium of 70 mEq/L, a potassium of 26 mEq/L, and a urine osmolality of 240 mOsm/kg. A urinalysis shows speciﬁc gravity of 1.006, trace protein, and negative glucose..
Question: Which ONE of the following is the MOST appropriate next step in management?
A. Increase hydrochlorothiazide to 25 mg twice daily
B. Add amiloride at 10 mg daily
C. Add intranasal desmopressin at 10 mg daily
D. Decrease dietary sodium intake to 2–3 g/d
Answer: D
Subject: Electrolyte Acid-Base Disorders
A 53-year-old man is admitted to the intensive care unit with urosepsis. His serum sodium level has risen slowly from 140 to 155 mEq/L over the past 5 days. He is lethargic, but responds appropriately to simple questions. His BP is 130/70 mmHg off vasopressor agents. The pulse rate is 80/min. His weight is 60 kg. The remainder of the examination is unremarkable. His current urine output is 2 L/d. Laboratory studies show serum osmolality of 329 mOsm/kg, sodium of 155 mEq/L, potassium of 3.6 mEq/L, chloride of 122 mEq/L, total CO2 of 20 mmol/L, BUN of 36 mg/dl, creatinine of 1.5 mg/dl, and glucose of 88 mg/dl. Urinary studies show sodium of 60 mEq/L, potassium of 40 mEq/L, and osmolality of 315 mOsm/kg..
Question: Assuming insensible water losses of 0.8 L/d, which ONE of the following is the total amount of free water that should be administered to decrease the serum sodium to 145 mEq/L over the next 24 hours?
A. 4.0 L
B. 3.2 L
C. 2.3 L
D. 1.6 L
Answer: A
Subject: Electrolyte Acid-Base Disorders
A 25-year-old woman marathon runner becomes confused after completing the run in 5 hours and 15 minutes. Her serum sodium at end of the run is 125 mEq/L. On physical examination, she is obtunded. The BP is 140/80 mmHg, and the pulse rate is 86/min. Skin turgor is normal. The remainder of the examination is normal..
Question: Which ONE of the following is MOST important in the pathogenesis of her hyponatremia?
A. Excessive water intake and retention
B. Sequestration of water in the gastrointestinal tract
C. Sodium chloride loss in sweat
D. Decreased extracellular ﬂuid volume
Answer: A
Subject: Electrolyte Acid-Base Disorders
A 70-year-old woman with type 2 diabetes mellitus, stage G3b CKD, and hypertension is admitted for treatment of hypovolemia after 1 week of recalcitrant nausea, vomiting, and diarrhea. Her medications include metformin at 500 mg twice daily, irbesartan at 150 mg/d, and chlorthalidone at 25 mg daily. On physical examination, she is alert, oriented, and does not appear toxic. The skin turgor is reduced. She is afebrile, with a BP of 100/60 mmHg and a pulse rate of 112/min. The remainder of the physical examination is unremarkable. Laboratory studies show serum sodium of 143 mEq/L, potassium of 4.9 mEq/L, chloride of 112 mEq/L, total CO2 of 16 mmol/L, BUN of 46 mg/dl, creatinine of 2.2 mg/dl (increased from a recent baseline level of 1.4 mg/dl), and glucose of 102 mg/dl. A complete blood count shows a leukocyte count of 5600/microliter, hemoglobin of 13.3 g/dl, and platelet count of 356,000/microliter. An arterial blood gas on ambient air shows pH 7.32, PaCO2 of 32 mmHg, bicarbonate of 18 mEq/L, and PaO2 of 94 mmHg. The arterial lactate level is 4 mmol/L. Urinalysis shows speciﬁc gravity of 1.018, trace protein, and no glucose. The urine sediment is bland. The urine sodium level is < 10 mEq/L..
Question: In addition to discontinuing her current medi-cations and volume expansion with isotonic crystalloid, which ONE of the following is the next BEST step in management?
A. Obtain a serum metformin level to guide further therapy
B. Continuous RRT at 25 ml/kg per hour
C. Acute hemodialysis with a blood ﬂow of 450 ml/h for 4 hours
D. Observation of clinical status after correction of hypovolemia
Answer: D
Subject: Electrolyte Acid-Base Disorders
Question: Question 2625:
Compared with furosemide, which ONE of the following statements is CORRECT regarding torsemide?
A. Torsemide has increased bioavailability and a longer half-life
B. Torsemide inhibits proximal tubular sodium reabsorption
C. Torsemide is more kaliuretic
D. Torsemide is more potent because it directly inhibits the activity of the epithelial sodium channel (ENaC) in the collecting duct
Answer: A
Subject: Electrolyte Acid-Base Disorders
You are asked to make management recommendations for a 70-year-old woman with recently diagnosed SIADH. She is asymptomatic and has a normal physical examination. Laboratory studies show serum sodium of 128 mEq/L, potassium of 4.0 mEq/L, chloride of 94 mEq/L, total CO2 of 24 mmol/L, BUN of 6 mg/dl, creatinine of 0.6 mg/dl, glucose of 80 mg/dl, and osmolality of 263 mOsm/kg. Urine studies show sodium of 40 mEq/L, potassium of 22 mEq/L, and osmolality of 250 mOsm/kg. The daily urine volume is 2 L. You recommend ﬂuid restriction and liberalization of dietary sodium intake..
Question: Assuming 0.8 L insensible losses of water per day, which ONE of the following is the maximum amount of solute-free water that she can drink without a further decrease in the serum sodium?
A. 0 L
B. 1.8 L
C. 2.3 L
D. 2.8 L
Answer: B
Subject: Electrolyte Acid-Base Disorders
You are asked to see a 65-year-old woman with chronic obstructive lung disease and congestive heart failure in consultation for alkalemia. She was admitted with 2 days of increased dyspnea, fever, nausea, vomiting, and cough. Medications are ipratropium, furosemide, and enalapril. On physical examination, she is tachypneic, with a respiratory rate of 24/min. The BP is 90/60 mmHg, the pulse rate is 108/min, and the temperature is 38.3C. The lung examination shows right basilar crackles. There is no edema. A dense right lower inﬁltrate is seen on a chest radiograph. Laboratory studies show sodium of 140 mEq/L, potassium of 3.4 mEq/L, chloride of 85 mEq/L, total CO2 of 35 mmol/L, BUN of 35 mg/dl, creatinine of 1.2 mg/dl, and glucose of 82 mg/dl. An arterial blood gas on ambient air shows pH 7.45, PaCO2 of 54 mmHg, bicarbonate of 36.5 mEq/L, and PaO2 of 52 mmHg..
Question: Which ONE of the following BEST describes this woman’s acid-base status?
A. Simple metabolic alkalosis
B. Metabolic alkalosis and metabolic acidosis
C. Respiratory acidosis and metabolic alkalosis
D. Respiratory acidosis, metabolic alkalosis, and metabolic acidosis
Answer: D
Subject: Electrolyte Acid-Base Disorders
A 20-year-old woman is referred for hypokalemic metabolic alkalosis. Over the past several years, she has noted progressive worsening of polyuria, thirst, salt craving, weakness, and fatigue. She does not have vomiting and is on no medications. On physical examination, the BP is 110/70 mmHg, and the pulse rate is 74/min. The remainder of the examination is normal. Laboratory studies show sodium of 140 mEq/L, potassium of 2.2 mEq/L, chloride of 88 mEq/L, total CO2 of 42 mmol/L, BUN of 12 mg/dl, creatinine of 0.9 mg/dl, glucose of 90 mg/dl, calcium of 9.2 mg/dl, and magnesium of 1.7 mg/dl. The plasma renin activity is 102 ng/ml per hour (reference range 50.6–3.0 ng/ml per hour), and the plasma aldosterone concentration is 56.5 ng/dl (reference range 52–5 ng/dl). Urinary electro-lytes are sodium of 45 mEq/L, potassium of 50 mEq/L, and chloride of 60 mEq/L. The urine calcium-to-creatinine ratio is 280 mg/g..
Question: Which ONE of the following is the MOST likely diagnosis?
A. Primary hyperaldosteronism
B. Gitelman syndrome
C. Bartter syndrome
D. Surreptitious vomiting
E. Liddle syndrome
Answer: C
Subject: Electrolyte Acid-Base Disorders
A 65-year-old man is evaluated 3 weeks after receiving a deceased donor kidney transplant. He is doing well and asymptomatic. His medications include tacrolimus, mycophenolate mofetil, prednisone, carvedilol, dapsone, and acyclovir. On physical examination, the BP is 160/94 mmHg. The allograft is nontender and without bruit. He has trace pretibial edema. The remainder of the examination is normal. Laboratory studies show sodium of 138 mEq/L, potassium of 5.8 mEq/L, chloride of 109 mEq/L, total CO2 of 18 mmol/L, BUN of 18 mg/dl, creatinine of 1.4 mg/dl, and glucose of 108 mg/dl. A 12-hour tacrolimus trough level is 8 ng/ml. An ultrasound of the kidney transplant shows normal vasculature and no hydronephrosis..
Question: In addition to a low-potassium diet, which ONE of the following is the BEST management of this patient’s hyperkalemia?
A. Reduce tacrolimus to achieve trough levels of 4–5 ng/ml
B. Start chlorthalidone
C. Start ﬂudrocortisone
D. Start sodium bicarbonate
Answer: B
Subject: Electrolyte Acid-Base Disorders
A 55-year-old woman with stage G4 CKD due to diabetic kidney disease is referred for management of persistent hyperkalemia. She has been adherent with dietary potassium restriction. Her medications include insulin glargine, omeprazole, metoprolol, lisinopril, amlodipine, and furosemide. The physical examination shows a BP of 130/82 mmHg, background diabetic retinopathy, and decreased sensation in the feet. The remainder of the examination is normal. Laboratory studies show sodium of 140 mEq/L, potassium of 5.9 mEq/L, chloride of 109 mEq/L, total CO2 of 22 mmol/L, BUN of 26 mg/dl, creatinine of 4.2 mg/dl, eGFR of 17 ml/min per 1.73 m2, glucose of 138 mg/dl, calcium of 8.9 mg/dl, magnesium of 1.8 mg/dl, and phosphorus of 5.4 mg/dl. You prescribe patiromer calcium..
Question: This patient is at risk for which ONE of the following complications related to treatment with patiromer calcium?
A. Hypomagnesemia
B. Hypercalcemia
C. Metabolic alkalosis
D. Hypophosphatemia
Answer: A
Subject: Electrolyte Acid-Base Disorders
A 50-year-old woman is referred for evaluation of new-onset hypertension. Two weeks ago, she noted onset of headache and muscle cramps. She is an avid tea drinker and recently starting drinking an imported tea from Egypt. She has not smoked cigarettes. On physical examination, she is a healthy-appearing woman in no acute distress. The body mass index is 19.5 kg/m2. The BP is 220/100 mmHg, and the pulse rate is 88/min. There are no abdominal or ﬂank bruits, and there is no radiofemoral delay. Laboratory studies show sodium of 146 mEq/L, potassium of 2.9 mEq/L, chloride of 104 mEq/L, total CO2 of 32 mmol/L, BUN of 9 mg/dl, creatinine of 0.6 mg/dl, calcium of 9.2 mg/dl, magnesium of 1.8 mg/dl, and phosphorus of 2.4 mg/dl. Urine electrolytes show potassium of 50 mEq/L, so\dium of 45 mEq/L, and chloride of 40 mEq/L. The plasma renin activity is 0.1 ng/ml per hour (reference range 50.6–3.0 ng/ml per hour), and the plasma aldosterone concentration is < 1.0 ng/dl (reference range 52–5 ng/dl). The plasma deoxycorticosterone level is normal. The 24- hour urine free cortisol is 170.25 microgram/g creatinine (reference range < 24 microgram/g), the 24-hour urine cortisone is 42 microgram/g creatinine (reference range 58–65 microgram/g), and the 24-hour urine cortisol-to-cortisone ratio is 4.0..
Question: Which ONE of the following is the MOST likely cause of this patient’s hypokalemia?
A. Decreased activity of 11β-hydroxysteroid dehydrogenase
B. Liddle syndrome
C. Cushing syndrome
D. Ectopic adrenocorticotropic hormone syndrome
Answer: A
Subject: Electrolyte Acid-Base Disorders
An 82-year-old man with stage G5 CKD and hypothyroidism is evaluated during a follow-up visit for hyperkalemia. His medications are amlodipine, furosemide, and levothyroxine. He has decided to forego dialysis in favor of medical management. His serum potassium level is 6.2 mEq/L, despite adherence to a potassium-restricted diet. You prescribe sodium polystyrene sulfonate..
Question: Which ONE of the following would you advise this patient with regard to sodium polystyrene sulfonate therapy?
A. The frequency of colonic necrosis is approximately 0.1%
B. It can be safely coadministered with his other medication
C. There is no evidence supporting its use for the treatment of hyperkalemia in CKD
D. Use of a sorbitol-free preparation eliminates the risk of colonic necrosis
Answer: A
Subject: Electrolyte Acid-Base Disorders
Question: Question 2633:
Which ONE of the following MOST likely contributes to the pathogenesis of salt-sensitive hypertension in individuals consuming a low-potassium diet?
A. Increased aldosterone production
B. Increased activity of the NCC in the distal convoluted tubule
C. Increased activity of the ENaC in the aldosterone-sensitive portion of the distal tubule and collecting duct
D. Inhibition of WNK1 in the distal convoluted tubule
Answer: B
Subject: Electrolyte Acid-Base Disorders
A 24-year-old man is evaluated for weakness and recently documented hypokalemic metabolic alkalosis. He indicates that he has always craved salty foods and had intermittent leg cramps since age 15 years old. Over the past 2 months, he noted onset of diffuse myalgias, polyuria, weakness, and wors-ening leg cramps. He is on no medications and does not have vomiting or diarrhea. On physical examination, his stature is normal. The BP is 118/60 mmHg, and the pulse rate is 88/min. The neuro- logic examination shows mild diffuse weakness. The remainder of the examination is normal. Laboratory studies show sodium of 142 mEq/L, potassium of 3.2 mEq/L, chloride of 102 mEq/L, total CO2 of 30 mmol/L, BUN of 9 mg/dl, creatinine of 0.8 mg/dl, glucose of 87 mg/dl, calcium of 9.6 mg/dl, magnesium of 1.4 mg/dl, and phosphorus of 2.8 mg/dl. Urine electrolytes show potassium of 50 mEq/L, sodium of 63 mEq/L, and chloride of 87 mEq/L. The plasma renin activity is 11 ng/ml per hour (reference range 50.6–3.0 ng/ml per hour), and the plasma aldosterone concentration is 17 ng/dl (reference range 52–5 ng/dl). A urinalysis shows speciﬁc gravity of 1.015, pH 7, and no protein or blood. A comprehensive urine diuretic screen is negative..
Question: Which ONE of the following diagnostic tests is MOST appropriate to perform next?
A. 24-hour urine collection for potassium
B. Genetic testing for mutations in the CLCNKB gene
C. Urine calcium-to-creatinine ratio
D. Fractional chloride clearance in response to hydrochlorothiazide at 50 mg
Answer: C
Subject: Electrolyte Acid-Base Disorders
A 65-year-old woman is referred for evaluation of hypokalemia and hypomagnesemia. She recently completed concurrent radiochemotherapy for stage 3 nonsmall cell lung cancer. The chemotherapy regimen included cisplatin plus vinblastine. On physical examination, the BP is 110/60 mmHg, and the pulse rate is 96/min. There are decreased breath sounds at the left lung base. There is no edema. The remainder of the examination is normal. Laboratory studies show sodium of 133 mEq/L, potassium of 3.2 mEq/L, chloride of 101 mEq/L, total CO2 of 29 mmol/L, BUN of 32 mg/dl, creatinine of 1.3 mg/dl, calcium of 8.9 mg/dl, magnesium of 1.1 mg/dl, and phosphorus of 3.5 mg/dl. The urine sodium is 72 mEq/L, the urine chloride is 56 mEq/L, and the urine potassium is 65 mEq/L. The urine calcium-to-creatinine ratio is 26 mg/g..
Question: Dysfunction of which ONE of the following nephron segments is contributing the MOST to this woman’s hypomagnesemia?
A. The thick ascending limb of the loop of Henle
B. The medullary collecting duct
C. The descending limb of the loop of Henle
D. The early distal convoluted tubule
Answer: D