UCtheBean
Review Course:1) Pre-Course Quiz (at bottom of page)2) Lecture PDFs and Worksheets3) Post-Module Exam
Renal Tubular Acidosis: An Interview
A 32-year-old man is brought in by paramedics after being found unconscious in the garage at home. Patient is unarousable upon arrival to the emergency department. Laboratory findings: Serum chemistry: Sodium 144 mmol/L Potassium 3.1 mmol/L Chloride 101 mmol/L Total CO2 12 mmol/L Blood urea nitrogen 9 mg/dL Creatinine 1.5 mg/dL Calcium 7.8 mg/dL Magnesium 1.5 mg/dL Phosphorus 2.1 mg/dL Arterial blood gas: pH 7.10, pCO2 40 mm Hg.What acid–base disorders does this patient have?
A 47-year-old man with a history of metastatic colorectal carcinoma and alcohol abuse was admitted to the emergency department following a fall. Fourteen hours following admission, he developed a generalized tonic–clonic seizure requiring the administration of lorazepam bolus followed by a continuous infusion of 2 mg/h. He was intubated and required continuing lorazepam support up to 50 mg/h over the next 3 days. Over this time period, he became more and more hypotensive requiring the addition of two vasopressors. Laboratory findings revealed worsening metabolic acidosis with pH and lactic acid level at 7.0 and 14.7 mmol/L respectively. His liver function test was notable for marked transaminitis. He was placed on linezolid and ertapenem pending full infectious evaluation.Which one(s) of the following may contribute to this patient’s lactic acidosis?
A 25-year-old man with a 10-year history of type 1 diabetes mellitus becomes anorexic after developing gastroenteritis and reducing his insulin dose. He then develops nausea, vomiting, polyuria, and dyspnea and presents to the ED. The patient also has a long history of depression and is taking fluoxetine. He has orthostatic hypotension. His breath has a fruity odor. The initial laboratory studies reveal SUN, 40 mg/dL; creatinine, 1.5 mg/dL; glucose, 800 mg/100 mL; [Na+], 120 mEq/L; [Cl−], 75 mEq/L; [HCO3−], 12mEq/L; K+, 3.0 mEq/L; ([AG], 32 mEq/L); and albumin, 4.0 g/100 mL. The measured osmolality is 330 mOsm/L; serum β-hydroxybutyrate, >8 mEq/L; and urine ketones, 3+ by dipstick. Blood ethanol level is nondetectable. ABG values are pH 7.16; PO2, 90 mm Hg; pCO2, 35 mm Hg; and [HCO3−], 12 mEq/L.What is the most likely cause of this patient’s 25 mOsm/L osmolal gap?
A 32-year-old woman presents to the hospital with generalized fatigue. She has no known diarrhea and denies taking any medications. Physical examination reveals a thin woman, otherwise unremarkable. Blood pressure 95/57 mm Hg, heart rate 55 beats/min, respiratory rate 12 breaths/min. Laboratory findings: Sodium 132 mmol/L Potassium 3.3 mmol/L Chloride 80 mmol/L Total CO2 39 mmol/L Blood urea nitrogen 5 mg/dL Creatinine 0.5 mg/dL Calcium 7.8 mg/dL Magnesium 1.6 mg/dL Albumin 3.8 g/dL Arterial blood gas: pH 7.49, Pco2 50 mm Hg, HCO3− 38 mmol/L Urine sodium 12 mmol/L, chloride 16 mmol/L, potassium 37 mmol/L Which one of the following is the most likely diagnosis?
A 25-year-old man with a 10-year history of type 1 diabetes mellitus becomes anorexic after developing gastroenteritis and reducing his insulin dose. He then develops nausea, vomiting, polyuria, and dyspnea and presents to the ED. The patient also has a long history of depression and is taking fluoxetine. He has orthostatic hypotension. His breath has a fruity odor. The initial laboratory studies reveal SUN, 40 mg/dL; creatinine, 1.5 mg/dL; glucose, 800 mg/100 mL; [Na+], 120 mEq/L; [Cl−], 75 mEq/L; [HCO3−], 12mEq/L; K+, 3.0 mEq/L; ([AG], 32 mEq/L); and albumin, 4.0 g/100 mL. The measured osmolality is 330 mOsm/L; serum β-hydroxybutyrate, >8 mEq/L; and urine ketones, 3+ by dipstick. Blood ethanol level is nondetectable. ABG values are pH 7.16; PO2, 90 mm Hg; pCO2, 35 mm Hg; and [HCO3−], 12 mEq/L.What is his acid-base disorder?
A 38-year-old woman with a history of severe restrictive lung disease had a bilateral lung transplant 4 months ago. She has had a complex posttransplant course with several episodes of successfully treated acute lung rejections. She also had 2 episodes of AKI, and now has a persistently reduced GFR. Her poor oral intake required placement of a gastric feeding tube. She is very depressed and reports persistent pain at the site of her G-tube. She has been taking acetaminophen, 650 mg 3 times a day, for the past 3 weeks. She denies use of any other medications and said she would not try to harm herself. Physical examination shows normal vital signs and malnutrition, with temporal wasting and diffuse muscle wasting. The G-tube exit site is erythematous but without drainage. Her serum chemistries are glucose, 90 mg/100 mL; SUN, 10 mg/dL; creatinine, 0.7 mg/dL; [Na+], 140mEq/L; K+, 4.2 mEq/L; [Cl−], 106 mEq/L; [HCO3−], 12 mEq/L. Her ABG values are pH 7.21; paCO2 26 mm Hg; [HCO3−], 10 mEq/L. Her albumin is 3.0 g/dL, and L-lactate is 0.8 mmol/L. Her urine is negative for ketones, and her serum β-hydroxybutyrate is normal at 0.5 mEq/L. Serum osmolality (by freezing point depression) is 290 mOsm/L. Serum salicylate is undetectable. Acetaminophen level is in the therapeutic range. The most likely cause of the patient’s HAGMA is:
A 59-year-old woman with history of Type 2 diabetes and epilepsy (last known seizure 2 years prior. Medical history well controlled with Metformin and levetiracetam. She was found by her spouse in the garage in ICU for management of status epilepticus. After failing treatment with propofol, the sedative regimen was changed to continuous infusion of pentobarbital. Admission labs: (mEq/L) Na+ 142, K+ 4.3, Cl- 105, HCO3- 22, creatinine 1.4, BUN 25, glucose 100, Hematocrit 36, pH 7.35, pCO2 45, pO2 75. Serum osmolality 302mOsm/l. After 24 hours of seizure control repeat labs show: (mEq/l) Na+ 138, K+ 4.8, Cl- 100, HCO3- 10, creatinine 1.8, BUN 28, glucose 120, Serum osmolality 330 mOsm/lWhich is the most likely cause of the electrolyte disturbances in this patient?
A 9-yr-old girl complains of profound weakness, dizziness, and polyuria. She is taking no medications and has no gastrointestinal complaints. Pertinent clinical finding is BP of 90/50 mmHg with orthostatic dizziness. Laboratory data reveal the following: Na 140 mEq/L, K 2.5 mEq/L, Cl 100 mEq/L, CO2 33 mEq/L, blood urea nitrogen 25 mg/dl, and creatinine 0.7 mg/dl. A 24-h urine collection reveals the following: Sodium 90 mEq, potassium 60 mEq, Cl 110 mEq, and calcium 280 mg. Plasma renin and aldosterone are elevated. These findings are MOST suggestive of which ONE of the following?
A 26-year-old woman with no known past medical history is referred to you for persistent hypokalemia. She denies taking any medications or herbs. Vital signs: height 160 cm, weight 48 kg, blood pressure 96/61 mm Hg, pulse 72 beats/min, respiratory rate 14 breaths/min. Patient is nonorthostatic. Physical examination is benign. Laboratory findings: Sodium 134 mmol/L Potassium 3.1 mmol/L Chloride 92 mmol/L Total CO2 30 mmol/L Blood urea nitrogen 5 mmol/L Creatinine 0.6 mg/dL Calcium 9.2 mg/dL Magnesium 1.7 mg/dL Arterial blood gas: pH 7.43, Pco2 45 mm Hg. Both plasma renin activity (PRA) and aldosterone level are slightly elevated. Urine electrolytes: sodium 52 mmol/L, potassium 37 mmol/L, chloride 92 mmol/L, creatinine 92 mg/dL, calcium 35 mg/dLUrinalysis: specific gravity 1.009, pH 6.0, no protein, blood, cells, or casts. Which one of the following is the most likely diagnosis?
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