Fluid, electrolyte, and acid-base disorders Q. 1 A 56-year old man with a 25-pack-year history, distant cerebrovascular accident, and a 10 year history of hypertension treated with hydrochlorothiazide is evaluated because of generalized fatigue. Blood pressure is 110/70 mm Hg. Serum Na 128 Serum potassium 3.3 Serum chloride 79 Serum bicarbonate 38 Arterial blood gases on room air: pH 7.50, PCO2 50, PO2 74 Which of the following best explains the patient's acid-base status? A. Metabolic alkalosis B. Respiratory acidosis C. Respiratory alkalosis D. Metabolic acidosis Q. 2 A 63-year old man is evaluated because of upper and lower extremity cramps and diffuse muscle weakness of 2 weeks duration. He has been taking aspirin for 6 weeks because of low back pain. The PE is normal. Serum Na 135 K 2.6 Cl 117 Bicarb 15 ABG: PH 7.3, PCO2 31 Urine pH 5.0 Which of the following best explains his acid-base status? A. Ethylene glycol toxicity B. Lactic acidosis C. Proximal RTA D. Salicylate toxicity
Q. 3 and 4 A 39 year old man is evaluated in the ER because of severe left flank pain and hematuria after playing softball. The pain is sharp and radiates to the groin. He vomited eight times before presentation. He has a non-obstructing, calcium-containing kidney stone at the ureteropelvic junction on the left side. On initial evaluation, his BP is 130/90 and HR 110 Serum Na 141 K 4.0 Cl 100 Bicarb 34 ABG: pH 7.61, PCO2 36 Which of the following best describes this patient's acid/base disorder? A. Metabolic acidosis and respiratory alkalosis B. Metabolic alkalosis C. Metabolic alkalosis and respiratory acidosis D. Metabolic and respiratory alkalosis
E. Respiratory alkalosis
The preceding patient is given IV infusion of 0.9% normal saline at 200 cc/h. Two days later, his flank pain worsens dramatically, but nausea and vomiting have resolved. Blood pressure and heart rate are unchanged. BUN 8 mg/dL Serum creat 0.9 Na 138 K 4.0 Cl 105 Bicarb 22 ABG pH 7.48, PCO2 30 Which of the following best describes his acid/base status? A. metabolic acidosis with respiratory alkalosis B. metabolic alkalosis and respiratory alkalosis C. Respiratory acidosis and metabolic alkalosis D. Respiratory alkalosis Q. 5 A 60 year old woman with a history of essential hypertension is admitted to hospital after 7 days of vomiting. On PE, she appears ill. The systolic blood pressure is 110 seated and 70 standing. The HR while seated is 120. The abdominal examination reveals rebound tenderness and no bowel sounds. Serum Na 140 K 3.2 Cl 80 Bicarb 11 ABG: pH 7.29, PCO2 24 Which of the following describes her acid/base status? A. AGMA B. AGMA + metabolic alkalosis C. NAGMA + metabolic alkalosis D. NAGMA
Q. 6 An 18 year old male high school student is evaluated in the ER because of confusion, nausea, headache and decreased vision after a camping trip. The patient's friends state that he became ill 14 hours ago. BUN 14 creat 1.9 Na 140 Cl 100 K4 Bicarb 12 Glucose 108 Serum osm 326
Serum ketones neg Serum lactate 0.7 ABG pH 7.29, PCO2 26 Ingestion of which of the following best explains the acid/base abnormalities? A. Ethanol B. Isopropyl alcohol C. Methanol D. Salicylate Q. 7 A 28 year old woman is evaluated because of recurrent calcium-containing kidney stones. She currently has no symptomsof renal coli. For several years, she has had dry eyes, dry mouth and Raynaud's phenomenon. Crohn's disease was diagnosed 10 years ago; she is currently asymptomatic and passes one formed stool daily. She takes no medications. On PE, BP 115/74, HR 72 and temp 98.6. PE is unremarkable. Plain abdominal radiograph shows multiple calcifications within the renal parenchyma bilaterally. Serum Na 138 K 2.8 Cl 109 Bicarb 19 Calcium 9.1 phosphorus 3.2 UA pH 6.0, SG 1.020, trace hematuria, no proteinuria ABG: pH 7.29 Which of the following is the most likely etiology of her renal stone disease? A. Distal RTA B. Enteric hyperoxaluria C. Idiopathic hypercalciuria D. Primary hyperparathyroidism
