For each patient with
hyperchloremic metabolic acidosis described below, select the most likely cause
of the acidosis (A-E).
A. Proximal (Type II) renal tubular acidosis
B. Classic distal (Type I) renal tubular acidosis
C. Hyporeninemic hypoaldosteronism (Type IV renal tubular acidosis)
D. Gastrointestinal hydrogen ion loss
E. Hippurate intoxication
1.28-year-old man with Type I diabetes mellitus complicated by
diabetic nephropathy, chronic renal failure with a serum Cr of 2.2 mg/dL,
autonomic neuropathy and chronic diarrhea. The urine sodium is 5 mEq/L,
potassium 15 mEq/L and chloride 64 mEq/L.
2. 20-year-old woman with osteosarcoma of the femur, undergoing
chemotherapy with ifosfamide. The serum potassium is 2.8 mEq/L, glucose 124
mg/dL, phosphate 1.8 mg/dL. The urinalysis shows pH 7.5, 1+ protein, 3+ glucose. The urine sodium is 56 mEq/L,
potassium 45 mEq/L and chloride 58 mEq/L.
3. 18-year-old male college student with a history of polysubstance
abuse. The serum potassium is 3 mEq/L and the urine sodium is 40 mEq/L,
potassium 55 mEq/L and chloride 15 mEq/L. The urine sediment shows numerous
needleshaped crystals.
4. 67-year-old woman with Type II diabetes mellitus, diabetic
nephropathy, and chronic renal insufficiency with a serum Cr of 2 mg/dL. She is
unable to tolerate angiotensin-converting enzyme inhibitors due to
hyperkalemia. The urine pH is 5.0 and the urine sodium is 40 mEq/L, potassium
15 mEq/L and chloride 34 mEq/L.
5. 34-year-old woman with dry eyes and poly arthritis. The serum
potassium is 3.5 mEq/L, the urine pH is 6.5 and the urine sodium is 30 mEq/L,
potassium 45 mEq/L and chloride 62 mEq/L.
(Questions and Answers courtesy of Dr. Alan Yu, University of Kansas Medical Center)
