Match each clinical presentation with the most likely corresponding serum and urine laboratory findings.
- A 32-year-old woman with Sjögren syndrome presenting with proximal muscle weakness and recurrent calcium phosphate nephrolithiasis.Hypokalemia, normal anion gap metabolic acidosis, and urine pH > 5.5
- A 58-year-old man with long-standing diabetic nephropathy and an estimated GFR of 35 mL/min/1.73 m² on routine follow-up.Hyperkalemia, normal anion gap metabolic acidosis, and urine pH < 5.5
- A 45-year-old man with a history of recurrent peptic ulcer disease presenting with 3 days of intractable, non-bilious emesis.Hypokalemia, metabolic alkalosis, and spot urine chloride < 20 mEq/L
- A 65-year-old man with a heavy smoking history presenting with hemoptysis and a newly diagnosed central lung mass.Hyponatremia, serum osmolality < 275 mOsm/kg, and spot urine sodium > 40 mEq/L
- A 28-year-old man with bipolar disorder on long-term mood stabilizer therapy presenting with frequent voiding and severe thirst.Hypernatremia, serum osmolality > 295 mOsm/kg, and urine osmolality < 300 mOsm/kg
Answer
The correct matches correlate specific clinical syndromes with their pathognomonic acid-base and electrolyte derangements: Sjögren syndrome with Type 1 RTA, diabetic nephropathy with Type 4 RTA, vomiting with volume-responsive metabolic alkalosis, small cell lung cancer with SIADH, and lithium use with nephrogenic diabetes insipidus.
Each clinical vignette provides classic epidemiological and historical clues that point to a specific pathophysiology, which then dictates the expected serum and urine biochemical findings.
Step-by-Step Solution
Key Concept
Accurate diagnosis of acid-base and electrolyte disorders requires integrating the patient's clinical history (e.g., autoimmune disease, diabetes, fluid losses, malignancies, medications) with expected serum and urine biochemical patterns.
Estimated Time:3m 0s