nida
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Harrison's Q
A patient with a history of Sjögren's syndrome has the following laboratory findings: plasma sodium 139 meq/L, chloride 112 meq/L, bicarbonate 15 meq/L, and potassium 3.0 meq/L; urine studies show a pH of 6.0, sodium of 15 meq/L, potassium of 10 meq/L, and chloride of 12 meq/L. The most likely diagnosis is
A. type I renal tubular acidosis (RTA)
B. type II RTA
C. type III RTA
D. type IV RTA
E. chronic diarrhea
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| cyra
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A
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| msyamp
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A sjogren's RTA type 1
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If you think you can You can! If you think you cant you are right again!!
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| som
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type1 RTA
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| MAZI
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A
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| frank100
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(A), MSYAMP IS RIGHT.
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| nida
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The answer is A.
This patient has a normal anion gap metabolic acidosis (anion gap = 12). The calculated urine anion gap (Na+ + K+ - Cl-) is +3; thus, the acidosis is unlikely to be due to gastrointestinal bicarbonate loss. In this patient the diagnosis is type I renal tubular acidosis, or distal RTA. This is a disorder in which the distal nephron does not lower pH normally. It is associated with a urine pH > 5.5, hypokalemia, and lack of bicarbonaturia. This condition may be associated with calcium phosphate stones and nephrocalcinosis. Type II RTA, or proximal RTA, includes a pH < 5.5, hypokalemia, a positive urine anion gap, bicarbinaturia, hypophosphatemia, and hypercalciuria. This condition results from defective resorption of bicarbonate. Type III RTA is rare and most commonly is seen in children. Type IV RTA is also referred to as hyperkalemic distal RTA. Hyporeninemic hypoaldosteronism is the most common cause of type IV RTA and is usually associated with diabetic nephropathy.
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