A 35-year-old male has presented to the Emergency Department with weakness and constipation. Whilst in the Emergency Department he had the following results:
Test |
Value |
Normal Adult Range |
Sodium |
138 mmol/L |
135 – 145 |
Potassium* |
2.6 mmol/L |
3.2 – 4.5 |
Chloride* |
119 mmol/L |
100 – 110 |
Bicarbonate* |
10 mmol/L |
24 – 32 |
Glucose |
5.5 mmol/L |
3.0-6.0 |
Urea |
6.4 mmol/L |
2.7 – 8.0 |
Creatinine |
98 μmol/L |
65-115 |
Urine Sodium |
35 |
|
Urine Potassium |
50 |
|
Urine Chloride |
45 |
Give the likely cause of this disturbance and the rationale for your answer.
Distal (Type 1) RTA
Hyperchloraemic, normal AG acidosis and severe hypoK, with normal renal function and positive urinary anion gap.
Let us dissect these results systematically.
Given the extremely low bicarbonate value, and the hypokalemia, one might be tempted to call it a Type 1 (distal) renal tubular acidosis. Type 4 typically has a high potassium.
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