A 19-year-old male with a history of substance abuse presents to the Emergency Department with respiratory distress.
Parameter |
Patient Value |
Normal Adult Range |
FiO2 |
0.4 |
|
pH |
6.94* |
7.35 – 7.45 |
PO2 |
140 mmHg (18.4 kPa) |
|
PCO2 |
17* mmHg (2.2 kPa) |
35 – 45 (4.6 – 6.0) |
HCO3 |
4* mmol/L |
22 – 27 |
Base Excess |
-28 mmol/L* |
-2.0 – +2.0 |
Sodium |
127* mmol/L |
135 – 145 |
Chloride |
113* mmol/L |
95 – 105 |
Potassium |
3.9 mmol/L |
3.5 – 5.0 |
Urine pH |
7.2 |
4.6 – 8.0 |
a)Describe the acid-base disturbance.
b)What is the likely cause of the acid-base disturbance?
a) Normal anion gap severe metabolic acidosis with incomplete compensation.
b) Renal tubular acidosis Type 1 distal secondary to chronic toluene abuse.
Let us dissect these results systematically.
A result like this has you asking, what the hell are the kidneys doing? Why are they not acidifying the urine? The answer may lay in the history of this young man's substance abuse. One may eventually arrive at the conclusion that he is a connoisseur of volatile solvents.
The recreational enjoyment of toluene can lead to a nasty Type 1 (distal) renal tubular acidosis.
Batlle, D. C., S. Sabatini, and N. A. Kurtzman. "On the mechanism of toluene-induced renal tubular acidosis." Nephron 49.3 (1988): 210-218.