B. Aspirin – Explanation

The clinical picture here represents metabolic acidosis. This is likely from aspirin
poisoning. With aspirin overdose, they initially hyperventilate leadingto respiratory
alkalosis initially. The initial phase could last up to 12 hours. Following that, progressive
metabolic acidosis occurs. This usually occurs around the 24 hour mark after ingestion
for adults.

Paracetamol overdose may also cause metabolic acidosis in the early and late course
of poisoning and thus paracetamol as an answer is not completely wrong. However,
aspirin overdose is a more recognized cause of metabolic acidosis compared to
paracetamol.

Overdose of Enalapril (ACE inhibitor) or Diclofenac (NSAIDs) cause metabolic alkalosis
and not acidosis.

Overdose of Benzodiazepines would cause respiratory acidosis.

If suspecting metabolic acidosis do a blood gas. A metabolic acidosis picture with an
increased anion gap can be due to several drugs. Common ones are listed here:

•  Metformin
• Alcohol
•  Isoniazid
•  Iron
•  Aspirin
•  Digoxin

ARTERIAL BLOOD GAS, CAUSES