A 72-year-old presenting with an aspirin overdose will likely show which blood gas result?

In the scenario of aspirin overdose, the most common acid-base disturbance is a combination of metabolic acidosis and respiratory alkalosis. Aspirin (salicylate) can cause an increase in acid production (contributing to metabolic acidosis) while also stimulating the respiratory center, leading to hyperventilation and thus reducing pCO2 levels (respiratory alkalosis).

The choice indicating a pH of 7.45 is consistent with the respiratory alkalosis component, suggesting that hyperventilation has occurred as a response to the metabolic acidosis caused by the salicylate toxicity. The low pCO2 of 21 supports the hyperventilation, as the body attempts to compensate for the acidosis.

The bicarbonate level of 14 indicates a depletion likely due to metabolic acidosis, which aligns with aspirin's effects on the body. Therefore, in the context of an aspirin overdose, the findings show that while there is a degree of alkalosis, it is compensatory due to the respiratory response to the underlying metabolic disturbance.

This understanding of the acid-base balance is crucial in effectively assessing and managing patients with potential toxicity, including the physiological responses influenced by a toxic load.