The laboratory in the diagnosis and management of acetaminophen and salicylate intoxications.

Toxic ingestions of acetaminophen and aspirin are clearly distinct in clinical presentations and in implications for laboratory medicine. In acetaminophen ingestion, the serum drug level is the single most important factor in the decision for or against therapy. In aspirin ingestion, the serum drug level is useful at its extremes--when so low as to indicate no need for therapy, and when so high as to indicate the need for dialysis. In the majority of infants and children with clinically significant salicylism, the serum drug level is in an intermediate range. For the management of these patients, the absolute level of salicylate in blood has much less significance than the laboratory assessment of the effects of salicylate on intermediary metabolism, acid-base status, and electrolyte and water balance.