Acidemia promotes the entry of salicylate into the brain, worsening the intoxication. This creates the possibility of a death spiral involving hypercapnia, acidosis, and CNS dysfunction:
Salicylates in acute overdose classically cause a respiratory alkalosis by stimulating the respiratory centres in the brain followed by a metabolic acidosis by uncoupling oxidative phosphorylation.
Salicylate toxicity has potentially serious consequences, sometimes leading to significant morbidity and death. Patients with mild intoxication frequently have nausea and vomiting, abdominal pain, lethargy, ringing in the ears, and dizziness.
Acute salicylate toxicity typically results with ingestion of a total dose ≥ 150 mg/kg (approximately 7.5 to 10 g in adults). Salicylate poisoning can cause vomiting, tinnitus, confusion, hyperthermia, respiratory alkalosis, metabolic acidosis, and multiple organ failure.