Mechanical Ventilation Was Associated with Acidemia in a Case Series of Salicylate‐poisoned Patients

Abstract

Objectives: Despite little empiric evidence, mechanical ventilation (MV) in the setting of salicylate poisoning is considered by many to be harmful. When salicylate-poisoned patients are ventilated at conventional settings, the respiratory alkalosis is abolished, more salicylate is able to pass into the central nervous system (CNS), and neurotoxicity worsens. The objective of this study was to identify a relationship between MV, acidosis, and outcome in salicylate-poisoned patients. Methods:The authors electronically searched a poison control center (PCC) database (2001)(2002)(2003)(2004)(2005)(2006)(2007) for patients with salicylate poisoning, defined as a serum concentration >50 mg ⁄ dL, who had MV listed as a therapy. For the 7-year study period, a total of 3,144 salicylate-poisoning cases were identified. Eleven patients met the inclusion criteria of having both salicylate concentrations >50 mg ⁄ dL and required MV; only 7 of them had post-MV data available. Results:In all seven patients with post-MV blood gas data, the post-MV pH was <7.4. In five of six patients with recorded PCO 2 , the post-MV PCO 2 was >50 mm Hg. Two of the seven patients in the study group died following intubation (two patients died within 3 hours [serum salicylate concentrations, 85 and 79 mg ⁄ dL, respectively]). Another patient sustained severe neurologic injury (serum salicylate concentration, 84 mg ⁄ dL). The other four patients were ultimately discharged home. In the three patients with the worst clinical outcome, deterioration was reported within hours of intubation. Conclusions:Inadequate MV of patients with salicylate poisoning is associated with respiratory acidosis, acidemia, and clinical deterioration in this series of cases. This supports warnings about the danger of improper MV in patients with salicylate poisoning. A prospective study should be performed.ACADEMIC EMERGENCY MEDICINE 2008; 15:866-869 ª

Utility of serum lactate to predict drug-overdose fatality

“…Mechanisms to account for hyperlactatemia from specific drug overdoses are myriad and include the following: hypoperfusion because of vasoconstriction (e.g., ergots) 23 or hypotension (e.g., beta blockers); 24 muscle activity because of seizures (e.g., cocaine) 25 or myoclonus (e.g., serotonin syndrome); 26 altered metabolism of lactate because of increased production (e.g., propylene glycol) 27 or decreased clearance (e.g., metformin); 28 duration of unconsciousness; 5 mitochondrial DNA changes (e.g., nucleoside inhibitors); 29 and failure of cellular respiration because of poisoning of glycolysis (e.g., arsenic), 30 the Kreb’s cycle (e.g., monofluoroacetate), 31 electron transport (e.g., carbon monoxide), 32 or uncoupling of oxidative phosphorylation (e.g., salicylism). 33 …”

Death Due to Acute Salicylate Intoxication Despite Dialysis

“…Endotracheally intubating this patient would have provided more protection from aspiration. However, previous reports document death soon after intubation in acute salicylate toxicity, likely due to hypercarbia, worsening respiratory acidosis, and increased distribution of salicylate into target organs (9).…”

Acute salicylate poisoning: risk factors for severe outcome

“…This principle was similarly demonstrated in the setting of worse clinical prognosis following orotracheal intubation. 24 Aside from CNS-depressants, other co-ingestions (e.g. acetaminophen) can lead to renal pathophysiology, which may also contribute to the overall severity of outcome (e.g.…”