Serum lactate and carboxyhemoglobin as predictors of hyperbaric oxygen therapy in carbon monoxide poisoning: a retrospective study

Comprehensive Summary

Aykut et al., examined whether serum lactate and carboxyhemoglobin levels predict the need for hyperbaric oxygen (HBO) therapy in patients with carbon monoxide (CO) poisoning. This retrospective study included 292 CO poisoning patients divided into two groups based on whether they received HBO therapy (n=94) or not (n=198). Analyzed parameters included lactate levels, carboxyhemoglobin, and complete blood count values. Patients receiving HBO therapy demonstrated significantly elevated lactate and carboxyhemoglobin levels compared to those not receiving HBO. Both parameters were independent predictors of HBO therapy need in multivariate analysis (lactate OR 2.04; carboxyhemoglobin OR 1.32).The area under the curve (AUC) for lactate alone was 0.754, while combining lactate and carboxyhemoglobin yielded an AUC of 0.936, indicating excellent discriminatory ability for predicting HBO therapy need.

Outcomes and Implications

Carbon monoxide (CO) poisoning remains a leading cause of toxin-related morbidity and mortality worldwide. CO binds hemoglobin with 200-fold greater affinity than oxygen, reducing oxygen-carrying capacity and shifting the oxygen-hemoglobin dissociation curve leftward, impairing oxygen delivery to tissues. Additionally, CO directly impairs mitochondrial respiration, leading to cellular dysfunction particularly in high-oxygen-demand organs like the brain and heart. Hyperbaric oxygen (HBO) therapy accelerates CO elimination and may reduce delayed neurologic sequelae, but optimal patient selection remains controversial.