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

Carbon monoxide (CO) poisoning is a leading cause of toxicological emergencies worldwide. Although carboxyhemoglobin (COHb) levels are traditionally used to confirm exposure, they often fail to reflect clinical severity. This study aimed to evaluate the diagnostic performance of serum lactate and hematological parameters in predicting the need for hyperbaric oxygen therapy (HBOT) among patients with acute CO poisoning.

This retrospective cross-sectional study included 292 adult patients with confirmed CO poisoning admitted to a tertiary emergency department between 2020 and 2024. Patients were categorized according to HBOT administration. Laboratory values including lactate, COHb, and hematologic parameters and indices were analyzed. Multivariable logistic regression and ROC curve analysis were used to assess predictive performance.

Of the 292 patients, 94 (32.2%) received HBOT. Serum lactate and COHb were significantly higher in the HBOT group (p < 0.001 for both) and were identified as independent predictors of HBOT requirement (lactate OR = 2.04; COHb OR = 1.32). AUC for lactate alone was 0.754; combining lactate with hematologic markers modestly improved AUC to 0.769. The most robust model, incorporating lactate and COHb, achieved an AUC of 0.936. Hematologic markers alone showed limited predictive value.

Serum lactate, particularly when combined with COHb, provides strong diagnostic value in predicting HBOT need in CO poisoning. The integration of these readily available biomarkers may improve triage decisions in emergency care.