Neurological and Cardiac Determinants of Hyperbaric Oxygen Therapy in Carbon Monoxide Poisoning: A Retrospective Cohort Study

Introduction: Carbon monoxide (CO) poisoning remains a major global cause of morbidity and mortality. Although normobaric oxygen therapy (NBOT) is the standard initial treatment, hyperbaric oxygen therapy (HBOT) is often considered in patients with severe neurological or cardiac involvement. This study aimed to evaluate clinical, biochemical, electrocardiographic, and imaging factors associated with the selection of HBOT in patients presenting to the emergency department with CO poisoning. Methods: This retrospective cohort study included 272 adult patients diagnosed with CO poisoning between January 2020 and January 2025. Of these, 169 patients (62.1%) received NBOT and 103 patients (37.9%) received HBOT. Demographic characteristics, laboratory parameters (COHb, lactate, troponin, creatine kinase-MB [CK-MB]), Glasgow Coma Scale (GCS) scores, electrocardiographic (ECG) findings, and magnetic resonance imaging (MRI) results were analyzed. Multivariable logistic regression and receiver operating characteristic (ROC) analyses were performed. Results: Patients receiving HBOT had significantly lower GCS scores, higher cardiac biomarkers, and more frequent ischemic ECG findings. In multivariable analysis, lower GCS (OR 0.66, 95% CI 0.57– 0.76, p< 0.001), ischemic ECG findings (OR 7.31, 95% CI 1.56– 34.30, p=0.012), and lactate levels (OR 0.81, 95% CI 0.65– 0.99, p=0.043) were independently associated with HBOT selection. Lactate and COHb demonstrated limited discriminative ability (AUC 0.554 and 0.599, respectively). Conclusion: HBOT selection in CO poisoning is primarily associated with neurological status and cardiac involvement rather than biochemical parameters alone. These findings support a multidimensional clinical approach in emergency settings.