Efficacy of different oxygen delivery methods in carbon monoxide poisoning: a prospective observational study

Carbon monoxide (CO) poisoning impairs oxygen transport by forming carboxyhemoglobin (COHb). Normobaric oxygen (NBO) is standard therapy, but its COHb elimination rate is slow. This study compared the effectiveness of NBO, NIMV, and EzPAP in reducing COHb levels in acute CO poisoning.

This prospective cohort study included patients with acute CO poisoning in an emergency department. Participants received one of three treatment modalities: standard NBO therapy, NIMV with positive pressure support, or the EzPAP system. COHb levels were recorded at baseline, 30 min, and 60 min after initiation of therapy. The primary outcome was the change in COHb concentration over time.

A total of 66 patients were included in the study (NIMV: n = 29, EzPAP: n = 18, and NBO: n = 19). Significant differences were observed in symptom distribution, with headache more frequent in the EzPAP and NBO groups and dyspnea more common in NIMV and EzPAP groups (p < 0.001). Baseline COHb levels did not differ between groups (p = 0.849). At 30 and 60 min, NIMV achieved significantly greater COHb reduction compared to NBO (p < 0.001), while EzPAP showed superiority over NBO at 60 min (p = 0.031). Pairwise analyses indicated NIMV was also superior to EzPAP at 60 min (p = 0.003).

While NBO remains the standard therapy, this study suggests NIMV - and to a lesser extent, EzPAP - may serve as effective adjuncts in the management of CO poisoning. These findings provide a rationale for further randomized controlled trials.