Comparison of non-invasive CPAP with mask use in carbon monoxide poisoning

Carbon monoxide (CO) is one of the major causes of poisoning worldwide. We aimed to investigate the efficacy of the continuous positive airway pressure (CPAP) use in CO poisoning.

After CO poisoning, one group of patients was treated with a non-rebreather mask (NRB) and another group using the CPAP mode of mechanical ventilation (CPAP). All patients received at least 90 minute treatment. The carboxyhemoglobin saturation (SpCO) levels of all patients were measured from the fingertips with a portable CO-oximeter at 0, 30, 60 and 90 min. The rates of changes in the serially measured SpCO values were obtained using the Wilcoxon signed-rank test.

A total of 45 patients (24 in NRB and 21 in CPAP group) completed the study. The median initial SpCO levels were 24% (21-33) in NRB group, 25% (21-32) in CPAP group, with no statistically significant difference (p 0.323). At the 30th, 60th, and 90th minutes of treatment, significantly lower values were obtained from CPAP than NRB (p < 0.001). The COHb half-life was decreased significantly by CPAP [105(70-190) vs 45(30-120), p < 0.001]. In CPAP group, the fastest decline in the SpCO level was observed for the interval of 0-30 min [Median difference: 8(3-14), p < 0.001].

CPAP lowered the amount of CO in the blood faster than the mask; therefore, it may be effective in the treatment of CO poisoning.