EFFECTS OF MODE OF INHALATION OF CARBON-MONOXIDE AND OF NORMOBARIC OXYGEN ADMINISTRATION ON CARBON-MONOXIDE ELIMINATION FROM THE BLOOD

1 The half-life of carbon monoxide (CO) in blood was studied retrospec tively in 26 fire victims and in 19 cases of CO poisoning. Normobaric oxygen therapy was administered via mechanical ventilation in 19 fire victims, and by facial mask to the rest of the casualties. 2 Arterial pH was significantly lower (P <0.05) and PaO2 significantly greater (P <0.01) in the mechanically ventilated fire victims compared to the sp ontaneously breathing fire victims. 3 The blood CO half-lives were 91/-38 min for the 26 fire victims and 87+/-40 min for the 19 pure CO in toxications. 4 The blood CO half-lives were 92+/-40 min for the 19 mec hanically ventilated fire victims and 87+/-37 min for the 26 spontaneo usly breathing subjects. 5 We conclude that the elimination of CO from blood was a slow process with no significant effects on the blood CO half-life of either the cause of the CO poisoning or the mode of normo baric oxygen therapy. These data suggest that enhancement of the elimi nation of carbon monoxide by normobaric oxygen in both pure CO poisoni ng and fire victims is more difficult to achieve and more complex than has previously been reported.