Experimental Rat Model: Is Preoxygenation with 100% O2 Before Anesthesia Induction Appropriate or Not?

Abstract

Preoxygenation is recommended method for prolonging safe time due to airway concerns before induction of anesthesia. However, debates about the damages of hyperoxemia in intensive care patients and chest diseases have been made for a long time and the issues related to oxygen management have taken place in the guidelines. Our aim was to determine the pathological and biochemical results of preoxygenation with 100% O-2, based on the hypothesis that some damagescan be seen, even in the short duration of hyperoxia. Firstly, a container for rat model of preoxygenation was designed. Four and six month old healthy 16 male rats were randomly divided into two groups [Group21 (n=8): 21% O-2 and Group100 (n=8): 100% O-2]. Groups were sacrificed under the ketamine and xylazine (50 and 5 mg/kg, respectively) at the end of 5 min. Blood, lung, heart, liver, and kidney samples were taken for biochemical tests and histopathological grades of tissue damage. The data were analyzed statistically by Mann-Whitney-U test. This study is significant in terms of the direct toxic effects of preoxygenation with 100% O-2 before anesthesia induction. However, there is a need for further studies on the determination of the ideal O-2 concentration for preoxygenation in patients.