RESUMO
BACKGROUND: The most important route for elimination of inhalation anesthetics is exhalation. The lower anesthetic circuit volume and absorption by the anesthetic circuit maKes recovery more fast. The purpose of this study is to evaluate the effect of the elimination of CO2 absorption canisters on the rate of recovery from anesthesia. METHODS: Forty patients were randomly assigned into two groups. Group 1 patients recovered from enflurane anesthesia with CO2 absorption canisters (baralyme), but group 2 patients emerged from anesthesia without CO2 absorption canisters. The changes of expiratory enflurane and inspiratory nitrous oxide concentration at 30, 60, 90, 120, 150, 180 sec after the end of anesthetic administration, and time from the end of anesthetic administration to extubation were measured and compared between the groups. RESULTS: Enflurane and nitrous oxide concentrations after the end of anesthetic administration in group 2 were significantly lower than in group 1 at each time interval (P < 0.05). Time from the end of anesthetic administration to extubation in group 2, 7.7 +/- 1.4 min, was significantly shorter than in group 1, 10.5 +/- 2.6 min (P < 0.05). CONCLUSIONS: The results show that the patients emerging from anesthesia without CO2 absorption canisters can recover from anesthesia more rapidly than those with CO2 absorption canisters.