The Early Effects Of Sevoflurane And Desflurane On Oxygen Consumption

Objective: To observe the early effects of sevoflurane and desflurane on oxygen consumption in patients.Methods:inclusion criteria in this study. After the induction of general anesthesia,tracheal intubation or LMA was inserted.Oxygen concentration was rapidly decreased and maintained at 50%,and the patients were given 0.3L/min oxygen and 0.2L/min air through low-flow closed circuit MAC through decreasing and adjusting inhalation anesthesia concentration.The end-tidal carbon dioxide pressure was maintained between 35-45 mmHg by mechanical ventilation with volume controlled ventilation.When patients were in a steady state without surgical stimuli, hemodynamics and VO2 were recorded by indirect calorimetry.Atropine was given when heart rate was lower than 40 bpm,and esmolol was given when heart rate was higher than 120 bpm.Improving blood pressure by trendelenburg position ? speeding up liquildtransfusion and injection phenylephrine avoiding ephedrine.Results: There were respectively three and two patients quitted for significant differences regarding the backgrounds and hemodynamics. There Eighty patients,scheduled for orthopedics operations met the anesthesia.Turn on the vaporizer highest concentration to reach 1.0MAC.Sevoflurane and desflurane concentration was maintained at 1.0 was no statistically significant difference in VO2 between group sevoflurane(179.7±25.09) ml/min and desflurane(168.6±32.97)ml/min without surgical stimuli(P>0.05). But VO2 was lowered than basic level in both groups(P<0.05).Conclusion:General anesthesia can reduce VO2 of patients by mechanical ventilation, but there was no significant difference between the two kinds of inhalation anesthesia drugs.