RESUMO
STUDY OBJECTIVE: To compare vital signs and the speed of induction and emergence with sevoflurane versus halothane in pediatric patients. DESIGN: Prospective, randomized, open study. SETTING: Thomas Jefferson University Hospital. PATIENTS: 40 unpremedicated ASA Physical Status I and II children age 9 months to 16 years undergoing elective inpatient otorhinolaryngologic or orthopedic surgery. INTERVENTIONS: Standardized induction of anesthesia with sevoflurane (start: 1%, maximum: 7%) or halothane (start: 0.5%, maximum: 5%) in nitrous oxide/oxygen (N2O/O2). Intubation following vecuronium and 4 minutes of controlled ventilation with 2 minimum alveolar concentration (MAC) drug in O2; 1.5 MAC drug in N2O/O2 delivered for 20 minutes; then 0.75 MAC until the end of surgery. Fentanyl 1 mcg/kg was administered 15 minutes before the anticipated end of surgery, at which time anesthetics were stopped and mechanical ventilation continued until eye opening (emergence). MEASUREMENTS AND MAIN RESULTS: Blood pressure, heart rate (HR), oxygen saturation, end-tidal gas concentrations, and temperature were recorded. Induction and emergence times were measured to the nearest second. Induction (loss of eyelash reflex) was faster with sevoflurane (97 +/- 31 sec) than halothane (120 +/- 36 sec; p < 0.05), despite a lower inspired sevoflurane MAC. Emergence was faster with sevoflurane (9.9 +/- 2.9 min vs. 12.5 +/- 4.7 min; p < 0.05), despite a higher MAC multiple of end-tidal sevoflurane concentration at the end of surgery. Following intubation, HR (compared with the preinduction value in the operating room) was significantly higher in the halothane group (136.8% +/- 16.3% vs. 115.0% +/- 25.6%), as was mean arterial pressure (113.2% +/- 25.5% vs. 87.8% +/- 22.6%). This finding corresponded with a higher MAC multiple of end-tidal concentration in the sevoflurane group than in the halothane group. CONCLUSIONS: Induction of and emergence from anesthesia was faster with sevoflurane than halothane. Airway complications were low in both groups. Vital signs were more stable with sevoflurane during induction through intubation, and were comparable during maintenance. Sevoflurane is an excellent drug for inhalational induction in pediatric patients.
