During Inhalation Anesthesia with Sevoflurane Using LMA, Spontaneous Breathing is Feasible / 대한마취과학회지

ABSTRACT

BACKGROUND: Sevoflurane is used as an anesthetic agent is now commonly. Several studies have reported on the use of sevoflurane in spontaneous breathing patients. However none of these studies focused on spontaneous breathing under sevoflurane anesthesia with a laryngeal mask airway (LMA). The purpose of the present study was to assess the feasibility of spontaneous breathing during inhalation anesthesia using sevoflurane with an LMA. METHODS: We studied 50 patients undergoing elective upper/lower extremity surgery in which muscle relaxation was not required. All patients received thiopental sodium 5.5 mg/kg after glycopyrrolate 0.004 mg/kg premedication. They were allowed to breathe spontaneously after the insertion of an LMA under sevoflurane anesthesia. Ventilation was measured before induction and ventilatory variables of 3-4% sevoflurane were measured during spontaneous ventilation. Arterial blood gas analysis was also performed in both phases. RESULTS: During spontaneous breathing under sevoflurane anesthesia with LMA, tidal volume (TV) significantly reduced and respiration rate (RR) increased versus resting ventilation (P < 0.05). But, minute volume (MV) was not significantly different. PaCO2, HCO3-, total CO2, BE were all significantly increased (P < 0.05). CONCLUSIONS: It was concluded that spontaneous breathing can be maintained during clinical depth sevoflurane inhalation anesthesia in patients without a cardiopulmonary abnormality.