A Prospective Study of Single Breath Vital Capacity Inhalation Induction with High Concentration of Sevoflurane (Sbvc-Hc) for LMA Insertion in Adults for Short Surgical Cases

Abstract

Background: Sevoflurane is a new volatile anesthetic agent with rapid induction and recovery. A randomized study was carried to access conditions for LMA insertion using Sevoflurane in 25 ASA I & II patients undergoing short duration surgeries.Subjects and Methods:This prospective study was conducted at Department of Anesthesiology and Critical Care, SVS Medical College and Hospital, Mahabubnagar, Telangana, India. After obtaining the institutional ethics committee and written informed consent from the patients, 25 subjects of either sex were included in this study. Age of the subjects was 18 to 60 years. Patients received injection Fentanyl 1 – 2mcg/kg prior to induction. All patients were pre-oxygenated for 3 min with 100% oxygen using a fresh gas flow of 81/min. All patients received inhalational induction with 8% Sevoflurane and O2 flow at 8 L/min with single vital capacity breathe technique. Loss of verbal contact was considered as the desired endpoint for induction, which was assessed by the response to calling out the patient’s name. Then the time of loss of eyelash reflex and jaw relaxation was assessed by anesthesiologist. After adequate jaw relaxation, LMA insertion was attempted.Results:The mean loss of verbal contact was 65.40±9.67second, while the mean for time for loss of eyelash reflex and jaw relaxation were found to be 81.20±9.39 seconds and 103.20 ±12.07 seconds respectively. The mean time for LMA insertion was 122.00±15.61 and the mean attempts for successful LMA insertion was 1.12±0.33. LMA insertion was easy in 23 cases as against difficult in 2 cases. In 2 cases transient cough and biting were recorded. LMA insertion was excellent and satisfactory in 88.0 and 12 percent. However, the mean heart rate at 5 minute after induction showed a significant fall at 5 minutes after induction. The mean values of SBP, DBP and MAP did not differ significantly at pre and induction. However, a significant decrease in SBP was noticed at 1, 2 and at 5 minutes.Conclusion:Sevoflurane is an smooth inhalation anesthesia with rapid onset with adequate jaw relaxation for insertion of LMA in Adults for short duration surgeries. Sevoflurane has got good hemodynamic profile with lesser complications owing to choice of inhalation agent for insertion of LMA.