Abstract

Background: Laryngeal Mask Airway (LMA) is a useful advent in the airway management, filling a niche between the face mask and the tracheal tube in terms of both the anatomical position and the degree of invasiveness. Propofol is an intravenous anesthetic agent which depresses both laryngeal and pharyngeal reflexes and provides profound relaxation of pharyngeal muscles. Incidences of gagging coughing, laryngospasm are less while using propofol than thiopentone. Sevoflurane is pleasant smelling, non-irritating to the airway, has a low blood gas solubility coefficient, good muscle relaxant effect, and high inspired concentration can be given without side effects or discomfort. It allows rapid smooth inhalation induction with excellent recovery characteristics.
Objective: To compare the quality of the condition provided for successful LMA insertion by sevoflurane induction with propofol induction methods.
Materials and Methods: Study was carried out in 100 patients at the New Civil Hospital, Surat. Patients were randomly divided into 2 groups comprising of 50 patients each. In Group-P induction with propofol 3 mg/kg intravenously over 30 seconds and in Group-S induction have done with inhalational sevoflurane 8% and nitrous oxide 50% in oxygen.
Results: The mean pulse rate before induction in Group-P was 79.92±9.18 beats/min and in Group-S it was 80.96±10.11 beats/min, p>0.05. Following LMA insertion the mean pulse rate increased in both the groups. However, the mean pulse rate did not differ signifi - cantly between the groups at any time following LMA insertion, p>0.05. The mean systolic blood pressure before induction in Group-P was 119.92±9.44 mmHg and in Group-S it was 118.40±8.60 mmHg, p>0.05. Comparing the 2 groups, this difference was insignificant. Following LMA insertion the mean systolic blood pressure decreased but mean systolic blood pressure did not differ significantly on comparing both groups at any time following LMA insertion, p>0.05. The mean SPO % at baseline in Group-P was 99.54±0.89% and 2 in Group-S it was 99.72±12.7%, p>0.05. The mean time for cessation of verbal communication in Group-P was 32.9±7.07 seconds and in Group-S, it was 33.7±5.13 seconds. The mean time to successful LMA insertion in Group-P was 79.4±27.63 seconds and in Group-S, it was 128.5±19.46 seconds, p<0.001. Comparing the groups, the difference between both the groups was highly statistically significant. The mean time to successful LMA insertion was faster in Group-P compared to Group-S. In Group-P, in 40 (80%) patients, LMA insertion was done in the first attempt within the mean time of 68.12±12.14 seconds while in Group-S, in 32 (64%) patients, LMA was inserted in the first attempt within the mean time of 117.6±14.41 seconds. Comparing both groups, this difference was highly significant p<0.001. The second attempt was required in 8 (16%) patients in Group-P with the mean time of LMA insertion of 120.6 seconds compared to in 14 (28%) patients in Group-S with a mean time of LMA insertion of 143 seconds while comparing both the groups. Conclusion: From this study, we conclude that inhalation of sevoflurane is quite effective, reliable and safe for laryngeal mask airway insertion when compared with intravenous propofol induction. It maintains stable hemodynamic profile during induction, produces attenuation of laryngeal reflexes, and has a lower complication rate during LMA insertion.