A randomized prospective study comparing characteristics of Desflurane with Isoflurane under low flow anaesthesia using equilibration time

Introduction: Equilibration point of an inhalational agent is the transition point when ratio of expired (Fe) to inspired (Fi) concentration of inhalational anaesthetic agent (Fe/Fi) reaches 0.8 or when uptake of volatile agent reaches 80%. It helps in reducing the duration of initial high gas flows before switching over to low flows. Aim: To compare Desflurane with Isoflurane for equilibration time, intraoperative hemodynamic parameters and post extubation recovery parameters. Materials and Methods: Depending on the volatile anesthetic agent being used patients were randomly allocated into two groups. Group I (n =25) received Desflurane and Group II (n=25) received Isoflurane as inhalational anesthetic agent. In all patients low flow anaesthesia was given after achieving equilibration time and that time was noted. Other parameters measured were intraoperative heart rate, mean blood pressure, mean EtN2O, mean EtFe (End tidal volatile anesthetic agent concentration), recovery parameters (recovery time, recovery score and vitals) and any complications if any. Statistics: Analysis was performed on SPSS (Statistical package for social sciences) version 17.0 Statistical Analysis Software. Result: The equilibration point for group I was achieved in 2.18 ± 0.84 min and for group II was achieved in 10.08 ± 2.36 min and this difference was statistically significant. The intraoperative heart rate and MAP did not differ significantly (p>0.05) between the two groups at all time periods. On comparing, post extubation vitals i.e. HR (8.1%) and recovery time (69.9%) they were found significantly (p<0> Conclusion: Desflurane use results in shorter equilibrium time and earlier reduction of FGF with early and better recovery than Isoflurane.