Comparison of low (1 L/min) with medium (2 L/min) flow anaesthesia using Desflurane:effects on Oxygen concentration, Desflurane consumption and recovery profile

Low flow anaesthesia is defined as any technique where the fresh gas flow is less than the alveolar ventilation.Low solubility inhalational anaesthetic agents and high precision monitoring techniques have enabled modern day anaesthesiologists to employ low flow anaesthesia on a daily basis.Therefore we planned to conduct this study to determine the efficacy of low flow Desflurane anaesthesia by comparing the effects of low flow Desflurane anaesthesia (1 L/min) with those of medium flow anaesthesia (2L/min) on Oxygen and Desflurane concentration, Desflurane consumption and recovery profile.

After obtaining approval from the institutional ethics committee, a randomised controlled study with two groups of patients(30 in each) of Low flow (1L/min) and Medium flow(2L/min) anaesthesia was conducted, comparing inspired and expired Oxygen and Desflurane concentrations, recovery profile of patients and Desflurane consumption between the two.

The parameters monitored in both the groups were heart rate, blood pressure, mean arterial pressure, pulse oximetry,nasopharyngealtemperature,capnography,inspired and expired concentrations of Oxygen, inspired and expiredconcentrationsof Nitrous oxide, inspiredand expired concentrations of Desflurane,minimum alveolar concentration, bispectral index,arterial blood gas analysis. Modified Aldrete score was used for assessing recovery profile and total Desflurane consumption was calculated.

Based on the values of the above mentioned parameters the statistical analysis shall be formulated using the student’s t test and a p value of <0.05 will be considered statistically significant.