Objective:
Desflurane causes sympathetic stimulation at high end-tidal concentrations. We conducted this study to compare the haemodynamic response to inhalational bolus with desflurane in normotensive and hypertensive patients undergoing laparoscopic cholecystectomy.
Methods:
In this prospective, clinical trial, 40 patients aged 18-60 years and undergoing laparoscopic cholecystectomy were divided into normotensives (Group N; n=20) and hypertensives (Group H; n=20). Heart rate (HR), mean arterial pressure (MAP) and bispectral index (BIS) were measured at baseline and every 60 s for 5 min after induction, intubation, initiation and inhalational bolus of desflurane. The primary objective was to compare haemodynamic response, and the secondary objective was to assess the need for inhalational boluses and to compare the number of overcorrections and undercorrections in BIS value after each inhalational bolus. An independent t-test was used to compare the means of the study parameters between the groups, and a dependent t-test was used to compare the percentage change in the means of the study parameters within the same group. Statistical significance was defined as p<0.05.
Results:
No statistically significant difference in the percentage of patients responding with a decrease, increase or no change of HR or MAP were seen between the two groups after inhalational bolus of desflurane. An overcorrection of BIS (value <45) was seen in 60% of the patients in Group H and 15% of the patients in Group N (p=0.003). None of the patients in either group had an undercorrection (BIS>55).
Conclusion:
BIS-guided desflurane administration and BIS-triggered inhalational boluses of desflurane is safe, feasible and does not cause sympathetic stimulation in either normotensive or hypertensive patients.
Keywords: Anaesthetics inhalational, bolus, cardiovascular effects, complications, desflurane