Anaesthesia for videoarthroscopy of the knee. A comparison between desflurane and sevoflurane

The newer inhalational agents desflurane and sevoflurane have a low blood-gas partition coefficient and are not very fat soluble, and consequently recovery is rapid and smooth. Very few studies have been published concerning adults where a direct comparison has been made between sevoflurane and desflurane in the ambulatory setting.

This study was done to assess aspects of recovery following minor ambulatory videoarthroscopic knee surgery in 50 ASA I-II patients. Baseline values were obtained on the following psychomotor tests: digit symbol substitution test (DSST), perceptive accuracy test (PAT) and simple reaction time (SRT). The patients were then randomly allocated to one of two groups according to an open (unblinded) study design: Group D (Desflurane) were maintained on desflurane while Group S (Sevoflurane) were maintained on sevoflurane. Propofol was used as the induction agent in all patients and the larynx mask was used to maintain a free airway. Oxygen and air (FiO2 0.33) were used as the carrier gases. The concentration of desflurane or sevoflurane was adjusted in order to maintain adequate anaesthesia and stable haemodynamics. Alfentanil was given at induction and every 15 min as an analgesic. At the end of the operation, the gases were turned off abruptly and 100% oxygen was delivered at 6 L/min until eye-opening. Early recovery was measured by the time to eye-opening, giving name and date of birth. Intermediate recovery was measured by psychomotor testing every 30 min, and the time to sitting up in bed, drinking fluids and discharge home by a nurse who was blinded to the anaesthetic technique.

Early recovery was quicker in the desflurane compared to the sevoflurane group (P<0.001). Psychomotor recovery as measured by the PAT occurred significantly earlier in the desflurane compared to the sevoflurane group at 15 and 45 min (P<0.001) and as measured by the DSST at 30 min (P<0.05). The number of patients who could not perform the SRT test at 15 min was greater in the sevoflurane compared to the desflurane group (13 vs 0) (P<0.01). No differences were found in other recovery parameters, including home discharge, between the groups. The incidence of pain and other minor postoperative complications was similar between the groups except for sore throat which was higher in the desflurane group.

Early and intermediate (psychomotor) recovery is quicker in the desflurane compared to the sevoflurane group, but there is no difference in discharge times between the groups.