[Comparative study of the recovery phase. Laparoscopic cholecystectomy following isoflurane, methohexital and...

Total intravenous anaesthesia (TIVA) is increasingly used in short-stay surgery such as laparoscopic cholecystectomy. TIVA may provide fast recovery of psychomotor function, thus being of benefit to both the patient's behaviour and postoperative management. The purpose of this prospective study was to compare postoperative recovery from TIVA using propofol or methohexitone as the hypnotic component and balanced anaesthesia with isoflurane. PATIENTS AND METHODS. After giving informed consent and approval by the ethical committee of our hospital, 51 patients (ASA I, II) were investigated in a prospective study. Patients were randomised to receive either isoflurane, methohexitone, or propofol. Perioperative management with regard to premedication, intraoperative analgesia, relaxation, ventilation, and postoperative analgesia was carried out identically for all groups. Postoperative vigilance, pain, and nausea scores were assessed 15, 30, 60, 120, and 360 min after extubation with a visual analogue scale (VAS). At the same points, psychomotor recovery was investigated with the following assays: sedation as shown in Table 1; orientation with ten questions as to person, time, and location; memory as expressed by the patient's ability to repeat five words; a calculation test with five subtractions of the number 7 beginning from 100; and word generation by the number of words with an initial "m" given within 1 min and with animal names. Data were analysed with Kruskal Wallis' test for multiple comparisons between the groups and with Friedman's test for repeated measurements. All values are given as medians (interquartile range) or ranges. RESULTS. There was no difference between the groups' physical condition (Table 2). All intraoperative parameters compared well between groups; the management of anaesthesia was smoother with isoflurane than with the other anaesthetics. Psychomotor recovery was somewhat faster in the propofol group than the methohexitone group, as indicated by sedation score, orientation, memory and calculation tests (Table 4), word generation tests (Fig. 4), and subjective vigilance score (Fig. 3). The difference in recovery time between the propofol and isoflurane groups was minimal and without any significance or relevance. The incidence of postoperative nausea was significantly lower after balanced anaesthesia with isoflurane (24%, P < 0.05) as compared to TIVA with either propofol (53%) or methohexitone (41%). However, there were only minor differences between the groups; the ability to cooperate and be mobilised was not limited. DISCUSSION. Each of the three techniques used in this study is suitable for anaesthesia in patients undergoing laparoscopic cholecystectomy. Since fast recovery of vigilance and psychomotor function is very important in outpatient surgery, opioid-supplemented propofol anaesthesia is well established. Inhalation anaesthesia with isoflurane in air/oxygen without adding nitrous oxide compares well to propofol TIVA for laparoscopic surgery.