The impact of bolus versus continuous infusion of intravenous ketamine on bispectral index variations and desflurane administration during major surgery: The KETABIS study

The objective of this study was to compare the impact of intravenous ketamine (given either as a continuous infusion or as a bolus) on BIS and to compare desflurane administration and postoperative outcomes between the groups. DESIGN Prospective, randomised, parallel-group, open-label study. SETTING University hospital, operating room. PARTICIPANTS Fifty patients, scheduled for major abdominal surgery. INTERVENTIONS AND MAIN OUTCOMES MEASURES Patients were randomised into two groups: ketamine by intravenous continuous infusion – group (KI) and ketamine by i.v. bolus – group (KB). In the KI group, ketamine at a rate of 0.25 mg kg−1 h−1 was commenced at skin incision (T0) and maintained at this rate for the duration of surgery. In group KB, a ketamine bolus of 0.25 mg kg−1was administered at T0 and repeated every hour. The difference in BIS between the groups was compared from T0 onwards. The amount of desflurane administered to keep BIS within the usual recommended range (40–60) was compared, as were the doses of phenylephrine and remifentanil. Postoperative pain and recovery outcomes were also assessed. RESULTS After T0, the BIS increased significantly from baseline in group KB compared with group KI: the rise in BIS was 20 ± 8 vs. 11 ± 6, respectively (P = 0.0001). The between-group mean difference (95% confidence interval (CI), was 9 (5 to 13). In group KB, desflurane administration significantly increas...
Source: European Journal of Anaesthesiology - Category: Anesthesiology Tags: Anaesthesia Source Type: research