Background and objective: Total intravenous anaesthesia (TIVA) with ketamine-midazolam (KM) can be used for prolonged abdominal surgery. We compared this technique with halothane-nitrous oxide-oxygen anaesthesia using haemodynamic and endocrine stress responses as primary outcomes and adequacy of operating conditions and recovery profile as secondary outcomes.
Methods: Fifty adult patients undergoing radical cystectomy and bladder substitution were randomly assigned to receive either TIVA with KM (n = 25) or halothane, nitrous oxide and oxygen anaesthesia (n = 25). Invasive haemodynamic and oxygenation variables were monitored along with plasma cortisol and growth hormone concentrations. Operative conditions and recovery profiles were registered.
Results: Cardiac index and vascular resistance remained stable during and after surgery. Cortisol concentrations doubled during surgery and remained elevated in the recovery period. Growth hormone increased after induction, peaked during surgery and decreased during recovery. Neither the haemodynamic variables nor the plasma hormone concentrations differed significantly between the two groups. Intestinal loops were collapsed in the KM groups providing better operative conditions and a reduced need for postoperative analgesics.
Conclusions: The stress responses during KM anaesthesia for prolonged abdominal surgery were comparable to those during halothane-nitrous oxide-oxygen anaesthesia. However, KM anaesthesia provided better surgical conditions and better recovery.