Intravenous ketamine attenuates arterial pressure changes during the induction of anaesthesia with propofol

Background and objective To investigate whether the administration of ketamine before induction with propofol produces a smaller decrease in arterial pressure. Methods Twenty-two patients were assigned to one of two groups to receive either propofol with ketamine (n = 11) or propofol alone (n = 11, control). Anaesthesia was induced with 2 mg kg−1 propofol and 0.5 mg kg−1 ketamine or 2 mg kg−1 propofol alone. Ketamine was administered 1 min prior to induction with propofol. Immediately after induction with propofol, vecuronium (0.15 mg kg−1) was administered. Four minutes after administration of vecuronium, tracheal intubation was performed. Anaesthesia was maintained using sevoflurane (0.5%) in 66% nitrous oxide until 3 min after intubation. Systolic, diastolic and mean arterial pressure and heart rate were recorded on arrival, directly before induction with propofol, prior to tracheal intubation, immediately after intubation and at 3 min after intubation. Results and conclusions Administration of ketamine before induction with propofol preserved haemodynamic stability compared with induction with propofol alone.