Pulse oximetry during ketamine anaesthesia in war conditions

Ketamine anaesthesia with spontaneous breathing of air is a common method of anaesthesia in Red Cross hospitals for war wounded. Arterial oxygen saturation of 65 patients was measured with a portable pulse oximeter during the anaesthesia and the first 30 min of recovery. The patients were young (12-47 yr), haemodynamically stable and underwent peripheral surgery. Fifty-seven measurements were free from artefacts and were analyzed. The results showed that during induction six patients (11%) had a brief period (40-420 sec) of oxygen saturation under 90%. Two of these patients showed signs of upper airway obstruction and four breathed normally. During maintenance one patient had short periods (40-80 sec) of saturation under 90%, when he snored. No periods of desaturation occurred during the recovery period. It is concluded that arterial oxygen saturation remained acceptable when patients breathed air during ketamine anaesthesia.