VENTILATION DURING TOTAL INTRAVENOUS ANESTHESIA WITH KETAMINE

Total intravenous anaesthesia with ketamine (TIVAK) is widely used thr oughout the world especially in precarious conditions. Although ketami ne is usually considered to provide good respiratory function and may be used with spontaneous ventilation, recent studies have shown that d esaturations may occur Seventy-six adults and 64 children scheduled fo r peripheral surgery were randomly allocated to breathe spontaneously room air or 40% oxygen during TIVAK. Pulse oximetry was continuously a ssessed during anaesthesia and recovery. Desaturation (SpO(2) < 92%) o ccurred immediately after induction in 20 adults breathing air and in only three adults breathing oxygen (P < 0.05). Respiratory abnormaliti es were sufficiently severe to warrant tracheal intubation in two pati ents. Desaturations were not observed during the recovery period. Very similar results were observed in children although desaturations obse rved after induction in paediatric patients breathing room air were le ss frequent than in adults occurring in only nine patients. These desa turations were also less severe and never required tracheal intubation . The high incidence of arterial desaturation observed immediately aft er induction of anaesthesia with intravenous ketamine should prompt an aesthetists to provide oxygen in every adult patient at least for the first 15 min. The large decrease in SpO(2) sometimes observed requires that trained personnel be present and that equipment for tracheal int ubation be available.