Maintenance of oxygenation during total intravenous anaesthesia with ketamine while breathing air.

OBJECTIVE

To determine the variation in arterial oxygen saturation during intravenous ketamine anaesthesia while breathing air.

DESIGN

Prospective study.

SETTING

General Hospital, Anuradhapura.

PATIENTS AND METHOD

65 patients of both sexes between the ages 10 to 60 years scheduled for minor surgery lasting five to 15 minutes were selected. Anaesthesia was induced with intravenous diazepam and ketamine and patients were allowed to breathe air.

MEASUREMENTS

Arterial oxygen saturation, respiratory rate, degree of analgesia both during and one hour after surgery, incidence of nausea, vomiting and hallucinations after recovery were recorded.

RESULTS

Five patients (7.6%) showed a fall in oxygen saturation to less than 90%. Three of them had airway obstruction and the other two were obese. Nausea and vomiting occurred in eight patients (12%). Hallucinations were noted in five patients (7%). Postoperative analgesia was present one hour after surgery in 54 patients (83%).

CONCLUSION

Young and otherwise healthy patients maintained normal oxygen saturation while breathing air provided airway patency is maintained. However, facilities for administration of oxygen, intubation and ventilation should be available during ketamine anaesthesia.