Ketamine in the treatment of bronchospasm during mechanical ventilation.

The effect of ketamine on bronchospasm during mechanical ventilation was evaluated in a prospective, placebo-controlled, double-blind trial. Fourteen mechanically ventilated patients with bronchospasm were randomly allocated to either ketamine 1 mg/kg or saline placebo. In the ketamine-treated patients, PO2 increased from 10.5 (+/- 0.5) kPa to 16.4 (+/- 2.7) kPa (P < .05), whereas PO2 in the placebo-treated patients remained unchanged. The PCO2 was constant in the ketamine group, although it increased from 5.6 (+/- 0.9) kPa to 6.1 (+/- 0.9) kPa in the placebo group (P < .05). The pulmonary stethoscopic bronchospasm improved immediately after the administration of ketamine, whereas the thoracic compliance remained unchanged. In conclusion, the ketamine-treated patients showed an improvement by stethoscopic examination, in PO2 and in PCO2, suggesting that ketamine might be useful in the treatment of bronchospasm during mechanical ventilation. However, further studies are required to decide whether ketamine should be considered the drug of choice in patients with severe bronchospasm during ventilator treatment.