Comparison of the effects of laryngeal and face masks on arterial oxygen saturation and duration of convulsion in patients undergoing electroconvulsive therapy

Hypoxia following electroconvulsive therapy(ECT) causes hemodynamic instability and increases the threshold of convulsion. In this study we evaluated the effects of laryngeal and face masks ventilation on oxygen saturation, hemodynamic changes and duration of convulsion after ECT. Sixty-six patients with chronic depression aged 20-60 scheduled for ECT were randomly divided into two groups of 33. In both groups anesthesia was induced with intravenous sodium thiopental 2 mg/kg and succinylcholine 0.5 mg/kg. Ventilation with %100 oxygen was carried out by laryngeal mask in group I and face mask in group II. Systolic and diastolic blood pressures, heart rate, oxygen saturation and convulsion duration before and after ECT in all patients were measured and recorded. Oxygen saturation after ECT was higher in group I compared with group II (p<0.05). In both groups systolic and diastolic blood pressures 3 and 5 min after ECT were higher than those before ECT. Increased diastolic blood pressures 3 and 5 min after ECT, and systolic blood pressure 3 min after ECT were higher in group I (p<0.05). The duration of convulsion in group II (38.8 ± 11 seconds) was longer than that in group I (30.2 ± 11 seconds) (p<0.05). the results of the current study revealed that laryngeal mask decreases convulsion duration and increases oxygen saturation during ECT so it is recommended that ventilation to be performed by laryngeal mask rather than the face mask.