The Effects of Different Preoxygenation Techniques on Heart Rate and Blood Pressure Alterations in Patients Undergoing Electroconvulsive Therapy

Electroconvulsive therapy (ECT) is one the most common methods of treatment in many kinds of psychiatric disorders. Because of increased muscle contractions and subsequent increase in oxygen consumption and heart rate during ECT, preoxygenation and respiratory support are of the utmost importance. Therefore, we decided to investigate the effects of various methods of preoxygenation on hemodynamic changes in such patients. This was a clinical-trial study conducted on 64 patients under 25 years of age, undergoing ECT, randomly divided into three equal groups. The patients were preoxygented for 5 (first group) or 3 minutes (second group) through a basic facemask, or four deep breaths (third group) prior to the induction of anesthesia. Blood pressure, heart rate, and blood oxygen saturation (SPO2) were measured and recorded, and the mean values compared in each group, before preoxygenation, one minute after induction, and at 1, 5, and 10 minutes after seizure remission. Findings: The mean arterial pressure (MAP) at 1 minute after induction, and 1 and 5 minutes after seizure had the highest amounts in the third group and lowest in the first group, with statistically significant difference (P < 0.050). The heart rate 1 minute after induction, and 1 and 5 minutes after seizure had the highest amounts in the third group and the lowest in the first group, with statistically significant difference (P < 0.001). The mean seizure duration had the shortest period in the first group and longest period in the third group (P < 0.001). Preoxygenation, 5 minutes before ECT, caused a significant decrease in changes in blood pressure and heart rate. On the other hand, the arterial oxygen saturation in this group showed less decline than the other groups.