Comparison of Tidal Volume Breathing and Deep Breathing Preoxygenation Techniques for a Cesarean Section / 대한마취과학회지

BACKGROUND: Preoxygenation is routine prior to rapid sequence induction of general anesthesia for a cesarean section. The aim of this study was to evaluate the preoxygenation techniques of tidal volume breathing (TVB) and deep breathing (DB) for a cesarean section. METHODS: One hundred twenty ASA I and II patients scheduled for a cesarean section under general anesthesia participated in the study. Preoxygenation was performed with 5, 7, and 10 L/min 100% oxygen. The following techniques were tested: 1) normal TVB for a 5-min period (TVB/5 min) and 2) DB for a 2-min period (4 DB/0.5 min, 8 DB/min, 12 DB/1.5 min and 16 DB/2 min). Inspired (FIO2) and end-tidal oxygen fraction (FETO2), end-tidal carbon dioxide pressure (ETCO2) and oxygen saturation (SpO2) were measured at 0.5-min intervals. RESULTS: During TVB, FETO2 increased rapidly between 0.5 and 3.5 min and plateaued by 3.5 min at 78.5%, 83.3% and 90.8% with 5, 7 and 10 L/min 100% oxygen, respectively. Four DB/0.5 min increased FETO2 to 64.7%, 67.2% and 72.3% at 5, 7, and 10 L/min 100% oxygen, respectively. As compared with four DB/0.5 min, the values of FETO2 with TVB/1.5 min and TVB/2 min were high at 7, 10 and 5 L/min 100% oxygen. CONCLUSIONS: We concluded that TVB/2 min was more effective than four DB/0.5 min in achieving preoxygenation but eight DB/min could be used in case of an emergent operation.

Effect of Midazolam, Fentanyl and Propofol for Intravenous Anesthesia in Patients Undergoing the Cardioversion / 대한마취과학회지

BACKGROUND: Elective cardioversion is a short procedure performed under amnesia, sedation or anesthesia for the treatment of cardiac dysrhythmia. Midazolam, fentanyl and propofol on hemodynamic changes and side effects were studied. METHODS: Thirty patients scheduled for an elective cardioversion in the coronary care unit received propofol 500microgram/kg I.V., followed by a continuous infusion with 25 75microgram/kg/min until they lost consciousness as determined by cessation of response to verbal command. All patients received midazolam 0.02 mg/kg and fentanyl 2microgram/kg I.V. 5 minutes before induction. In addition, the cardiologist administrated the electric shock. Blood pressures and heart rates were measured prior to induction, after the administration of midazolam and fentanyl, after cardioversion, 5 minutes after cardioversion and recovery. The recovery time from terminating drug administration to awakening, and the total dose of propofol were recorded. Patients were observed for side effects. RESULTS: Systolic, mean, and diastolic blood pressures were significantly decreased 5 minutes after cardioversion and recovery. Heart rates were significantly decreased after cardioversion, 5 minutes after cardioversion and recovery. Recovery times were 22.1 14.9 minutes and the total dose of propofol was 0.79 0.39 mg/kg. Incidence of apnea (> 30 s) was 30%. CONCLUSIONS: We concluded that midazolam, fentanyl and propofol in patients undergoing an electric cardioversion decreased blood pressure and heart rate, but the cardiovascular status was maintained within clinically acceptable levels.