The Effect of Midazolam, Fentanyl and a Small Dose of Etomidate for Prevention of Myoclonus during Induction of Anesthesia with Etomidate / 대한마취과학회지

BACKGROUND: The hypothesis that subcortical disinhibition is the reason for etomidate-induced myoclonus suggest that drugs acting on the subcortical area may reduce myoclonus. To verify the hypothesis, premedication with placebo, etomidate of a small dosage, midazolam and fentanyl were compared. METHODS: Sixty ASA physical status I or II patients undergoing elective surgery were allocated into four groups. All groups were induced with etomidate 0.3 mg/kg and vercuronium 0.1 mg/kg and maintained with 50% N2O and 1.5-2% enflurane. Group I (n = 15) received normal saline 3 ml 5 minutes before the etomidate 0.3 mg/kg administration, group II (n = 15) received 0.05 mg/kg etomidate 50 seconds before the etomidate 0.3 mg/kg administration, group III received midazolam 0.05 mg/kg 5 minutes before the etomidate 0.3 mg/kg and group IV received 2 microgram/kg fentanyl 5 minutes before the etomidate 0.3 mg/kg. In all patients, the grade, starting time, maintenance time of myoclonus and vital signs were checked and compared between the four groups. RESULTS: In group IV, myoclonus did not develope except in one patient and there were no differences in the incidence of myoclonus between the others. All premedicating drugs do not affect vital signs. CONCLUSIONS: We find that fentanyl reduces the incidence of etomidate-induced myoclonus but midazolam and a small dose of etomidate are not effective.

General Anesthesia for Emergency Cesarean Section in a Patient with Severe Aortic Stenosis / 대한마취과학회지

A 34-year-old female underwent emergency cesarean section with general anesthesia. The patient was a para 1-0-0-1, referred at 39 weeks in labor with known severe aortic stenosis due to a bicuspid aortic valve. She has been treated with digoxin and furosemide for 5 years. At first, she tried a normal spontaneous vaginal delivery, but dyspnea was aggravated during delivery, so an emergency operation was decided. Anesthesia was induced using ketamine 80 mg, fentanyl 50 microgram and vecuronium 6 mg and maintained with 50% nitrous oxide in oxygen. After fetal delivery and infusion of oxytocin, the systolic blood pressure decreased to 60 mmHg or less, so we injected phenylephrine 100 microgram bolus. However, the blood pressure did not increase, so we injected phenylephrine continuously ( 0.5 microgram/kg/ min). One month postpartum, echocardiography was done. The left ventricle-aortic pressure gradient was 140 mmHg, so the cardiologist recommended an aortic valve replacement operation. She refused the operation and has been medicated with digoxin and furosemide up to date.