Prevention of etomidate-induced myoclonus: which is superior: Fentanyl, midazolam, or a combination? A Retrospective comparative study.

BACKGROUND: In this retrospective comparative study, we aimed to compare the effectiveness of fentanyl, midazolam, and a combination of fentanyl and midazolam to prevent etomidate-induced myoclonus. MATERIAL AND METHODS: This study was performed based on anesthesia records. Depending on the drugs that would be given before the induction of anesthesia with etomidate, the patients were separated into 4 groups: no pretreatment (Group NP), fentanyl 1 µg·kg-1 (Group F), midazolam 0.03 mg·kg-1 (Group M), and midazolam 0.015 mg·kg-1 + fentanyl 0.5 µg·kg-1 (Group FM). Patients who received the same anesthetic procedure were selected: 2 minutes after intravenous injections of the pretreatment drugs, anesthesia is induced with 0.3 mg·kg-1 etomidate injected intravenously over a period of 20-30 seconds. Myoclonic movements are evaluated, which were observed and graded according to clinical severity during the 2 minutes after etomidate injection. The severity of pain due to etomidate injection, mean arterial pressure, heart rate, and adverse effects were also evaluated. RESULTS: Study results showed that myoclonus incidence was 85%, 40%, 70%, and 25% in Group NP, Group F, Group M, and Group FM, respectively, and were significantly lower in Group F and Group FM. CONCLUSIONS: We conclude that pretreatment with fentanyl or combination of fentanyl and midazolam was effective in preventing etomidate-induced myoclonus.

A comparison of the effects of hyperbaric and isobaric bupivacaine spinal anesthesia on hemodynamics and heart rate variability.

AIM: To compare the effects of hyperbaric and isobaric bupivacaine spinal anesthesia on hemodynamics and heart rate variability (HRV) in nonobstetric surgery. MATERIALS AND METHODS: Sixty patients were randomly allocated to 2 groups. Group I (n = 30) received 15 mg (3 mL) of hyperbaric bupivacaine and Group II (n = 30) received 15 mg (3 mL) of isobaric bupivacaine for spinal anesthesia. Hemodynamic parameters were recorded before and after spinal anesthesia over 30 min. Analyses of HRV were performed on the day of surgery, after volume loading, and 20 min after spinal injection. Low frequency (LF) values, high frequency (HF) values, and LF/HF ratios were recorded. The incidences of hypotension and alterations of HRV parameters in both groups were investigated. RESULTS: The incidence ofhypotension was 26.6% and 23.3% in Groups I and II, respectively. There were no significant differences in the LF and HF values and LF/HF ratios between groups. In Group I, LF/HF ratios were significantly lower and HF values were significantly higher at 20 min after spinal anesthesia, in comparison to the baseline value (P < 0.05). CONCLUSION: Hyperbaric bupivacaine caused a significantly greater decrease in LF/HF ratios and a significantly greater increase in HF values.