Purpose: Analgesia and sedation, routinely used as adjunct medications for regional anesthesia, are rarely used in the pregnant patient because of concerns about adverse neonatal effects. In an effort to obtain more information about maternal analgesia and sedation we studied neonatal and maternal effects of iv fentanyl and midazolam prior to spinal anesthesia for elective Cesarean section.
Methods: In this double-blinded, randomized, placebo-controlled trial, 60 healthy women received either a combination of 1 microg x kg(-1) fentanyl and 0.02 mg x kg(-1) midazolam intravenously or an equal volume of iv saline at the time of their skin preparation for a bupivacaine spinal anesthetic. Sample size was based on a non-parametric power analysis (power > 0.80 and alpha = 0.05) for clinically important differences in Apgar scores. Fetal outcome measures included Apgar scores, continuous pulse oximetry for three hours, and neurobehavioural scores. Maternal outcomes included catecholamine levels, and recall of anesthesia and delivery.
Results: There were no between-group differences of neonatal outcome variables (Apgar score, neurobehavioural scores, continuous oxygen saturation). Mothers in both groups showed no difference in their ability to recall the birth of their babies.
Conclusions: Maternal analgesia and sedation with fentanyl (1 microg x kg(-1)) and midazolam (0.02 mg x kg(-1)) immediately prior to spinal anesthesia is not associated with adverse neonatal effects.