Uterotonics and tocolytics for anesthesiologists.

PURPOSE OF REVIEW: Obstetric anesthesiologists are supposed to understand the uterotonics and tocolytics used in the perinatal period to provide a better clinical practice. This review describes current consensus of uterotonics and tocolytics used in the perinatal period that an obstetric anesthesiologist should know. RECENT FINDINGS: Rational use of uterotonics for cesarean section has been well studied in the past decades. Oxytocin remained as a first line uterotonics for cesarean section. For continuous infusion, it is reported that ED90 is higher for laboring parturients than for nonlaboring parturients (6.2 vs. 44.2 IU/h) implying that protocol for oxytocin infusion should be different between laboring patients with prior exposure to oxytocin and nonlaboring patients. For bolus administration, 'rule of three' has been proposed and its efficacy has been reported. When oxytocin fails to achieve sufficient uterine contraction, second-line agents must be administered, and it has been reported that methylergonovine is a superior second-line uterotonic to carboprost. On the other hand, the role of tocolytic agents in obstetric anesthesia has not been well studied. SUMMARY: Anesthesiologists involved in obstetric anesthesia should be able to determine the appropriate uterotonic for cesarean section and know the indication of tocolytics in perinatal period.

The use of intravenous nitroglycerin for cervico-uterine relaxation: a review of the literature.

The safety, predictability, and ease of intravenous administration of nitroglycerin (NTG) have been firmly documented. In recent years, intravenous NTG has come to the attention of the obstetrician as a potent uterine relaxant. Intravenous nitroglycerin has been used to relax the uterus during manual extraction of retained placenta and to permit replacement of a contracted, completely prolapsed, inverted uterus. The use of this agent as a tocolytic has previously been reported in cesarean delivery of twins, in cases of intra partum external cephalic version, and for internal intrapartum podalic version of the second twin. This new procedure was also used for fetal head entrapment after vaginal breech delivery. The authors report a review of the literature about this subject.