Uterotonic Medications: Oxytocin, Methylergonovine, Carboprost, Misoprostol.

Uterine atony is a common cause of primary postpartum hemorrhage, which remains a major cause of pregnancy-related mortality for women worldwide. Oxytocin, methylergonovine, carboprost, and misoprostol are commonly used to restore uterine tone. Oxytocin is the first-line agent. Methylergonovine and carboprost are both highly effective second-line agents with severe potential side effects. Recent studies have called into question the effectiveness of misoprostol as an adjunct to other uterotonic agents, but it remains a useful therapeutic in resource-limited practice environments. We review the current role these medications play in the prevention and treatment of uterine atony.

The median local analgesic dose of intrathecal bupivacaine with hydromorphone for labour: a double-blind randomized controlled trial.

PURPOSE: Neuraxial hydromorphone has been reported to provide rapid onset of labour analgesia, effective segmental pain relief, and a longer duration of action than commonly used lipophilic opioids. This study was conducted to test the hypothesis that intrathecal hydromorphone reduces the dose requirement for intrathecal bupivacaine to induce rapid analgesia for women in the first stage of labour. METHODS: In this double-blind randomized controlled sequential allocation trial, 88 labouring parturients received combined spinal-epidural analgesia at 2-6 cm cervical dilation. Participants received intrathecal bupivacaine alone or bupivacaine plus hydromorphone 100 µg with the bupivacaine dose determined using up-down sequential allocation. An effective dose was defined as a visual analogue pain score of ≤10 mm (on a 100-mm pain scale) reported within 20 min of injection. The median effective doses were calculated using the formula of Dixon and Massey and verified using isotonic regression. RESULTS: A decrease was observed in the median local analgesic doses (effective dose [ED50]) estimated according to the formulas of Dixon and Massey, with a between-group difference of -0.45 mg. The precision of the estimate was wide-ranging (95% confidence interval -1.23 to 0.33), so no definitive conclusion can be drawn. CONCLUSION: Further research is needed to determine whether or not intrathecal hydromorphone 100 µg changes the dose of intrathecal bupivacaine required to induce labour analgesia within 20 min. TRIAL REGISTRATION: The trial was conducted in 2007 prior to widespread acceptance of the standard for clinical trial registration.

Less is more: the recent history of neuraxial labor analgesia.

Labor analgesia researchers have pursued better and safer ways to provide pain relief in labor. Although some pharmacologic investigations have focused on alternative mechanisms to target and medications to employ, a large part of the recent obstetric anesthesiology literature has contributed toward the safety and efficacy of techniques dependent on traditional therapeutics, specifically local anesthetics given through a neuraxial anesthetic technique. Investigators have worked to demonstrate and remove doubts that neuraxial anesthesia can be a safe method of labor analgesia. Pharmacodynamic studies during the last 3 decades have revealed ways to achieve adequate analgesia with minimal doses and correspondingly minimal risks. Dose-sparing opiate adjuncts to local anesthetics are now commonplace. To avoid excessive dosages, clinical up-down sequential allocation experiments identified the minimum amounts of local analgesia needed. Modifications to the administration of drug allowed total doses to be further reduced. This historical overview highlights some of these important advances in the present and recent past of neuraxial labor analgesia, and it traces how desired outcomes are being achieved with less and less total drug.