Abstract and Introduction
Obstetric anesthesia has evolved over the course of its history to encompass comprehensive aspects of maternal care, ranging from cesarean delivery anesthesia and labor analgesia to maternal resuscitation and patient safety. Anesthesiologists are concerned with maternal and neonatal outcomes, and with preventing and managing complications that may present during childbirth. The current review will focus on recent advances in obstetric anesthesia, including labor anesthesia and analgesia, cesarean delivery anesthesia and analgesia, the effects of maternal anesthesia on breastfeeding and fever, and maternal safety. The impact of these advances on maternal and neonatal outcomes is discussed. Past and future progress in this field will continue to have significant implications on the health of women and children.
Obstetric anesthesiology has historically bridged multiple disciplines including obstetrics, maternal-fetal medicine, neonatology, general surgery, and anesthesiology. Virginia Apgar, a surgeon turned obstetric anesthesiologist, is best known for her namesake neonatal assessment scoring system. She is widely credited for early advances in neonatology. Her contributions exemplify how obstetric anesthesiologists sought answers to scientific questions about anesthetic effects on the mother, fetus, and neonate. Early investigations focused on the use of volatile agents for labor anesthesia, shifted to opioids and amnestics, and then to neuraxial techniques. Studies focused on the effects of these interventions on labor and the newborn.
The "birth" of obstetric anesthesia began with the introduction of ether labor analgesia by obstetrician James Young Simpson in 1847. While Simpson publicized this intervention as effective and innovative, he expressed reservations about its unknown effects on labor and the fetus. The medical community expressed concerns about safety and toxicity. Women's rights to request and receive labor pain relief was controversial—religious mores of the nineteenth century viewed pain, including labor pain, as divine punishment, and interference was considered sinful. Ultimately, the clinical use of ether and chloroform for labor analgesia was not driven by the scientific community, but by a shift in the social attitudes of patients who demanded it, persuaded by public rhetoric from feminist advocates. In the early twentieth century, "twilight sleep," a combination of morphine and scopolamine, became common, but was ultimately abandoned due to its depressant effects on the neonate. In the mid-twentieth century, general anesthesia for cesarean delivery gave rise to airway complications, including failed tracheal intubations, maternal aspiration, and Mendelsohn syndrome (aspiration pneumonitis). Anesthesiologists began focusing their efforts on reducing anesthesia-related adverse maternal and neonatal outcomes, including airway-associated morbidity and mortality. As a result, neuraxial labor anesthesia became increasingly used by the 1980s, although it was simultaneously feared to be a risk factor for cesarean delivery. Fortunately, most concerns were resolved by rigorous research, and by refining regional anesthesia approaches. Advances that led to reductions in anesthesia-related maternal morbidity and mortality included the use of an epidural test dose, incremental epidural injection of local anesthetic, elimination of bupivacaine 0.75% for epidural anesthesia, and lipid emulsion therapy for local anesthetic systemic toxicity. Past and ongoing research in obstetric anesthesiology has contributed to a substantial reduction of anesthesia-related maternal mortality.
Obstetric anesthesiologists have contributed to interdisciplinary initiatives advancing maternal safety (Figure 1). Randomized control trials and impact studies improved understanding that neuraxial labor analgesia does not independently influence the risk for cesarean delivery. Postpartum pain management has improved, and multimodal strategies have been enhanced such that analgesic efficacy is maximized while maternal and fetal side effects are minimized. Anesthesia effects on lactation, maternal fever, neonatal acid-base status, and cognitive development continue to be explored. Safer care systems emphasize low-dose neuraxial anesthesia, hemorrhage preparedness and management, and team crisis simulation. In this review, we focus on obstetric anesthesia advancements over the last two decades, with emphasis on the past decade. Continuing progress will have important consequences to obstetric medicine, anesthesiology, and perioperative patient care.
Subject areas of obstetric anesthesiology research advancements on maternal and neonatal outcomes over the last decade. Bubble size indicates relative publication volume of each topic. Topic list is not comprehensive.
Anesthesiology. 2018;129(1):192-215. © 2018 American Society of Anesthesiologists | Lippincott Williams & Wilkins