RESUMEN
Background: Although nitrous oxide (N2O) has been used since the 1880s for labor analgesia, its popularity has only recently increased in the United States. In 2011, only 3 centers in the country offered N2O, but as of 2020, several hundred labor units have adopted its use. Methods: We reviewed the literature and summarize the mechanism of action, clinical uses, and efficacy of N2O for labor analgesia, as well as patient satisfaction related to its use. Results: N2O has several proposed mechanisms of action that make it a viable option for all 3 stages of labor and postpartum procedures. N2O has been shown to be a safe option for both mom and baby during labor and delivery. Studies support N2O as an analgesic for laboring. Even though 40% to 60% of women who use N2O convert to a labor epidural analgesia, satisfaction surveys indicate that analgesia is not the only factor contributing to the use of N2O during labor. Conclusion: The use of N2O has increased in labor and delivery units across the United States since 2011. Despite inferior analgesic properties compared to epidural analgesia, N2O offers a safe alternative for many parturients who want a greater sense of control and mobility.
RESUMEN
A patient with Klippel-Feil syndrome, morbid obesity, and scoliosis required cesarean delivery. Her previous cesarean deliveries were performed under general anesthesia. She desired a regional technique. Following aspiration prophylaxis and placement of standard monitors, ultrasound was used to identify midline and L(2-3) interspace. Unintentional dural puncture occurred at 10 cm, with an inability to advance the catheter. On second attempt, an epidural catheter was placed easily. After negative test dose, 18 ml of 2% lidocaine with epinephrine was administered to the patient. A T4 level was achieved. The patient tolerated surgery well. Complete block resolution occurred at 4 hours with no neurologic sequelae.