Does nitrous oxide labor analgesia influence the pattern of neuraxial analgesia usage? An impact study at an academic medical center

Nitrous Oxide Use for Pain in Labor, Conversion to Neuraxial Anesthesia and Birth Outcome

INTRODUCTION

A variety of labor pain management options is essential to patients and their care providers. Inhaled, patient controlled nitrous oxide (N2O) is a valuable addition to these options. The purpose of this study was to examine laboring patient, newborn, and provider characteristics associated with N2O use for pain relief in labor and to examine the association between N2O, conversion to neuraxial analgesia, and cesarean birth.

METHODS

This was a retrospective observational cohort study of the first year of N2O use in one large academic medical center. Patients at least 37 weeks' gestation who were admitted for labor with intended vaginal birth from August 1, 2018, to June 30, 2019, were included (N = 2605). Laboring patient and newborn factors and their relationship to N2O use were calculated as unadjusted and adjusted relative risks (RRs). Poisson regression was used to model the association between N2O use and subsequent use of neuraxial analgesia and type of birth for both nulliparous and multiparous patients.

RESULTS

Overall, 20.2% of patients used N2O during labor. Multiparous patients were 24% less likely to use N2O than nulliparous patients (RR, 0.76; 95% CI, 0.69-0.84). Use of N2O did not differ significantly between patients cared for by midwives compared with patients cared for by physicians (RR, 0.95; 95% CI, 0.90-1.00). In multivariable modeling, N2O use in multiparous patients was associated with a 17% decrease in use of neuraxial analgesia (RR, 0.83; 95% CI, 0.73-0.94). There was no association between N2O use and use of neuraxial analgesia in nulliparous patients (RR, 0.99; 95% CI, 0.93-1.06). N2O use was not associated with cesarean birth in either group.

DISCUSSION

N2O is an important pain management option for laboring patients and those who care for them. Study results may assist midwives, physicians, and nurses in counseling patients about analgesia options.

A Comprehensive Review on the Efficacy of Nerve Blocks in Reducing Postoperative Anesthetic and Analgesic Requirements

The purpose of this article review is to investigate whether or not nerve blocks are beneficial in minimizing the amount of postoperative anesthetic and analgesic medication required, hence improving patient outcomes and reducing healthcare costs. This review investigates several different kinds of nerve blocks, their administration techniques, and the anatomical and physiological aspects that influence nerve block effectiveness. It analyzes the impact of nerve blocks on opioid use, postoperative pain scores, and the incidence of opioid-related adverse effects by compiling the findings of numerous large-scale, randomized, controlled trials. Infection, hematoma, nerve injury, and systemic toxicity are some potential complications of nerve blocks discussed in the article. It concludes with recommendations for optimizing nerve block techniques in clinical practice and identifies areas that require further research, such as the development of new anesthetics and the identification of patient subgroups that would benefit the most from nerve blocks. In addition, it provides recommendations for optimizing nerve block techniques in clinical practice.

The impact of withholding nitrous oxide in labour during the COVID-19 pandemic on maternal and neonatal outcomes

Nitrous oxide is commonly used in Australia for labour analgesia. Its use in labour is potentially associated with aerosol generation. During the first wave of the COVID-19 pandemic of 2020, nitrous oxide was suspended on many birthing units to reduce the risk of transmission. We aimed to determine the impact of withholding nitrous oxide for labour analgesia, during the COVID-19 pandemic, on epidural rates, opioid analgesia use, and maternal and neonatal outcomes. Withholding nitrous oxide for labour analgesia did not alter epidural rates but did significantly increase opioid analgesia use. Caesarean section rates, post-partum blood loss and neonatal APGAR scores did not change.

Pro-Con Debate: Nitrous Oxide for Labor Analgesia

This Pro-Con debate will provide the practitioner with an evidence-based knowledge approach to assist the clinician in determining whether to employ (Pro) or not to employ (Con) this technique in the obstetrical suite for labor analgesia. Nitrous oxide has been used safely in dentistry and medicine for many centuries. However, accumulating preclinical and clinical evidence increasingly suggests previously unrecognized adverse maternal and fetal effects of nitrous oxide, which warrants reconsideration of its use in pregnant women and a more detailed informed consent. Nitrous oxide is associated with metabolic, oxidative, genotoxic, and transgenerational epigenetic effects in animals and humans that may warrant limiting its usefulness in labor. This debate will discuss and review the clinical uses, advantages, and disadvantages of nitrous oxide on occupational effects of nitrous oxide exposure, neuroapoptosis, FDA warning on inhalational anesthetics and the developing brain, research limitations, occupational exposure safety limits, effects on global warming, and potential for diversion.

Nitrous Oxide Utility in Labor and Birth: A Multipurpose Modality

The use of nitrous oxide (N2O) for labor and birth has very recently emerged as a viable modality in the United States, despite a long history of use in Canada and Europe. Usually associated with dental procedures, there are significant differences between dental and parturition utility, efficacy, and staff exposure. In addition to using it for pain relief and anxiolysis, those centers utilizing it have noted it to be multipurpose and useful for such situations as: external cephalic version, manual removal of placenta, intravenous starts, during placement of urinary catheters and intracervical Foley bulbs. Nitrous oxide has proven to be especially helpful for repair of lacerations under local anesthesia and is a multiuse modality that should be available to women in all birth settings. This article explores the history of N2O use, provides a comparison of obstetrical use to use in the dental industry, examines the contraindications to, and implications for usage, and discusses logistical points of consideration for clinicians working with women using N2O for labor and birth.