ABSTRACT
Background: Entonox (Nitrous oxide in 50% oxygen) is commonly used for labor analgesia in obstetric units. During the pandemic uncertainties around the risk of aerosol generation and virus transmission led to withholding Entonox for women in labor for a 3-week period at our institution. We aimed to determine if withdrawing Entonox for labor analgesia impacted primarily on epidural rates, opioid analgesia use and several other secondary outcomes. Methods: The audit population included all women laboring during March 9-28 (the Entonox group), and March 29-April 16, 2020 (the COVID group). Women who delivered prior to, or within 30 mins of arriving on the birthing unit;as well as women with an intrauterine foetal death and those with incomplete clinical records were excluded. Binary outcomes were analysed using logistic regression and skewed continuous outcomes were logtransformed and analysed by linear regression. Models were adjusted for maternal and clinical risk factors, such as primiparity and induction of labor. Results: There were 122 and 121 women in the Entonox and COVID groups, respectively. Maternal demographics were similar between the groups (Table 1). Epidural requests were similar. Opioid use was significantly higher when Entonox was not available, but there were no significant differences in any maternal and neonatal outcomes (Table 2). Conclusion: Results from our study suggest that withholding Entonox in labor did not result in higher epidural rates. Opioid analgesia requirements were significantly increased. Withholding Entonox appeared safe and did not impact on any maternal and neonatal outcomes. (Figure Presented).