Nitrous Oxide and Neuraxial Labor Analgesia Use on Maternal Fetal Outcomes (NOLA)

Evaluation of Maternal and Fetal Outcomes Following Nitrous Oxide and Neuraxial Labor Analgesia

The purpose of this study is to evaluate maternal and neonatal outcomes in parturients who used nitrous oxide and neuraxial labor analgesia during labor.

Study Overview

• Status: Withdrawn
• Conditions: Pregnancy
• Intervention / Treatment: Drug: Nitrous Oxide; Procedure: Neuraxial analgesia

Detailed Description

The use of nitrous oxide during labor is common in several countries including the United Kingdom, Finland, Canada, Australia and New Zealand.1, 2 The use of nitrous oxide during labor has undergone a resurgence in popularity recently in the United States and became available at Brigham and Women's hospital in August 2014.

Inhaled nitrous oxide has a rapid onset (30-50 seconds) and clearance with a half-life of about 5 minutes.3 It can be used for analgesia during the first, second and third stages of labor, as well as during post-delivery procedures such as laceration repair, manual removal of the placenta, and uterine curettage. It is also commonly used to facilitate the initiation of epidural analgesia.4 At the Brigham and Women's Hospital, a pneumatically driven gas mixer is designed to deliver a 50% oxygen and 50% nitrous oxide mixture to patients. Nitrous oxide passes readily across the placenta, and reaches equilibrium within a few minutes; the fetal maternal concentration ratio after 2 minutes of inhalation is 0.64.5 Hence, when administered at 50% concentration to the mother, the fetal concentration approximates at 32%.

Despite its long track record of maternal safety reported in numerous countries, the effect of nitrous oxide on the fetus is less well-studied. A number of studies have published data on the use of nitrous oxide for labor analgesia, including the effectiveness in labor analgesia, maternal satisfaction and maternal fetal adverse effects. Most of these studies have not identified adverse neonatal outcomes. However, these studies used Apgar scores or neonatal behavior scores as outcome measures and the quality of these studies was predominately poor.

The purpose of this study is to evaluate maternal and neonatal outcomes in parturients who used nitrous oxide and neuraxial labor analgesia during labor.

• Study Type: Observational

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (ADULT, OLDER_ADULT)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: Female

• Sampling Method: Non-Probability Sample

Study Population

Pregnant patients requesting for pain relief with neuraxial analgesia and/or nitrous oxide

Description

Inclusion Criteria:

• Pregnant patients requesting for pain relief with neuraxial analgesia and/or nitrous oxide
• health patients with no comorbidities
• singleton, vertex gestation at term

Exclusion Criteria:

• Refuse informed consent
• evidence of anticipated fetal anomalies
• significant medical or pregnancy-related diseases

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
neuraxial analgesia only; Receiving neuraxial analgesia only for labor	Drug: Nitrous Oxide; Nitrous Oxide Inhalational Agent
NO2 and neuraxial analgesia; Receiving nitrous oxide and neuraxial analgesia for labor	Drug: Nitrous Oxide; Nitrous Oxide Inhalational Agent; Procedure: Neuraxial analgesia; Epidural Labor Analgesia Placement; Other Names: Epidural placement

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Fetal and Neonatal Outcomes	Presence of Apgar Score < 7 (0-10)	At 1 minute following birth
Fetal and Neonatal Outcomes	Presence of Apgar Score < 7 (0-10)	At 5 minutes following birth
Fetal and Neonatal Outcomes	Presence of Apgar Score < 7 (0-10)	At 10 minutes following birth

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Maternal Outcome	Visual Analogue Score (0-10)	During Labor at 90 minute intervals
Maternal Outcome	Conversion to Alternative Analgesia Method (Neuraxial or General Anesthesia)	Any Time During Labor
Maternal Outcome	Mode of Delivery (Vaginal or Cesarean Delivery)	At Delivery

Collaborators and Investigators

• Sponsor: Brigham and Women's Hospital

Study record dates

Study Major Dates

• Study Start (ACTUAL): July 1, 2016
• Primary Completion (ANTICIPATED): July 1, 2018
• Study Completion (ANTICIPATED): July 1, 2018

Study Registration Dates

• First Submitted: January 21, 2017
• First Submitted That Met QC Criteria: March 23, 2021
• First Posted (ACTUAL): March 24, 2021

Study Record Updates

• Last Update Posted (ACTUAL): March 24, 2021
• Last Update Submitted That Met QC Criteria: March 23, 2021
• Last Verified: March 1, 2021

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Central Nervous System Depressants; Peripheral Nervous System Agents; Analgesics; Sensory System Agents; Anesthetics, General; Anesthetics; Analgesics, Non-Narcotic; Anesthetics, Inhalation; Nitrous Oxide
• Other Study ID Numbers: NOLA

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO