Pethidine Versus Nitrous Oxide for Pain Relief During Labor

Study Overview
=================
Brief Summary
-----------------
Systematic opioids and inhaled nitrous oxide (N2O ) are common methods for pain relief during labor. The aim of the current study is to evaluate the efficacy of systemic pethidine compared to N2O given for pain relieve in term, multiparous women in labor.

Detailed Description
-----------------
Pain relief during labor and delivery is an essential part of good obstetrical care. Labor pain and its relief have implications on the course of labor, maternal and fetal outcomes and the satisfaction with childbirth overall. Many women would like to have a choice in pain relief during labor but also would like to avoid invasive methods of pain management in labor (as epidural). Both, inhaled analgesia and parenteral opioids are common pharmacological interventions aim to relieve the pain of labor.Nitrous oxide in a 50/50 mix with oxygen is the most common concentration used for labor pain management. It is self-administered via facemask, intermittently, and has rapid onset and offset effect. Main side effects, including nausea, vomiting, dizziness and drowsiness. Pethidine is one of the most frequently used opiate agonists. It can be given intravenous or intramuscularly. Its analgesic effect starts within 10-20 minutes and lasts 2-4 hours. Reported maternal side effects include nausea, vomiting and dysphoria. Pethidine may lead to changes in fetal heart rate tracing during labor, respiratory depression, impaired sucking reflex and restlessness. Given the fact that these two routine interventions are given in different ways and have different side effects profile, the investigators aim in this randomized controlled trial to compare the analgesic effect of these two methods and their maternal and perinatal secondary effects in multiparous laboring women.

Official Title
-----------------
Pethidine Versus Nitrous Oxide for Pain Relief During Labor Among Multiparous. A Randomized Controlled Trial

Conditions
-----------------
Labor Pain

Intervention / Treatment
-----------------
* Drug: IV Meperidine
* Drug: Nitrous Oxide


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Multiparity (para 2 or more). Term pregnancy: 37-42 weeks of gestation. Singleton pregnancy. Vertex presentation. In labor: at least 2 contraction in ten minutes and cervical dilatation of 2 centimeters or more. Exclusion Criteria: Women who desire epidural as a first line analgesia during labor. Women receiving pethidine during the last 24 hours (prior to entering labor room). Contra-indication for vaginal delivery. Contra-indication or allergic reaction to either pethidine or nitrous oxide. History of drug abuse. Previous cesarean delivery.

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 45 Years

Sexes Eligible for Study
-----------------
Female

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: IV Meperidine<br>Intravenous injection of meperidine 50mg given in 100cc NaCl 0.9% over 10 minutes. Repeated doses (if needed) will be given in intervals of 2 hours minimum until a maximum of 4 doses. | Drug: IV Meperidine<br>* Intravenous meperidine 50mg in 100cc NaCl 0.9% . Repeated doses (if needed): intervals of 2 hours minimum until a maximum of 4 doses. In cases of nausea or vomiting intravenous metoclopramide 10mg will be offered to the parturient. If pain intensity (according to visual analogue scale), 20 to 30 minutes from administration, will not decline or the parturient will ask for a different type of analgesia, inhaled nitrous oxide or epidural analgesia will be offered.<br>* Other names: Pethidine;|
| Active Comparator: Inhaled Nitrous Oxide<br>Nitrous oxide in a 50/50 mix with oxygen given via self-administered face mask. The parturient will be advised to place the mask tightly on her face and to breathe through it at the first sign of forthcoming uterine contraction. Between contractions, the parturient will be advised not to breath through the mask. | Drug: Nitrous Oxide<br>* Nitrous oxide in a 50/50 mix with oxygen given via self-administered face mask. The parturient will be advised to place the mask tightly on her face and to breathe through it at the first sign of forthcoming uterine contraction. Between contractions, she will be advised not to breathe through the mask. In cases of nausea or vomiting intravenous metoclopramide 10mg will be offered to the parturient. If pain intensity (according to visual analogue scale), 20 to 30 minutes from administration, will not decline or the parturient will ask for a different type of analgesia, intravenous meperidine or epidural analgesia will be offered.<br>* Other names: N2O;|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pain intensity | Visual analogue scale | 20-30 minutes after drug administration. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pain intensity | Visual analogue scale | 60, 120 and 180 minutes from drug administration. | 
| Time from drug administration to labor. |  | 24 hours | 
| Need for additional analgesia | Number of women that needed additional analgesia. | 24 hours | 
| Side effects. | nausea, vomiting, itching, headache, mouth dryness, drowsiness | During 60 minutes from drug administration. | 
| Breast feeding |  | Up to 48 hours after birth | 
| Participants satisfaction and the usefulness of pain relief | Scale of excellent, very good, good, fair or poor. | Within 48 hours after birth | 
| Changes in electronic fetal heart rate monitoring |  | 24 hours | 
| Occurence of meconium stained amniotic fluid | Number of women with meconium stained amniotic fluid. | 24 hours | 
| Umbilical artery PH | Number of women with Umbilical artery PH less than 7.1. | Up to 5 min from birth, after performing cord clamping. | 
| Apgar score |  | At 1 and 5 minutes after birth | 
| Need for respiration |  | Within 48 hours after birth | 
| Neonatal Intensive Care Unit (NICU) administration | Number of neonates that admitted to neonatal intensive care unit within 48 hours after birth. | Within 48 hours after birth | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Labor analgesia, Nitrous Oxide, Meperidine, Multiparous, Visual analogue scale