A Randomised Controlled Trial of Remifentanil Intravenous Patient Controlled Analgesia (PCA) Versus Intramuscular Pethidine for Pain Relief in Labour

Condition(s) targeted: Pain Relief in Labour

Intervention: Pethidine (Drug); Remifentanil (Drug)

Phase: Phase 4

Status: Recruiting

Sponsored by: Dr Matthew Joseph Anthony Wilson

Official(s) and/or principal investigator(s):
Matthew JA Wilson, Principal Investigator, Affiliation: Sheffield Teaching Hospitals NHS Foundation Trust

Overall contact:
Leanne E Homer, Phone: 0121 415 9108, Email: l.e.homer@bham.ac.uk

Childbirth can be an extremely painful and the provision of pain relief during labour is a vital component of a positive maternal experience. The majority of women who deliver in modern obstetric units choose a pharmacological method of pain relief, including Entonox, the injection of opioids or epidural placement. The commonest opioid used in labour is pethidine administered by intramuscular (im) injection. The effectiveness of pain relief provided by pethidine has long been challenged. Its shortcomings are more serious when set against known side effects including maternal sedation, nausea and potential transfer across the placenta to the foetus. More than a third of women who receive pethidine subsequently require an epidural due to inadequate pain relief. Epidurals provide highly effective pain relief, but increase the risk of a forceps or suction delivery resulting in prolonged hospital stay. Therefore, there is a clear need for a safe, effective, easy to administer analgesic alternative.

Official title: A Randomised Controlled Trial of Remifentanil Intravenous Patient Controlled Analgesia (PCA) Versus Intramuscular Pethidine for Pain Relief in Labour

Study design: Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Open Label, Primary Purpose: Treatment

Primary outcome: The proportion of women who receive epidural analgesia for pain relief in labor, in each group, after randomisation.

Secondary outcome:

• The effectiveness of pain relief provided by each technique, quantified by Visual Analogue Scale

The incidence of maternal side effects

Delivery mode (Spontaneous, Instrumental Vaginal, Caesarean Section)

Incidence of foetal distress requiring delivery

Neonatal status at delivery

Rate of initiation of breast feeding within the first hour of birth

Maternal satisfaction with childbirth experience determined by postpartum questionnaire prior to discharge from the delivery ward

Resources used intra- and post-operatively, including PCA consumables, anaesthetist attendance

Costs of staff training

Service procurement

Provision of care

Detailed description: Patient Controlled Analgesia (PCA) comprises drug administration into an intravenous drip with a small dose given each time a woman presses a button, giving her control over her own pain relief. The pump is programmed to ensure that the maximum dose allowable is within the safe range. This form of delivery of pain relief matches the drug dose to pain sensation within the relevant time frame, which is not possible using a single dose intramuscular injection. Whilst PCA is in widespread use for acute pain relief it has only a limited role in obstetrics. The most common drug given by PCA is morphine, however, since it has a long duration of action and crosses the placenta, the potential for accumulation in the foetus and consequent neonatal sedation at delivery restricts its utility (within obstetrics) to contexts where neonatal status is not relevant, such as intra-uterine foetal death or foetal abnormality incompatible with survival. Remifentanil is a novel synthetic opioid with a very rapid onset (blood-brain equilibration 1. 2-1. 4 minutes) and short duration of action (context specific half-life 3 minutes), giving it an analgesic profile which potentially makes it ideal for providing pain relief over 1-2 uterine contractions after a single intravenous dose. It is subject to rapid redistribution and metabolism by non-specific blood and tissue esterases negating the potential for accumulation in mother or foetus. Administration of remifentanil by PCA has been investigated in several small studies in comparison to pethidine and shown to provide useful, although not complete, pain relief in labour. 10-12 Thus far, there is no evidence of detrimental neonatal effects in comparison to other opioids.

Minimum age: 16 Years. Maximum age: N/A. Gender(s): Female.

Criteria:

Inclusion Criteria: Women who are admitted to labour ward who fulfil all the following criteria will be eligible to be randomised:

- Requesting systemic opioid analgesia

- 16 years of age or older

- Beyond 37 weeks gestation

- In established labour with vaginal birth intended

- Able to understand all information (written and oral) presented (using an interpreter

if necessary)

- Not participating in any other clinical trial of a medicinal product

- Live, singleton pregnancy with cephalic presentation

Exclusion Criteria:

- Contraindication to epidural analgesia

- Contraindication to intramuscular injection

- History of drug sensitivity to pethidine or remifentanil

- Patients taking long term opioid therapy including Methadone

- Systemic pain relief opioid in the last 4 hours

Leanne E Homer, Phone: 0121 415 9108, Email: l.e.homer@bham.ac.uk

Birmingham Clinical Trials Unit, Birmingham, West Midlands B15 2TT, United Kingdom; Recruiting

Trial website

Starting date: May 2014
Last updated: May 14, 2015