Diamorphine for pain relief in labour : a randomised controlled trial comparing intramuscular injection and patient‐controlled analgesia

Abstract

Objectives To compare the efficacy of diamorphine administered by a patient-controlled pump (patientcontrolled analgesia) with intramuscular administration for pain relief in labour. Design Randomised controlled trial.Setting The South Glasgow University Hospitals NHS Trust.Sample Primigravidae and multigravidae in labour at term (37 -42 weeks).Methods Women were randomised in labour to the study (patient-controlled analgesia) or control group (intramuscular). Randomisation was achieved through a random permuted block design stratified by parity. Study group women were given a loading dose of 1.2 mg diamorphine intravenously and then attached to the pump. Control group women received intramuscular diamorphine as per hospital protocol. Participants were also given 3 mg of buccal Stemetil. Data were collected throughout labour and at six postnatal weeks. Main outcome measures Analgesia requirements during labour and women's satisfaction with the method of pain relief. Results Women in the study group (patient-controlled analgesia) used significantly less diamorphine than women in the control group (intramuscular) but were significantly more likely to state that they were very dissatisfied with their use of diamorphine and were significantly more likely to opt out of the trial before the birth of the baby. The majority of women in both groups used other analgesia concurrent with diamorphine such as Entonox, aromatherapy or TENS. Conclusions Patient-controlled analgesia administration of diamorphine for the relief of pain in labour offers no significant advantages over intramuscular administration. The results also suggest that diamorphine is a poor analgesic for labour pain irrespective of the mode of administration.

Maternal Satisfaction as an Outcome Criterion in Research on Labor Analgesia

“…69,88 Some included preoperative expectation of pain, 69 expectation of treatment, 39 actual versus expected pain, 69,73 or actual versus expected overall experience of labor. In these, using MS as an outcome, the method used was very variable.…”

Pain relief in labor: a survey of awareness, attitude, and practice of health care providers in Zaria, Nigeria

“…This may not be surprising because this method is widely used. Worldwide, many institutions have reported a high frequency of use of systemic opioids like pethidine, pentazocine, morphine, and meperidine 4,5,34,35. Pethidine remains a common choice worldwide, despite a lack of convincing evidence for its analgesic effectiveness and safety during labor 36,37.…”

Prescribing intramuscular opioids for labour analgesia in consultant-led maternity units: a survey of UK practice

“…The geographical distribution of responses was: (total number of units in each country shown in brackets) England: 138 (189), Scotland 16 (21), Wales 9 (13) and Northern Ireland 4 (11).…”

“…Our survey has shown that intramuscular pethidine is still used widely in consultant-led units (84.4% of units) despite research demonstrating its lack of efficacy as an analgesic and its adverse effects on both mother and neonate. [3][4][5][6][7]11,13,14 Since 1968 midwives have also been able to administer diamorphine via the exemption list (1968 Medicines Act). The results of one Scottish study, 9 and anecdotal evidence relating to improved analgesia with fewer side effects, have led to a renewed interest in its use.…”

“…Diamorphine has been reported to provide moderate analgesia associated with euphoria and less vomiting than is associated with the use of pethidine. [9][10][11] The use of diamorphine in labour has increased in the absence of any large randomised controlled trials to support its use.…”