The RESPITE trial: remifentanil intravenously administered patient-controlled analgesia (PCA) versus pethidine intramuscular injection for pain relief in labour: study protocol for a randomised controlled trial

Background The commonest opioid used for pain relief in labour is pethidine (meperidine); however, its effectiveness has long been challenged and the drug has known side effects including maternal sedation, nausea and potential transfer across the placenta to the foetus. Over a third of women receiving pethidine require an epidural due to inadequate pain relief. Epidural analgesia increases the risk of an instrumental vaginal delivery and its associated effects. Therefore, there is a clear need for a safe, effective, alternative analgesic to pethidine. Evidence suggests that remifentanil patient-controlled analgesia (PCA) reduces epidural conversion rates compared to pethidine; however, no trial has yet investigated this as a primary endpoint. We are, therefore, comparing pethidine intramuscular injection to remifentanil PCA in a randomised controlled trial. Methods/design Women in established labour, requesting systemic opioid pain relief, will be randomised to either intravenously administered remifentanil PCA (intervention) or pethidine intramuscular injection (control) in an unblinded, 1:1 individual randomised trial. Following informed consent, 400 women in established labour, who request systemic opioid pain relief, from NHS Trusts across England will undergo a minimised randomisation by a computer or automated telephone system to either pethidine or remifentanil. In order to balance the groups this minimisation is based on four parameters; parity (nulliparous versus multiparous), maternal age (<20, 20 < 30, 30 < 40, 40+ years), ethnicity (South Asian (Pakistani/Indian/Bangladeshi) versus Other) and induced versus spontaneous labour. The effectiveness of pain relief provided by each technique will be recorded every 30 min after time zero, until epidural placement, delivery or transfer to theatre, quantified by Visual Analogue Scale. Incidence of maternal side effects including sedation, delivery mode, foetal distress requiring delivery, neonatal status at delivery and rate of initiation of breastfeeding within the first hour of birth will also be recorded. Maternal satisfaction with her childbirth experience will be determined by a postpartum questionnaire prior to discharge from the delivery ward. Discussion The RESPITE trial’s primary outcome is the proportion of women who have an epidural placed for pain relief in labour in each arm. Trial Registration Current Controlled Trials registration number: ISRCTN29654603. Registered on 23 July 2013

Medicolegal issues in labor analgesia

Within surgical disciplines, obstetrics and anesthesia carry a greater risk of medicolegal liability although with improved monitoring and practice standards issued by national scientific societies such as the American College of Obstetricians and Gynecologists (ACOG) and the American Society of Anesthesiologists (ASA). Pain relief is becoming an area of concern. Analgesia refers to the relief of pain without the loss of consciousness. Modalities of analgesia during childbirth include regional analgesia, systemic opioid analgesia, continuous labor support, pudendal blocks, immersion in water during the first stage of labor, sterile water injections in the lumbosacral spine, hypnosis, and acupuncture [1]. Even though there are multiple options for labor pain management, women often experience pain during childbirth in accordance with their expectations. The ASA Closed Claims database [2] has shown that since the1990s the proportion of claims associated with general anesthesia has progressively declined while the proportion associated with regional analgesia has steadily increased although the majority of maternal injuries are minor (e.g., headache, back pain, pain during analgesia, neuropsychological consequences). In addition, [3] it reported that postnatal depression may be more common when analgesia is not used and pain during labor has been correlated with the development of posttraumatic stress disorder. Furthermore, men are also affected by severe labor pain. A survey of first-time fathers showed that the men whose partners received an epidural felt three times as helpful and involved during labor and delivery and had less anxiety and stress, as compared with men whose partners did not receive an epidural [3]. All these situations may reflect unrealistic expectations and dissatisfaction with parturient care, and litigation serves the purpose not only of reparation of injury and deterrence of standard of care but also of emotional vindication. This is especially true in Italy where labor analgesia is becoming an important public health issue with its introduction free of charge in SSN as LEA (Essential Levels of Assistance) (DPCM April 23, 2008, art. 37) but, at the same time, it is not performed in all hospitals [4] due to lack of funding. The problem is clear. Labor analgesia has to be considered an important aspect of the obstetric anesthesia practice, and the provision of adequate pain relief and management has foundation in the law of negligence. The law of medical negligence emphasizes taking reasonable care in all aspects of patient management and, with respect to this particular issue, doctors (the anesthetist as well as the obstetrician, midwife, neonatologist, and labor and delivery nurses) may breach their standard of care by failing to exchange information with the parturient and also with other members of the woman’s family as well as with the obstetric team; by failing to provide appropriate prenatal education and to acquire informed consent; by treating the pain inadequately or by failing to counteract adverse reaction and eventually perform acute resuscitation. © Springer International Publishing Switzerland 2015. © Springer International Publishing Switzerland 2015