Intrathecal Opioids for Combined Spinal-Epidural Analgesia during Labour

Abstract

In <25 years, intrathecal administration of opioids (i.e. spinal analgesia) has evolved from an experimental model into an important therapy for obstetric analgesia and anaesthesia. A small dose of opioid delivered into the CSF provides almost immediate relief from labour pain with minimal risks to the mother and fetus. Careful attention, and prompt treatment when needed, can ameliorate the adverse effects of fetal bradycardia, respiratory depression and pruritus. The major limitation of intrathecal opioids for labour analgesia is the short duration of effect: 90-180 minutes under ideal circumstances. To address this problem, and to increase flexibility for anaesthesia as well as analgesia, the combined spinal-epidural (CSE) technique was developed. The CSE technique involves injection of drugs into the CSF and placement of an epidural catheter. An intrathecally administered opioid provides a rapid onset of labour analgesia without motor block or significant haemodynamic perturbation. The epidural catheter allows ongoing administration of medications to maintain labour analgesia and provides a means of delivering anaesthesia for operative delivery. This review will focus on intrathecally administered opioids as used as part of CSE analgesia. Considerable research has focused on the optimum dose of opioids when delivered intrathecally, with or without adjuncts, in the CSE technique. Fentanyl and sufentanil, two of the lipophilic synthetic opioids, have emerged as the most useful. Bupivacaine, a long-acting local anaesthetic, is often added to prolong the duration of analgesia, although this tends to increase the likelihood of motor blockade of the lower extremities. Comparisons of the CSE technique with standard epidural practices have shown that both are effective means of providing analgesia during labour. Controversy revolves around the incidence of fetal bradycardia following CSE and whether this phenomenon increases the rate of operative deliveries. The rapid onset of analgesia with intrathecally administered opioids must be balanced against the added risks of dural puncture and considered in the context of the whole duration of labour. Ultimately, the decision to choose a CSE technique depends on the experience of the anaesthesia provider and the local availability of drugs, equipment and monitoring capabilities.

Hemodynamic Impact of Intrathecal versus Epidural Analgesia with Sufentanil in the Early Phase of Labor: A Randomized Controlled Trial

“…On the contrary, the above mentioned Cochrane Review found higher rates of these two side effects when pain relief was provided with epidural analgesia; this could be due to the fact that our study included a smaller number of women. Remarkably, pruritus has been even defined as the "hallmark of intrathecal opioid", reaching an incidence >80% [22]. Accordingly, in our study pruritus was also more common in CSEA group.…”

Anesthésie ďune parturiente en travail, atteinte ďurticaire pigmentaire

“…The use of fentanyl in the spinal canal may be questioned since intrathecal fentanyl has been known to produce pruritus. [19][20][21][22] While the incidence of pruritus was related to the intrathecal dose of fentanyl in one study, 22 this was not the case in another. 21 However, both studies showed pruritus to be common at intrathecal doses as low as 5 or 10 µg (33-75%).…”

The Therapeutic Potential of Nociceptin/Orphanin FQ Receptor Agonists as Analgesics without Abuse Liability

“…While systemic administration of morphine is used in opioid therapy targeting chronic pain, intrathecal administration of MOP agonists has been one major breakthrough in pain management during the past three decades and has since become the most common way of inducing analgesia in obstetrics and for surgery. 10,12 However, spinal administration of MOP agonists is most often accompanied by the unwanted itch sensation (pruritus) in patients. 12,13 In obstetrics, pruritus has been a long-term concern that requires the use of antipruritic drugs.…”