CME Module 6: Patient-Controlled Epidural Analgesia (PCEA) for Labour Next >

 

Introduction

 

Continuous epidural analgesia is the most effective way of providing and maintaining labor analgesia. Over the past 20 years, the technique has undergone a number of modifications that increased the safety, efficacy and patient satisfaction. In the early 1980’s intermittent bolus doses of relatively large amounts of local anesthetic were administered by the anesthesiologist or nurse/midwife. This may lead to periods of comfort and discomfort throughout the labor. Intense motor block was common because of the large doses of drug in use at the time. The technique required a lot of nursing time because of monitoring requirements after each bolus. While the technique was safe in most cases, the parturient was exposed to a number of bolus doses that could, if the catheter migrated, lead to symptoms of intravascular or intrathecal injection.

Table 1. Characteristics of the ideal epidural analgesic for labour.

  • High quality analgesia
  • Maternal safety
  • Neonatal safety
  • High degree of maternal satisfaction
  • No interference with the progress of labour
  • No motor block
  • No side effects
  • Ease of use
  • Reduced nursing/physician workload

In the early 1980’s continuous infusion techniques became popular[1]. This method of delivery reduced the variability of analgesia during labor especially when the high concentrations of local anesthetic were replaced by low concentrations with the addition of lipophilic opioid. Unfortunately, this modality did not suit all patients and, although many combinations of infusion rate, concentration of local anesthetic, and additives were investigated, none was suitable for all patients. Many patients still required clinician-initiated topups or experienced unacceptable motor block.

Patient controlled epidural analgesia (PCEA) was first described in 1988[2]. Because labor pain has a highly variable intensity and the character of the pain often changes as labor progresses, it makes sense that patients might be the best managers of their own pain relief. By allowing the patient a degree of control, PCEA allows some individualization of labor analgesia.

Over the past 20 years, PCEA has been studied and the technique refined. Table 1 lists some of the characteristics of the ideal analgesic in labor. In the following sections, we will compare PCEA to other epidural techniques for each of these characteristics. Much of the data presented comes from a systematic review that we performed using a computerized search of Medline, Embase and the Cochrane library, supplemented by articles from various bibliographies. We included all published randomized trials that compared 1) PCEA to a continuous epidural infusion (CEI), 2) PCEA to intermittent bolus (IB), or 3) PCEA with and without a background infusion. In all, more than 1600 patients in seventeen investigations have been studied.

 

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