Patient Controlled Epidural Analgesia (PCEA) for Labour and Delivery Analgesia

This technique is similar to IV PCA however, the mother self-administers small boluses of a local anaesthetic- opioid mixture via her epidural.

PCEA was introduced because it was predicted that it would offer several potential advantages over continuous infusion or bolus administration methods. These include patient autonomy in determining level of pain relief, more easily titrated sensory level with minimisation of drug dose, optimal analgesia with minimal side effects, high patient satisfaction, and a reduced demand on professional time. It has in fact been difficult to convincingly prove that any one method is superior to the others. Nonetheless, PCEA has become the standard method of epidural pain relief in some centres.

Clinical Use

Satisfactory epidural blockade must be established before the PCEA regimen is instituted. The epidural catheter is connected to a syringe containing a dilute mixture of local anaesthetic and opioid that is loaded onto a special delivery pump. The delivery of the drug from the pump is controlled by the mother with a push button. When the pain of contractions begin to be felt, she presses the button and a small amount of pain relieving medication is delivered via the epidural catheter. The button can be pressed as often as she wishes, but the pump will release the dose of drug only after a certain time has elapsed. This is called the lockout period and is usually 10-15 minutes. The lockout time ensures that the drug has had enough time to work before the next dose is given, because there is usually a lag of 5-10 minutes between delivery of drug into the epidural catheter and onset of effect. The lockout time protects the mother from giving herself too much drug. If she still feels discomfort from her contraction after the lockout period has elapsed, she may access another dose of medication from the pump by pressing the button. It is important that only the mother presses the button, as only she knows how much her contractions hurt and how much pain relief she needs. This also ensures that she does not get too much medication.

If analgesia is inadequate the bolus dose and lockout interval can be adjusted, and/or extra local anaesthetic can be given. Sometimes a continuous background infusion is administered in addition. The mother’s level of comfort and degree of sensory and motor blockade must be assessed on an ongoing basis, particularly as the nature, site, and severity of labour pain will vary.

PCEA is a useful and safe alternative for labour analgesia, provided that bolus doses of dilute local anaesthetic are small, that the lockout period and hourly maximum dose are appropriate, and that the mother is regularly assessed by the anaesthetist.