Regional anaesthesia may require intraoperative narcotic supplementation, but usually a single anaesthetist-administered dose suffices. Intraoperative Patient Controlled Analgesia (PCA) during Caesarean Section (CS) does not seem warranted because of the additional complexity of the technique and the need for specialised apparatus.
Mainly on the basis of patient preference for control, rather than absolute quality of analgesia, intravenous PCA (IV-PCA) has become the 'de facto' standard for post-CS analgesia in many obstetric units (1) (Chapter 99). In general, those caring for the mother have shown poor clinical judgment of both the degree of pain and the level of sedation experienced by the patients following CS (2). The quality of analgesia produced by IV-PCA is similar to that obtained following intramuscular narcotic administration, but is inferior to analgesia obtained from intraspinal opioids. In some series, maternal satisfaction has related more to the quality of analgesia than to the patient's ability to control her pain (3).
Overall side effects of IV-PCA (especially nausea and vomiting), when compared to epidural morphine, have been less in some (but not all) series (4). Sedation has been less and ambulation earlier for IV-PCA when compared to conventional intravenous infusion or intramuscular analgesia despite a greater total dose of drug (5). Post-surgical recovery seems similar, whatever the analgesic modality used. Pethidine has been the commonest narcotic used, though its metabolites will accumulate in breast milk and lead to a reduced neonatal neurobehavioural score (6). Larger bolus doses tend to produce greater patient satisfaction (4).
Morphine or fentanyl provide similar analgesia, and morphine may be less troublesome, in achieving the desired analgesia (7). Whilst IV-PCA may seem to be an inherently safer method of analgesic administration, there are no large number series comparing safety of one method with another.
The overall benefits seem to be subjective rather than objective in the caesarean section setting. The additional cost of the apparatus and delivery system is small compared to the benefits experienced by the patient as a result of use of the technique and to the savings in nursing time.
2. Olden AJ, Jordan ET, Sakima NT, Grass JA. Patients' versus nurses' assessments of pain and sedation after cesarean section. J Obstet Gynecol Neonatal Nurs 1995;24:137-41.
7. Howell PR, Gambling DR, Pavy T, McMorland G, Douglas MJ. Patient-controlled analgesia following cesarean section under general anesthesia: a comparison of fentanyl with morphine. Can J Anaesth 1995;42:41-45.