To the Editor:- The main purpose of Sharma et al.'s trial was to establish the effect of epidural analgesia on the rate of cesarean deliveries. It compared epidural with patient-controlled analgesia (PCA) with intravenous meperidine. That technique has never been widely used in obstetrics, but their trial has established again that it is not as effective as epidural analgesia, but it is still an valuable method.
My experience [2,3]with a Welsh population of mixed social and economic status (there is no private obstetric practice in Cardiff) in contrast to poor, Hispanic, or black patients (pointed out by Chestnut as a restriction in Sharma's trial) is similar, even though the equipment, dosage, and lockout times differed. Mean (+/- SD) meperidine doses were 139 mg (100 mg) for Sharma et al. and 171 mg (74.9) for nulliparous women and 158.9 mg (74.2) for multiparous women in our trial. In this study with PCA, nearly 65% reported good-to-excellent pain relief, and 70% would use the method again. In our study women receiving epidural anesthesia had linear analogue scores of 88.5% with epidural block compared with 67.2% with intramuscular meperidine. [2,3](PCA and intramuscular analgesia in Cardiff had similar scores). About two thirds of women would choose the same method, epidural or meperidine, again.
Chestnut is concerned about the neonatal effects of high-dose opioids, which were not discussed in this report. These have been studied previously. [4–7]It has been shown that naloxone, 40 [micro sign]g, can reverse the respiratory effects for a time, and intramuscular naloxone, 200 [micro sign]g, will reverse ventilatory, auditory, and feeding effects for at least 48 h after birth. The babies of women who had intramuscular naloxone and meperidine had significantly fewer effects, especially on muscle tone than those whose mothers received epidural block with bupivacaine (Mean +/- SD, 130 +/- 61.7 mg).
There can be no doubt that epidural block is the most effective form of pain relief in labor. Although there are risks associated with this method, it is largely safe administered under skilled obstetric anesthesiology care. Nevertheless, Sharma et al. have demonstrated clearly again that PCA meperidine is an reasonable option in some circumstances, acceptable to mothers in the United States and in the United Kingdom. It can be made safe for the neonate.
Sharma et al. believe that this useful alternative does not require the involvement of an anesthesiologist. I dispute that. Like postoperative pain relief, only an team led by an anesthesiologist is likely to introduce and maintain interest in effective techniques in the labor and delivery areas.
Michael Rosen, LL.D., F.R.C.A., F.R.C.O.G.
Formerly Professor in Anesthetics; University of Wales College of Medicine; Cardiff, United Kingdom