In Reply:- It is interesting to know that Dr. Michael Rosen's experience in terms of satisfaction with patient-controlled intravenous analgesia (PCIA) using meperidine during labor in a population of mixed social and economic status was similar to our experience. In our obstetric unit, although we allow nurses to initiate and maintain PCIA, an anesthesiologist is always available on an immediate basis.

Dr. Deborah Wilson's concerns regarding the safety with PCIA and its effectiveness have been well discussed in our manuscript and in the accompanying editorial by Dr. David Chestnut published in the September 1997 issue of Anesthesiology. Our manuscript has clearly suggested that epidural analgesia provides better analgesia than PCIA during labor and that epidural analgesia should be preferred to PCIA. However, in view of the complete satisfaction expressed by 65 - 70% of women in the PCIA group and minimal crossover, it was reasonable to state that PCIA is also an effective method of pain relief during labor. Professor Rosen has supported this view in his letter to the editor. Regarding neonatal outcome, we have also clearly indicated in our manuscript that our primary purpose in the study was to evaluate the rate of cesarean section. However, in our manuscript there was no difference between the two groups with regards to immediate neonatal outcome in terms of objective criteria such as Apgar scores and cord pH, PCO (2), and PO2, except for an increased requirement for naloxone in the PCIA group. Further, we had enough power to draw this conclusion (to determine a two-tailed significant difference of 0.05 between a mean [+/- SD] umbilical arterial pH of 7.30 +/- 0.06 and 7.25 +/- 0.06 in the two groups for 80% power, only 24 acid base measurements per group are required). We did not compare neonatal neurobehavioral changes, so interpreting it either way would be incorrect. The clinical significance of subtle differences in neurobehavior is unclear. Overall our manuscript and the accompanying editorial clearly suggest that PCIA using meperidine is a reasonable option in some circumstances.

Shiv K. Sharma, M.D., F.R.C.A.

Assistant Professor; Department of Anesthesiology and Pain Management; University of Texas Southwestern Medical Center, Dallas; Dallas, Texas

Kenneth J. Leveno, M.D.

Professor; Department of Obstetric and Gynecology; University of Texas Southwestern Medical Center, Dallas; Dallas, Texas