In Reply:-We appreciate Moore's interest in our uniport epidural catheter insertion study ; however, it appears quite clear that he has misinterpreted the focus, findings, and conclusions of this study. In his criticism, Moore refers to recommendations on epidural catheter insertion by Brown, Shnider et al., and Bromage. Ironically, recommendations such as these were the specific impetus for our evaluation of epidural catheter insertion. These recommendations are based solely on “clinical experience” rather than systematic, scientific examination. Our study was the first prospective randomized study to systematically evaluate uniport epidural catheter insertion in laboring patients.
Moore asks, “Can investigations based on clinical performance … determine precisely the optimal distance to insert lumbar catheters in mobile patients?” Our anesthetic practice involves direct clinical patient care; therefore, actual patients are the most appropriate model in which to ask, examine, and attempt to answer clinical questions. Volunteer or animal studies would provide little clinically relevant information for this patient population. In addition, Moore suggests that roentgenographic studies were necessary after delivery to “conclusively prove the optimal distance to insert lumbar epidural catheters….” We believe that postdelivery roentgenograms would provide no clinically pertinent information. Documenting the particular distance within the epidural space an epidural catheter's distal tip rests after delivery would provide irrelevant information. What is relevant is that the patient experienced adequate analgesia throughout labor and delivery.
Moore seeks irrefutable proof of the “optimal distance” an epidural catheter should be inserted into a mobile patient. Our findings indicate that no single insertion length is ideal for all patients; and, we conclude that epidural catheter insertion should vary, depending on the expected duration of labor. Uniport epidural catheters should be inserted either 2 cm when rapid labor is anticipated or 6 cm when longer labors or cesarean section are anticipated. In addition, even optimal insertion distances will only reduce the risk of complications, not eliminate them.
Moore further states, “Neither Beilin et al. or D'Angelo have presented anything new.” We emphatically disagree. These studies were the first prospective randomized examinations of multiport and uniport epidural catheter insertion in laboring patients, respectively. Findings and conclusions from both studies are remarkably similar, yet differ considerably from the aforementioned recommendations [2–4]based on “clinical experience.” We have changed our practice and our teaching to reflect what we have learned from our patients. Clinicians may now choose an epidural catheter insertion length that minimizes associated complications in laboring patients.
Robert D'Angelo, M.D.
Assistant Professor of Anesthesiology
J.C. Gerancher, M.D.
Instructor of Anesthesiology
Section of Obstetric Anesthesia; Department of Anesthesia; Wake Forest University Medical Center; Bowman Gray School of Medicine
Winston-Salem, North Carolina 27157
(Accepted for publication December 12, 1996.)