Correspondence  |   March 1997
Epidural Catheter Insertion and Satisfactory Analgesia-The Mobile Versus the Immobile Patient
Author Notes
  • Department of Anesthesiology, B2-AN, Virginia Mason Medical Center, P.O. Box 900, 1100 Ninth Avenue, Seattle, Washington 98111–0900 (Moore).
Article Information
Correspondence   |   March 1997
Epidural Catheter Insertion and Satisfactory Analgesia-The Mobile Versus the Immobile Patient
Anesthesiology 3 1997, Vol.86, 747-748. doi:
Anesthesiology 3 1997, Vol.86, 747-748. doi:
To the Editor:-The distance a catheter is inserted into the epidural space, whether it be 1 or more cm, does not guarantee satisfactory analgesia. What does result in satisfactory analgesia is whether the catheter remains in the epidural space. If an epidural block immobilizes the patient as for surgery and if the catheter is to be removed immediately after the operation, the distance it is inserted may be 1 cm or more. If the patient is not immobilized, as may occur in obstetrics or when used to relieve postoperative pain, then enough of the catheter must be inserted to assure that, during movement, its orifice(s) is not dislodged from the epidural space. But what is enough?
In his letter, [1] Beilin, evidently confining his remarks to the mobile parturient, states:“… the optimal length for insertion of an epidural catheter is 5–6 cm and not 2–3 cm, as previously recommended (Brown 2–3 cm, [2] Shnider et al. 1–2 cm [3]).” Why didn't he reference Bromage, who in 1978 advised 3–4 cm?[4] In a previous article, Beilin et al. [5] did reference the roentgenographic study of Bridenbaugh et al. but neglected to state that, in 198 patients, it showed “the futility of attempting to thread a plastic tube more than 2 inches (5 cm) cephalad within the epidural space.”[6] Since that finding, the distances catheters are threaded at the Mason Clinic into the epidural space, regardless of whether the patient is mobile or immobile, is 4–5 cm.
Can investigations based on clinical performance (observation and judgment by anesthesiologists, as done by Beilin et al. [5] and D'Angelo et al. [7]) determine precisely “the optimal distance” to insert lumbar catheters in mobile patients? I don't think so, and neither do others who were critical of the article by Beilin et al. [8,9] If either Beilin et al. [5] or D'Angelo et al. [7] want to prove conclusively the “optimal distance” to insert lumbar epidural catheters in mobile parturients or any other mobile patients is 5–6 cm, as stated in their correspondence, [1] they should obtain roentgenograms immediately before withdrawal of the catheter, so as to determine the length of catheter remaining in the epidural space and where its tip lies.
To conclude, neither Beilin et al. [5] or D'Angelo et al. [7] have presented anything new. In addition, they cannot irrefutably state that the “optimal distance” to insert an epidural catheter in mobile patients is 5–6 cm, nor can Beilin be critical of others whose insertion distance may or may not apply to mobile patients. [1] Beilin et al. [5] state that a roentgenographic study “… is obviously an unrealistic recommendation for women in labor,” and they are right. But this does not rule out roentgenographic studies in them after delivery and immediately before removing the lumbar catheter.
Daniel C. Moore, M.D. (Emeritus)
Department of Anesthesiology, B2-AN; Virginia Mason Medical Center
P.O. Box 900; 1100 Ninth Avenue; Seattle, Washington 98111–0900
(Accepted for publication December 12, 1996.)
Beilin Y, D'Angelo R: Epidural catheter insertion and satisfactory analgesia (correspondence). Anesthesiology 1996; 84:1524-5.
Brown DL: Spinal, epidural and caudal anesthesia, Anesthesia. 4th edition. Edited by Miller RD. New York, Churchill Livingstone, 1994, p 1525.
Shnider SM, Levinson G, Ralston DH: Regional anesthesia for labor and delivery, Anesthesia for Obstetrics. 3rd edition. Edited by Shnider SM, Levinson G. Baltimore, Williams and Wilkins, 1993, p 143.
Bromage PR: Epidural analgesia. Philadelphia, W. B. Saunders, 1978, p 546.
Beilin Y, Bernstein HH, Zucher-Pinchoff: The optimal distance that a multiorifice catheter should be threaded into the epidural space. Anesth Analg 1995; 81:301-4.
Bridenbaugh LD, Moore DC, Bagdi PA, Bridenbaugh PO: The position of plastic tubing in continuous-block techniques: An x-ray study of 552 patients. Anesthesiology 1968; 29:1047-9.
D'Angelo RD, Berkebile BL, Gerancher JC: Prospective examination of epidural catheter insertion. Anesthesiology 1996; 84:88-94.
Kempen PM, Beilin Y, Bernstein H, Zucker-Pinchoff B: How far should a catheter be inserted into the epidural space (letter)? Anesth Analg 1996; 82:893-5.
Baylis R, Marjot R, Beilin Y, Bodian CA, Bernstein H, Zucker-Pinchoff B: The optimal distance that a multiorifice epidural catheter should be threaded into the epidural space (letter). Anesth Analg 1996; 82:894-5.