In Reply:-We agree with Dr. Shah that our case report illustrates the difficulty in the diagnosis of postpartum headache, although his suggestion that a cerebrospinal fluid (CSF) leak be demonstrated before performing epidural blood patch for postdural puncture headache (PDPH) does not conform with current practice. [1–3] The history of dural puncture followed by a postural headache establishes the diagnosis in a manner sufficient to proceed with epidural blood patch.

Shah advocates the insertion of an epidural catheter for establishing the presence of low CSF pressure [4] and CSF leak and for injection of the epidural blood patch. Although effective in supporting the diagnosis of PDPH, epidural catheter insertion could have several drawbacks, if used in all cases of PDPH. Because the epidural blood patch should be injected as close to the site of dural puncture as possible [1,5,6] and because the spread of the blood is typically cephalad, [7] the insertion of a catheter might reduce the accuracy of the injection. Also, vascular injury by the catheter could cause bleeding in the epidural space, thus unnecessarily increasing the volume of the blood patch.

Shah has suggested that epidural catheter insertion for CSF aspiration might be helpful when a patient has a postural headache after multiple attempts at epidural needle placement and when the stilette was not removed from the needle, resulting in the possibility of an unrecognized dural puncture. [8] In our case report, the atypical headache appeared after the second epidural blood patch. An epidural catheter inserted at this time might have entered the previously placed blood patch, thus rendering pressure measurements and aspiration testing useless.

Stanley E. Borum, M.D.

Department of Anesthesiology

L. Gill Naul, M.D.

Department of Radiology; Texas A&M University Health Science Center

Charles McLeskey, M.D.

Department of Anesthesiology; Scott & White Clinic and Memorial Hospital; Scott, Sherwood and Brindley; Texas A&M University Health Science Center; College of Medicine; Temple, Texas

Schneider SM, Levinson G: Anesthesia for cesarean section, Anesthesia for Obstetrics, 3rd Edition. Edited by Schneider SM, Levinson G. Baltimore: Williams & Wilkins, 1993, p 224.
Weeks SK: Postpartum headache, Obstetric Anesthesia. Edited by Chestnut DH. St. Louis: Mosby-Year Book, Inc, 1994, p 613.
Chadwick HS, Bonica JJ: Complications of regional anesthesia, Principles and Practice of Obstetric Analgesia and Anesthesia, 2nd Edition. Edited by Bonica JJ, McDonald JS, Baltimore, Williams & Wilkins, 1995, p 559.
Coombs DW, Hooper D: Subarachnoid pressure with epidural blood “patch.” Reg Anesth 1979; 4:3-6.
Szeinfeld M, Ihmeidan IH, Moser MM, Machado R, Klose KJ, Serafini AN: Epidural blood patch: Evaluation of the volume and spread of blood injected into the epidural space. Anesthesiology 1986; 64:820-2.
Abouliesh E: Effects of vertebral blocks on the respiratory system, Pain Control in Obstetrics. Edited by Abouliesh E. Philadelphia: JB Lippincott, 1977, p 132.
Beards SC, Jackson A, Griffiths AG, Horsman EL: Magnetic resonance imaging of extradural blood patches: Appearances from 30 min to 18 h. Br J Anaesth 1993; 71:182-8.
Shah JL, Veness AM: Epidural blood patch using a catheter. Diagnosis of an unrecognised dural tap. Anaesthesia 1985; 40:1120-3.