To the Editor:--A recent case report by Pinczower and Gyorke [1]addressed a clinically important but rarely reported subject--an infectious complication of epidural anesthesia and analgesia. Because of clustering and pure chance, prospective studies on epidural anesthesia were not large enough to detect rare events such as epidural abscess or vertebral osteomyelitis. [2]A recent, large, retrospective study that analyzed 288,000 epidural catheterizations suffers from potential misclassification bias and other restrictions linked to retrospective analysis by a questionnaire. [3]In addition, symptoms of infectious complications related to an epidural catheter may present so late that they are not traced back to the previous epidural catheter. Recognizing catheter-related infections such as epidural abscess [4]or vertebral osteomyelitis [1]is important, because they can result in permanent neurologic damage. The need for an increased level of awareness of catheter-related osteomyelitis is stressed by two previous case reports of this complication and by a time delay of 8 and 15 weeks between onset of symptoms and definite diagnosis in these patients. [5,6]The question of whether the epidural catheter only serves as a nidus for hematogenous spread or as a primary entrance port of infection can rarely be answered in the individual case and has no influence on course and treatment of this complication. However, it is interesting that the patient reported by Pinczower and Gyorke and one of the previously reported patients [6]were both diagnosed with vertebral osteomyelitis secondary to Pseudomonas aeruginosa, whereas the most common organism in epidural catheter-related infections is Staphylococcus aureus. [7]An important aspect is that all three patients with catheter-related osteomyelitis were immunocompromised. Pinczower and Gyorke's patient received systemic methylprednisolone therapy and, of the previously reported patients, one received triamcinolone and betamethasone epidurally, in addition to suffering from diabetes mellitus, [5]and the other patient was immunocompromised by a history of pancreatitis and high alcohol intake. [6].

It is necessary to increase the index of awareness among physicians for infectious complications of epidural anesthesia and analgesia, and special care should be exercised with epidural catheters in immunocompromised patients.

Christoph H. Kindler, MD; Staff Anesthesiologist, Manfred D. Seeberger, MD; Staff Anesthesiologist, Department of Anesthesia, University of Basel, Kantonsspital, CH-4031 Basel, Switzerland.

(Accepted for publication May 8, 1996.)

Pinczower GR, Gyorke A: Vertebral osteomyelitis as a cause of back pain after epidural anesthesia. ANESTHESIOLOGY 1996; 84:215-7.
Dahlgren N, Tornebrandt K: Neurological complications after anaesthesia. A follow-up of 18,000 spinal and epidural anaesthetics performed over three years. Acta Anaesthesiol Scand 1995; 39:872-80.
Palot M, Visseaux H, Botmans C, Pire JC: Epidemiologie des complications de l'analgesie peridurale obstetricale. Cah Anesthesiol 1994; 42:229-33.
Borum SE, McLeskey CH, Williamson JB, Harris FS, Knight AB: Epidural abscess after obstetric epidural analgesia. ANESTHESIOLOGY 1995; 82:523-6.
Wenningsted-Torgard K, Heyn J, Willumsen L: Spondylitis following epidural morphine. A case report. Acta Anaesthesiol Scand 1982; 26:649-51.
Lynch J, Zech D: Spondylitis without epidural abscess formation following short-term use of an epidural catheter. Acta Anaesthesiol Scand 1990; 34:167-70.
Pegues DA, Carr DB, Hopkins CC: Infectious complications with temporary epidural catheters. Clin Infect Dis 1994; 19:970-2.