Prolonged Intrathecal Fentanyl Analgesia via 32-Gauge Catheters After Thoracotomy Jean-Philippe Guinard, MD, DEAA*, Ren6 Chiolero, MD, PD*, Philippe Mavrocordatos, MD*, and Randall L. Carpenter, MDt *Service dAnesthesiologie, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland, and tDepartment of Anesthesiology, Virginia Mason Medical Center, Seattle, Washington We hypothesized that intrathecal fentanyl infusion would provide excellent analgesia, require lower doses than necessary for the epidural or intravenous route of administration, and reduce the incidence and/or severity of side effects. Accordingly, we stud- ied 12 patients during 48 h after thoracotomy (three pneumonectomies, six lobectomies,and three multiple resections of metastases or pleural surgery). The mean dose of fentanyl infused intrathecally was 0.81 zyxwvut 2 0.26 pg.kg-’.h-‘, and plasma fentanyl concentrations ranged between 0.49 zyxwvuts 5 0.19 and 0.72 zyxwvuts -t 0.34 ng/ml. Four patients needed a supplementary bolus of intra- thecal fentanyl. Pain scores decreased below zyxwvut 30/ 100 within 1 h when measured at rest but required 24 h to decrease to the same level during coughing. Pulmonary function tests returned to approximately 50% of preoperative values within 1 h of fentanyl in- fusion. Mean respiratory rates averaged 19 4, and no episode of apnea was detected. Pruritus, nausea, and headache occurred, respectively, in four, one, and zero patients. Excessive pressure in the infusion system oc- curred frequently, limiting fentanyl infusion in two patients. All catheters were removed intact; however, one broke outside of the patient’s back. This study demonstrates that intrathecal fentanyl infusion can safely provide rapid and intense analgesia but that current 32-gauge intrathecal catheters are not well suited for prolonged postoperative use. (Anesth Analg 1993;77936-41) W ‘ e recently reported good pain relief with prolonged thoracic epidural fentanyl ad- ministration after thoracotomy (1). Al- though there were some benefits provided by insert- ing the epidural catheter at a thoracic (T4-T5) level, they were relatively minor when compared with lum- bar (LPL5) catheter placement or intravenous (IV) fentanyl administration. Specifically, thoracic place- ment did not result in better pain relief, a reduction in fentanyl dosages, or a reduction in side effects. These results caused us to question whether a different route of fentanyl administration might result in improved analgesia and a reduction in side effects. We wondered whether intrathecal administration might provide these advantages. Numerous reports have documented the excellent and prolonged analgesia that can result from intra- thecal injection of long-acting opioids (2-11). How- ever, single injection techniques provide analgesia for Presented in part at the 17th Annual Meeting of the American Accepted for publication July 12, 1993. Address correspondence to Jean-Philippe Guinard, MD, DEAA, Service d’AnesthCsiologie, Centre Hospitalier Universitaire Vaudois, 1011, Lausanne, Switzerland. Society of Regional Anesthesia, Tampa, FL, March 26-29, 1992. an unpredictable and limited duration and cannot be ”titrated to effect.” Insertion of an intrathecal catheter would address these deficiencies. Consequently, we designed this prospective open study to determine whether continuous intrathecal opioid infusion would be a suitable method to provide analgesia after thora- cotomy. To limit the risk of drug accumulation and delayed respiratory depression, we used the highly lipid-soluble fentanyl instead of morphine. We also chose to utilize 32-gauge intrathecal cath- eters in an attempt to minimize the risk of postdural puncture headache (PDPH) (12-16). Also, to the best of our knowledge, no case of cauda equina syndrome has been reported with the use of 32-gauge intrathecal catheters, in contrast to the larger (20-28-gauge) cath- eters (17-19). Methods Twelve patients scheduled for elective lung resection were studied after institutional review board approval and informed consent. The study was conducted before the recall of spinal microcatheters by the FDA. Patients were excluded from the study if they had: age <20 yr, ASA physical status > 111, active infectious pulmonary 936 Anesth Analg 1993;7793641 01993 by the International Anesthesia Research Society 0003-2999 /93 / $5.00