PROLONGED INTRATHECAL FENTANYL ANALGESIA VIA 32-GAUGE CATHETERS AFTERTHORACOTOMY

We hypothesized that intrathecal fentanyl infusion would provide excel lent 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 studied 12 patients during 4 8 h after thoracotomy (three pneumonectomies, six lobectomies, and thr ee multiple resections of metastases or pleural surgery). The mean dos e of fentanyl infused intrathecally was 0.81 +/- 0.26 mug.kg-1.h-1, an d plasma fentanyl concentrations ranged between 0.49 +/- 0.19 and 0.72 +/- 0.34 ng/ml. Four patients needed a supplementary bolus of intrath ecal fentanyl. Pain scores decreased below 30/100 within 1 h when meas ured at rest but required 24 h to decrease to the same level during co ughing. pulmonary function tests returned to approximately 50% of preo perative values within 1 h of fentanyl infusion. Mean respiratory rate s averaged 19 +/- 4, and no episode of apnea was detected. Pruritus, n ausea, and headache occurred, respectively, in four, one, and zero pat ients. Excessive pressure in the infusion system occurred 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 rap id and intense analgesia but that current 32-gauge intrathecal cathete rs are not well suited for prolonged postoperative use.