CONTINUOUS THORACIC EPIDURAL ANALGESIA FOLLOWING THORACOTOMY

Abstract

S290 Introduction: Logas [1] reported that the quality of post-thoracotomy pain control was similar in patients treated with epidural morphine 0.1% alone or in combination with bupivacaine 0.1%. Others [2,3] have shown that the combination therapy of bupivacaine and other opioids are more effective than epidural opioids alone. We investigated the quality of pain relief and outcomes in post-thoracotomy patients treated with continuous thoracic epidural infusion of morphine 0.1% alone or in combination with bupivacaine 0.125%. After obtaining IRB approval and informed consent 23 ASA Class I, II or III patients undergoing open thoractomies were enrolled for this randomized, double blind, prospective study. Epidural catheters were placed preoperatively at the T6-T7 interspace and epidural placement was confirmed by obtaining appropriate sensory levels after injection of 2% lidocaine. All patients were given general anesthesia and IV fentanyl was limited to a maximum of 5 [micro sign]g/kg. Intraoperatively the epidural catheters were bolused with morphine and bupivacaine on a time contingent basis. Upon arrival in the PACU, the patients were randomly assigned to receive either morphine 0.1 mg/cc with or without bupivacaine 0.125% as a continuous infusion. If the initial VAS was > 3, the patient was bolused with epidural morphine, fentanyl, and study solution to achieve VAS < 3. Once a VAS below 3 was achieved, the patient was started on the appropriate epidural infusion at 5 mL/hr. Infusion rates were titrated (maximum of 7 mL/hr) in an attempt to keep VAS level < 3. Patients were monitored for 72 hrs postoperatively with measurement of VAS, side effect scores and epidural infusion rates Results Demographic data were similar among both groups. Of the 23 patients, 5 had to be discontinued from the study. In the morphine group, 3 patients were discontinued, 1 for persistent VAS > 3, 1 for catheter occlusion and a third at her own request. In the combination group, 2 patients were discontinued, 1 for persistent VAS > 3 and the second for refractory hypotension. Examination of the data showed no significant differences between both groups with respect to VAS (at rest and with cough), number of epidural boluses, supplementary non-opioid analgesia (Toradol), total number of postop days and epidural morphine requirement. There were no significant differences with respect to incidence of nausea/vomiting, sedation, mental confusion, respiratory depression and hypotension. Discussion: Based on the lack of significant differences between groups, in the measured variables, epidural bupivacaine 0.125%, at rate of 5-7 mL/hr, appears to provide no additional benefit over the use of morphine alone. Epidural morphine alone provides adequate analgesia for the management of postoperative thoracotomy pain. (Table 1)Table 1