Abstracts of Posters Presented at the International Anesthesia Research Society; 72nd Clinical and Scientific Congress; Orlando, FL; March 7-11, 1998: Local Anesthesia/Pain
Introduction: Remifentanil is a specific [micro sign]-opioid agonist which is rapidly metabolized with an ultra-short half-life (approximately 3-10 min) and no accumulation after prolonged infusion. The rapid clearance and lack of accumulation allow an infusion to be titrated to optimize postoperative pain control. The aim of this study was to compare the analgesic efficacy of intravenous remifentanil infusion and thoracic epidural infusion in patients undergoing lung transplant surgery.
Methods: The charts of 13 consecutive single or bilateral sequential lung transplant patients were reviewed. The patients were divided into two groups according to the anesthetic technique. Patients in Group 1 (n = 7) received a thoracic epidural infusion of either ropivacaine 0.2% (n = 4) or a combination of bupivacaine 0.06% and fentanyl 10[micro sign]g/ml along with a light general anesthetic consisting of isoflurane. Patients in Group 2 (n = 6) received a total intravenous anesthetic technique consisting of remifentanil 0.2 to 0.4 [micro sign]g/kg/min and propofol 100-150 [micro sign]g/kg/min infusions. Muscle relaxation was achieved with vecuronium and patients were ventilated with air and oxygen combination. Patients in Group 1 continued to receive the epidural infusion, while those in Group 2 received an intravenous infusion of remifentanil for postoperative pain management. The data recorded included age, gender, weight, the anesthetic requirements, the duration of anesthesia, times to awakening (i.e., response to verbal command) and extubation, the duration of intensive care unit stay, the need for supplemental analgesics and visual analog pain scores (with 0 = no pain and 10 = severe pain). The data were analyzed using students t-test with a p value of less than 0.05 considered statistically significant.
Results: The two groups were similar with respect to demographic data and the duration of anesthesia. There were no statistically significant differences between the time to extubation, visual analog pain scores and the need for supplemental analgesic medications. Although the duration of intensive care unit stay was shorter in the patients receiving thoracic epidural infusion, and the time to awakening was less in the remifentanil groups, these did not achieve statistical significance. However, the duration of analgesic infusions were significantly (p < 0.05) shorter in patients receiving remifentanil (compared to those receiving thoracic epidural). (Table 1)
Conclusion: The results of this study suggests that intravenous remifentanil infusion is a satisfactory alternative to thoracic epidural analgesia. It also avoids the risks associated with epidurals, particularly, in patients requiring heparinization and cardiopulmonary bypass.