Pain relief after arthroscopic knee surgery: a comparison of intra-articular ropivacaine, fentanyl, and dexmedetomidine: a prospective, double-blinded, randomized controlled study

ABSTRACT

Postoperative pain is very common distressing symptom after any surgical procedure. Different drugs in different routes have been used for controlling post-arthroscopic pain. No one proved to be ideal. We have compared the analgesic effect of ropivacaine, fentanyl, and dexmedetomidine when administered through the intra-articular route in arthroscopic knee surgery. From March 2008 to July 2010, 99 patients undergoing arthroscopic knee surgery were randomly assigned into three groups [A,B,C] in a prospective double-blinded fashion. Group A received 10 ml of 0.75% ropivacaine, where Group B received 50 microg fentanyl, and Group C received 100 microg of dexmedetomidine through the intra-articular route at the end of procedure. Pain assessed using visual analog scale and diclofenac sodium given as rescue analgesia when VAS >4. Time of first analgesia request and total rescue analgesic used in 24 hours were calculated. Demographic profiles are quite comparable among the groups. Time for requirement of first postoperative rescue analgesia in Group A was 380.61 +/- 22.973 min, in Group B was 326.82 +/- 17.131 min and in Group C was 244.09 +/- 20.096 minutes. Total rescue analgesia requirement was less in Group A [1.394 +/- 0.496] compared to Group B [1.758 +/- 0.435] and Group C [2.546 +/- 0.546]. Group A had higher mean VAS score at 6th and 24th postoperative hours. No side effects found among the groups. Therefore, it suggests that intra-articular ropivacaine gives better postoperative pain relief, with increased time of first analgesic request and decreased need of total postoperative analgesia compared to fentanyl and dexmedetomidine.