The use of intraarticular tramadol for postoperative analgesia after arthroscopic knee surgery: a comparison of different intraarticular and intravenous doses.

We aimed to determine the optimal dose of tramadol when administered intraarticularly after arthroscopic knee surgery under general anesthesia in patients with an American Society of Anesthesiologists (ASA) physical status score of I-II. When the surgical procedure was completed, patients were assigned to one of seven groups ( n=30 for each) in a double-blinded and randomized manner according to a table of random numbers. Group I received 100 mg tramadol, Group II received 50 mg tramadol, Group III received 20 mg tramadol and Group IV received 0.9% NaCl intraarticularly in 20 ml solutions. Group V received 100 mg tramadol, Group VI received 50 mg tramadol and Group VII received 20 mg tramadol intravenously. Pain was evaluated by using the Visual Analogue Scale (VAS) at 0 min (when the patient was cooperated after extubation), 30 min, 1 h, 4 h, 6 h, 12 h, 18 h and 24 h postoperatively. Patients were administered diclofenac sodium 75 mg intravenously (i.m.) when they experienced pain. The intraarticular tramadol groups had longer duration of analgesia than i.v. tramadol groups who were administered the same doses (I vs V; II vs VI; III vs VII; p <0.001). Group I had the longest duration of analgesia ( p<0.001). Group II had a longer time to the first analgesic request than all other groups ( p<0.001) except Group I. Consequently, Group I and II needed less analgesics than other groups ( p<0.001). Pain scores were 0-3 on the VAS in Groups I, II and V at first assessment, in Groups I and II at 30 min and 1 h, and in Group I at 4 h and 6 h postoperatively ( p<0.01). In Group V, vomiting was more a more frequent complication than with other groups ( p<0.05). It is concluded that tramadol provides analgesia with a peripheral mechanism when administered intraarticularly. The side effects of intraarticular 100 mg tramadol were no more severe than those for intraarticular 50 mg tramadol. Moreover, intraarticular 100 mg tramadol provided excellent analgesia after arthroscopic surgery.