(227) Comparative Study of Intra‐Articular Morphine, Fentanyl or Bupivacaine for Knee Surgery

Introduction: After identification of peripheral receptors, a possibility was open to apply peripheral opioids in an attempt to use the strong analgesic effects of such drugs and, at the same time, avoid undesirable side effects. The aim of this study was to evaluate the analgesic effect of intra-articular morphine, fentanyl and bupivacaine in knee surgeries. Methods: Forty patients physical status ASA I or II scheduled for arthroscopic knee surgery were randomized to one of four groups. GI (10 patients) received 10 ml of 0.9% saline; GII (10 patients) received 10 ml of 0.25% bupivacaine with epinephrine; GIII received 2 mg of morphine diluted in 0.9% saline to 10 ml; GIV (10 patients) received 100 mcg of fentanyl diluted to 10 ml with saline. All patients were submitted to spinal anesthesia with 15 mg of 0.5% hyperbaric bupivacaine and at the end of the surgery received analgesic solutions. Pain intensity was evaluated through analogical visual scale at 0, 6, 12, 18 and 24 hours. T0 was considered the time when the patient entered the post-anesthetic care unit. Results: There were no pain intensity differences during different periods (Table 1). No side effects were observed. Conclusions: Morphine was similar to bupivacaine but needed more additional analgesics. All groups showed effective analgesia during 24 hours. Table 1.  Pain intensity in different periods Groups Periods   T0 T6 T12 T18 T24 G I saline 0 ± 0 1.6 ± 2.3 3.0 ± 2.5 2.3 ± 1.2 2.2 ± 1.3 GII bupivacaine 0.5 ± 1.1 2.1 ± 1.8 1.6 ± 0.9 1.7 ± 1.4 1.6 ± 1.2 G III morphine 0.2 ± 0.8 2.2 ± 1.8 2.2 ± 1.5 2.0 ± 1.7 1.5 ± 1.2 G IV fentanyl 0.2 ± 0.6 0.5 ± 0.4 1.1 ± 1.1 1.1 ± 0.9 1.4 ± 0.9