Analgesic efficacy of wound infiltration with fentanyl or bupivacaine or bupivacaine with fentanyl in arthroscopic anterior cruciate ligament reconstructive surgery: A double blind randomized control trial

Patients undergoing anterior cruciate ligament reconstructivesurgery commonly complain of high-intensity pain in the postoperative period due to tear of muscles and ligaments etc. Postoperative pain is the leading cause of prolonged hospital stay and delayed rehabilitation. Conventionally, postoperative pain relief in anterior cruciate ligament reconstructive surgery is achieved by using systemic analgesics, preferably opioids, which have their own set of deleterious effects like nausea, vomiting, pruritus, respiratory depression, and sedation etc. Epidural morphine has also been shown to be effective for pain relief but it needs technical expertise and its use is associated with side effects like sedation and respiratory depression. Local infiltrative analgesia is advantageous in terms of fewer side effects and ease of application, but its analgesic effect is short-lasting. Many local anaesthetic agentslike bupivacaine are being used as local infiltrative analgesiabut has limited duration of action (4-6 hours). The peripheral analgesic effect of fentanyl was reported long back and recent scientific evidence has finally unravelled the presence of activated opioid receptors at the incision site. Initial few studies have shown a promising analgesic effect and therefore, it has rekindled interest in local infiltration of fentanyl for its potent peripheral analgesic effect. Interestingly, the localinfiltration of fentanyl is devoid of the distressing side effects of systemic opioids as mentioned above.

We aim to conduct a double blind randomized controlled trial comprising of three groups with 35 patients in each group. Group â€˜B’ will be infiltrated with 10 ml of 0.25% bupivacainehydrochloride.  Group â€˜F’ will be infiltrated with 50 micrograms of Fentanyl citrate diluted in 10 ml of normal saline and Group â€˜BF’ will be infiltrated with 10 ml of solution containing 9ml of 0.25% bupivacaine hydrochlorideand 50 micrograms (1 ml) of fentanyl citrate at the surgical wound site in patients undergoing anterior cruciate ligamentreconstructive surgery under general anaesthesia. Post-surgery, we plan to assess pain relief with the help of visual analogue scale (VAS) and the total analgesic requirement of supplemental analgesic drugs will be recorded for 24 hours from infiltration of drug. Side effects of opioids namelynausea, vomiting and sedation will be assessed in all the threegroups. We anticipate that analgesic efficacy of fentanyl will be better than bupivacaine for wound infiltration in patients undergoing anterior cruciate ligament reconstructive surgeryunder general anaesthesia.