Evaluation of adding Acetaminophen to Fentanyl in Patient-Controlled IV Analgesia (PCIA) after Lower Limb Orthopedic Surgery

Postoperative analgesia is one of the most concerns of anesthesiologist and patients. Systemic opioids administration is the gold standard in reducing the severe pain after surgery but some side effects prevent the use of adequate doses of opioids. The aim of this study was evaluation of adding acetaminophen on fentanyl in patient-controlled iv analgesia (PCIA). In this randomized clinical trial, 120 patients candidate for lower limb orthopedic surgery (ASA I-II) were recruited in Rasoul-Akram Medical Center in a 12- month period. They randomly allocated in two groups for postoperative pain, group F (Fentanyl) ((n=60) and group AF (Acetaminophen/ Fentanyl) (n=60) by patient-controledl intravenous analgesia (PCIA) groups. The pump has a continuous infusion of 5 ml per hour, bolus dose 2 ml and the lock out time 30 minutes was left. Each ml of solution in group F containing 10 mcg of fentanyl and in the group AF containing 5 mcg fentanyl and 20 mg acetaminophen. Pain score, sedation score, satisfaction, nausea and vomiting was evaluated for 48 hours after surgery. The demographic characteristics of the two groups did not differ significantly. Pain scores befor pump in F and AF groups were 6.8±1.6 and 6.5±1.4, respectively. After 24 and 48 hours pain scores (2.4± 0.8, 1.7± 0.7) and (1.9± 0.6, 1.2± 0.5) decreased (P<0.001). Changes in pain scores were similar in both groups. Level of sedation, nausea and vomiting in the F group and satisfaction in the AF group was higher. This study showed adding iv acetaminophen to fentanyl through an PCIA is effective in controlling pain in patients undergoing lower limb orthopedic surgery. Moreover, acetaminophen and fentanyl combination and has fewer side effects such as nausea, vomiting and sedation and more satisfaction than fentanyl alone.