Oral acetaminophen as an adjunct to continuous epidural infusion and patient-controlled epidural analgesia in laboring parturients: a randomized controlled trial.

BACKGROUND: Intravenous acetaminophen is safe and effective as an adjunct to labor analgesia with combined spinal-epidural (CSE) analgesia and patient-controlled epidural analgesia (PCEA). Oral acetaminophen is a much cheaper and safe option but has not been studied as an adjunct to labor analgesia till date. The aim of the present study is to evaluate the effect of oral acetaminophen as an adjunct in patients receiving local anesthetic-opioid combination using CSE analgesia.

METHOD: In this ethically approved randomized double-blind placebo-controlled trial, 60 consenting parturients were randomly allocated to two groups of 30 each: acetaminophen (who received oral acetaminophen 1 g) or placebo, 45 min before the procedure. CSE was administered as per hospital protocol. All the patients received continuous epidural infusion (CEI) of levobupivacaine 0.1% and fentanyl 2 mcg/mL at 5 ml/h and PCEA boluses of 5 mL of the same drug with a lockout interval of 15 min if needed. The primary outcome was hourly mean consumption of levobupivacaine and fentanyl mixture (mL/h). Secondary outcomes included pain score, sensory and motor block, hemodynamic parameters of mother, duration of the second stage of labor, mode of delivery, maternal satisfaction, Apgar scores, fetal heart rate, and adverse effects.

RESULTS: The mean drug consumption per hour was significantly less in the acetaminophen group than in the placebo group (7.66 mL/h, SD 2.01 vs. 9.01 mL/h, SD 2.83; p = 0.04). The requirement for bolus was also significantly less in the acetaminophen group than in the placebo group (median 2.5, IQR 3 vs. median 3.5, IQR 2; p = 0.04).

CONCLUSION: The use of 1 g of oral acetaminophen could be a cheap, safe, and effective adjunct to CEI plus PCEA in labor analgesia.