The effect of preoperative pentoxifylline on postoperative pain and development of secondary hyperalgesia in patients undergoing laparoscopic appendectomy; a randomized, double-blind, placebo-controlled trial study.

BACKGROUND After surgery and loss of anesthetic effect, postoperative pain can annoy the patient and affect patient satisfaction with treatment. This study was aimed at evaluating the effect of preoperative pentoxifylline (PTX) on postoperative pain and development of secondary hyperalgesia in patients undergoing laparoscopic appendectomy (LA). METHODS This randomized, double-blind, placebo-controlled clinical trial study was conducted on 91 eligible subjects with acute appendicitis referred to Shahid Beheshti hospital of Sabzevar, Iran in 2018. The intervention and control groups were administered with a single oral dose of PTX (10 mg kg-1) and placebo an hour before surgery respectively. Postoperative pain was measured within 24 hours after surgery using a Visual Analog Score (VAS) and the area of secondary hyperalgesia was measured 24 hours after surgery using Stubhaug et al. method. RESULTS The mean age of the subjects was 26.74±9.99 and 57.14% were female. Pain intensity during rest was significantly greater in the control group as compared to PTX at 24th hours after surgery (2.19±0.49 and 3.13±0.66; P <0.001 respectively). Moreover, pain intensity during cough was substantially lower in the PTX compared with the control group at 24th hours after surgery (2.65±1.90 and 4.10±2.60; P = 0.003 in turn). The dynamic hyperalgesia was significantly greater in the control group as compared with the PTX group (3.80±1.82 and 7.43 ±2.38; P <0.001). CONCLUSIONS Findings suggest that oral administration of PTX one hour before surgery in patients undergoing LA can reduce postoperative pain in patients and prevent secondary hyperalgesia at a surgical site.