effect of pre vs. post incision inguinal field block on postoperative pain after pediatric herniorrhaphy, a different approach

backgrounds: the aim of this study was to determine if preemptive local anesthesia yields better postoperative pain control than infiltration of local anesthesia at the time of wound closure. methods: forty patients aged between 1 and 10 years were randomly allocated to one of the two groups by using a sealed envelope technique. group 1 received 0.5 mg/kg bupivacaine 20 minutes before the incision of skin and the same volume of normal saline at the end of skin suture. group 2 received 0.5 mg /kg bupivacaine at the end of skin suture and the same volume of normal saline 20 minutes before the incision of skin. pain scores of patients in the recovery room, 6, 12 and 24 hours after surgery were measured. if patients complained of post surgical wound pain, 30 mg/kg of acetaminophen was administered by rectal suppository. data were analyzed by chi-square test, t -test and anova. results: there were no statistical significance between the two groups for age, weight and sex. the overall mean of pain was 4.6 ± 2.6 for group 1 and 18.6 ± 8.7 for group 2 and the difference between the two groups was statistically significant (p<0.001). the mean dosage of acetaminophen administration was significantly higher in group 2 compared with group 1 (p<0.05). conclusions: pre-surgical infiltration of bupivacaine in the surgical field is a useful method in decreasing both post-surgical wound pain for up to 24 hours and analgesic consumption after inguinal hernia repair.