impact of subcutaneous infiltration of 0.5% bupivacaine on postoperative c-reactive protein serum titer after craniotomy surgery

background: tissue injuries may provoke neuro-hormonal response which in turn may lead to release of inflammatory cytokines. we hypothesize that block of afferent sensory pathways by infiltration of 0.5% bupivacaine in the scalp may decrease neuro-hormonal response in the neurosurgical patient. methods: after obtaining informed consent, forty asa physical statuses i, ii, or iii patients between the ages of 18 and 65 years were enrolled randomly into two equal groups to receive either 20 ml of 0.5% bupivacaine (group a) or 20 ml of 0.9% normal saline as a placebo (group b) in the site of pin insertion and scalp incision. as the primary outcome we checked serum c-reactive protein (crp) levels before implementation of noxious stimulus, 24h, and 48h after the end of surgery to compare these values between groups. in addition, mean arterial pressure (map) and heart rate (hr) were checked at baseline (after the induction of anesthesia), one minute after pin fixation and 5, 10, and 15 minute after skin incision and the recorded values were compared between groups. results: no significant difference was found between serum crp levels of the two groups. comparison of mean hr between groups shows no significant difference. the mean of map was significantly lower in the group a in comparison with the group b (p < 0.001). conclusion: the results of this study confirm that 0.5% bupivacaine scalp infiltration before skull-pin holder fixation and skin incision could not decrease post-operative c-reactive protein level.