Effect of scalp nerve blocks on post-craniotomy pain in the patients undergoing craniotomy

ABSTRACT

BACKGROUND: Sympathetic stimulation associated with post-craniotomy pain might subsequently increase blood pressure resulting in postoperative complications. We studied whether scalp nerve blocks would reduce the severity of postoperative pain. METHODS: Thirty-two patients undergoing craniotomy were randomly allocated to either the ropivacaine group (n = 16) or the saline group (n = 16). After the skin closure, we carried out scalp nerve blocks with ropivacaine (0.75%) or saline (0.9%). Visual analog scale scores (VAS), mean arterial pressure, and heart rate were measured at 0.5, 1, 2, 4, 6, 12, 24, and 48 h after extubation. Tramadol 50 mg iv was used as rescue analgesic. The delay before administration of the first analgesic and cumulative dose of rescue analgesic for the first 48 h postoperatively were measured. RESULTS: The ropivacaine group had lower analgesic requirements than the saline group (P = 0.008). The delay before administration of the first analgesic was not different significantly between two groups. VAS was similar between the two groups at each time interval. Postoperative MAP and HR were not significantly different between two groups. VAS did not correlate with these hemodynamic variables. CONCLUSIONS: Although scalp nerve blocks with ropivacaine reduced the analgesic requirement, they did not provide the sufficient pain relief.