Effect of Scalp Block vs Sphenopalatine Ganglion Block with Posterior Occipital Nerve Block on Hemodynamic Response Following Skull Pin Application.

Sphenopalatine ganglion (SPG) block combined with occipital nerve block can attenuate the hemodynamic response to the painful stimulus of skull pin application. About 60 patients, aged 18-65 years, were randomly assigned to two groups. All patients were classified as American Society of Anesthesiologists (ASA) grades I and II, had a Glasgow Coma Scale (GCS) score of 15/15, and were scheduled for elective craniotomy. Group S was given a scalp block with 0.25% bupivacaine, while group SPG was given a bilateral transnasal SPG block with 0.5% bupivacaine, along with greater and lesser occipital nerve blocks using 0.25% bupivacaine. The primary objective was to assess the change in mean arterial pressure (MAP) following skull pin application. The dose of propofol used as rescue was also noted. All 60 patients completed the study. The MAP differed significantly in group SPG from prior to pin insertion to 2 (p-value = 0.034) and 3 minutes (p-value = 0.026) following pin insertion. The maximum percent change from the prior to pin insertion timepoint was observed at 2 minutes (p < 0.001). The heart rate (HR) also differed significantly in group SPG from the prior to pin insertion to 2 (p-value = 0.001) and 3 (p-value = 0.006) minutes following pin insertion. The maximum percent change from the prior to pin insertion was observed at 2 minutes following pin insertion (p < 0.001). There was no significant difference in the percent change in HR between the two groups from prior to pin insertion to any of the timepoints. Bilateral SPG block with posterior scalp block can attenuate the hemodynamic response following skull pin insertion in patients undergoing craniotomy under general anesthesia.