Gabapentin premedication decreases the hemodynamic response to skull pin insertion in patients undergoing craniotomy.

Background: In patients undergoing craniotomy, skull pin insertion produces significant increases in heart rate (HR) and blood pressure. We investigated whether premedication with gabapentin would prevent or attenuate this increase.

Methods: Forty-seven ASA I and II patients, 18 to 60 years, undergoing elective craniotomy for intracranial tumor surgery were recruited prospectively and randomly divided into 3 groups; L (oral placebo plus 2% lidocaine infiltration at pin sites; n=12), G (oral gabapentin 900 mg plus normal saline infiltration; n=21) and GL (oral gabapentin 900 mg plus 2% lidocaine infiltration; n=14). The oral medications were administered 2 hours before induction of anesthesia. Measurements were made at preinduction baseline, before skull pin insertion and at every 1 minute from pin insertion till end of 10 minutes.

Results: Forty-three patients completed the study (L, n=11; G, n=20; GL, n=12). Premedication with gabapentin significantly attenuated the rise in systolic (SBP) and mean arterial pressure (MAP) after pin insertion when compared with placebo (for SBP, P<0.001 at 1 and 2 min and <0.05 at 3 to 5 min between L and G; P<0.001 at 1 to 4 min and <0.05 at 5 min between L and GL; for MAP, P<0.05 at 1 min, <0.001 at 2 min and <0.05 at 3 to 4 min between L and G; P<0.001 at 1 to 2 min and <0.05 at 3 to 5 min between L and GL). HR responses were also attenuated in patients premedicated with gabapentin; however, the responses were more variable in group G (P=0.03 between L and G at 4 min after pin insertion) as compared with group GL (P<0.05 at 1 min, <0.001 at 2 min and <0.05 at 3 to 10 min between L and GL).

Conclusion: In conclusion, 900 mg of gabapentin, administered orally 2 hours before induction of anesthesia along with lidocaine scalp infiltration abolished the hemodynamic response after skull pin insertion. Premedication with gabapentin alone significantly attenuated the SBP and MAP; however, HR responses were more variable. A larger trial is required to corroborate the findings of the study before clinical recommendations would be warranted.