Effect of add-on Gabapentin premedication on hemodynamic response to skull pin insertion

Effectiveness of oral gabapentin premedication in suppressing response to laryngoscopy and tracheal intubation suggests its potential for attenuating skull pin insertion response. The present study was therefore planned to evaluate the effect of add-on oral gabapentin premedication to local anesthetic injection at pin insertion site in obtunding hemodynamic response.

Sixty adult patients posted for elective craniotomy were enrolled for a prospective, randomized and double-blinded study. Group I patients received gabapentin 900 mg orally as premedication whereas Group II patients received oral placebo. Both groups were administered subcutaneous (s.c.) injection (Inj) 2% lignocaine 2 mL at all four pin insertion sites. Mean arterial pressure (MAP) and heart rate (HR) were measured every 30 s for the initial 10 min. Increases in HR beyond 20% and MAP 30% above baseline were treated with bolus intravenous (IV) Inj propofol 30 mg. Quantitative data was compared using Student's t-test and Mann Whitney U test, while categorical data was compared using Chi-square (χ²) test.

The increase in HR and MAP from baseline was significantly greater and it remained above baseline levels longer in Group II as compared to Group I. Twenty-one patients (70%) received rescue boluses of propofol with a mean dose of 45.00 ± 39.98 mg in Group II as compared to nine (30%) patients receiving mean of 18.20 ± 29.04 mg in Group I. (P = 0.015). The mean emergence time and sedation scores in both the groups were statistically similar (P = 0.060).The incidence of adverse effects like hypotension, bradycardia, nausea/vomiting, sedation or dry mouth were similar in both the groups.

Add-on oral gabapentin premedication potentiates the effect of s.c. lignocaine Inj for suppression of skull pin insertion response.