Comparison of The Efficacy of Sterile Silicone Studs vs Lidocaine for the Attenuation of the Hemodynamic Response to Skull Pin Insertion: A Randomized Controlled Trial: The role of sterile silicone studs and scalp infiltration with lignocaine in the attenuation of the hemodynamic response to skull pin insertion.

BACKGROUND: Skull pin insertion causes hypertension and tachycardia that adversely affects cerebral hemodynamics. We compared the efficacy of sterile silicone studs (SS) and pin site infiltration with lidocaine in attenuation of the sympathetic response to skull pin insertion.

METHODS: One hundred and twenty adult patients undergoing supratentorial craniotomy under general anesthesia were randomized to receive either medical-grade sterile SS (Group SS) or 2 ml of 2% plain lidocaine infiltration at each pin site (Group LO). The primary objective was the comparison of the hemodynamic (heart rate [HR] and mean arterial pressure [MAP]) response to skull pin insertion at baseline and 0, 1, 2, 3 and 5 minutes of skull pin insertion. The secondary objectives were to assess the requirement of rescue analgesia (fentanyl), complications like pin-site bleeding, and the surgeon satisfaction score.

RESULTS: The HR in Group LO was significantly greater at 0, 1, 2, 3 and 5 mins post pin insertion as compared to Group SS (P <0.05). The MAP was also significantly higher in Group LO at 0, 1, 2, and 3 mins post pin insertion (P = 0.001, 0.01, 0.034 and 0.042 respectively) as compared to Group SS. The number of patients requiring fentanyl [17/60 (28.3%) v/s 40/60 (66%), P=0.001] was lower in Group SS. The incidence of pin site bleeding was also lower in Group SS along with a greater surgeon satisfaction score.

CONCLUSION: Sterile SS appears to be more effective than lidocaine infiltration in attenuating the hemodynamic response to skull pin insertion with minimal adverse effects. Further multi-centre studies are necessary to conclusively establish the safety and efficacy of sterile SS.