Hemodynamic and Bispectral Changes During Pin Insertion in Craniotomy - Effect of Locally Infiltrated Bupivacaine.

Introduction Cranial pins insertion is a method for head stabilization and together with the scalp incision is one of the biggest noxious stimulus associated with arousal and rapid increase of the blood pressure leading to pathological increase of the intracranial pressure. The aim of this investigation is to study the superiority of the locally infiltrated anesthetic bupivacaine just before the skull pin insertion and the scalp incision in craniotomy under general anesthesia. Methods In the study thirty patients of both genders aged 24-72 years were included. They were categorized as ASA 1 and 2 and divided into two group of 15 patients each, group B (bupivacaine) and group S (saline). We recorded the bispectral (BIS) index, the mean arterial pressure (MAP) and the pulse rate (PR) in five time intervals: t 0-2 min before pin insertion; t 1-2 min after pin insertion; t 2-5 min after; t 3-10 min after and t 4-15 min after. Results Significant difference p<0.05 was achieved in group S for all three followed parameters: blood pressure, heart rate and bispectral index. The difference is present in all four time intervals compared to the initial one before the pin insertion. With further analysis it was demonstrated that the investigated BIS index participates the most in the overall significance in group F. Conclusion The scalp infiltration with local anesthetic bupivacaine results with stable hemodynamic parameters and stable intracranial pressure during the painful procedures as craniotomy.