A STUDY ON HAEMODYNAMIC RESPONSE ATTENUATION DURING HEAD HOLDER APPLICATION FOR CRANIOTOMY COMPARING IV DEXMEDITOMIDINE AND LOCAL LIGNOCAINE

Abstract

Background; One of the goals of neuro anesthesia is to ensure stable perioperative cerebral hemodynamics, thus avoiding a sudden rise in intracranial pressure and prevent acute brain swelling.1 The intense surgical stimuli associated with craniotomy frequently causes sympathetic activation, which results in changes in heart rate (HR), blood pressure (BP), and cerebral blood ow (CBF). These changes may increase intracranial pressure (ICP) and a reduction in cerebral perfusion pressure (CPP). Finally, it leads to cerebral ischemia, especially in patients with impaired autoregulation and compromised cerebral compliance2,3. Thus, it is essential to preserve cerebral homeostasis and to prevent abrupt changes in hemodynamics. Smooth and rapid recovery from anesthesia allows immediate neurological assessment. Application of skull pin head holder is a necessity for stabilizing the head during craniotomy. Mayeld device or head holder is a clamp thatconsists of a C-shaped metal piece with three sharp interchangeable metal pins arranged triangularly to one another.4 These pins forced through the layers of scalp and periosteuminto the external lamina of the skull. Skull pins support the head without allowing any direct pressure on the face, allow access to the airway, and hold head rmly in one position that can nely be adjusted for optimal neurosurgical exposure. This study was conducted in fty ASA grade 1 or 2 patients who were adm Methods: itted at Government General Hospital, Guntur afliated to Guntur Medical College, Guntur, to undergo elective craniotomies under general anesthesia. After getting Ethical committee approval, a total of fty patients were allocated into two groups of 25 each. They were connected to the non-invasive monitors, and the basal heart rate and mean arterial pressure were recorded.Patients randomized to group dexmedetomidine received 1mcg/kg of dexmedetomidine diluted to 10ml with 0.9% saline over 10 min through a syringe pump, after recording pre-induction baseline hemodynamic parameters. Before the pin application, these patients received inltration of the pin sites with 0.9% saline (3ml for each site). Patients randomized to group lidocaine received infusion of 10ml of 0.9% saline over 10min, after recording baseline hemodynamic parameters. They then received inltration of the pre-marked pin sites with 2% lidocaine (without adrenaline), 3ml for each site. Heart rate and mean arterial pressure were recorded at various time intervals.Baseline, preinltration, post inltration, pre pin, 1 minute after post pin, 2minutes after post pin, 3 minutes, 5 miutes, 10 minutes and 15 minutes after post pin application. The result was analyzed using student t-test, and a P value of less than 0.05 was taken as signicant. ResultsWith patients matched for demographic data, the results showed there was no signicant difference in baseline values between the two groups. Heart rate and mean arterial pressure were comparable between the groups at various time intervals in the study. Thus both dexmedetomidine and lidocaine are equally effective in controlling the hemodynamic response to skull pin application. Despite being comparable to lidocaine inltration, dexmedetomidine causes signicantlymore episodes of hypotension and bradycardia, which could be detrimental in neurosurgical patients. Dexmedetomidine 1mcg/kg infusion and 2% li Conclusion gnocaine inltration both are equally effective in controlling the hemodynamic response to skull pin placement. Despite being comparable to lignocaine inltration, dexmedetomidine causes signicantly more episodes of bradycardia and hypotension, so they need rescue medication, which could be detrimental in a neurosurgical patient. We conclude that 2% of local lignocaine inltration is better in controlling hemodynamic responses to skull pin head holder application and does not cause any adverse effects in any of the patients.