Evaluation of Dexmedetomidine as anaesthetic adjunct to Propofol during Bispectral Index guided anaesthesia for cerebello-pontine angle surgeries

Cerebello-pontine angle (CPA) surgeries tend tocarry the surgeon’s knife uncomfortably close to the brainstem, putting variouscranial nerves at risk for damage. For preventing this, cranial nerve monitoringusing continuous electromyography (EMG) of the regional motor supply of thenerve or evoked potentials is utilized. It has been recommended in literature that propofolas a primary hypnotic component of anaesthesia would provide better conditionsfor cranial nerve monitoring compared to inhalational agents. High dose of propofol has certain undesirableeffects as such as occasional delayed awakening, metabolic acidosis withincreased lactate levels and myocardial depression causing hypotension. Dexmedetomidine has been used as an anaesthetic adjunct to propofol and has been shown to reduce propofol requirements, whenused along with processed EEG monitoring. Inthis study, we propose to quantify the probable dose reduction of propofol withuse of dexmedetomidine during CPA surgeries and compare the recovery profile,adequacy of cranial nerve monitoring, acid base status and intraoperative haemodynamicswith and without the usage of dexmedetomidine.