Comparison of Intraoperative Hypotension Outcomes with and Without Hypotension Prediction Index Tool in Patients Undergoing Brain Tumour Surgery: A Study Protocol for a Randomised Controlled Trial.

Intraoperative hypotension (IOH) is a common occurrence during general anaesthesia for neurosurgery. Hypotension Prediction Index (HPI) is a recently available novel tool that uses arterial waveform features to predict IOH. This study aims to evaluate the role of HPI-integrated haemodynamic management protocol on IOH outcomes during brain tumour surgery. This is a single-centre, parallel-group, randomised controlled trial, approved by the Institute's Ethics Committee and the Clinical Trial Registry of India, and funded by the Indian Council of Medical Research. Consenting and eligible adult patients undergoing brain tumour decompression surgery will be randomised to either HPI-guided (n = 90) or conventional (n = 90) haemodynamic management in a 1:1 allocation ratio using a computerised random allocation sequence. Our primary outcome is the duration of IOH. Our secondary outcomes are the time-weighted average of IOH of mean arterial pressure < 65 mmHg, and incidence, severity, and timing of IOH. We will collect data about adverse effects of IOH, including vasopressor use, myocardial ischaemia, acute kidney injury, emergence and postoperative delirium, duration of intensive care unit, and hospital stay. If our study results demonstrate a beneficial effect of HPI, this will change current anaesthetic practice and approach to IOH, and improve perioperative outcomes after brain tumour surgery.