After IEC-HR permission, all patients admitted in neurosurgical wards for neurosurgical procedure, satisfying all inclusion and exclusion criteria will be considered for inclusion into the study. All patients or their near relations will be explained about the study and a written valid informed consent for their willingness to participate in the study will be taken. All demographic data of the patients will be noted from the patient’s history and case sheets. Later, a detailed preoperative assessment will be done on the patient and following scores will be applied. 

·       American society of anaesthesiologists physical status( ASA-PS)

·       Glasgow coma scale (GCS)

·       Karnofsky performance score (KPS)

·       SKALE- Sex, Karnofsky performance score, American society of anaesthesiologist class, location of tumour and peritumoural edema grading system

·       Charlson Comorbidity Index

Each individual feature of a particular scoring system is understood and thus marked whichever describes the patient’s condition the best. Total score will be calculated for each scoring system.

Following intraoperative variables will be noted.

·       Duration of surgery

·       Position of surgery

·       Intraoperative blood loss

·       Intraoperative adverse events if any.

o   Hypotension > 25% baseline

o   Arrhythmias

o   Hypoxia (spO₂ <90%)

o   Air embolism

o   Any other event affecting outcome

Need for ventilator support with duration will be noted. Post surgery, the patient will be reassessed on post operative day 1(POD1). All patients will be followed up till discharge for noting their postoperative course in ward, any complications that may develop and if any resurgery is needed. Karnofsky performance score will be assessed again prior to discharge and will be compared with the preoperative status.

Different scoring systems will be evaluated for their preoperative scores and their predictability of post operative outcome.