After obtaining written informed consent, 50 patients, meeting the inclusion criteria will be recruited for the study. All patients will undergo thorough pre anaesthetic evaluation. All routine investigations along with necessary special investigations will be asked for. Location of tumor, nature of the lesion, maximum tumor diameter, and features of preoperative raised intracranial pressure(ICP) as evidenced by the presence of peri tumoral edema, mass effect, and/or hydrocephalus also will be noted. After overnight fasting on the morning of surgery, venous blood sample is sent for Serum electrolytes, Blood urea nitrogen (BUN) and Random blood sugar levels.

In the operation theatre, standard monitors (electrocardiogram [ECG], non‑invasive blood pressure [NIBP], and pulse oximeter [SpO2]) will be attached and baseline parameters noted. An 18 G intravenous cannula will be inserted into one of the forearm veins. Patients are then randomized allocated to two groups of 25 patients each based on randomly generated numbers as obtained from websitewww.randomizer.org. Allocation concealment will be done using serially numbered opaque envelope (SNOSE) method. The patients in the NS group will receive only NS as the maintenance fluid during the intra operative period flow rate of 2 ml/kg /hr. Patients in the NSRL group will receive NS followed by RL administered alternatively through same IV port at flow rate of 2 ml/kg /hr. The operating neurosurgeon will be blinded to the infused fluid by covering the label. Standard induction protocol (fentanyl 2 micrograms/kg, propofol 2 mg/kg and vecuronium 0.1 mg/ kg, IV) will be followed in all the patients. Post induction, side stream airway gas and neuro muscular blockade monitoring will be done. Direct laryngoscopy and tracheal intubation Will be performed 3‑5 minutes after administration of the neuromuscular blocker. After intubation with appropriate size endotracheal tube and confirming the correct placement of endotracheal tube, patients will be maintained on intermittent positive pressure ventilation with Oxygen-Nitrous oxide 40:60 with isoflurane. Injection Mannitol 0.5 gm/kg will be administered intravenous over 20 minutes to all patients before opening of dura. Blood transfusion will be carried out in accordance with the ASA (American society of anaesthesiology)practice guidelines and as per institutional protocol. Following completion of surgery, the decision for tracheal extubation will be at the discretion of the attending anesthesiologist in consultation with operating neurosurgeon. The patients are then shifted to the neurosurgical intensive care unit for immediate postoperative management and subsequently to the surgical ward.

Qualitative variables are entered as frequency and percentage and quantitative data as number and mean in MS Excel sheets after filtering of data will be analyzed applying appropriate statistical tests using latest version of SPSS software Armonk, NY: IBM Corp. All qualitative data will be compared using chi square test/Fisher Exact test and all quantitative data will be compared using student ‘t’ tests if data distribution is normal. P value <0.05 is considered as statistically significant.