Preoperative Coadministration of Low-concentration Carbohydrate and Nitrates Loading vs Low- Concentration Carbohydrate Loading Alone in Patients Undergoing Open Gynecological Surgeries

Patients in the CHON group will be given 400 mL of a clear carbohydrate drink (12.5 g/100 mL maltodextrin, 50 kcal/100 mL) and 2 capsules of beet root extract 1 gm on the evening before surgery (8 hours) and another 200 mL of the carbohydrate drink and 1 capsule of beet root extract 1 gm on the day of surgery, 2 h before anesthesia induction.

Patients in the CHO group will be given the same carbohydrate drink in the CHON group with 2 placebo capsules with the evening drink and one with the morning drink.

Patients in the W group will be given equivalent volume of drinking water with placebo capsules by evening and in the morning of surgery.