A randomized control trial will be carried out at the department of Anesthesiology of Rural Medical College, Loni. All patients who will fulfill inclusion and exclusion criteria at Pravara Rural Hospital (PRH), Loni will be included as study subjects. Pertinent data will be collected using a pre-validated and pre-tested study tool, from all study subjects, who will receive Vitamin C and combination of Vitamin C, Vitamin D and Zinc as mentioned below, during a study period of March 2021 to February 2022. 

Group A- All patients aged 18 years to 65 years undergoing surgeries under general anesthesia who will receive Tablet Vitamin C.

Group B- All patients aged 18 years to 65 years undergoing surgeries under general anesthesia who will receive a combination of Vitamin C, Vitamin D and Zinc.

CONSENT: The patients will be explained in detail regarding the anaesthetic procedure and the study. Written and verbal consent will be taken for the procedure, as well as for his/her inclusion in the proposed study.

PREPARATION: As per routine protocol of the institution, the patients will be thoroughly evaluated by a pre-anaesthetic check-up with general, physical and systemic examination on the evening prior to the proposed surgery. The severity of POST was explained to patients graded from 0 to 3, with 0 corresponding to no sore throat and 3 to severe sore throat with change of voice, hoarseness and severe throat pain. All the patients will receive vitamin C and or combination of Vitamin C, Vitamin D and Zinc 1 day prior to surgery at night. Patients will be fasted for a period of 6 hours pre-operatively.

PROCEDURE: On the day of surgery, patients will receive vitamin C and or combination of Vitamin C, Vitamin D and Zinc in preoperative area with instruction to dissolve it in mouth by sucking on it 30 minutes prior to procedure. Patients will then be shifted to the operating room and standard monitoring, including electrocardiogram, mean arterial blood pressure, respiratory rate and oxygen saturation will be started using multi-para monitors. The anaesthesia machine, breathing circuits, emergency resuscitation trolley and airway equipment will be kept ready.

All the patients in group A and B will be given general anesthesia. Premedication IV injection of Glycopyrrolate(0.008mg/kg), Midazolam(0.04mg/kg) and Fentanyl (1mcg/kg) will be given. Induction will be done with Inj. Propofol (2 mg/kg) followed by orotracheal intubation facilitated by Inj. Succinylcholine (2 mg/kg). Laryngoscopies will be performed by Macintosh blade 3 and 4 to insert endotracheal tubes of inner diameter 7 to 8.5 mm. The laryngoscopic view will be graded according to Cormack Lehan Grading. Anaesthesia will be maintained with Isoflurane and Inj. Vecuronium (0.08 mg/kg) followed by top-ups of 0.01 mg/kg. Intermittently, every half hour cuff pressure will be measured and adjusted to 30 cm of water. Intra operatively use of steroids and anti-inflammatory drugs was noted. After surgical procedure patient is extubated after reversal with Inj. Neostigmine (0.05mg/kg) and Inj. Glycopyrrolate (0.01mg/kg) and coughing or bucking will be noted at the time of emergence.

At the end of the surgery, the patients will be shifted to the post- anaesthesia care unit, and will receive the same basic standard of post-operative care.

OBSERVATIONS:

Primary Variable:

An immediate evaluation for presence and severity sore throat after extubation (time = 0) and then in postoperative care unit will be done, using a standardized scale in postoperative care unit. This evaluation will be repeated at 30 mins, 1 hour, 2 hrs, 4 hrs, 6 hrs and 24 hrs.

Secondary Variables:

·         Mean Duration of Laryngoscopy (Seconds)

·         No of intubation attempts

·         Mean duration of Anesthesia (Minutes)

·         Mean Surgery Duration( Minutes)

·         Cormack Lehan Grading:

    Grade 1 –– full glottic view

    Grade 2 –– only posterior extremity of glottis visible

    Grade 3 –– only epiglottis visible