Effect of Preemptive Dexamethasone via nebulization versus intravenous route on Postoperative sore throat after spine surgery in prone position: A Randomised, Double-blinded study.

All patients fulfilling inclusion and exclusion criteria will be identified the day before surgery and The patient information sheet will be given to the study participants  who will be informed about the study protocol Written informed consent will also be obtained from all the study participants for the conduct of the study  Age gender and body mass index (BMI) will be measured and noted  American Society of Anesthesiologists physical grade and planned surgery will also be noted and We will do computer-based permuted block randomisation using the blockrand R package  A random sequence will be generated with varying block sizes and kept in 160 opaque sealed envelopes It will be prepared and administered by an independent trained anesthesiologist He/she will prepare a nebulisation solution and an intravenous solution with a 5 ml volume The drug dexamethasone will be in the solution based on the group to which the patient is allocated Double blinding will be done An anaesthetist not part of the study will prepare the intervention drugs No one in the anesthesiology team responsible for the patient’s care during and after surgery will know the patient’s group allocation The anaesthetist will assess the outcome data and the patient will be blinded to the group allocation

In the study by Ramamurthy et al comparing intravenous with nebulised dexamethasone the incidence of POST(post operative sore throat) was 51.4% 42.9% 23.6% 17.1% in the intravenous group compared to 74.3% 65.7% 60% 37.1% in the nebulization group at 2 6 12 and 24 hours respectively Using the clinical.com sample size calculator at the above-mentioned time points Hence, the sample size for 2 6 12 and 24 hours comes out to be 138 148 56 and 152 respectively We will recruit the highest sample size of 152 patients Adding a dropout of 5% the final sample size comes to be 152+ 8= 160 patients

Upon arrival in the preoperative room the patients will receive nebulization with a 5 ml solution for 15-20 minutes and intravenous injection of a 5 ml volume clear solution before wheeling into the operating theatre The intervention will be as per the group allocated as follows

Group I (Intravenous Dexamethasone)- Nebulization with 0.9% saline (5ml) and intravenous injection of Dexamethasone 0.2 mg/kg diluted to a total volume of 5 ml with 0.9% saline

Group N Nebulization with Dexamethasone 0.2 mg/kg diluted to a total volume of 5 ml with 0.9% saline and 0.9% saline (5 ml)

 Anaesthesia management will be as per standard institutional protocol Induction of anaesthesia will be with opioids like fentanyl 2 microgram/kg midazolam 0.03 mg/kg and intravenous anaesthetic drugs like propofol 2-3 mg/kg Trachea will be intubated 3 minutes after administering a non-depolarising neuromuscular blocking agent by a conventionally trained anesthesiologist to minimize injury due to inexperience or inadequately relaxed vocal cords Low-pressure high-volume cuffed wire-reinforced armoured endotracheal tube will be used for intubation according to the patient’s gender and build 7-7.5 mm ID(internal diameter) and 8-8.5 mm Internal diameter for females and males respectively Anaesthesia will be maintained with oxygen air plus inhaled anaesthetic agent [Isoflurane/ sevoflurane 1-1.5 MAC(minimum alveolar concentration)]supplemented with intravenous agents like propofol fentanyl etc After intubation we will inflate the cuff with the minimum room air required to prevent an audible air leak with a cuff pressure less than 25 cm of H2O measured using a cuff pressure monitor The number of attempts for intubation time taken for intubation and any difficulty/ trauma during intubation/ laryngoscopy will be noted The fixation distance of the endotracheal tube at the angle of the mouth will be noted We will not insert a Nasogastric tube The patient will be made prone per standard protocol and the endotracheal tube cuff pressure will be rechecked to ensure it is less than 25 cm H2O

During the change of position from supine to prone the breathing circuit will be disconnected to avoid drag on the endotracheal tube At the end of the operation PONV(post operative nause and vomiting) prophylaxis will be given with Injection Ondansetron 0.1 mg/kg The patient will be made supine Displacement of the endotracheal tube if any will be noted The ETT(endotracheal tube) cuff pressure will be rechecked After surgery with the patient adequately anaesthetised the oropharynx will be cautiously toileted with a 12-14Fr disposable soft suction catheter reversal of neuromuscular blockade will be done by IV Neostigmine 0.05 mg/kg along with IV Glycopyrrolate 0.01mg/kg after return of spontaneous ventilation The trachea will be extubated as per standard protocol.We will note the demographic data the time needed for intubation [time from start of laryngoscopy to confirmation of EtCO2(end tidal carbondioxide) on monitor] intubation period (time from intubation to extubation) grade of laryngoscopic view using the Cormack Lehane score number of attempts of intubation incidence of bucking or coughing during tracheal intubation application of external laryngeal pressure to facilitate endotracheal intubation blood in the secretions or endotracheal tube and recovery time (time from the end of the operation to extubation)

Postoperatively at 2 6 12 and 24 hours, the patients will be asked for the presence of postoperative sore throat and hoarseness of voice (which is the change in the quality of speech/voice perceived by the patient themselves or the bystander in the postoperative period or presence of aphonia) dysphagia (known as the difficulty or discomfort in swallowing liquid or solid or both) and stridor (which is a harsh sound during breathing)