Preoperative Nebulized Dexmedetomidine Versus Nebulized Magnesium Sulphate in Reducing Emergence Agitation in FESS

Type of Study: Prospective, randomized, double-blind, comparative clinical study.

Study Setting: Ain Shams University hospitals, Cairo, Egypt. Study Period: 6-12 months. Study Population: Adult patients scheduled for elective functional endoscopic sinus surgery.

Sampling Method: Random sampling Sample Size Based on the results of Ahmed et al 2022, with the mean VAS in patients treated with magnesium sulphate 7.2 ± 1.9 while the mean in Dexmedetomedine group 2.7 ± 0.9 Alpha error 5%,power of study 80% the required sample size is 50 patients, 25 patients in each group. The program for sample size calculation is STATA 10.

Ethical Considerations:

The study protocol will receive ethical approval from the Research Ethical Committee, Faculty of Medicine Ain Shams University. Informed consent will be obtained from all participants before starting study.

Randomization and blinding:

Group allocation will be contained in sequentially numbered, sealed opaque envelopes, which will be opened by the primary investigator. the data analyzer will be blinded about the study group.

Study Procedures:

All patients will be assessed preoperatively by careful history taking, airway examination and systemic examination. Complete blood count (CBC), coagulation profile, liver and kidney function tests for all patients and electrocardiogram (ECG) for patients older than 40 years of age will be reviewed from patients medical records. A written informed consent will be signed by all patients before the surgery. All patients will be admitted after completing fasting hours for both solid food and clear fluids. Upon arrival to the operating room (OR), IV access of the size 20 gauge (G) will be inserted..

In the preoperative holding area, heart rate (HR), mean blood pressure (MBP) and peripheral blood oxygen saturation (SpO2) will be measured immediately before nebulization either dexmedetomidine or magnesium sulphate,.and regulary every 5 minutes until the end of nebulization.

Patients in Group D will be nebulized with 1 μg/kg nebulized dexmedetomidine completed to 3 ml using normal saline 30 min before operation and the patients in Group M will be nebulized with 250 mg nebulized magnesium sulfate completed to 3 ml using normal saline. The solution for nebulization will be administered by an anesthesiologist.

All patients will be monitored with a five-lead ECG, non-invasive blood pressure (NIBP) measurement and finger pulse oximetry. Baseline vital data (MAP, HR, and oxygen saturation (SO2)) will be recorded. HR and SO2 will be monitored continuosly and BP will be measured every 5 minutes (min) till the end of the surgery.

All patients will be premedicated with 0.03 mg/kg IV midazolam. Preoxygenation will be performed using 100% oxygen at a fresh gas flow (FGF) of 10 L/min via face mask for 3 minutes, followed by induction of general anesthesia.

Anesthesia will be induced with fentanyl 2 mcg/kg and propofol 2 mg/kg. Tracheal intubation will be facilitated by atracurium 0.5 mg/kg.

Both groups will be mechanically ventilated using volume control mode with tidal volume 7-10 ml/kg/min, positive end-expiratory pressure (PEEP) 5 cmH2O and oxygen-air mixture with fraction of inspired oxygen (FiO2) 50% and FGF of 3 L/min, and respiratory rate adjusted with target end-tidal carbon dioxide (ET CO2) 30-40 mmHg. 0.1 mg/kg IV atracurium will be given as needed to maintain muscle relaxation. 0.5 mcg/kg fentanyl will be given if HR or MAP increase ≥20% from their basal value. HR and MAP ≤20% of the basal value will be treated with needed doses of atropine and ephedrine, respectively. All patients will be extubated in the operating room and transferred to postanesthesia care unit (PACU).

Presence of emergence agitation will note in first 30 minutes in PACU using Aono's four-point scale scores after anesthesia.

Aono's four-point scale is used to assess post-anesthesia emergence agitation, where a score of 1 is calm, 2 is not calm but easily consoled, 3 is moderately agitated or restless, and 4 is combative, excited, or disoriented. Scores of 3 and 4 are generally considered to represent the presence of agitation and at this stage of agitation search for the cause and manage it .

In the postoperative ward, patients were also monitored for any drug-related side effects.

End point of study : After discharge of patients from PACU. The main researcher (Haidy Atef ) of the study will be the principal investigator responsible for the preparation and conduct of the study under supervision of the director (Prof. Dr. Moustafa Kamel) and co-directors(Prof. Dr. Hany Abdelfattah, Prof. Dr. Aktham Adel, Dr. Ahmed Saoudy). Each member of the team will ensure that the study is conducted according to the protocol approved in their meetings that will be arranged on regular basis. Results of the study and any complications that might occur during the study will be recorded and reported by the principal investigator and revised by the director and co-directors.

Statistical Analysis The collected data will be revised, coded and introduced to a PC using statistical package for social science (SPSS 23). Data will be presented as mean and standard deviation (±SD) for quantitative parametric data, median and range for quantitative non-parametric data and as numbers and percentage for qualitative data. Suitable analysis will be done according to the type of data obtained. P< 0.05 will be considered significant.

Inclusion criteria

• Adult patients between 21 and 50 years of age undergoing elective functional endoscopic sinus surgery.
• American Society of Anesthesiologists physical status classification (ASA) I and II.

Exclusion criteria

• Patient's refusal.
• Complicated sinus surgery.
• History of allergy to any of the study drugs.
• Baseline HR≤60 beat/min.
• Baseline mean arterial pressure (MAP)≤70 mmHg.
• Psychiatric illness.
• Cerebrovascular insufficiency.
• Pregnancy.