Dexmedetomidine in gastrointestinal endoscopic procedures for ERCP : Comparison of two different infusion regimes and ketamine usage : A double blinded randomised prospective controlled trial

We hypothesize that the combination of ketamine and appropriate dexmedetomidine infusion without loading dose would ameliorate any adverse effects like bradycardia , hypotension etc and is equally effective as compared Dexmedetomidine when loading dose is used, allowing the endoscopist to perform the procedure more effectively.

This randomised prospective controlled trial will include 206 patients who will be randomly assigned to two groups of 103 each : Group A (Dexmedetomidine given @ 1mcg/kg over 10 min followed by infusion @ 0.7 mcg/kg/hr) and Group B ( Dexmedetomidine started at 1.5 mcg/kg/hr).

After obtaining valid consent and applying inclusion and exclusion criteria for patients undergoing gastrointestinal endoscopic procedures , study will be commenced.

The patients’ preoperative evaluation will include a history, physical examination, and laboratory tests (complete blood picture, liver, and renal function tests). All patients will have a coagulation profile and an electrocardiogram. After a fasting period of six hours for solids and two hours for clear liquids, patients will be premedicated 0.2 mg of glycopyrrolate, 0.03mg/kg of Midazolam , 0.5mcg/ kg of Fentanyl, 4mg of Ondansetron and 0.5mg/kg of Ketamine .

Standard monitoring will be applied (ECG, BP, SpO2, EtCO2) . A nasal prong will be connected to a 2–3 litre/min oxygen flow rate. A 18 G peripheral cannula will be inserted into the dorsum of the hand, and Ringer’s Lactate solution @ 6– 8 ml/kg/hr started.

In Group A , after loading dose of 1mcg/kg over 10 min of dexmedetomidine the infusion rate of Dexmedetomidine will be started at 0.7mcg/kg/hr.

In Group B , the infusion of Dexmedetomidine will be started @ 1.5 mcg/kg/hr and procedure will commence 10 mins thereafter.

The Dexmedetomidine will be prepared in a dilution of 4mcg/ml in a 50ml syringe. Additional 100 mg of ketamine prepared in a 10 mL syringe to be given as supplementary IV boluses at a dose of 0.25 mg/kg to patients in both groups if there is any perceived movements. Throughout the procedure, we will aim to maintain a sedation level of 3-5 according to Ramsay Sedation Scale (RSS).

Dexmedetomidine infusion will be stopped as soon as the endoscope taken out after the procedure finished . Awakening time will be noted which is defined as the time from the stoppage of infusion to any perceived movement or response to verbal stimuli. The patient is subsequently followed up in the Post Anaesthesia Care Unit (PACU) till he/she achieves a Modified Aldrete Score of 9/10.

The study will be double blinded. The anaesthesiologist managing the case and giving Ketamine boluses will not be aware of the infusion dosage of Dexmedetomidine which will be decided based on randomisation by another anaesthesiologist. The Data collection will be done by a third person who will neither be aware of the group allocation nor the infusion regimes