The effect of Dexmedetomidine infusion on post-operative delirium (POD) in patients on pump coronary artery bypass grafting (CABG)

Determining the impact of dexmedetomidine infusion during coronary artery bypass grafting with cardiopulmonary bypass on the incidence of postoperative delirium

A phase 3, double-blind, randomized controlled trial with parallel groups involving 100 patients. Randomization will be conducted using a block randomization method.

This double-blind randomized trial is conducted at Imam Reza and Ghaem Hospitals, Mashhad, on 100 on-pump CABG patients. After cognitive and psychological screening and informed consent, patients are randomly assigned to dexmedetomidine or control groups. Anesthesia and monitoring follow a uniform protocol. Study drug or placebo is infused until surgery ends. Delirium is assessed postoperatively in ICU by a nurse blinded to group allocation.

Adults (18–80 years) undergoing on-pump CABG are eligible with informed consent, normal cognition/psychological status (MMSE, PHQ-4), no pre-op delirium, or major organ failure. Exclusions: valve surgery, emergency CABG, dexmedetomidine allergy, coma/intubation, hearing loss, bradycardia, hypotension, early reoperation, or consent withdrawal.

In the intervention group, intravenous dexmedetomidine infusion at 0.6 µg/kg/h starts after anesthesia induction and continues intraoperatively based on the patient's hemodynamic status. In the control group, an equal volume of normal saline is administered as placebo under the same conditions until the end of surgery.

Cognitive status is assessed using MMSE, and psychological status using PHQ-4 before surgery and postoperatively in ICU. Delirium is evaluated with CAM-ICU and Neecham scales. Vital signs are recorded every 15 minutes intraoperatively and in ICU.

Eligible patients will be allocated to the two study arms using a block randomization method. A total of 10 random blocks with variable sizes of 4 and 6 and differing sequences have been prepared. The contents of each block are sealed in opaque envelopes. As patients are enrolled, the envelopes are opened sequentially, and based on the sequence within the block, the patient is assigned to one of the study arms. Subsequently, after completing the first block, the next block is randomly selected, and this process continues until the final block is used and the last patient is assigned. As a result, with the allocation of the last entry in the final block, an equal number of patients will be assigned to each study arm, ensuring balance between the groups.

Participant: The participant consented to be randomly allocated to either the intervention group or the control group after understanding the study procedures. Researcher: The researcher was not allowed bedside access prior to randomization to prevent any potential bias. Assessor: The assessor was unaware of the treatment received by the participant and solely recorded the outcomes