Dexmedetomidine to Reduce the Incidence of POCD After Open Cardiac Surgery

Dexmedetomidine to Reduce the Incidence of Persistent Cognitive Dysfunction After Open Cardiac Surgery: A Pilot Randomized Trial

Anesthesia is a drug induced, reversible, comatose state that facilitates surgery and it is widely assumed that cognition returns to baseline after anesthetics have been eliminated. However, many patients have persistent memory impairment for weeks to months after surgery. Cardiac surgery appears to carry the highest risk of postoperative cognitive dysfunction (POCD). These cognitive deficits are associated with increased mortality, prolonged hospital stay and loss of independence. The investigators propose to investigate the role of Dexmedetomidine (DEX) in preventing long-term POCD after cardiac surgery and enhancing early postoperative recovery. It is anticipated that DEX will be the first effective preventative therapy for POCD, improve patient outcomes, and reduce length of stay and healthcare costs.

Study Overview

• Status: Active, not recruiting
• Conditions: Depression; Delirium; Cognitive Impairment; Postoperative Cognitive Dysfunction; Dexmedetomidine
• Intervention / Treatment: Drug: Dexmedetomidine Hydrochloride Group

Detailed Description

Dexmedetomidine (DEX), a highly potent and selective α2-adrenoceptors (α2R) agonist used in clinical practice for sedation, analgesia, and anxiolysis, was recently shown to have beneficial effects on early cognitive changes by reducing delirium in humans.It also reduced memory impairment after surgery and isoflurane anesthesia, both in elderly mice (20-22 months) and in pups exposed to anesthesia in the early postnatal period. Importantly, co-treatment with DEX has been shown to restore learning and memory function in rats exposed to propofol in utero. Therefore, the investigators set out to investigate whether DEX has an effect on cognitive dysfunction months after surgery and whether it accelerates cognitive recovery from anesthesia and surgery.

Participants will be randomized 1:1 in permuted blocks of 4 to 8. The randomization sequence will be computer generated and stratified by 2 factors, planned procedure (CABG/CABG + valve or valve only procedure) and study site (for full multicentre trial).

In hospital outcomes include delirium (assessed twice daily post-operative day (POD) 0-10, death, hemodynamic instability requiring vasopressors, time to extubation, re-intubation (and reason), length of stay (in Cardiovascular Intensive Care Unit and total hospital), POCD, depressive symptoms between POD 4-10, post-operative complications (infection [surgical site, sepsis, pneumonia], myocardial infarction, renal replacement therapy, re-operation, cumulative opioid consumption (to POD 4), in-hospital mortality.

Post-operative outcomes include POCD (3/6/12 months), depression (3/6/12 months), mild cognitive impairment (MCI) at 3/6/12 months (defined as 1-2 standard deviations below age matched controls), persistent surgical site pain at sternotomy/thoracotomy/graft harvest site (Brief Pain Inventory, 3/6/12 months), recovery (3,6, 12 months).

• Study Type: Interventional
• Enrollment (Estimated): 90
• Phase: Phase 4

Contacts and Locations

Study Locations

• Canada
  • Ontario
    • Toronto, Ontario, Canada, M4N 3M5
      • Sunnybrook Health Sciences Centre

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 60 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Planned CABG (including off-pump) or valve replacement (+/- CABG) via sternotomy/thoracotomy, with initial recovery in the Cardiovascular Intensive Care Unit (CVICU)
• age ≥60

Exclusion Criteria:

• Lack of patient consent
• Pregnant or nursing females
• Pre-operative major cognitive dysfunction (CogState Brief Battery score < 80)
• Aortic arch replacement/re-implantation (Bentalls)
• Allergy/contraindication to dexmedetomidine (untreated 2nd degree type 2 or 3rd degree heart block (pacemaker), cirrhosis, HR < 50 , grade 4 LV, renal failure or on renal replacement therapy)
• Unlikely to comply with study assessments (e.g. no fixed address, cannot complete cognitive tests at the 3, 6, and 12 month timepoints)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Dexmedetomidine Hydrochloride Group; Patients will receive a loading dose of 1 μg/kg dexmedetomidine prior to transfer to CVICU over 20 min immediately postoperative, followed by continuous infusion of 0.1- 1.0 μg/kg/h for up to 24 hours or until patient is ready for discharge from CVICU (whichever is earlier).	Drug: Dexmedetomidine Hydrochloride Group; Dexmedetomidine will be initiated prior to transfer to the CVICU with loading dose of 1 ug kg-1 over approximately 20 minutes. This will be followed by an infusion at 0.1-1.0 ug kg-1h-1 in CVICU for up to 24 hours from the time DEX infusion started or until the patient is ready for discharge from the CVICU (whichever is earlier).; Other Names: Dexmedetomidine Hydrochloride
No Intervention: Standard of Care Group; Standard sedation protocols will be followed at the discretion of the attending physician.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Rate of recruitment	Ability to recruit 15% a full trail sample size (90 participants)	12 Months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Completion of follow-up assessments	Ability to achieve 90% follow-up of administering cognitive assessment 3 months after surgery	3 months

Collaborators and Investigators

• Sponsor: Sunnybrook Health Sciences Centre
• Investigators: Principal Investigator: Sinziana Avramescu, MD,PhD,FRCPC, Sunnybrook Health Sciences Centre; Principal Investigator: Stephen Choi, MD,MSc,FRCPC, Sunnybrook Health Sciences Centre

Study record dates

Study Major Dates

• Study Start (Actual): August 9, 2018
• Primary Completion (Estimated): July 1, 2026
• Study Completion (Estimated): December 1, 2026

Study Registration Dates

• First Submitted: March 21, 2018
• First Submitted That Met QC Criteria: March 26, 2018
• First Posted (Actual): March 27, 2018

Study Record Updates

• Last Update Posted (Actual): March 25, 2025
• Last Update Submitted That Met QC Criteria: December 19, 2024
• Last Verified: November 1, 2024

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Mental Disorders; Postoperative Complications; Pathologic Processes; Neurocognitive Disorders; Cognition Disorders; Postoperative Cognitive Complications; Cognitive Dysfunction; Physiological Effects of Drugs; Molecular Mechanisms of Pharmacological Action; Peripheral Nervous System Agents; Central Nervous System Depressants; Sensory System Agents; Analgesics, Non-Narcotic; Analgesics; Neurotransmitter Agents; Hypnotics and Sedatives; Adrenergic alpha-2 Receptor Agonists; Adrenergic alpha-Agonists; Adrenergic Agonists; Adrenergic Agents; Dexmedetomidine
• Other Study ID Numbers: 2018

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No