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Cognitive Outcomes After Dexmedetomidine Sedation in Cardiac Surgery Patients

Phase 4
Recruiting
Conditions
Delirium
Cognitive Dysfunction
Cognition Disorder
Neurocognitive Disorders
Neurologic Manifestations
Physiological Effects of Drugs
Analgesics, Non-Narcotic
Analgesics
Molecular Mechanisms of Pharmacological Action
Mental Disorders
Interventions
Registration Number
NCT04289142
Lead Sponsor
Sunnybrook Health Sciences Centre
Brief Summary

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.

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.

This is a multi-site trial facilitated by Clinical Trials Ontario (CTO). 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.

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 5), 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).

Recruitment & Eligibility

Status
RECRUITING
Sex
All
Target Recruitment
2400
Inclusion Criteria
  • Planned CABG (+/- valve, including off-pump) or valve replacement via sternotomy/thoracotomy, with initial recovery in the Cardiovascular Intensive Care Unit (CVICU)
  • Age ≥60
Exclusion Criteria
  • Lack of patient consent
  • 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 time points)

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
Dexmedetomidine Hydrochloride GroupDexmedetomidine Hydrochloride GroupPatients will receive a loading dose of 1.2 μg/kg dexmedetomidine prior to transfer to CVICU over 20 min immediately postoperative, followed by continuous infusion of 0.3 μg/kg/h for up to 12 hours or until patient is ready for discharge from CVICU (whichever is earlier). Any additional sedatives necessary at the discretion of ICU.
Primary Outcome Measures
NameTimeMethod
Post-operative cognitive dysfunction3 months

Presence of POCD assessed by CogState Brief Battery (CBB)

Secondary Outcome Measures
NameTimeMethod
DeliriumAnytime up to post-operative day 10

Confusion Assessment Method (CAM/CAM-ICU) or Intensive Care Delirium Screening Checklist (ICDSC), binary scale to determine if delirium is present or absent

Length of stayAn average of 5 -14 days

ICU and total hospital stay

Depressive symptoms3, 6, and 12 months

Evaluated by PHQ-9 (Patient Health Questionnaire, scale 0-27, higher score is worse outcome)

Persistent Surgical Site Pain3, 6, and 12 months

Evaluated by Brief Pain Inventory

Quality of Surgical Recovery3, 6, 12 months

Evaluated by QoR- (Quality of Recovery) 40 questionnaire (scale: 0-200, higher is better outcome)

Mild Cognitive Impairment3, 6, and 12 months

Presence of MCI assessed by CogState Brief Battery (CBB)

In-hospital mortality for index surgerythrough initial inpatient admission, average of 1 week

death before hospital discharge after surgery

Opioid consumption to POD 44 days

Cumulative opioid consumption

Post-operative cognitive dysfunction (POCD) at 1 week, 6 months, 12 months after surgery1 week, 6 and 12 months

POCD assessed by CogState Brief Battery (CBB)

Time to extubationthrough ICU stay, average of 12 hours

Time from ICU arrival to cessation of mechanical ventilation

Trial Locations

Locations (1)

Sunnybrook Health Sciences Centre

🇨🇦

Toronto, Ontario, Canada

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