An Intervention to Reduce Delirium After Cardiac Surgery

August 10, 2016 updated by: Charles Brown, MD, Johns Hopkins University

Patients that have cardiac surgery may suffer from unrecognized cerebral ischemia or loss of blood flow to the brain temporarily during surgery. This temporary loss of blood flow to the brain may result in a condition called delirium. Delirium is a type temporary confusion. There are some strategies that can help reduce cerebral ischemia during cardiac surgery which can help lead to a reduction in the incidence of delirium. The investigator believes that a strategy called remote ischemic preconditioning will help to reduce the incidence of delirium incidence after cardiac surgery.

Remote ischemic preconditioning is a brief exposure to ischemia. This brief exposure to ischemia occurs in an area of the body that is not undergoing a procedure. This brief exposure to ischemia is not long enough to cause any damage to the body and it has been demonstrated to help protect against more severe ischemic injury that may occur later during surgery. In this study the investigator will use remote ischemic preconditioning to see if it can reduce the incidence delirium after cardiac surgery.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Delirium is common after cardiac surgery, occurring in 45-55% of patients, and is independently associated with increased postoperative complications, reduced functional capacity, cognitive decline, and increased mortality. Although the pathophysiology of delirium is unclear, a leading hypothesis is that delirium results from unrecognized cerebral ischemia during surgery. In preliminary data from the investigators group, delirium was reduced in patients randomized to optimal blood pressure control during cardiopulmonary bypass, using novel technology that determines an individual patient's lower limit of cerebral autoregulation. Thus, patients undergoing cardiac surgery may suffer from unrecognized cerebral ischemia that contributes to delirium, and strategies to attenuate the effects of cerebral ischemia may reduce the incidence of delirium.

Ischemic preconditioning represents a novel strategy to attenuate the effects of cerebral ischemia during cardiac surgery. Exposure to a brief period of ischemia, below the threshold for tissue injury, has been demonstrated to protect against the harmful effects of a subsequent more severe ischemic insult, in both animal and human studies. The protection provided by ischemic preconditioning may also be effective when the preconditioning is applied to a location remote from the organ of interest (i.e. a limb). Recently, a large randomized trial in patients undergoing cardiac surgery demonstrated a survival benefit among patients randomized to remote ischemic preconditioning vs. placebo. Remote ischemic preconditioning was achieved by simple inflation of a blood pressure cuff to supra-systolic pressures for 5 minutes, repeated for 3 cycles. However, neurological outcomes were not assessed in this trial, although animal models support potential neurological protection following remote ischemic preconditioning.

In this study the investigator will examine whether remote ischemic preconditioning can reduce delirium, functional decline, and biomarkers of cerebral injury after cardiac surgery. The investigator will explore the mechanism of preconditioning by examining proteomic analyses in a subset of patients. These results will provide data to support an NIH trial to examine the protective effects of remote ischemic preconditioning in cardiac surgery, identify potential mechanisms of action and potential targets for therapeutic pharmacologic interventions.

Study Type

Interventional

Enrollment (Actual)

53

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Maryland
      • Baltimore, Maryland, United States, 21287
        • The Johns Hopkins Hospital

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

65 years and older (Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • ≥65 years old
  • Undergoing coronary artery bypass and/or valve surgery

Exclusion Criteria:

  • Mini mental state exam < 23
  • Delirium at baseline
  • Inability to speak and understand English
  • Severe hearing impairment, resulting in inability to converse
  • Planned use of intraoperative ketamine
  • Inability to place or tolerate upper extremity tourniquet
  • Hemoglobinopathy (e.g. sickle cell disease)

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

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

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Placebo Comparator: Control: Usual care
This group will receive usual care and delirium assessments.
Behavioral: Delirium Assessment
The Delirium assessment consist of a validated psychiatric screening tool called the Confusion Assessment Method. We will use this tool to determine if patients have any confusion after surgery.
Experimental: Treatment: Ischemic Pre-conditioning
Remote Ischemic pre-conditioning before cardiac surgery and delirium assessments.
Behavioral: Delirium Assessment
The Delirium assessment consist of a validated psychiatric screening tool called the Confusion Assessment Method. We will use this tool to determine if patients have any confusion after surgery.
Procedure: Remote ischemic pre-conditioning
Remote ischemic preconditioning is exposure to a brief period ischemia to an area or limb that is not involved in surgery. This intervention is believed to reduce the incidence of cerebral (brain) ischemia during cardiac surgery.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Incident Delirium
Time Frame: First four postoperative days
Delirium will be assessed using the Confusion Assessment Method (CAM) on three of the first four postoperative days. The primary outcome will be positive if delirium occurs by CAM criteria at any of these assessments
First four postoperative days

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Levels of novel cerebral injury biomarkers
Time Frame: Within 1 hour before the surgical incision, immediately after cardiopulmonary bypass, 2 hours after cardiopulmonary bypass, and 20 hours after skin closure
Biomarkers include inflammatory proteins, and markers of neuronal damage or change in homeostasis, including glial fibrillary acidic protein and neurotrophic factors
Within 1 hour before the surgical incision, immediately after cardiopulmonary bypass, 2 hours after cardiopulmonary bypass, and 20 hours after skin closure

Other Outcome Measures

Outcome Measure
Time Frame
Instrumental Activities of Daily Living
Time Frame: 1 month and 6 months after surgery
1 month and 6 months after surgery

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Johns Hopkins University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

June 1, 2014

Primary Completion (Actual)

December 1, 2015

Study Completion (Actual)

December 1, 2015

Study Registration Dates

First Submitted

July 9, 2014

First Submitted That Met QC Criteria

October 23, 2015

First Posted (Estimate)

October 27, 2015

Study Record Updates

Last Update Posted (Estimate)

August 11, 2016

Last Update Submitted That Met QC Criteria

August 10, 2016

Last Verified

August 1, 2016

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • IRB00030360

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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