Measuring and Treating Brain Oxygen Levels in Open Heart Surgery

This study is currently recruiting participants. (see Contacts and Locations)
Verified November 2013 by Mount Sinai School of Medicine
Sponsor:
Information provided by (Responsible Party):
Mount Sinai School of Medicine
ClinicalTrials.gov Identifier:
NCT01539382
First received: February 21, 2012
Last updated: November 25, 2013
Last verified: November 2013
  Purpose

The purpose of this study is to test whether keeping the amount of oxygen delivered to the brain above a certain level during surgery and 24-hours after surgery improves recovery.

Hypothesis 1: keeping the amount of oxygen delivered to the brain above a certain level during surgery and 24-hours after surgery improves cognitive and neurological outcomes after cardiac and aortic surgery.

Hypothesis 2: keeping the amount of oxygen delivered to the brain above a certain level during surgery and 24-hours after surgery helps reduce major organ problems after cardiac and aortic surgery.

To test our hypotheses, the investigators will conduct a randomized control trial. Patients will be randomly assigned to one of two possible study groups. In the Treatment Group, the brain oxygen level will be watched by doctors and used to guide care in the operating room and the first day in the intensive care unit after surgery. Doctors will try to keep the brain oxygen level in a normal range by adjusting your blood pressure, carbon dioxide and blood acidity levels, and blood count. In the Control Group, the doctors will not be aware of the brain oxygen level unless it falls below a level that may be dangerous. If a patient's brain oxygen falls below such a level, the doctors will adjust the blood pressure, carbon dioxide and blood acidity levels, and blood count to increase the brain oxygen level. All other procedures will be part of regular medical care and will be performed according to the standard of care.


Condition Intervention
Cardiac Surgery
Procedure: Cerebral oxygenation intervention

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Single Blind (Subject)
Primary Purpose: Prevention
Official Title: Optimizing Cerebral Oxygenation in Cardiac Surgery

Resource links provided by NLM:


Further study details as provided by Mount Sinai School of Medicine:

Primary Outcome Measures:
  • Postoperative neurocognitive decline [ Time Frame: Baseline (before surgery) ] [ Designated as safety issue: No ]
    Postoperative cognitive deficit as defined as negative changes in Z-score of greater than or equal to 1.0 in any of the four neurocognitive domains tested by neurocognitive assessment (Response Speed, Processing Speed, Attention, and Memory).

  • Postoperative neurocognitive decline [ Time Frame: 3 months after surgery ] [ Designated as safety issue: No ]
    Postoperative cognitive deficit as defined as negative changes in Z-score of greater than or equal to 1.0 in any of the four neurocognitive domains tested by neurocognitive assessment (Response Speed, Processing Speed, Attention, and Memory).

  • Postoperative neurocognitive decline [ Time Frame: 6 months after surgery ] [ Designated as safety issue: No ]
    Postoperative cognitive deficit as defined as negative changes in Z-score of greater than or equal to 1.0 in any of the four neurocognitive domains tested by neurocognitive assessment (Response Speed, Processing Speed, Attention, and Memory).


Secondary Outcome Measures:
  • Neurological dysfunction [ Time Frame: During the hospitalization for postoperative recovery, average 8 days ] [ Designated as safety issue: No ]
    Delirium, stroke with neurological deficit at hospital discharge, persistent vegetative state, or brain death.

  • Multiple organ dysfunction [ Time Frame: During the hospitalization for postoperative recovery, average 8 days ] [ Designated as safety issue: No ]
    Non-neurological postoperative organ dysfunction, defined as any of the following: intraoperative or non-neurological death within 1 year of surgery; ICU Length of Stay > 10 days; Acute Respiratory Distress Syndrome or respiratory failure > 5 days; need for renal replacement therapy; bilirubin > 3mg/dl, diagnosis of SIRS, sepsis, or DIC; multiple organ dysfunction syndrome (MODS), as defined by SOFA score > 5 at any time during ICU stay.


Estimated Enrollment: 500
Study Start Date: November 2011
Estimated Study Completion Date: November 2015
Estimated Primary Completion Date: November 2014 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Cerebral oxygenation intervention
Cerebral oxygenation levels for people in this group will be monitored and maintained above 60%. If levels decrease to below 60%, a protocol is followed to guide possible interventions to increase cerebral oxygenation levels above 60%
Procedure: Cerebral oxygenation intervention
The protocol for interventions to increase cerebral oxygenation levels above 60% optimizing pH, PaO2, PaCO2, bispectral index, central venous pressure, mean arterial pressure, venous oxygen saturation, and hematocrit. In addition, cerebral perfusion pressure of 70-80 mm Hg and flow >2.0 l/min/m2 will be maintained during cardiopulmonary bypass. In the ICU, temperatures will be maintained below 38 degrees by administering antipyretics or cooling, and dexmedetomidine will be used if the patient is agitated.
Other Name: Intervention
No Intervention: Cerebral oxygenation control
Cerebral oxygenation levels for people in this group will be masked and thus doctors and care staff will not use the cerebral oxygenation levels to make any interventions. If the cerebral oxygenation levels drop to below 40%, the cerebral oxygenation levels will be unmasked so that doctors can follow the protocol to increase levels to above 60%.

Detailed Description:

Background

There is a high incidence of cognitive dysfunction, neurological dysfunction, and multi-system organ dysfunction syndrome following cardiac surgery. There is preliminary evidence that optimization of cerebral oxygenation is associated with improved neurological and clinical outcomes.

Cerebral oximetry using near infrared spectroscopy (NIRS) is based on the ability of near-infrared light to penetrate scalp and skull, and its differential intracranial absorbance by oxyhemoglobin (HbO2) and deoxyhemoglobin (Hb). Cerebral oximetry measures regional cerebral tissue oxygen saturation (SctO2) at the microvascular level (arterioles, venules, and capillaries) and provides information on the availability of oxygen in brain tissue. Unlike digital pulse oximetry, SctO2 reflects regional cerebral metabolism and the regional balance of cerebral oxygen supply and demand. NIRS SctO2 is the most promising monitoring technology for the purpose of guiding interventions targeted to improve brain and other organ preservation. The reasons for this include: (1) SctO2 is continuous, non-invasive, and available at the point of care; and (2) SctO2 is a sensitive index of cerebral hypoxia and/or cerebral ischemia, which are the main causes of brain injury in clinical settings. The preliminary work of Murkin strongly suggests that optimizing tissue perfusion using protocol-based treatments that optimize SctO2 decrease end-organ dysfunction in cardiothoracic surgical patients.

Recruitment Methods

Potential subjects are patients who are planned to undergo elective cardiac surgery at Mount Sinai Hospital. Potential subjects will be identified by checking the pre-admission schedule f or cardiothoracic surgery on a daily basis. Patients will be recruited at the surgical pre-admission screening; written informed consent will be obtained.

Risks to Subjects

Cerebral oximetry and computerized neurocognitive testing pose no known risk of harm to subjects.

Cerebral oximetry is an evolving technology that is not currently or imminently becoming a standard of care in monitoring for cardiothoracic surgical patients. The expense and the lack of outcome data make this a discretionary monitoring technology that is advocated by some, but that is not incorporated into any evidence-based guidelines or practice parameters. Therefore, compared with the existing standards of care, patients are not exposed to additional risk by withholding cerebral oximetry information from the practitioners.

Interventions to maintain cerebral oximetry above threshold values could be potentially injurious (e.g., initiating a red blood cell transfusion when it would not otherwise be given), however, any potential risk that is imparted by the interventions to maintain cerebral oximetry values are justified by the benefits of averting low or very low period of cerebral oximetry within the context of this research protocol.

  Eligibility

Ages Eligible for Study:   18 Years and older
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • Adult patients scheduled to undergo elective cardiac or thoracic aortic surgery requiring cardiopulmonary bypass

Exclusion Criteria:

  • Severe preoperative cognitive impairment (i.e., dementia or developmental intellectual disability)
  • Sensory or motor impairment that would preclude reliable operation of a computer and keyboard
  • Lack of access to use computer-based cognitive evaluation
  • Non-English speaking patients
  • Renal failure requiring dialysis
  • Respiratory failure requiring home oxygen use
  • Child's B or C hepatic failure
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT01539382

Contacts
Contact: Suzan Uysal, PhD 212-241-1836 suzan.uysal@mountsinai.org
Contact: Muoi Trinh, MD 212-241-4203 muoi.trinh@mssm.edu

Locations
United States, New York
Icahn School of Medicine at Mount Sinai Recruiting
New York, New York, United States, 10029
Contact: Suzan Uysal, PhD    212-241-1836    suzan.uysal@mountsinai.org   
Contact: Muoi Trinh, MD    212-241-4203    muoi.trinh@mssm.edu   
Principal Investigator: Muoi Trinh, MD         
Sponsors and Collaborators
Mount Sinai School of Medicine
Investigators
Principal Investigator: Muoi Trinh, MD Mount Sinai School of Medicine
  More Information

No publications provided

Responsible Party: Mount Sinai School of Medicine
ClinicalTrials.gov Identifier: NCT01539382     History of Changes
Other Study ID Numbers: GCO 11-0891
Study First Received: February 21, 2012
Last Updated: November 25, 2013
Health Authority: United States: Institutional Review Board

Keywords provided by Mount Sinai School of Medicine:
cardiac surgery
neurocognitive assessment
neurocognitive function

ClinicalTrials.gov processed this record on October 16, 2014