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NCT Number: NCT04766554

Cerebral Oxygen Saturation Monitoring In Cardiac Surgery (COSMICS)

Neurological dysfunction continues to be one of the complications of considerable concern in patients undergoing cardiac surgery. It was previously reported in the literature, that cerebral oxygen desaturation during cardiac surgery was associated with an increased incidence of cognitive impairment. This study aims to determine whether continuous monitoring of cerebral oximetry improves the neurocognitive outcome in coronary artery bypass surgery when associated with predetermined intervention protocol to optimize cerebral oxygenation.

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Key information

Age range

60 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Instituto Nacional de Cardiologia, Rio de Janeiro, Brazil

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About this study

Despite all the progress over the last decades regarding the improvement of the perioperative care of patients with heart disease and the development of new surgical techniques, neurological dysfunction continues to be one of the complications of the greatest concern in patients undergoing cardiac surgery with cardiopulmonary bypass. Brain injury can manifest itself through permanent or temporary injury, contributing to the increase in-hospital mortality, in the length of stay in intensive care, in the length of hospital stay, to a higher incidence of motor dysfunction requiring rehabilitation, and consequently, to reduced quality of life.

Even though the causes of brain injury are multifactorial, perioperative cerebral hypoperfusion, tissue hypoxia, and thromboembolic events are among the main factors related to neurological dysfunction.

Several clinical studies have indicated an association between cerebral desaturation and the increase of neurological complications. Cerebral oximetry monitoring using near-infrared spectroscopy (NIRS) is a non-invasive technique used to estimate regional cerebral oxygen saturation (rSO2) and has been associated with diminishing the incidence of neurological complications.

There is no consensus in the literature about its real benefit, mainly due to the absence of well-designed scientific studies that demonstrate that cerebral desaturation associated with intervention measures to improve rSO2, are related to the prevention of neurological dysfunction in adult cardiac surgery.

The study hypothesis evaluates whether continuous monitoring of cerebral oximetry improves the neurocognitive outcome in coronary artery bypass surgery when associated with early interventions to optimize rSO2.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Age 60 or older
  • Elective coronary artery bypass graft surgery using cardiopulmonary bypass
  • Preoperative cognitive assessment by means of Mini-Mental State Examination (MMSE) test, greater than or equal to 24
  • Signed informed consent

Exclusion criteria

  • Patients with focal neurologic deficit
  • Carotid artery stenosis greater than 70%
  • Patients with pre-existing cognitive dysfunction
  • Patients with psychotic disorders
  • History of allergy to adhesive part of the electrode
  • History of craniofacial surgery

Treatment and study plan

Cerebral oximetry monitor (The INVOS® Cerebral/Somatic Oximeter) and protocol-based interventions

Device

In the intervention group, an alarm threshold below 15% of the baseline rSO2 value will be established. Based on the predetermined algorithm the rSO2 will be maintained at or above 85% of the baseline measurements. If the rSO2 reaches levels below 15% of the baseline values or below 50% in absolute value for over 30 seconds, protocol-based interventions will be performed to restore rSO2 to baseline levels.

Primary outcomes

  1. Preoperative cognitive function

    Time frame: Pre-surgery (within 10 days before)

    Mini Mental State Examination (MMSE)

  2. Postoperative cognitive dysfunction - delayed cognitive recovery

    Time frame: Post-surgery (7 days after surgery)

    Mini Mental State Examination (MMSE)

  3. Postoperative cognitive dysfunction - neurocognitive disorder

    Time frame: Post-surgery (90 days after surgery)

    Mini Mental State Examination (MMSE)

  4. Preoperative cognitive function II

    Time frame: Pre-surgery (within 10 days before)

    Montreal Cognitive Assessment (MoCA) test

  5. Postoperative cognitive dysfunction - delayed cognitive recovery II

    Time frame: Post-surgery (7 days after surgery)

    Montreal Cognitive Assessment (MoCA) test

  6. Postoperative cognitive dysfunction - neurocognitive disorder II

    Time frame: Post-surgery (90 days after surgery)

    Montreal Cognitive Assessment (MoCA) test

  7. Preoperative cognitive function III

    Time frame: Pre-surgery (within 10 days before)

    The Telephone Interview for Cognitive Status (TICS)

  8. Postoperative cognitive dysfunction - delayed cognitive recovery III

    Time frame: Post-surgery (7 days after surgery)

    The Telephone Interview for Cognitive Status (TICS)

  9. Postoperative cognitive dysfunction - neurocognitive disorder III

    Time frame: Post-surgery (90 days after surgery)

    The Telephone Interview for Cognitive Status (TICS)

Secondary outcomes

  1. Incidence of postoperative delirium

    Time frame: Delirium assessment CAM-ICU preoperatively (baseline) and postoperatively twice a day during the first seven days or until discharge

    Delirium will be assessed postoperatively for seven days or until discharge

  2. Neurological injury type I (stroke)

    Time frame: Post-surgery (until 30 days after surgery)

    The incidence of neurological injury type I will be evaluated for 30 days

  3. Duration of mechanical ventilation

    Time frame: Post-surgery (until 30 days after surgery)

    The duration of mechanical ventilation will be evaluated

  4. Length of stay at the intensive care unit (ICU)

    Time frame: Post-surgery (until 30 days after surgery)

    The length of stay at the intensive care unit (ICU) will be evaluated

  5. Length of stay at the hospital

    Time frame: Post-surgery (until 30 days after surgery)

    The length of stay at the hospital will be evaluated

  6. Incidence of mortality resulting from all causes

    Time frame: Post-surgery (until 30 days after surgery)

    All causes of mortality will be assessed for 30 days

Sponsors and collaborators

Lead sponsor

Instituto Nacional de Cardiologia de Laranjeiras

Other

Registry information

Official study title

A Multicenter, Randomized, Controlled Clinical Trial of Cerebral Oxygen Saturation Monitoring In Cardiac Surgery (COSMICS)

Acronym: COSMICS

Important dates

Study start
2021
Primary completion
2024
Study completion
2024
First posted
Feb 23, 2021
Registry last updated
Jan 28, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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