Feasibility Trial to Maintain Normal Cerebral Oxygen Saturation in High-Risk Cardiac Surgery

Study Overview
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Brief Summary
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Using the brain and the heart as index organs, perioperative interventions to optimize cerebral oxygen saturation and cardiac contractility in high-risk patients undergoing cardiac surgery should have a beneficial systemic effect for enhancing global tissue perfusion and improve outcomes.

Detailed Description
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The proportion of high-risk patients requiring cardiac surgery and of high-risk cardiac surgeries is increasing. These populations of patients are at increased risk of perioperative morbidity and mortality. Transesophageal echocardiography (TEE) evaluation in cardiac surgery has been shown to impact on the perioperative management of patients and to improve outcomes. Near infrared-reflectance spectroscopy (NIRS) is a technique that has been employed since the mid-1970's and that can be used as a non-invasive and continuous monitor of the balance between cerebral oxygen delivery and consumption. Two recent randomized trials have shown an association between correction of cerebral desaturation and shorter recovery room and hospital stay in non-cardiac surgery, and with a decrease in major organ dysfunction and in intensive care length of stay after coronary artery bypass. By combining NIRS and TEE in high-risk patients, optimal tissue perfusion could be achieved and perioperative morbidity and mortality could be reduced.

Official Title
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Perioperative Interventions to Optimize Cerebral Oxygen Saturation (rSO2) in High-risk Patients Undergoing Cardiac Surgery Should Have a Beneficial Systemic Effect for Enhancing Global Tissue Perfusion and Improve Outcomes.

Conditions
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Cerebral Hypoxia

Intervention / Treatment
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* Procedure: strategies to reverse decrease in rSO2


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients with EUROSCORES ≥ 10. Planned complex surgery including more than one procedure, or redo procedures. Patient able to read and understand the consent form. Patients ≥ 18 years of age. Exclusion Criteria: High risk patients undergoing of off pump coronary artery bypass. Emergency surgeries less than 6 hours from diagnosis. Patient unable to read and understand the consent form. Patients with and IABP or a ventricular assist device Planned circulatory arrest Planned surgery of the descending aorta. Patients with acute endocarditis.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Intervention<br>an alarm threshold at a value of 90% of the resting baseline cerebral saturation value (baseline - 10%) will be established. To minimize the probability of patients reaching significant decreases rSO2 values, interventions to improve cerebral oxygenation will be initiated according to the strategies described in the algorithm. The success and failure of these interventions will be noted. As in the Control group, the screen will remain blinded in the ICU and the intensivist will not see the values. | Procedure: strategies to reverse decrease in rSO2<br>* an alarm threshold at a value of 90% of the resting baseline cerebral saturation value (baseline - 10%) will be established. To minimize the probability of patients reaching significant decreases rSO2 values, interventions to improve cerebral oxygenation will be initiated according to the strategies described in the algorithm. The success and failure of these interventions will be noted. As in the Control group, the screen will remain blinded in the ICU and the intensivist will not see the values.<br>* Other names: Cerebral Oxymetry decrease;|
| No Intervention: Control<br>the cerebral oxymetry screen will be blinded and changes in NIRS values will be unknown to the anesthesiologist. The management of the case will proceed as per normal local practice. The screen will remain blinded in the ICU and the intensivist will not see the values. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Success rate of reversing decreases in cerebral oxygen saturation below 10% of baseline values to values within 10% of baseline in the INTERVENTION group. | Consensus on the appropriate strategies to prevent and reverse cerebral oxygen desaturations remains controversial. In a recent study by Slater and al.12, randomization into an intervention group failed because anesthesiologists were unable to follow the protocol aimed at strategies to reverse decreases in rSO2. A group from the Montreal Heart Institute has developed a physiologically oriented algorithm to help with the task of reversing decreases in rSO2. The goal of the present study is therefore to confirm that this approach can be used with success by most institutions. | Up to 12 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| First 30 days post-operative outcomes | readmission to hospital within 30 days death | 30 days | 
| ICU data | ICU admission and discharge times tracheal extubation time in hours | Up to 48 hours | 
| First 24 hours complications | clinical stroke manifested as focal neurological deficit persisting 24hr and confirmed by brain computed tomography imaging prolonged ventilation defined as extubation at > 24 h postoperatively new, persistent Q-wave myocardial infarction | 24 hours | 
| Post-operative complications | renal failure as defined by the RIFLE criteria reoperation for any cause arrhythmia requiring treatment Hospital length of stay wound infection requiring specific antibiotic coverage | Up to 7 days | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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cerebral, hypoxia