Cerebral Hypoxia
Conditions
Keywords
cerebral, hypoxia
Brief summary
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
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.
Interventions
PROCEDUREstrategies to reverse decrease in rSO2
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.
Sponsors
Université de Montréal
Montreal Heart Institute
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
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.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Success rate of reversing decreases in cerebral oxygen saturation below 10% of baseline values to values within 10% of baseline in the INTERVENTION group. | Up to 12 hours | 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. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| First 30 days post-operative outcomes | 30 days | * readmission to hospital within 30 days * death |
| ICU data | Up to 48 hours | * ICU admission and discharge times * tracheal extubation time in hours |
| First 24 hours complications | 24 hours | * 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 |
| Post-operative complications | Up to 7 days | * 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 |
Countries
Canada
Outcome results
None listed