The Effect on Cerebral Oxygenation of Retrograde Autologous Priming of the Cardiopulmonary Bypass Circuit in Cardiac Surgery Patients

Study Overview
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Brief Summary
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The effect of retrograde autologous priming (RAP) on regional cerebral oxygenation (rSO2) still remains unclear, because studies are limited in sample size and study design, and because of the absence of prospective studies. The investigators hypothesize that RAP limits the degree of hemodilution and thereby limits prolonged intraoperative cerebral desaturation during cardiopulmonary bypass (CPB), compared to the conventional priming method. The primary objective of this study is to determine whether RAP limits the degree of hemodilution and limits prolonged intraoperative cerebral desaturation during cardiopulmonary bypass, compared to the conventional priming method. Prolonged intraoperative cerebral desaturation will be assessed by rSO2 desaturation score50. rSO2 desaturation score50 > 3000 is associated with increased risk of cognitive decline. The investigators hypothesize that RAP limits the degree of hemodilution and thereby limits the incidence of rSO2 desaturation score50 > 3000 with a relative difference of 50%. The subjects who are divided in the RAP group, the retrograde autologous priming technique will be used, where the patient's own circulating blood partially will be replaced by the priming solution in the cardiopulmonary bypass. In the Control group the conventional priming method will be used. The main study parameters is rSO2 desaturation score50.

Official Title
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The Effect on Cerebral Oxygenation of Retrograde Autologous Priming of the Cardiopulmonary Bypass Circuit in Cardiac Surgery Patients: a Randomized Controlled Trial

Conditions
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Postoperative Cognitive Dysfunction

Intervention / Treatment
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* Procedure: retrograde autologous priming


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Elective combined cardiac surgical procedures Exclusion Criteria: Elective single cardiac surgical procedures off-pump procedure re-operation emergency operation methylene blue administration

Ages Eligible for Study
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Minimum Age: 70 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: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: RAP (retrograde autologous priming) group<br>In the RAP (retrograde autologous priming) group, the priming solution is partially replaced by the patient's own circulating blood, before initiation of CPB. After initiation of cardiopulmonary bypass the priming volume is approximately 900 ml. | Procedure: retrograde autologous priming<br>* Retrograde autologous priming (RAP) is a technique where, the patient's own circulating blood partially replaces the priming solution in the CPB.<br>* Other names: RAP;|
| No Intervention: Control group<br>In the control group, the priming volume of the arterial and venous line will not be replaced by patient's own blood. The priming volume of cardiopulmonary bypass is 1300 ml in the control group. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| prolonged intraoperative cerebral desaturation | The primary study parameter of this study is prolonged intraoperative cerebral desaturation and will be assessed by rSO2 desaturation score50. rSO2 desaturation score50 > 3000 is associated with increased risk of cognitive decline. Formula described by Slater et al. : rSO2 score = 50% rSO2 - current rSO2 (%) x time (s) will be used to calculate the rSO2 score; from the intraoperative cerebral oximetry data. | Participants will be followed for the duration of the operation period, an expected average of 3 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| cerebral oxygenation desaturation episodes (CODE) | CODE will be defined by a reduction of 20% baseline value of rSO2 at least one minute or an absolute reduction of 50% | participants will be followed for the duriation of the operation period, an expected average of 3 hours | 
| Subjective Cognitive Failure Questionnaire (CFQ) | Three and six months after randomization the Subjective CFQ will be sent to the patients to evaluate cognition. | 3 months and 6 months after randomization | 
| blood transfusions (amount) | The amount of red blood cell transfusions the patient receive pre, peri and postoperatively during their stay in the hospital | participants will be followed for the duration of ICU stay, an expected average of 2 days/ And participants will be followed for the duration of hospital stay, an expected average of 3 weeks |