TACO Crossover TRIAL

Study Overview
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Brief Summary
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This is an open-label, prospective crossover randomized controlled trial to investigate wether TACO is solely hydrostatic pressure overload or arises from a combination of hydrostatic pressure overload and capillary leakage, by investigating the difference in change in static pressure parameters (PCWP), dynamic volume parameters (PICCO) as indirect measurements of volume status and capillary leakage after autologous transfusion or saline infusion. The investigators will estimate effective circulating volume following autologous transfusion or saline infusion. Furthermore, the investigators will investigate the effect of fluid loading on the microcirculation.

Detailed Description
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Coronary arterial bypass grafting surgery patients with reduced left ventricular function will be allocated to either infusion of 300mL saline with a subsequent autologous RBC (cell saver) transfusion of 300 mL at a rate of 10mL/min, or the same in the reversed order. Prior to start of the intervention, 15 minutes following start of infusion and a the end of infusion, the investigators will measure right-ventricular pressure and wedge pressure (PCWP), as well as extravascular lung water index (EVLWI) and CO estimation through PICCO® and Pulmonary Artery Catheter. The investigators will identify fluid responsiveness by performing a passive leg raise test (PLR). The investigators aim to measure total vessel density (TVD), perfused vessel density (PVD), proportion of perfused vessels (PPV), microvascular flow index (MFI), and blood vessel diameters (Øbv) from the oral microcirculation by CytoCam microscope system. The investigators will estimate the effective circulating blood and plasma volume through dilutional infusion of indocyanine green prior to initial infusion, between and at the end of subsequent infusion.

Official Title
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A Cross-over Randomized Controlled Trial; Pulmonary Edema Detection After Fluid Loading With Blood Versus Saline in Patients After CABG

Conditions
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Transfusion-associated Circulatory Overload, Blood Transfusion Reaction

Intervention / Treatment
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* Procedure: Autologous RBC transfusion
* Procedure: Saline transfusion


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age >18 years Elective (non-redo) coronary arterial bypass grafting surgery Reduced left ventricular ejection fraction (<55%) Transfusion of autologous blood (cell saver blood, 300ml, HCT60%, 30min) Informed consent Exclusion Criteria: Patients with no indication for autologous RBC transfusion Patients with pulmonary hypertension, congenital heart disease, mitral or tricuspid valve disease. Contraindications for PAC placement; coagulopathy, bundle branch block, defibrillator or pacemaker (risk of displacement). External pacemaker placed during surgery is no exclusion criterium. Patients for acute, non-elective surgery Chronic kidney disease stage 4 or higher (eGFR < 30) Massive transfusion Previous randomization in the current trial Postoperative ongoing bleeding Bypass duration > 2 hours Infusion of high dose corticosteroids Hemodynamic instability with a mean arterial pressure (MAP) < 60 mmHg, central venous pressure > 20 mmHg or dependence on high dosages of inotropic drugs after admittance to the ICU Severe arrhythmias Development of severe pulmonary edema during infusion of autologous blood or saline. Elevated liver enzymes Iodine allergy

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: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Interventional Model Description: Open-label, prospective cross-over randomized controlled trial.
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Group A<br>Patients will receive infusion of 300mL saline with a subsequent autologous Red Blood Cells (RBC) transfusion of 300 mL at a rate of 10mL/min | Procedure: Autologous RBC transfusion<br>* Autologous RBC transfusion 300ml 10 ml/min<br>Procedure: Saline transfusion<br>* Saline transfusion 300ml 10ml/min<br>|
| Other: Group B<br>Patients will receive infusion of 300mL autologous RBC with a subsequent saline transfusion of 300 mL at a rate of 10mL/min | Procedure: Autologous RBC transfusion<br>* Autologous RBC transfusion 300ml 10 ml/min<br>Procedure: Saline transfusion<br>* Saline transfusion 300ml 10ml/min<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Hydrostatic pressure overload | Hydrostatic pressure overload defined as delta pulmonary capillary wedge pressure | 1 hour | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Capillary leakage | Capillary leakage defined as delta extra vascular lung water index | 1 hour | 
| Cardiac output | Volume overload measured by cardiac output | 1 hour | 
| Mean arterial pressure | Volume overload measured by mean arterial pressure | 1 hour | 
| Pulse pressure variation | Volume overload measured by pulse pressure variation | 1 hour | 
| Stroke volume variation | Volume overload measured by stroke volume variation | 1 hour | 
| Extra vascular lung water index | Volume overload measured by extra vascular lung water index | 1 hour | 
| Systemic vascular resistance | Volume overload measured by systemic vascular resistance | 1 hour | 
| Colloid osmotic pressure | Colloid osmotic pressure measured by membrane colloid osmometer | 1 hour | 
| Estimated circulating volume | Estimated circulating blood volume measured by indocyanine green | 1 hour | 
| Estimated circulating volume | Estimated circulating plasma volume measured by indocyanine green | 1 hour | 
| Microcirculation | Total vessel density in the sublingual microcirculation measured by Cytocam | 1 hour | 
| Microcirculation | Perfused vessel density in the sublingual microcirculation measured by Cytocam | 1 hour | 
| Microcirculation | Proportion of perfused vessels in the sublingual microcirculation measured by Cytocam | 1 hour | 
| Microcirculation | Microvascular flow index in the sublingual microcirculation measured by Cytocam | 1 hour | 
| Microcirculation | Blood vessel diameters in the sublingual microcirculation measured by Cytocam | 1 hour | 
| Fluid responsiveness | Fluid responsiveness defined by Passive Leg Raise test (increase in cardiac output > 10%) | 1 hour | 
| TACO | Transfusion associated circulatory overload criteria 6 hours after infusion of autologous blood transfusion | 6 hours |