Predicting Fluid Responsiveness in on Pump Coronary Artery Bypass Graft Using Extra Systoles

Study Overview
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Brief Summary
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The purpose of this study is to determine if extra systoles can be used to predict fluid responsiveness perioperatively in patients undergoing on pump coronary artery bypass graft (CABG) surgery. As an additional study we will investigate the ability of a mini fluid challenge to predict response of a larger volume of fluid.

Detailed Description
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From induction of anaesthesia to cardioplegia we will serve two fluid challenges. Before and after each challenge we will collect hemodynamic data and use this to asses our two hypotheses. Fluid responsiveness (the outcome to predict) will be defined as a 15% increase in stroke volume(SV) from immediately before fluid infusion is initiated (baseline) to after the full fluid infusion. Stroke volume is derived from the gold-standard pulmonary artery catheter measurement of cardiac output(CO), which is standard monitoring for these patients (SV = CO/heart rate). From subsequent offline analysis of the extracted curve data we will investigate if post-ectopic characteristics from identified extra systoles during the baseline period can predict fluid responsiveness (i.e. the SV change). This analysis addresses the primary hypothesis. Also, we will analyse the arterial waveform related to the mini fluid challenge for morphologic changes (comparing heart beats before the infusion with heart beats during the infusion) and see if such transient changes, e.g. in systolic blood pressure, are able to predict fluid responsiveness. This analysis addresses the secondary hypothesis.

Official Title
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Predicting Fluid Responsiveness in on Pump Coronary Artery Bypass Graft Using Extra Systoles and Investigation of a Novel Mini Fluid Challenge Ability to Predict Fluid Responsiveness

Conditions
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Hypovolemia, Coronary Artery Disease, Fluid Overload

Intervention / Treatment
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* Procedure: Fluids


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Predominant sinus rhythm (No atrial fibrillation, trigemini, 2nd and 3rd degree atrioventricular block also if pacing is present etc.) Exclusion Criteria: Ejection fraction < 35% (Safety limit minimising risk of fluid overload) Haemodialysis (safety precaution for patients with end-stage kidney failure) Pregnancy Mentally retarded (due to lack of capability to sign an informed consent)

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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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Fluid Therapy<br>Systematisation of fluids during CABG surgery | Procedure: Fluids<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Cardiac output changes | From initiation of fluid infusion | At 5 minutes | 
| Systolic arterial pressure changes | In relation to extra systoles | 10 minutes prior to fluid infusion | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Arterial waveform changes | From initiation of the mini fluid challenge (part of the compiled fluid challenge) | 10 seconds | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Fluid responsiveness, Perioperative, Extra systoles, Coronary artery bypass, Systolic arterial pressure