Evaluation of Patients After Cardiac Surgery: Novel Ultrasound Parameters for Quantification of Renal Perfusion & Analysis of Phenylephrines' Effect on Invasive Haemodynamics and Echocardiographic Measures

Study Overview
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Brief Summary
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To investigate the influence of PEEP (Positive end-expiratory pressure), changes in preload (patient position) and changes in afterload (phenylephrine) on ultrasound measures of renal perfusion in patients after uncomplicated cardiac surgery. To investigate the effects of phenylephrine on both invasive measures of the systemic- and pulmonary circulation and, secondarily, to assess the induced changes in echocardiographic indices of left- and right ventricular systolic- and diastolic function.

Official Title
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Evaluation of Patients After Cardiac Surgery: Novel Ultrasound Parameters for Quantification of Renal Perfusion & Analysis of Phenylephrines' Effect on Invasive Haemodynamics and Echocardiographic Measures

Conditions
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Ultrasonography, Renal, Cardiac Surgery, Hemodynamics, Phenylephrine, Renal Perfusion, Echocardiography, Anesthesia

Intervention / Treatment
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* Drug: Phenylephrine
* Other: Combination of PEEP and positioning


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: All patients ≥ 18 years scheduled for open elective cardiac surgery at the Department of Cardiothoracic & Vascular Surgery, Aarhus University Hospital. Exclusion Criteria: Insufficient ultrasonographic imaging of the kidneys Known morphological kidney disease Preoperative dialysis Chronic atrial fibrillation Planned mitral valve surgery

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: Diagnostic
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: All patients included<br> | Drug: Phenylephrine<br>* Three time points: before, during and 20-30 minutes after infusion of phenylephrine. Patients will receive an infusion of up to 1 mcg/kg/min phenylephrine intravenously to raise mean arterial pressure with 20 mmHg for 10 minutes. Infusion of phenylephrine will start at 0.1 mcg/kg/min with subsequent titration to effect.<br>Other: Combination of PEEP and positioning<br>* Six time points based on combinations of the following: Three different levels of PEEP (as set on the ventilator): 0, 6 and 12 mmHg. Two different positions: 1) torso elevated 30 degrees, legs horizontal and 2) torso horizontal, legs elevated 30 degrees.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Renal arterial resistive index (RI). |  | 75 minutes | 
| The ratio SVR/PVR (systemic vascular resistance/pulmonary vascular resistance) |  | 75 minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Renal venous impedance index. |  | 75 minutes | 
| Renal venous stasis index. |  | 75 minutes | 
| Portal vein pulsatility fraction. |  | 75 minutes | 
| Cardiac output |  | 75 minutes | 
| Arterial blood pressure, central venous pressure, pulmonary blood pressure, pulmonary capillary wedge pressure. |  | 75 minutes | 
| Transoesophageal measurement of left and right ventricular function 1 | Systolic measure (ejection fraction (EF)) | 75 minutes | 
| Transoesophageal measurement of left and right ventricular function 2 | Systolic measure (s') | 75 minutes | 
| Transoesophageal measurement of left and right ventricular function 3 | Systolic measure (strain) | 75 minutes | 
| Transoesophageal measurement of left and right ventricular function 4 | Diastolic measures (E, A,) | 75 minutes | 
| Transoesophageal measurement of left and right ventricular function 5 | Diastolic measures (e', a') | 75 minutes | 
| Transoesophageal measurement of left and right ventricular function 6 | Diastolic measure (deceleration time) | 75 minutes |