The Effect of Hydroxyethylstarch 6% 130/0.4 in a Balanced Electrolyte Solution (Volulyte®) Compared to Gelatine (Geloplasma®) on Microvascular Reactivity and Tissue Oxygen Saturation During Haemodilution Measured With Near-infrared Spectroscopy

Study Overview
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Brief Summary
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The aim of this study is to compare 6% hydroxyethyl starch (HES) 130/0.4 in a balanced electrolyte solution (Volulyte®) with modified fluid gelatin (Geloplasma®) as the priming solution for the cardiopulmonary bypass (CPB) circuit. The microvascular reactivity and the effects on tissue (StO2) and cerebral (ScO2) oxygen saturation will be examined using near-infrared spectroscopy (NIRS).

Official Title
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The Effect of Hydroxyethylstarch 6% 130/0.4 in a Balanced Electrolyte Solution (Volulyte®) Compared to Gelatine (Geloplasma®) on Microvascular Reactivity and Tissue Oxygen Saturation During Haemodilution Measured With Near-infrared Spectroscopy

Conditions
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Microvascular Reactivity, Tissue Oxygen Saturation

Intervention / Treatment
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* Drug: Volulyte 6%
* Drug: Geloplasma


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adult consenting patients scheduled for elective coronary artery bypass grafting surgery on moderately hypothermic (> 32°C) CPB without blood transfusion. Age ≥ 18 years. Exclusion Criteria: Exclusion criteria are an ejection fraction < 25%, a known allergy to HES, admission of HES or gelatines within the preceding 2 weeks, renal insufficiency (creatinine > 2.0 mg/dl), significant hepatic disease (liver function tests > 3x upper limit of normal), history of cerebrovascular disease, significant carotid artery stenosis (> 60%), perioperative use of corticosteroids, and need for vasopressor or inotropic therapy before surgery. An expected haematocrit on CPB, calculated based on preoperative haematocrit, calculated blood volume and amount of cardioplegia, of < 23% is also considered an exclusion criterium

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: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Volulyte 6%<br>- Volulyte 6% (HES 130/0.4 in an isotonic composition). In 1000 ml: Maize starch 60 gr. Molar substitution 0.38-0.45. 130000 Da Na acetate trihydrate 4.63 gr Sodium Chloride 6.02 gr Potassium Chloride 0.3 gr MgCl 0.3 gr Sodium hydroxide-hydrochloric acid & H2O | Drug: Volulyte 6%<br>* During elective coronary artery bypass grafting surgery, patients need to be attached to a cardiopulmonary bypass circuit. Administration of Volulyte 6% to the cardiopulmonary bypass circuit.<br>|
| Active Comparator: Geloplasma<br>In 1000 ml: Modified fluid gelatin 30 gr Sodium Chloride 5.4 gr Potassium Chloride 0.37 gr MgCl 0.14 gr Sodium lactate 3.36 gr | Drug: Geloplasma<br>* During elective coronary artery bypass grafting surgery, patients need to be attached to a cardiopulmonary bypass circuit. Administration of Geloplasma to the cardiopulmonary bypass circuit.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Value of the StO2 recovery slope (recStO2) after postocclusive ischaemia. | Values are measured, using near-infrared spectroscopy. | after 3 minutes of postocclusive ischaemia | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change of values of ScO2 during cardiopulmonary bypass (CPB ). |  | Continuously during cardiopulmonary bypass (= maximum 3 hours). | 
| Change of value of StO2 during cardiopulmonary bypass. |  | Continuously during cardiopulmonary bypass(= maximum 3 hours). | 
| Change of blood gas analyses during cardiopulmonary bypass. |  | Continuously during cardiopulmonary bypass(= maximum 3 hours). | 
| Change of haemodynamics during cardiopulmonary bypass. |  | Continuously during cardiopulmonary bypass(= maximum 3 hours). | 
| Urinary output during cardiopulmonary bypass. |  | At the end of cardiopulmonary bypass(= after maximum 3 hours).. | 
| Use of vasoactive medication during cardiopulmonary bypass. |  | During complete cardiopulmonary bypass(= maximum 3 hours). |