Elimination of CO2-insufflation-induced Hypercarbia in Open Heart Surgery

Study Overview
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Brief Summary
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The study aim was to evaluate if an additional separate venous reservoir eliminates CO2-insufflation induced hypercapnia and keeps sweep gas flow of the oxygenator constant during open heart surgery.

Detailed Description
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Background: CO2-gas insufflation is used for continuous de-airing during open heart surgery. The study aim was to evaluate if an additional separate venous reservoir eliminates CO2-insufflation induced hypercapnea and keeps sweep gas flow of the oxygenator constant. Methods: A separate small reservoir are used during CPB in addition to a standard large venous reservoir. The small reservoir receive drained wound blood and CO2-gas continuously via a suction drain (1 L/min) and handheld suction devices from the open surgical wound. CO2-gas is insufflated via a gas-diffuser in the open surgical wound at 10 L/min. During cross-clamping, gas and blood are either continuously drained to the standard large venous reservoir or not, every 5 minutes after steady state of PaCO2 is observed, after adjustment of sweep gas flow as necessary. Mean values for each setup (2-4 times) for each patient will be analyzed with Wilcoxon rank-sum test.

Official Title
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Elimination of CO2-insufflation-induced Hypercarbia in Open Heart Surgery Using a Separate Reservoir for Suction of Blood From the Open Surgical Wound

Conditions
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Adult Patients Undergoing Open Heart Replacement of the Aortic Valve for Aortic Stenosis or Insufficiency

Intervention / Treatment
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* Procedure: Tube clamping


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: adult patients undergoing open heart replacement of the aortic valve Use of perioperative cardiopulmonary bypass Exclusion Criteria: Denied participation in the study

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: Non-Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| No Intervention: conventional setup<br>Blood and gas from the coronary and cardiotomy suction devices is continuously evacuated via the additional reservoir to the standard reservoir. | |
| Experimental: Intervention setup<br>The connecting tube between the additional and standard venous reservoir is clamped. Thus, blood and gas from the coronary and cardiotomy suction devices are collected in the additional venous reservoir. During the intervention setup, the blood in the additional venous reservoir is only evacuated to the standard reservoir if the volume exceeded 800ml, and always with a remaining volume of 100 mL blood to keep the CO2-gas trapped in the additional venous reservoir. | Procedure: Tube clamping<br>* Clamping of the tube between the additional and standard venous reservoir<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Difference in PaCO2 (kPa) |  | At 5 minutes steady state | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Oxygenator sweep gas flow rate (L/min) |  | At 5 minutes steady state |