The Effect of Continuous Renal Replacement Therapy on the Efficiency of Extracorporeal CO2 Removal

Study Overview
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Brief Summary
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In the design of extracorporeal carbon dioxide removal (ECCO2R) combined with continuous renal replacement therapy (CRRT) equipment, in model of continuous veno-venous hemofiltration (CVVH) , the HCO3- concentration in the pre membrane lung blood is diluted by the replacement solution, and a decrease in HCO3- leads to a decrease in PCO2. On the other hand, in continuous veno-venous hemodialysis (CVVHD), HCO3- in post membrane blood will exchange interaction. The exchange results of HCO3- determine the impact of CVVHD on the CO2 removal efficiency of the ECCO2R combined CRRT system. This study aims to investigate the effects of CVVH and CVVHD on in vitro CO2 clearance efficiency.

Detailed Description
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In the design of extracorporeal carbon dioxide removal (ECCO2R) combined with continuous renal replacement therapy (CRRT) equipment, the pre dilution replacement solution for continuous veno-venous hemofiltration (CVVH) enters the extracorporeal bloodstream upstream of the membrane lung, so the HCO3- concentration in the pre membrane lung blood is diluted by the replacement solution. HCO3- and dissolved CO2 are in a dynamic and rapid equilibrium state, and a decrease in HCO3- leads to a decrease in PCO2. On the other hand, in continuous veno-venous hemodialysis (CVVHD), the blood after the membrane needs to undergo material exchange with the dialysate through a filter. The dialysate is usually HCO3- with normal plasma concentration, so HCO3- in post membrane blood will exchange interaction. The exchange results of HCO3- determine the impact of CVVHD on the CO2 removal efficiency of the ECCO2R combined CRRT system. This study aims to investigate the effects of CVVH and CVVHD on in vitro CO2 clearance efficiency.

Official Title
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The Effect of Continuous Renal Replacement Therapy on the Efficiency of Extracorporeal CO2 Removal

Conditions
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Respiratory Failure With Hypercapnia

Intervention / Treatment
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* Other: continuous renal replacement therapy


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Using Extracorporeal carbon dioxide removal combined with continuous renal replacement therapy 18 years ≤ age ≤ 85 years; Exclusion Criteria: Severe hemodynamic instability (increased dosage of vasoactive drugs or MAP ≤ 65mmHg within two hours); Severe electrolyte deficiency (including severe hyponatremia (blood sodium<130mmol/L) and hypokalemia (blood potassium<3.0mmol/L)); Participate in other intervention studies within 30 days; Do not consent this research

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 85 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 |
| --- | --- |
| Extracorporeal carbon dioxide removal combined with continuous renal replacement therapy<br>extracorporeal carbon dioxide removal combined with continuous veno-venous hemofiltration or continuous veno-venous hemodialysis.CVVH and CVVHD set-up: predilution 30 ml/kg/h, dialysate dose 30 ml/kg/h, ultrafiltration rate was equal to the total rate of substitution fluid infusion. | Other: continuous renal replacement therapy<br>* continuous veno-venous hemofiltration or continuous veno-venous hemodialysis set-up: predilution 30 ml/kg/h, dialysate dose 30 ml/kg/h, ultrafiltration rate was equal to the total rate of substitution fluid infusion<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| extracorporeal CO2 removal rate | extracorporeal CO2 removal rate was calculated as the difference of total CO2 content before membrane lung and after hemofilter, and normalized to an inlet PCO2 of 45 mmHg | after 30min of continuous renal replacement therapy |