Multi-omics Study on Gut Microbiota in Critical Ill Patients After Cardiopulmonary Bypass

Study Overview
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Brief Summary
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Using metagenomics as well as metabolomics, the variation of the gut microbiota and host metabolite profiles of patient after undergoing CPB were explored.

Detailed Description
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This protocol is designed as a prospective observational case-control study in patients who underwent cardiopulmonary bypass (CPB) due to cardiac surgery. 30 healthy persons were selected as control group. The case group included patients admitted to intensive care unit (ICU) after cardiac surgery and extracorporeal circulation which is performed by the Department of cardiac surgery of Peking Union Medical College Hospital. The patients enrolled should be divided into two groups according to their primary outcomes: one grouped fever and/or hemodynamic instability after cardiopulmonary bypass and the other grouped normothermia and normal hemodynamic during 48 hours after surgery(cause an infection manifested >48 hours after admission was defined as hospital acquired. ). Sample collection was terminated when both groups received 30 cases. These 60 cases would regard as the case group. Additionally, all the CPB patients we observed will be divided into survivors and non-survivors based on the 28-day survival. Feces and blood samples will be obtained at certain time points（initial sampling at least one day before the surgery, repeat sampling within 24-48 hours after CPB）. The fecal samples analysis will apply metagenomics and the feces and blood samples will be analyzed using untargeted metabolomics method. In this study, the stratification of gut microbial communities in patients underwent extracorporeal circulation were explored and analysed the variation of metabolite in patients's plasma and fecal samples. Predictive bio-markers and possible pathogenesis of fever and/or hemodynamic instability after CPB will be also provided by clinical outcomes analysis combined with multi-omics study.

Official Title
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Clinical and Multi-omics Study on Gut Microbiota in Critical Ill Patients After Cardiovascular Surgery Combined Cardiopulmonary Bypass With or Without Sepsis（CPB-MUL-GM Study): a Prospective Study Protocol

Conditions
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Sepsis, Cardiopulmonary Bypass

Intervention / Treatment
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* Procedure: extracorporeal circulation during cardiac surgery


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients will be admitted to ICU between 18 and 85 years of age who will undergo extracorporeal circulation during cardiac surgery and provided written informed consent will be enrolled as candidates of case group. Healthy volunteers will be enrolled as control group. Exclusion Criteria: Patients had a fever before surgery, regardless of the etiological evidence of infection; had anti-infective treatment before surgery; had gastrointestinal surgery which left the digestive system dysfunctional; had a history of CPB in 6 month; reject or abandon ICU therapeutic intervention.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| the control group<br>30 healthy people as the control group. | |
| the case group<br>60 patients were admitted to intensive care unit (ICU) as the case group after cardiac surgery and extracorporeal circulation. This group should contain 30 patients with fever and/or hemodynamic instability and 30 patients with normothermia and normal hemodynamic. | Procedure: extracorporeal circulation during cardiac surgery<br>* We will observe the cardiopulmonary bypass status and time of patients undergoing cardiac surgery and extracorporeal circulation due to their medical needs.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Surgery | cardiovascular surgery with cardiopulmonary bypass VS. non-surgery non-surgery is defined as healthy people who don't need surgery. | During sample collection | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Anal temperature | Fever VS. non-fever Definition: Fever: The axillary body temperature is over 38.3℃. Non-fever: The axillary body temperature is below or equal to 38.3℃. | within 24-48 hours after cardiopulmonary bypass | 
| Hemodynamics | Hemodynamic instability VS. normal hemodynamic Definition: Hemodynamic instability: Vasopressor therapy needed to elevate MAP (mean artarial pressure) ≥65 mmHg. | within 24-48 hours after cardiopulmonary bypass | 
| survival | survivors vs. non-survivors survivor: Patients survive for 28 days or more after CPB. non-survivors: Patients survive less than 28 days after CPB. | within 28 days after CPB | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Cardiopulmonary Bypass, Gastrointestinal Microbiome, Thoracic Surgery, Metagenomics, Metabolomics, sepsis