A Prospective Study of The Complement Depletion in Patients With Severe Abdominal Sepsis

Study Overview
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Brief Summary
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The role of complement system in bridging innate and adaptive immunity has been confirmed in various invasive pathogens. The aim of this study is to investigate the alteration of complement C3 in patients with severe abdominal sepsis and evaluate the role of complement C3 depletion in prognosis of such patients. The relationship between complement C3 depletion and adaptive immunity is studied meanwhile.

Detailed Description
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Severe abdominal sepsis remains a significant cause of death in patients undergoing intra-abdominal infection, in despite of recent declines in overall mortality. There is a abundant evidence to suggest complement activation during sepsis. While there is great interest in complement by-products in human sepsis, few studies focus on the persistent consumption of complement components and its role in prognosis of sepsis. Complement C3 is indispensable community pathway for complement activation. In a way, the alteration of C3 levels can affect the whole status of complement biological functions. In clinical practice, the severe abdominal sepsis would develop compromised immune function if the intra-abdominal infection is not well controlled. The down-regulated T- and B-cell immune responses to sepsis are correlated to the decreased immune defense. To our knowledge, there are few human data that have investigated the relationship between complement depletion and adaptive immunity in severe abdominal sepsis. The investigators hypothesize that the complement C3 depletion during sepsis has a stronger association with the down-regulated adaptive immunity and can be regarded as a essential risk factor to predict the prognosis of such critical illness. The purpose of this prospective study is two-fold. First, the investigators observe, in a cohort of patients with severe abdominal sepsis, the levels of complement components and percentages of T cell subsets after admission to evaluate the relationship between complement system and adaptive immunity. Second, the investigators also evaluate the application of the C3 related-indexes (C3, C3a, Factor H, DAF, etc.) to patients undergoing severe abdominal sepsis and to develop an alternative model to predict its prognosis.

Official Title
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The Complement C3 Depletion in Patients With Severe Abdominal Sepsis: Risk Prediction and the Association With Down-regulated Adaptive Immunity

Conditions
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Severe Sepsis, Pancreatitis, Abdominal Abscess, Appendicitis, Digestive System Fistula

Intervention / Treatment
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* Drug: Norepinephrine
* Procedure: Open abdomen
* Other: enteral nutrition
* Other: parenteral nutrition


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Clinical diagnosis of severe abdominal sepsis Exclusion Criteria: Age < 18 or > 60 years Pregnancy Leucopenia from radiochemical therapy due to malignant tumor Any primary diagnosis other than sepsis Confirmed immunodeficiency Requirement for blood transfusion, plasmapheresis, or immediate surgery

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 60 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: Screening
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Intervention/Treatment |
| --- |
|Drug: Norepinephrine|Intravenously, 10 ug/min, 24 hours|
|Procedure: Open abdomen|IAH >=20 mmHg, and ACS emerged, such as low urine and decreased FiO2 quickly.|
|Other: enteral nutrition|500-1500 kcal/day; Nasogastric tube feeding;|
|Other: parenteral nutrition|3000 mL parenteral nutrition fluid, intravenously.|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| All cause mortality | Patients died within the first three days of admission would be excluded from this study. | within the first 28 days after admission to our hosptial | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Postoperative complications | wound complications; pulmonary infection; incisional hernia, and bleeding. | within the first 28 days after admission to our hosptial |