Enterocyte Injury and Acute Gastrointestinal Dysfunction in Critical Illness

N/ANot Yet RecruitingNCT07440368

The First Hospital of Jilin University500 enrolled

Overview

Acute gastrointestinal injury (AGI) is a common but not fully understood organ dysfunction in critically ill patients. Current AGI grading systems rely primarily on clinical presentation and feeding tolerance, which are inherently subjective and may not accurately reflect the underlying biological severity of intestinal damage. Intestinal fatty acid-binding protein (I-FABP) is a protein expressed almost exclusively in the cytoplasm of mature small intestinal epithelial cells. In cases of ischemia, inflammation, or mechanical injury, I-FABP is rapidly released into the bloodstream and subsequently excreted in the urine. These characteristics make I-FABP a highly specific biomarker for intestinal epithelial cell injury and intestinal ischemia. A prospective study combining paired blood and urine I-FABP measurements, standardized AGI assessment, and careful consideration of surgical status was conducted to elucidate the role of intestinal epithelial cell injury in acute gastrointestinal dysfunction.

This study is a prospective observational cohort study conducted in an adult intensive care unit. Biological samples and clinical data will be prospectively collected according to a pre-defined protocol, without any intervention other than standard treatment. Primary objective: To prospectively assess the association between serum and urinary I-FABP levels and the severity of acute gastrointestinal injury in critically ill patients. Secondary objectives: To investigate the relationship between serum and urinary I-FABP levels and clinical outcomes (including severe AGI and mortality); to explore whether the intestinal epithelial cell injury patterns reflected by serum and urinary I-FABP are associated with different sepsis subphenotypes; and to evaluate the impact of gastrointestinal surgery on I-FABP levels and its modifying effect on the association between I-FABP and AGI severity.

Study Type

OBSERVATIONAL

Enrollment

500

Conditions

Patients Admitted to the ICU

Eligibility

Sex: ALLMin age: 18 Years

Medical Language ↔ Plain English

Inclusion Criteria: * 1、 Age ≥18 years. * 2 、Admission to the ICU with an expected ICU stay ≥48 hours. * 3 、Availability of paired plasma and urine samples within 24 hours of ICU admission. * 4 、Feasible daily gastrointestinal function assessment to complete AGI grading (ESICM definition). Exclusion Criteria: * 1、 Pre-existing inflammatory bowel disease. * 2 、Short bowel syndrome. * 3、 Chronic intestinal failure requiring long-term parenteral nutrition. * 4、 Pregnancy. * 5 、Refusal or withdrawal of informed consent.

Outcomes

Primary Outcomes

Maximum AGI grade during ICU stay (ESICM 0-IV)

AGI severity will be assessed daily during ICU stay and graded as an ordinal outcome (0, I, II, III, IV) according to the ESICM Working Group definition. The primary outcome is the maximum (worst) AGI grade observed from ICU admission (Day 1) through ICU discharge or death, up to 28 days. Effect modification by gastrointestinal surgery will be explored using an interaction term.

Time frame: From ICU admission (Day 1) through ICU discharge or death, assessed daily, up to 28 days.

Secondary Outcomes

Severe AGI during ICU stay (AGI grade III-IV)

AGI severity will be assessed daily during ICU stay and graded (0, I, II, III, IV) according to the ESICM Working Group definition. Severe AGI is defined as any occurrence of AGI grade III or IV during the assessment period and will be reported as a binary outcome (yes/no).

Time frame: From ICU admission (Day 1) through ICU discharge or death, assessed daily, up to 28 days.

28-day all-cause mortality

Death from any cause within 28 days after ICU admission.

Time frame: Up to 28 days after ICU admission.

ICU length of stay

ICU length of stay, defined as the number of days from ICU admission to ICU discharge or death.

Time frame: From ICU admission(Day 1) through ICU discharge or death, up to 28 days.

Sepsis subphenotype characterized by an intestinal epithelial cell injury pattern

A biomarker-defined sepsis subphenotype characterized by an intestinal epithelial cell injury pattern will be identified according to a prespecified definition/algorithm based on I-FABP profiles (plasma and urine) measured within 24 hours of ICU admission and on ICU day 3 (categorical classification).

Time frame: Within 24 hours of ICU admission and ICU day 3 (for classification), with outcomes assessed during ICU stay and/or up to day 28 as applicable.