Fecal Lactate and Resuscitation Outcomes in Critical Illness

N/AActive Not RecruitingNCT07658001

Hospital H+ Queretaro40 enrolled

Overview

This study evaluates the prognostic value of fecal lactate and the fecal-to-serum lactate gradient as early biomarkers of tissue hypoperfusion in critically ill patients. While serum lactate is widely used, it may not accurately reflect splanchnic perfusion. This prospective observational study aims to determine whether fecal lactate levels obtained within the first 12-24 hours can predict poor response to resuscitation at 24 hours. The primary outcome is a composite of increased vasopressor requirements, persistent hyperlactatemia, worsening organ dysfunction, or death.

Tissue hypoperfusion is a central mechanism in the development of organ dysfunction in critically ill patients. Although serum lactate is commonly used as a marker of hypoxia and a target for resuscitation, it may not adequately reflect regional perfusion, particularly in the splanchnic circulation. Persistent splanchnic hypoperfusion contributes to intestinal barrier dysfunction, bacterial translocation, and progression to multiple organ failure. This study is based on the hypothesis that, under ischemic conditions, the intestinal mucosa behaves as a semipermeable membrane, allowing equilibration of lactate produced in the intestinal wall into the lumen. Therefore, fecal lactate may serve as a direct and early marker of intestinal hypoperfusion. This is a prospective, observational, single-center cohort study conducted in an intensive care unit. Adult patients (≥18 years) with evidence of tissue hypoperfusion will be included. Fecal samples will be collected within the first 12-24 hours and processed through dilution, homogenization, centrifugation, and colorimetric analysis of the supernatant to quantify L-lactate levels. Simultaneously, serum lactate will be measured, and the fecal-to-serum lactate gradient will be calculated. The primary outcome is poor response to resuscitation at 24 hours, defined as a composite endpoint including increased vasopressor requirements, serum lactate clearance \<10% or persistent lactate \>2 mmol/L, worsening organ dysfunction measured by SOFA score (increase ≥1 point), or death. Secondary objectives include evaluating the correlation between fecal lactate and organ dysfunction severity, as well as determining the optimal cut-off value for fecal lactate to predict adverse outcomes using receiver operating characteristic (ROC) curve analysis. This study aims to identify fecal lactate as a non-invasive, early, and specific biomarker of splanchnic hypoperfusion, potentially improving clinical decision-making and guiding resuscitation strategies in critically ill patients.

Study Type

OBSERVATIONAL

Eligibility

Sex: ALLMin age: 18 YearsMax age: 100 Years

Medical Language ↔ Plain English

Inclusion Criteria: * Adult patients ≥18 years admitted to the intensive care unit (ICU) * Evidence of tissue hypoperfusion defined by at least ONE of the following: Arterial serum lactate ≥2.0 mmol/L or Hypotension requiring vasopressors to maintain mean arterial pressure (MAP) ≥65 mmHg * Clinical signs of hypoperfusion (capillary refill time \>3 seconds or mottling score ≥2) * Availability of fecal sample within the first 24 hours of ICU admission Exclusion Criteria: * Active gastrointestinal bleeding * Recent abdominal surgery (\<48 hours) with intestinal resection or stoma * Confirmed Clostridioides difficile infection * Do-not-resuscitate (DNR) orders at ICU admission

Outcomes

Primary Outcomes

Poor Response to Resuscitation at 24 Hours

Composite outcome defined by the presence of at least one of the following within 24 hours: increase in vasopressor requirements compared to baseline, serum lactate clearance \<10% or persistent lactate \>2 mmol/L, increase in SOFA score ≥1 point, or death.

Time frame: 24 hours

Secondary Outcomes

Correlation Between Fecal Lactate and Organ Dysfunction

Assessment of the association between fecal lactate levels and the severity of organ dysfunction measured by SOFA score at baseline and 24 hours.

Time frame: Baseline and 24 hours

Diagnostic Performance of Fecal Lactate for Predicting Poor Response

Evaluation of the predictive accuracy of fecal lactate levels for poor response to resuscitation using receiver operating characteristic (ROC) curve analysis and area under the curve (AUC).