Objectives: Small bowel dysfunction in critically ill patients is frequent, underdiagnosed, and associated with poor prognosis. Intestinal fatty acid-binding protein is a marker of enterocyte damage, and plasma citrulline concentration is a marker of functional enterocyte mass. Primary objective was to identify factors associated with intestinal fatty acid-binding protein in critically ill patients. Secondary objectives were to study factors associated with plasma citrulline concentration and its correlation with intestinal fatty acid-binding protein.
Design: Prospective observational study.
Setting: ICU in a University Hospital
Patients: Critically ill patients 18 years old or older with an expected length of ICU stay 48 hours or more, without pregnancy, chronic small bowel disease, or chronic renal failure.
Measurements and Main Results: Plasma intestinal fatty acid-binding protein and citrulline concentrations, and variables relating to prognosis and treatment, were measured at admission to the ICU. One hundred and three patients were included. Intestinal fatty acid-binding protein elevation at admission to the ICU was associated with catecholamine support, higher lactate concentration, higher Sequential Organ Failure Assessment score, and higher international normalized ratio (all p ≤ 0.001). Plasma citrulline concentration less than or equal to 10 μmol/L at admission to the ICU was associated with higher intra-abdominal pressure, higher plasma C reactive protein concentration, and more frequent antibiotic use (all p ≤ 0.005). There was no correlation between plasma levels of intestinal fatty acid-binding protein and citrulline. At ICU admission, Sequential Organ Failure Assessment score ≥12, plasma citrulline ≤ 12.2 μmol/L, and plasma intestinal fatty acid-binding protein concentration ≥355 pg/mL were all independently associated with 28-day mortality (odds ratio, 4.39 [1.48–13.03]; odds ratio, 5.17 [1.59–16.86]; and odds ratio, 4.46 [1.35–14.74], respectively).
Conclusions: In critically ill patients, enterocyte damage is frequent, and it is significantly associated with shock and 28-day mortality. The link between intestinal fatty acid-binding protein and plasma citrulline concentrations in critically ill patients needs to be further evaluated.