Application value of urinary I-FABP in the clinical diagnosis and mortality prediction of ARDS caused by severe pneumonia in adults

Objective: To investigate the value of urinary intestinal-fatty acid binding protein (I-FABP) in the clinical diagnosis and mortality prediction of acute respiratory distress syndrome (ARDS) caused by severe pneumonia in adults.Methods: A total of 197 patients with severe pneumonia admitted to our hospital from September 2017 to December 2021 were selected as the study subjects.Among them, 97 patients complicated with ARDS were included in the ARDS group, and 100 patients without ARDS progression were included in the non-ARDS group.In addition, the ARDS patients were divided into death subgroup and survival subgroup according to the survival in hospital for 28 days.The level of serum I-FABP was determined by enzyme-linked immunosorbent assay.Results: The level of urinary I-FABP in ARDS group was higher than that in non-ARDS group (P＜ 0.001).The area under receiver operating characteristic (ROC) curve (AUC) of urinary I-FABP level for predicting ARDS in severe pneumonia patients was 0.763 (95% CI: 0.697-0.830).The level of urinary I-FABP in the death subgroup was higher than that in the survival subgroup (P＜ 0.001).The increase of urinary I-FABP level was correlated with the baseline Acute Physiology and Chronic Health Evaluation Ⅱ (APACHE Ⅱ), Sequential Organ Failure Assessment (SOFA) and the length of stay in intensive care unit of the survivors (P＜ 0.05).Urinary I-FABP level, baseline APACHE Ⅱand SOFA score were independent risk factors for 28 d in-hospital death in patients with ARDS caused by severe pneumonia (P＜ 0.05).ROC curve analysis showed that the AUC of 28 d in-hospital death in ARDS patients predicted by urinary I-FABP level was 0.879 (95% CI: 0.812-0.947), and the AUC value of urinary I-FABP combined with APACHE Ⅱor SOFA was greater than that predicted by the two alone (P＜ 0.05).Conclusion: The level of urinary I-FABP in patients with ARDS caused by severe pneumonia generally increases, and I-FABP is expected to become a reliable marker for the clinical diagnosis of ARDS and the prediction of 28 d in-hospital mortality.