Diagnostic value of citrulline and intestinal fatty acid binding protein on acute gastrointestinal injury in critical patients: a prospective study of 530 patients

Abstract

To observe the incidence of acute gastrointestinal injury (AGI) in intensive care unit (ICU) patients, and to approach the value of serum citrulline and intestinal fatty acid binding protein (IFABP) on diagnosis of AGI in critical patients. A prospective study was conducted. 576 critical patients admitted to ICU of Yantai Yuhuangding Hospital from February 2016 to February 2017 were enrolled. According to the AGI classification proposed by European Society of Intensive Care Medicine (ESICM) in 2012, the AGI and severity of the patients were observed. The general data, severity and prognosis of patients with different AGI grades were recorded. According to the random number table, 20 patients with normal kidney function from AGI I to IV were selected. The femoral artery blood was collected within 12 hours of ICU admission, and serum citrulline level was detected by high performance liquid chromatography (HPLC). Serum IFABP level was determined by enzyme-linked immunosorbent assay (ELISA). Twenty healthy subjects were selected as controls. The receiver operating characteristic curve (ROC) was drawn, and the predictive values of citrulline and IFABP for AGI diagnosis were evaluated. (1) 576 patients were enrolled in the analysis. Of which 530 patients (92.0%) had AGI, and 289 patients with grade I (54.5%), 154 with grade II (29.1%), 64 with grade III (12.1%), and 23 with grade IV (4.3%). With the increase in AGI classification, acute physiology and chronic health evaluation system II (APACHE II) score, sequential organ failure score (SOFA), the length of ICU stay and 28-day mortality were gradually increased. (2) Compared with health control group, the levels of serum citrulline in patients with different AGI grades were significantly decreased, and IFABP was significantly increased. With the increase in AGI classification, the citrulline level was gradually decreased, and IFABP level was gradually increased [citrulline levels (μmol/L) in AGI I,II,III,IV groups were 14.1±3.6, 12.7±3.1, 8.3±2.7, and 5.6±3.4, F = 3.287, P = 0.027, and IFABP levels (ng/L) were 526.7±204.9, 698.4±273.8, 894.7±455.9, and 1 062.8±532.2, F = 2.903, P = 0.043]. ROC curve analysis showed that citrulline had a higher predictive value for AGI diagnosis. The area under the ROC curve (AUC) was 0.927. When the cut-off value of citrulline was 9.7 μmol/L, the sensitivity and specificity were 87.5% and 87.5%, respectively. The AUC of IFABP was 0.043, which has no predictive value for the diagnosis of AGI. The AGI is extremely common in ICU. The higher the AGI grade is, the worse the prognosis is. Citrulline has high diagnostic value for AGI in critical patients, but IFABP has no predictive value on the diagnosis of AGI.