Value of procalcitonin on predicting the severity and prognosis in patients with early ARDS: a prospective observation study / 中华危重病急救医学

ABSTRACT

Objective To investigate the value of procalcitonin (PCT) on predicting the severity and prognosis in patients with early acute respiratory distress syndrome (ARDS).Methods A prospective observation study was conducted. A total of 113 patients with ARDS undergoing mechanical ventilation admitted to intensive care unit (ICU) of Affiliated People's Hospital ofJiangsu University from October 2012 to April 2016 were enrolled. Based on oxygenation index (PaO2/FiO2), the patients were classified into mild, moderate, and severe groups according to Berlin Definition. Twenty-five healthy volunteers were served as controls. Demographics, acute physiology and chronic health evaluation Ⅱ (APACHE Ⅱ) score, and Murray lung injury score were recorded. Within 24 hours after diagnosis of ARDS, the serum levels of PCT and C-reactive protein (CRP) were determined by enzyme-linked fluorescence analysis (ELFA) and immune turbidimetric method, respectively. The patients were also divided into survival and non-survival groups according to clinical outcome within 28-day follow-up, and the clinical data were compared between the two groups. Spearman rank correlationwas applied to determine the correlation between variables. The predictive value of the parameters on 28-day mortality was evaluated with receiver operating characteristic curve (ROC). Kaplan-Meier survival curve analysis was used to compare different PCT levels of patients with 28-day cumulative survival rate. Results After excluding patients who did not meet the inclusion criteria and loss to follow-up, the final 89 patients were enrolled in the analysis. Among 89 ARDS patients analyzed, 27 of them were mild, 34 moderate, and 28 severe ARDS. No significant differences were found in age and gender between ARDS and healthy control groups. Infection and trauma were the most common etiology of ARDS (55.1% and 34.8%, respectively). Compared with healthy control group, both CRP and PCT in serum of ARDS group were higher [CRP (mg/L) 146.32 (111.31, 168.49) vs. 6.08 (4.47, 7.89), PCT (μg/L) 3.46 (1.98, 5.56) vs. 0.02 (0.01, 0.04), bothP 4.35μg/L for predicting 28-day mortality, the sensitivity and specificity was 92.2% and 63.2%, respectively, and the positive and negative likelihood ratios were 2.50 and 0.12 respectively. Kaplan-Meier survival curve analysis indicated that the patients whose PCT more than 4.35μg/L, had lower 28-day cummulative survival rate as compared with those with PCT ≤ 4.35μg/L (log-rank test χ2 = 5.013,P = 0.025).Conclusion The elevated serum PCT level in patients with ARDS seems to be correlated well with the severity of lung injury, and appears to be a useful prognostic marker of outcome in the early phases of ARDS.