Prognostic factors for ARDS: clinical, physiological and atypical immunodeficiency

Min Song,Hong Peng,Yijie Liu,Hong Luo,Zhiwen Lu,Ping Chen

doi:10.1186/s12890-020-1131-0

Abstract

BackgroundRisk factors affecting the prognosis of acute respiratory distress syndrome (ARDS) in adults were investigated. The aim was to identify new predictors for ARDS patient prognosis, including those with clinical, pathophysiological, and atypical immunodeficiency.MethodsARDS patients were retrospectively included. The patients were grouped and analysed according to different oxygenation index grades and prognosis, and factors influencing prognosis and survival were examined. Adolescent patients, patients with typical immunodeficiency and patients who died within 24 h after being diagnosed with ARDS were excluded. The predictive value for mortality was determined by Cox proportional hazard analysis.ResultsIn total, 201 patients who fulfilled the Berlin definition of ARDS were included. The severity of critical illness on the day of enrolment, as measured by the Acute Physiology and Chronic Health Evaluation (APACHE) II score (P = 0.016), Sequential Organ Failure Assessment (SOFA) score (P = 0.027), and PaO2/FiO2 (P = 0.000), worsened from mild to severe ARDS cases. Compared with survivors, non-survivors were significantly older and had higher APACHE II and SOFA scores. Moreover, significantly lower lymphocyte/neutrophil ratios and leukocyte counts were found among non-survivors than survivors (P = 0.008, P = 0.012). A moderate positive correlation between the lymphocyte/neutrophil and PaO2/FiO2 ratios (P = 0.023) was observed. In predicting 100-day survival in patients with ARDS, the area under the curve (AUC) for the lymphocyte/neutrophil ratio was significantly higher than those for the PaO2/FiO2 ratio alone, body mass index (BMI) alone, and the lymphocyte count alone (P = 0.0062, 0.0001, and 0.0154). Age (per log10 years), BMI < 24, SOFA score, leukocyte count, and the lymphocyte/neutrophil ratio were independent predictors of 28-day mortality in ARDS patients. Additionally, ARDS patients with a lymphocyte/neutrophil ratio < 0.0537 had increased 28-day mortality rates (P = 0.0283). Old age affected both 28-day and 100-day mortality rates (P = 0.0064,0.0057).ConclusionsAge (per log10 years), BMI < 24, SOFA score, lymphocytes, and the lymphocyte/neutrophil ratio were independent predictors of 100-day mortality in patients with ARDS. The lymphocyte/neutrophil ratio may represent a potential molecular marker to evaluate atypical immunosuppression or impairment in patients with ARDS.

Highlights

Risk factors affecting the prognosis of acute respiratory distress syndrome (ARDS) in adults were investigated
According to the Acute Physiology and Chronic Health Evaluation (APACHE) II score (P = 0.016), Sequential Organ Failure Assessment (SOFA) score (P = 0.027), and PaO2/FiO2 (P = 0.000), it can be seen that the severity of critical illness on the day of enrolment worsened from mild to severe ARDS, as shown in Tables 1 and 2
The area under the Receiver operating characteristic (ROC) curve (AUC) for the lymphocyte/neutrophil ratio for the prediction of 100-day survival in ARDS patients was 0.721 and was significantly higher than the area under the curve (AUC) for the PaO2/FiO2 ratio alone (0.625, 95% Confidence interval (CI) 0.554 to 0.692, P = 0.0062,), the AUC for body mass index (BMI) alone (0.593, 95% CI 0.521 to 0.661, P = 0.0001) or the AUC for the lymphocyte count alone (0.592,95% CI 0.520 to 0.660, P = 0.0154) (Fig.2)

Summary

Introduction

Risk factors affecting the prognosis of acute respiratory distress syndrome (ARDS) in adults were investigated. Few clinical studies on the immune status of ARDS patients have focused on aetiology, treatment and prognosis [11]. Some studies have shown that ARDS occurs in patients with previous immunodeficiencies, such as haematologic malignancies, active solid tumours, solid organ transplantation, and acquired immunodeficiency syndrome, as well as in patients taking long-term or high-dose corticosteroids or immunosuppressants, and those who use extra-corporeal membrane oxygenation (ECMO) may have a better prognosis [13]. There is currently a lack of uniform molecular markers for patients with atypical immunosuppression or impaired status. It is not well known whether the status of atypical immunodeficiency affects the prognosis of ARDS. Managing patients with atypical immunosuppression in intensive care unit (ICU) can be challenging, updated epidemiological and outcomes studies are needed to evaluate the condition of these patients

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