Objective: To study the risk factors associated with the hospital survival rate of elder patients with
acute respiratory distress syndrome (ARDS) in Medical/Respiratory Intensive Care Units (MICUs/RICUs) by evaluating the prognosis, and therefore to provide insight into patient treatment strategy. Methods: Twenty MICUs/RICUs of 19 general hospitals in mainland China participated in the multicenter prospective cohort study carried out from Mar 1st, 2016 to Feb 28th, 2018. Patients who met the criteria of Berlin ARDS and older than 65 years were recruited. Baseline data, risk factors of ARDS,
ventilator setup and prognosis data were collected from all patients. Univariant and multivariant regression analysis were conducted to analyze the factors associated with the prognosis. Results: 170 elder ARDS patients (age≥65 years) met the Berlin ARDS criteria, among whom 8.8% (15/170), 42.9% (73/170) and 48.2% (82/170) patients had mild, moderate and severe ARDS, respectively. The most common predisposing factor for elder ARDS was
pneumonia, which was present in 134 patients (78.8%). 37.6% (64/170) patients were treated with noninvasive
mechanical ventilation (NIV), but 43.8% (28/64) cases experienced treatment failure. 76.5% (130/170) patients were treated with invasive
mechanical ventilation. All patients 80 years or older were given invasive
mechanical ventilation. 51.8% (88/170) cases had complications of non-pulmonary organ failure. 61.8% (105/170) patients deceased during
hospital stay. Multivariant logistic analysis showed that the independent risk factors for hospital survival rate in elder patients with ARDS were SOFA score (P=0.030, RR=0.725, 95% CI 0.543-0.969),
oxygen index after 24 hours of ARDS diagnosis (P=0.030, RR=0.196, 95% CI 0.045-0.853), accumulated fluid balance within 7 days after diagnosis of ARDS (P=0.026, RR=1.000, 95% CI 1.000-1.000) and
shock (P=0.034, RR=0.140, 95% CI 0.023-0.863). Conclusion: Among 20 ICUs, the high mortality rate of elder patients with ARDS was correlated with higher 24 hour SOFA score, lower 24 hour
oxygen index after ARDS diagnosis, more positive fluid balance within 7 days and concomitant
shock. The conservative fluid strategy within 7 days of ARDS diagnosis may benefit the elder ARDS patients.