Risk Factors for Mortality Among Mechanically Ventilated Patients Requiring Pleural Drainage

Purpose: Pleural effusions are common in mechanically ventilated patients. However, the risk factors for poor outcomes after pleural drainage are poorly understood. This study aimed to identify factors that were associated with in-hospital mortality among mechanically ventilated patients who underwent pleural drainage. Methods: This retrospective study evaluated 82 consecutive patients who required chest tubes during mechanical ventilation at two university-affiliated hospitals in Korea between January 2015 and June 2020. Results: The median age was 76 years (interquartile range [IQR]: 64-84 years), and the median SOFA score was 11 (IQR: 7-13). Intensive care unit admission was most commonly because of pneumonia (n = 44, 53.7%) and 60 patients (77.9%) had exudative pleural effusions. During pleural drainage, the PaO2/FiO(2) was 210 (IQR: 153-253); 45 patients (54.9%) were receiving vasopressors, and 31 patients (37.8%) were receiving continuous renal replacement therapy (CRRT). The multivariable regression analysis revealed that poor overall survival was independently associated with receiving vasopressors (adjusted hazard ratio [aHR]: 3.81, 95% confidence interval [CI]: 1.65-8.81, p = 0.002) and receiving CRRT (aHR: 5.48, 95% CI: 2.29-13.12, p < 0.001). The PaO2/FiO(2) ratio was relatively stable through the third day of pleural drainage among survivors but decreased among non-survivors. The vasopressor dose decreased among survivors but remained relatively stable among non-survivors. Conclusion: Among mechanically ventilated patients who required pleural drainage, use of vasopressors and CRRT was significantly associated with in-hospital mortality. On the third day of pleural drainage, the changes in PaO2/FiO(2) and vasopressor dose were associated with in-hospital mortality.