[Risk and Mortality Factors for Pleural Effusions Requiring Diagnostic Thoracentesis]

Occurrence of malignant pleural effusion (PE) is known to be associated with a poor prognosis, but the mortality of patients with non-malignant effusions has not been sufficiently studied. Our objective was to describe the clinical course and explore risk factors associated with all-cause mortality at 1, 5 and 10 years in patients who develop a PE.

Retrospective observational study of patients undergoing diagnostic thoracentesis during the decade 2008-2017 in a pulmonology service. Demographic, biochemical, pathological and evolutionary variables were evaluated. The etiology of the effusions was determined using standardized criteria.

Pleural fluid samples from 358 patients with a mean age of 68.9 years (SD 15.1 years), 69.2% males, were analyzed. Malignant (29.4%), parapneumonic (19.8%) and secondary to heart failure (18.9%) effusions predominated. Patients with malignant and heart failure related PE had 1-year mortality rates of 60.0% and 30.8%, respectively, and 85% and 64.7% at 5 years. Male gender (hazard ratio [HR] 1.46; 95% CI: 1.03-2.07), positive cytology for malignancy (HR 1.66; 95% CI: 1.03-2.68) and effusion recurrence (HR 1.61; 95% CI: 1.17-2.21) were associated with a worse prognosis and 5-year mortality.

Patients undergoing thoracentesis for effusion have a high short and long-term mortality. In our series of hospitalized patients with PE, the factors associated with higher mortality at 1 and 5 years were age, male sex, recurrence of PE, and coexistence of malignancy.