Clinical relevance of bilateral pleural effusion in patients with acute pulmonary embolism

The clinical relevance of bilateral pleural effusion (BPE) in patients with acute pulmonary embolism (PE) is unclear.

To describe characteristics of patients with acute PE that present with BPE.

Patients with acute PE were retrospectively analysed and divided into three groups: without pleural effusion, unilateral pleural effusion and bilateral effusion. Clinical, laboratory and radiological characteristics were compared between the three groups.

The study population (n = 343) consisted of unilateral effusion group (n = 83), BPE group (n = 94) and without effusion group (n = 166). Several variables were noted in higher proportion (%), in the BPE group in comparison to both the unilateral effusion and without effusion groups: heart failure (17.0 vs 7.2 vs 6.7, P = 0.017), hypoalbuminaemia (59.3 vs 39.5 vs 25.6, P ˂ 0.001), PE occurrence in-hospital setting (51 vs 25.6 vs 15.1, P ˂ 0.001), major operation (31 vs 19.2 vs 15.2, P = 0.01) and mechanical ventilation (13.0 vs 4.9 vs 4.2, P = 0.019). Norton scale scores were found to be lower among patients with BPE in comparison to both patients with unilateral and without pleural effusion (15.55 vs 16.92 vs 17.36, P = 0.006). After adjusting confounding variables, patients with BPE have lower probability for in-hospital survival in comparison to both patients with unilateral pleural effusion (odds ratio = 0.30, 95% confidence interval 0.12-0.79), and patients without pleural effusion (odds ratio = 0.26, 95% confidence interval 0.11-0.61).

BPE in patients with acute PE may have significant clinical implications. It may signify serious underlying comorbidities which contribute to higher in-hospital mortality in comparison to both patients with unilateral pleural effusion and patients without pleural effusion.