Sleep in patients with large pleural effusion: impact of thoracentesis

Abstract

This study aimed to evaluate the sleep quality and impact of thoracentesis on sleep in patients with a large pleural effusion. Patients with large unilateral pleural effusion were evaluated by the Pittsburgh Sleep Quality Index (PSQI) questionnaire and dyspnea Borg scale. Full polysomnography (PSG) was performed on the night before and 36h after thoracentesis. We studied 19 patients, 11 males and 8 females, age 55 ± 18years and body mass index of 26 ± 5kg/m(2). The baseline sleep quality was poor (PSQI = 9.1 ± 3.5). Thoracentesis removed 1.624 ± 796mL of pleural fluid and resulted in a significant decrease in dyspnea Borg scale (2.3 ± 2.1 vs. 0.8 ± 0.9, p < 0.001). The PSG before and after thoracentesis showed no significant change in apnea-hypopnea index and sleep time with oxygen saturation <90%. There was a significant improvement in sleep efficiency (76% vs. 81%, p = 0.006), decrease percent sleep stage 1 (16% vs. 14%, p = 0.002), and a trend improvement in total sleep time (344 ± 92 vs. 380 ± 69min, p = 0.056) and percentage of rapid eye movement sleep (15% vs. 20%, p = 0.053). No significant changes occurred in six patients that performed two consecutive PSG before thoracentesis. The improvement in sleep quality was not associated with the volume of pleural fluid withdrawn or changes in dyspnea. Patients with large pleural effusion have poor subjective and objective sleep quality that improves after thoracentesis.