Effects of endobronchial coils for endoscopic lung volume reduction on sleep in COPD patients with advanced pulmonary emphysema

Purpose Treatment of advanced pulmonary emphysema with endobronchial coils can improve clinical outcomes like quality of life (QOL). Yet, patients with chronic obstructive pulmonary disease (COPD) are also known to suffer from reduced sleep quality. The effect of coil therapy on sleep has not yet been investigated. The primary aim of this study was to investigate sleep efficiency before and after coil treatment. Secondly, we investigated the effects on nocturnal breathing pattern, QOL, and physical activity. Methods Polysomnography (PSG) testing was performed before (T0), 6 month after (T3), and 12 months after (T4) treatment with endobronchial coils. Further examinations included QOL by St George's Respiratory Questionnaire (SGRQ) and COPD assessment test (CAT), and physical activity using an accelerometer for 1 week after each visit. Results Of 21 patients, 14 completed the study: 6 women; mean age 58.0 +/- 4.9 years; BMI 22.6 +/- 4.6 kg/m(2); FEV(1)28.6 +/- 7.1% predicted; residual volume (RV) 278.2 +/- 49.4% predicted. Sleep efficiency did not vary between baseline and follow-up examinations (T0 69.0 +/- 15.8%; T3 70.9 +/- 16.0%; T4 66.8 +/- 18.9%). Non-REM respiratory rate decreased compared to baseline (T0 19.4 +/- 3.9/min; T3 17.8 +/- 3.5/min; T4 17.1 +/- 3.1/min (p= 0.041;p= 0.030) and QOL improved meeting the minimal clinically important difference (MCID) (SGRQ, T3 -12.8 units; T4 -7.1 units; CAT: T3 -5.6 units; T4 -3.4 units). No increase in physical activity was recorded (light activity T0 31.9 +/- 9.9; T3 30.8 +/- 16.9; T4 26.3 +/- 10.6 h/week). Conclusions Treatment with endobronchial coils did not influence objectively measured sleep quality or physical activity, but reduced nocturnal breathing frequency and improved QOL in severe emphysema patients.