ABSTRACT
Mucociliary and airway functional impairment in COPD are partly due to abnormal sputum rheology determined by mucus glycoproteins [MGP]. To assess the short term effects of oscillating endobronchial positive expiratory pressure [PEP] on sputum viscosity [V], MGP, pulmonary function tests [PFT] in acute COPD exacerbation. Seventeen male COPD patients [mean age 66.1 +/- 12.7] receiving conventional therapy, except for mucolytics, entered the study during an acute exacerbation [group A]. Group B [control] included 10 male COPD patients [mean age 57.3 +/- 9.66 year] during a similar attack and they received the same treatment except for Flutter. An informed consent was obtained from all participants. Basal sputum viscosity [V], mucus glycoproteins [MGP], pulmonary function tests [PFT] and PaO[2] were assessed. Group A then performed physiotherapy using Flutter device which induces oscillations varying between 10-20 cm H[2]O in both intrabronchial pressure and flow of the exhaled air for 15 minutes 3 times a day and once more on the next morning. All parameters were repeated on the next morning for both groups. Values of FVC [%of predicted], FEV[1]/FVC and MMFR [%of predicted] were [55.9 +/- 28.1, 41.2 +/- 11.1 and 44.4 +/- 17.8] and significantly improved after flutter to reach [76.3 +/- 22.5, 51.3 +/- 13.9 and 50.8 +/- 25.9] respectively. Sputum viscosity [in poise] and MGP [in mg/dl] were 84.4 +/- 94 and 47.3 +/- 7.8 and showed significant decline after PEP [38.01 +/- 55 and 45 +/- 7]. There was also a significant change in PaO[2] before and after physiotherapy [50.7 +/- 21.2 and 66.6 +/- 15.6]. There was a significant positive correlation between MGP and V [p=0.001] and a significant negative one between MGP and FEV[1]/FVC [p=0.03]. In Group B, V [167.6 +/- 54.6] did not change significantly [166.4 +/- 55.6], FVC decreased from 64 +/- 4 to58 +/- 22 and FEV[1]/FVC from 78.9 +/- 21 to74.3 +/- 33.4 while MMFR increased from 59.5 +/- 45.9 to 66.2 +/- 40.7 [p=0.019]. Oscillating PEP significantly improves sputum viscosity. These changes are positively and significantly reflected on PFT and PaO[2] in acute exacerbation of COPD