RT Journal Article
SR Electronic
T1 The relationship between sleep respiratory disorder and daytime PaO2 in OSAS and in overlap syndrome
JF European Respiratory Journal
JO Eur Respir J
FD European Respiratory Society
SP p4016
VO 38
IS Suppl 55
A1 Lacedonia, Donato
A1 Salerno, Francesco
A1 Sabato, Roberto
A1 Guido, Patrizia
A1 Forte, Lucia
A1 Carpagnano, Giovanna E.
A1 Carone, Mauro
A1 Foschino, Maria P.
YR 2011
UL http://erj.ersjournals.com/content/38/Suppl_55/p4016.abstract
AB OSAS and COPD are often associated with daytime hypoxiemia. Overlap Syndrome (OS) increases the risk of daytime hypoxiemia. The aimof this study was to investigate the mechanisms which could justify the low oxygen's levelin these patients and the effect of CPAP therapy.563 consecutive OSAS patients were enrolled. According to pulmonary function test they were divided in 2 groups. Group 1: 473 OSAS/COPD +/-; Group 2: 90 patients OSAS/COPD +/+. All patients underwent blood gases, nocturnal polisomnography, postbronchodilator spirometry. A multivariate analysis was performed to evaluate which were the factors that determining the diurnal PaO2The groups were matched for BMI, for age and AHI.OS group showed lower level of daytime PaO2 compared with OSAS patients (71.6±9.7 vs 79.3±11 mmHg, p<0,001), the alveolar-to-arterial oxygen partial pressure difference (AaDO2) was higher in OS than in OSAS (28.3±9.9 vs 22,7±10,7, p<0.01), also the TST90 was higher in OS (34,8%±35,5 vs 24% ± 26). In OS group diurnal PaO2 correlated with age (coef=-0,41) with AHI (-0,18) and with FEV1 (0,21), while in OSAS group the correlation was found with age (coef=-0,27), FEV1 (-0,07) and mostly with BMI (0,46), but not with AHI.In both groups, patients with good compliance (>4H/night) of CPAP improve daytime PaO2 (p<0.001) whereas, in patients with poor compliance PaO2 was reduced (p<0.001).Our data suggest that daytime hypoxemia in OSAS patients is largely determinated by the increased of body weight. In the overlap patients daytime hypoxiemia has a more complex origin. However CPAP therapy has been shown to improve daytime PaO2 values both in OSAS than in OS patients with good compliance