Related Factors Of Nocturnal Saturation For Patients With Obstructive Sleep Apnea Hypopnea Syndrome

Objective To study the related factors of the lowest SaO2 (LSaO2) in patients with obsturctive sleep apnea hypopnea syndrome (OSAHS), and explorer the reason that AHI and LSaO2 were mismatched. Methods The parameters of body charactristics and PSG and lung function and ventilation perfusion ratio(V/Q) of 30 patients with OSAHS entered into linear correlation analysis to correlate with LSaO2. 40 subjects recruited into 3 groups including control, SaO2 matched group and mismatched group. Results LAT, MAT, TAT, AI were higher in matched group than in mismatched group. There was no difference in lung function and V/Q ratio between two groups. Ventilation and (or) perfusion defects were found in patients with OSAHS. V/Q in OSAHS were significantly lower andâ–³V/Q were significantly higher compared with control subjests. There was no difference in V/Q andâ–³V/Q between matched group and mismatched group. LSaO2 were inversely correlated with BMI and neck circumference (r=-0.378,-0.538 respectively); LAT, MAT, TAT, AI were inversely corrlated with LSaO2 (r=-0.776, -0.457, -0.511, -0.727 respectively); ERV, FVC, MVV were positively corrlated with LSaO2 (r =0.414, 0.282, 0.465); LSaO2 were inversely corrlated with RAW andâ–³V/Q (r =-0.405,-0.432 respectively). Conclusions Ventilation and (or) perfusion defects were found in patients with OSAHS by ventilation perfusion imaging. Perfusion defects situated mainly in lobe inferior. The segments of ventilation defect were not correspond to perfusion defects. LSaO2 decreased was found in some patients with mild or moderate OSAHS, which was not associated with longer apnea time or totle apnea time, but related their changs of lung function and mismatched V/Q, the mismatched AHI and LSaO2 were caused by those changes .Our findings indicated that obese, neck circumference, duration and frequency of obstructive sleep apnea, total time of obstructive sleep apnea, decreased lung volume, increased resistance of airway and mismatched V/Q ratio were all related to LSaO2.