The role of overnight pulse-oximetry in recognition of obstructive sleep apnea syndrome in morbidly obese and non obese patients.

ABSTRACT MATERIAL AND METHODS We prospectively evaluated 199 individuals with high pre-test clinical suspicion of OSAS. Of these, 123 patients were morbidly obese (Group A) and 76 were non-obese (Group B). We performed six channel cardio-respiratory polygraphy and assessed the correlation between the Desaturation Index (DI) and the Apnea Hypopnea Index (AHI) for both groups. RESULTS In group A: 116 patients (94.3%) were diagnosed with OSAS (AHI>5/hour); mean age: 59.4±10.9 years; mean BMI: 44.8±4.9 kg/m(2). The mean DI was 47.2±27.6/hour and the mean AHI: 46.5±27.6/hour. Mean average SaO2 was 88.5±6.3 %. In group B, 65 patients (85.52%) were diagnosed with SAS; mean age: 51.2 ± 12.7 years; mean BMI: 27.24±2.2 kg/m(2).The mean DI was 23.12 ± 18.35/hour and the mean AHI: 28.8 ± 18.5/hour. Mean average SaO2 was 93.7±2.07 %.A significant positive correlation (correlation index rA = 0.863 and rB= 0.877) was found between DI and AHI in both groups (p<0.001). CONCLUSION Assessment of the Desaturation Index by nocturnal pulse-oximetry maintains its utility as a screening method for OSAS in both obese and non-obese patients with high clinical pre-test suspicion, despite the fact that the basal nocturnal saturation was found to be lower in group A.