Abstract
OBJECTIVE Evaluate the diagnostic reliability of overnight pulse oximetry versus respiratory polygraphy in sleep apnea diagnosis.
METHODS Prospective study. Outpatient, aged 18-70 years who were tested with a home polygraphy. Patients with low level of collaboration or potential risk of nocturnal oxygen desaturation diseases, like morbid obesity (BMI›40), diagnosis of heart failure or respiratory failure were excluded.
The variables related to SapO2 at night were recorded, ODI3, ODI4 and T90 and it was calculated the highest diagnostic value by the area under the curve ROC for them, and the best cut-off point in order to discriminate between patients with or without OSAS and patients with severe OSAS.
RESULTS 104 patients were included, 73 males (70%), mean age of 52.7±10.1 years, BMI =30.4±4.1 and AHI= 28.9±23.2 /hour. Pulse oximetry analysis presented ODI4= 25.3±26.2/hour, ODI3= 40.3±26.2/hour and T90= 5±9.7. Pearson's correlation showed a significant relation between AHI and ODI4 (r=0.91, p<0.001). For AHI≥ 10, variables with better diagnostic performance were ODI3 with area under the curve=0.94 and ODI4= 0.98 and its best point of diagnostic discrimination was 5.4/hour. For AHI ≥30, ODI4 is the most predictor variable with an area under the curve of 0.92, its better cut- off point was 10.5/hour.
CONCLUSIONS In OSAS patients, there is a correlation between the SapO2 variables from the pulse oximetry and AHI from the home polygraphy. The variable with higher discrimination capacity between patients with or without OSAS and severe OSAS was ODI4.
- Copyright ©the authors 2017