[Agreement between oxygen desaturation index and apnea-hypopnea index in adults with suspected obstructive sleep apnea at an altitude of 2240 m].
OBJECTIVE
Altitude can affect the diagnostic accuracy of portable monitors used to diagnose suspected obstructive sleep apnea syndrome on the basis of oxygen desaturation measurements. The aim of this study was to determine agreement between the desaturation index measured by oximetry and the apnea-hypopnea index measured by polysomnography in Mexico City (2240 m above sea level). We also wished to determine agreement between the desaturation index and the respiratory disturbance index measured by monitoring airflow with a single-channel recording device.


METHODS
We used standard polysomnography and nocturnal oximetry to simultaneously measure the apnea-hypopnea index and the desaturation index, respectively, in a group of 38 patients aged over 18 years with suspected obstructive sleep apnea syndrome. In a second group of 30 patients, we compared the desaturation index to the respiratory disturbance index, which we measured using a single-channel device monitoring nasal airflow.


RESULTS
The mean (SD) intraclass correlation coefficient between the apnea-hypopnea index and the desaturation index was 0.89 (0.03) (95% confidence interval, 0.83-0.96), and the mean of the differences was -0.9 (14.2). The mean intraclass correlation coefficient for the desaturation index and the respiratory disturbance index was 0.93 (0.02) (95% confidence interval, 0.89-0.97), and the mean of the differences was -6.6 (8.3).


CONCLUSIONS
Agreement was high between the desaturation index and both the apnea-hypopnea index and the respiratory disturbance index in adults with suspected obstructive sleep apnea syndrome in Mexico City.
Torre-Bouscoulet
Luis
L
Clínica de Sueño, Instituto Nacional de Enfermedades Respiratorias, México, DF, México. luistorreb2001@yahoo.com.mx
Castorena-Maldonado
Armando
A
Baños-Flores
Rocío
R
Vázquez-García
Juan Carlos
JC
Meza-Vargas
María Sonia
MS
Pérez-Padilla
Rogelio
R
D000531:Altitude; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000378:metabolism*; D020181:Sleep Apnea, Obstructive / Q000378:metabolism*
D010100:Oxygen