Comparison between oximetry with airflow and polysomnography

Objective To evaluate the diagnostic accuracy of the oximetry with airflow for different degree of obstructive sleep apnea hypopnea syndrome.Methods Sixty-two volunteers with suspected obstructive sleep apnea-hypopnea syndrome underwent simultaneous nocturnal polysomnography and oximetry with airflow recordings.The apnea-hypopnea index and the lowest oxygen saturation recorded by oximetry with airflow were compared with those recorded by polysomnography that often was considered as the gold diagnostic standard for obstructive sleep apnea-hypopnea syndrome.Results There was a close correlation between the apnea-hypopnea index and the lowest oxygen saturation assessed by oximetry with airflow and polysomnography(r=0.964 and 0.816,P=0.000;respectively).With the polysomnography apnea-hypopnea index≥5 as the diagnostic threshold of obstructive sleep apnea-hypopnea syndrome,the sensitivity and specificity of the oximetry with airflow were 93.3% and 76.5% respectively.There was no statistic difference in apnea-hypopnea index of the group of normal and mild obstructive sleep apnea-hypopnea syndrome between oximetry with airflow and polysomnography(P0.05).The oximetry with airflow-apnea-hypopnea index was significantly lower than polysomnography-apnea-hypopnea index in the group of moderate and severe obstructive sleep apnea-hypopnea syndrome(P0.05).There was no statistic difference in the lowest oxygen saturation of different degree of obstructive sleep apnea-hypopnea syndrome between oximetry with airflow and polysomnography(P0.05).Conclusion Oximetry with airflow has diagnostic value for the primary diagnosis of obstructive sleep apnea-hypopnea syndrome.However,because of the significance of the apnea-hypopnea index in the group of moderate and severe,it is not formally recommended as a sole criterion for the judgement of severities of obstructive sleep apnea-hypopnea syndrome.