Value of pulse oximetry for diagnosing obstructive sleep apnea-hypopnea syndrome and evaluation of the effect of the continuous positive airway pressure therapy

Abstract

To explore the value of pulse oximetry for diagnosing obstructive sleep apnea hypopnea syndrome (OSAHS) and evaluation of the effect of the continuous positive airway pressure (CPAP) therapy. From January 2013 to March 2014, 244 OSAHS patients admitted to department of respiratory and critical care medicine of the first affiliated hospital of Fujian Medical University and department of respiratory and critical care medicine of People's Hospital of Peking University were recruited. According to apnea-hypopnea index (AHI), all patients were divided into mild, moderate and severe groups. The differences in pulse-associated indicators [nocturnal pulse elevation index (NPEI), namely counts of heart rate (HR) variation >6 bpm/h, average HR and standard deviation of HR] were compared among three groups before and after CPAP therapy. Spearman correlation analysis between pulse-associated indicators and AHI was performed to explore the optimal indicator. Receiver operating characteristic (ROC) curve were conducted and sensitivity and specificity were obtained. NPEI after CPAP treatment were significantly lower than before among all the three groups (mild group 15.4±12.4 vs 19.4±13.3, moderate group 15.4±9.1 vs 24.1±11.9, severe group 21.9±14.8 vs 48.8±20.3, all P<0.05); there were significant correlations of AHI with average HR, standard deviation of HR and NPEI (r=0.334, 0.337 and 0.660, respectively) (all P<0.05); ROC curve showed a NPEI of 30beat per hour had a sensitivity of 68.0% and a specificity of 73.0% in diagnosing OSAHS. Nocturnal oximetry could be a useful tool for screening OSAHS in clinical practice, and the NPEI can evaluate the efficacy of the CPAP therapy.