ApEn And SITi For The Assessment Of Hypoxemia Severity In Obstructive Sleep Apnea Hypopnea Syndrome Patients

Background:1、Current assessment of hypoxemia severity in obstructive sleep apnea hypopnea syndrome patients includes the lowest mean oxygen saturation (LO2), oxygen desaturation index (Oxygen Desaturation Index,ODI) and the oxygen saturation of less than90%for the entire recording time (T<90%).However, those parameters can only reflect one aspect of hypoxemia.2、polysomnography is the gold standard of diagnosis of obstructive sleep apnea hypopnea syndrome (OSAHS), but the operation is complex and high cost. Foreign scholars have pointed out by nocturnal oximetry may be initially instead of PSG on high risk patients screening examination, but the specific analytical methods are currently disputed.Objective:We use two new index ApEn (approximate entropy of oxygen saturation) and SITi (Saturation Impairment Time index) to diagnose and assess the severity of hypoxemia in OSAHS patients, and also to find the correlations of two new index with other parameters, and then to explore their clinical values. Methods:We did a retrospective analysis of500patients with OSAHS and snorers. Subject characteristics were collected. All subjects were recorded6hours of Sleep apnea monitoring. According to the level of AHI, subjects were divided into four subgroups.1> We compared ApEn and SITi values among the4groups, and then tried to find the correlations of ApEn, SITi and AHI. We also explored the correlations of ApEn and SITi with ODI, LO2and T<90%.2、Use AHI as the gold standard to find the diagnose value of ApEn and SITiin OSAHS.Results:500subjects were361male (72.2%)and139female(27.8%), and mean age was53.2+15.2years (range24-95).1、ApEn, SITi in each group were significantly different (P<0.001). ApEn and SITi increase synchronously with AHI. Significant difference of ApEn was found between each groups (P<0.001), and the same result was found in SITi (P<0.05, except in snorers and mild OSAHS group). Spearman correlation analysis showed that ApEn and SITi had a good correlation with AHI (correlation coefficient r0.765, r=0.678, P<0.01). ApEn and SITi had a good correlation with ODI, LO2and T<90%. According to the ROC analysis results, the Boundary value for OSAHS patients with mild, moderate, severe hypoxia was16.70,17.81,20.03, the corresponding SITi value was3.685,4.055,4.445.2、When used AHI≥5as gold standard, according to the ROC analysis and Youden’s index, the diagnostic sensitivity of ApEn for OSAHS was69.5%, and specificity was90.3%(Use ApEn value of16.70).Conclusion:1、ApEn and SITi increase synchronously with AHI. ApEn and SITi had good correlations with AHI, ODI, LO2and T<90%. ApEn and SITi have clinical values for assessment of hypoxia severity in OSAHS patients.2、ApEn showed a high sensitivity and specificity in the diagnosis of OSAHS.