Oxygen desaturation indexcan reflect nocturnal hyoxemia perfectly in patients with obstructive sleep apneahypopneasyndrome

Abstract

：Objective To investigatethe correlationship between nocturnal hyoxemia indexs and apnea-hypopnea index (AHI) inpatients with obstructive sleep apnea-hypopnea syndrome (OSAHS),then to explore the bestdeterminant of nocturnal hyoxemia and facilitate the use of this determinant in familyportable oximeter in such patients. Methods A total of 491 subjects who complained snoringand were suspected to have OSAHS were included in our study, all subjects underwentovernight polysomnography in our sleep laboratory. To analyze the correlation between AHIand body mass index (BMI),Epworth sleepiness scale (ESS), oxygen desaturation index (ODI),time spent below oxygen saturation of 90 % (TS90 % ), apnea-hypopnea time index ( AHTI),minimal saturation O2 ( MiniSO2 ), and also try to figure out the most significantdeterminant reflecting nocturnal hyoxemia, AHI and the most significant determinant werecompared by using linear correlation. Its sensitivity,specificity were computed 319.15, P=0.000), AHTI( χ 2 = 340. 53, P = 0.000),ODI(χ 2 = 347.87, P = 0. 000),TS90% ( χ 2 =significant correlation between ESS, AHTI, ODI, TS90 %, MiniSO2and AHI, correlation coefficient were 0. 822,0. 871,0. 893,0. 790 and -0. 742respectively(all P ＜0.01),especial ODI is the most significant cut offpoint,the sensitivity and specificity reached 89.36%, 90.00% respectively. When using ODI≥20 times/h as diagnostic cut offpoint for moderate and severe OSAHS,the specificity can reach to 95.2%.Conclusions ODI isa better index to reflect nocturnal hyoxemia, and it can use widely for screening OSAHSpatients with family portable oximeter. Key words: Sleep apnea; Obstructive; Nocturnal hyoxemia; Oxygendesaturation index; Screening