Applied values of hypopneic indices in the treatment for obstructive sleep apnea-hypopnea syndrome in adults

Objective To explore the relationship between the severity of obstructive sleep apnea hypopnea syndrome(OSAHS) and the degree of hypoxia in adults;and the applied value of every blood oxygen index in evaluating the degree of hypoxia.Methods 514 patients with snore suspected of OSAHS were monitored by polysomnography(PSG) and divided into 4 groups according to their PSG results.The percentage of valid sleep accounting for the total sleeping time(sleep efficiency),time of apnea or hypopnea,apnea-hypopnea index,average arterial oxygen saturation,lowest arterial oxygen saturation(LSaO2),the percentage of the total recorded time spent below 90% oxygen saturation(TS90%),the oxygen reduction index(ODI),the largest SaO2 reduction,and the duration of the largest SaO2 reduction were recorded and analyzed.Results The differences of LSaO2,TS90%,ODI,the largest SaO2 reduction,and the duration of the largest SaO2 reduction among above groups were statistically significant.And all these indices were significantly correlated with the severity of OSAHS.Among them,the correlation coefficient between TS90% and AHI was the largest(r=0.803,P=0.000).The reference value scopes of TS90% in the four groups were as follows: TS90%≤2%(normal group),2%TS90%≤12%(mild group),12%TS90%≤28%(moderate group),and TS90%28%(severe group).Conclusion The degree of nighttime hypoxia is positively correlated with the severity of OSAHS.TS90% is the most stable indicator to evaluate degree of hypoxia.