Application Value Analysis Of Upper Airway CT And Respiratory Resistance In Evaluating The Severity Of Obstructive Sleep Apnea Hypopnea Syndrome

Objective:To analysis the characteristics and clinical value of upper airway CT and respiratory resistance in evaluating the severity of obstructive sleep apnea hypopnea syndrome(OSAHS).Methods:A retrospective analysis of 178 patients with OSAHS confirmed at the Sleep Medicine Center of Shengjing Hospital from August 2018 to December2020.Their clinical manifestations,PSG report,upper airway CT index and respiratory resistance index were gathered.According to apnea hypopnea index(AHI),the patients divided into two groups: mild to moderate OSAHS group(85 cases)and severe OSAHS group(93 cases).The clinical manifestations,PSG report,respiratory resistance index and upper airway CT index were compared between the groups,and the correlation between minimum oxygen saturation and respiratory resistance index,between minimum oxygen saturation and upper airway CT index,between microarousal index and respiratory resistance index and between micro-arousal index and upper airway CT index were analyzed by SPSS 26.Results:1.There were significant differences in BMI,ESS score,nocturnal urination,dry mouth and hypertension between the two groups(P < 0.05).2.N2 latency,N3 latency,total sleep time,sleep efficiency,N1/TST%,N3/TST%,total number of micro-arousal in REM,total number of micro-arousal in NREM,total number of micro-arousal,total number of micro-arousal more than 15 seconds,microarousal index,AHI,total number of obstructive apnea,longest time of obstructive apnea and lowest oxygen saturation were statistically significant between the two groups(P< 0.05).3.R5,R20,R5-R20,R35,Z5 and Zrs were statistically significant between the two groups(P< 0.05).4.The length of the RP,the vertical distance between the inferior margin of the hard palate and the inferior margin of the hyoid,the vertical distance between the inferior margin of the hyoid and the inferior margin of the mandible,the length of the soft palate,the left and right diameter of the RP,the anterior and posterior diameter of RP,the cross-sectional area of the RP,the left and right diameter of the RG,the cross-sectional area of the RG,the anterior and posterior diameter of the EPG,the cross-sectional area of the EPG were statistically significant between the two groups(P<0.05).5.In patients with OSAHS,the minimum oxygen saturation was negatively correlated with R5,R20,R5-R20,R35,Z5(r =-0.379,-0.333,-0.336,-0.264,-0.388,P <0.05).And It was negatively correlated with the length of the RP,the vertical distance between the inferior margin of the hard palate and the inferior margin of the hyoid,the vertical distance between the inferior margin of the hyoid bone and the inferior margin of the mandible,the length of the soft palate and the posterior diameter of the EPG(r =-0.359,-0.48,-0.389,-0.294,-0.325,-0.221,P< 0.05),but positively correlated with the left and right diameter of the RP,the cross-sectional area of RP and the left and right diameter of RPG(r=0.454,0.373,0.315,P< 0.05).6.In patients with OSAHS,the microarousal index was positively correlated with the length of RP,the vertical distance between the inferior margin of the hard palate and the inferior margin of the hyoid,the vertical distance between the inferior margin of the hyoid and the inferior margin of the mandible,and the anterior and posterior diameter of EPG(r= 0.158,0.24,0.213,0.18,P<0.05).But it was negatively correlated with the left and right diameter of the RP,the cross-sectional area of the RP,the left and right diameter of RG,the cross-sectional area of RG(r=-0.277,-0.25,-0.311,-0.251,P<0.05).Conclusion:1.Some patients with OSAHS have mouth-opening breathing to compensate for nasal airflow limitation,which is characterized by dry mouth in the morning and is more common in patients with severe OSAHS.2.The respiratory impedance of severe OSAHS patients was higher than that of mild to moderate patients,but there was no difference in respiratory reactance between the two groups,which suggested that the increase of viscous resistance may aggravate OSAHS and decrease the blood oxygen saturation.But,there is no correlation between airway impedance and microarousal index.3.On the CT sagittal plane of the upper airway,the larger the measured values of the longitudinal diameter of the upper airway in patients with OSAHS(including the length of the RP,the vertical distance between the lower edge of the hard palate and the lower edge of the hyoid,the vertical distance between the lower edge of the hyoid and the lower edge of the mandible,and the length of the soft palate),the more serious of OSAHS and the more possibility of micro-awakening.On the horizontal plane of CT in the upper airway,the structures of the RP and RG are the main parts that could affect the severity of OSAHS.