Evaluation of upper airway obstruction site in OSAHS by Apneagraph and spiral CT

Objective To evaluate the clinical value of Apneagraph(AG200) and CT measurement in diagnosing obstructive sleep apnea hypopnea syndrome.Methods Twenty-eight snoring patients underwent one-night pressure monitoring by AG200 to measure the apnea hypopnea index(AHI),the site of upper airway collapse and the obstructive proportion of different level.The upper airway levels from the roof of nasopharynx to the inferior border of annular cartilage were scanned by spiral CT to calculate the areas of retropalatal and retroglossal space using image handling workstation.The obstruction level found in CT screening and determined by pressure monitored were compared.Results ① In 28 snoring cases,OSAHS was excluded in 6 and 22 were confirmed as OSAHS,of which including 4 mild,10 moderate and 8 severe.② In 28 upper airway CT screening,no obstruction area were found in 4 cases.16 patients in retropalatal and 2 patients in retroglossal area occurred obstruction respectively.In 6 cases,the obstruction was found in both retropalatal and retroglossal area.③ 22 OSAHS cases had obstruction pattern of upper and lower level obstruction,of which 18 mainly at upper level(one was totally at upper level) and 4 mainly at lower level.④ In 22 OSAHS cases,the obstruction mainly in retropalatal area was found in 18 cases by AG200 and in 15 cases by CT.There was no difference between two methods.The obstruction mainly in retroglossal area was found in 4 cases by AG200 and in 6 cases by CT.Conclusion Apneagraph can serve as a useful device to diagnose sleep disordered breathing.It is beneficial for evaluating upper airway obstruction combining with CT.