[Comparative study of VOTE classification in obstructive sleep apnea hypopnea syndrome patients between awake and sleep state]

Objective:To compare the differences of the sites of airway obstruction in OSAHS patients between awake and sleep state by using the VOTE classification system. Method:Forty OSAHS patients diagnosed by PSG underwent awake Müller's maneuver and drug-induced sleep endoscopy (DISE). Video and compare the observation. Its findings were described using the VOTE classification system which include the following features: level, degree and configuration of obstruction. Associations were analyzed between different degrees of obstruction, BMI, AHI, minimal SaO₂ and average SaO₂. Result:Our patients had 52.5% complete velum collapse and 30.0% complete oropharyngeal lateral wall collapse in awake Müller's maneuver. In DISE, airway closure of 95.0% cases related to velum occurred collapse in concentric configuration, and 90.0% cases showed completely obstructive. We found that 60.0% complete oropharyngeal lateral wall collapse and 17.5% complete tongue base collapse. There was a significant difference in the VOTE scores between DISE and awake Müller's maneuver, and the VOTE scores of DISE were higher in all levels (P<0.05). No association was found between degrees of obstruction, AHI, BMI, minimal SaO2 and average SaO₂ in Müller's maneuver (P>0.05). Complete velum collapse was just significantly associated with AHI and minimal SaO₂ in DISE (P<0.05). Conclusion:The VOTE scores of DISE were higher than awake Müller's maneuver, reflected by more obstructive levels and severe degree. The difference between different degrees of obstruction, BMI, AHI, minimal SaO₂ and average SaO₂ was not significant.