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 Muller'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 Muller'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 Muller's maneuver, and the VOTE scores of DISE were higher in all levels (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 Muller'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.