We thank Drs. Zhu and Zhang1 for their interest in our study comparing the effect of sedation with dexmedetomidine and propofol on upper airway collapsibility.2 We are also thankful for the opportunity to clarify facts regarding washout time between airway assessments during sedation with the two drugs.
It is true that without an adequate washout period, a sedative effect of the first drug could affect the result when evaluating the second drug in a crossover study. However, in our study, the time between testing airway collapsibility with the two drugs was 7 days or more. A residual effect of the first drug at the second airway assessment therefore seems very unlikely.
The authors declare no competing interests.