Comparison of median values of change of transcutaneous carbon dioxide partial pressures (PtcCO2) according to asthma definition during testing and during recovery after methacholine provocation testing.

Data is expressed as median (interquartile range). PtcCO2 = transcutaneous blood carbon dioxide partial pressures. PRE = PtcCO2 prior to methacholine bronchial challenge, 1MIN = PtcCO2 one minute after termination of methacholine bronchial challenge, 5MIN = PtcCO2 five minutes after termination of methacholine bronchial challenge. MCHPD20 = Fall in FEV1 ≥20% during bronchial challenge testing with methacholine.a = Not significant with p>0.1,b = Not significant with p* = Significant with p≤0.05.