TY - JOUR T1 - Water vapour and temperature dynamics in the upper airways of normal and CF subjects JF - European Respiratory Journal JO - Eur Respir J SP - 407 LP - 414 DO - 10.1183/09031936.93.01050407 VL - 1 IS - 5 AU - Primiano FP, Jr AU - GM Saidel AU - Montague FW, Jr AU - KL Kruse AU - CG Green AU - JG Horowitz Y1 - 1988/05/01 UR - http://erj.ersjournals.com/content/1/5/407.abstract N2 - Water vapour partial pressure (PH2O) and temperature (T) were measured together, continuously, at the airway opening (either lips or nares) and at the oropharynx of human subjects with normal lungs or with cystic fibrosis (CF). No apparent differences in PH2O or T were found between normal and CF groups breathing ambient air (22 +/- 2 degrees C). During inspiration the relative humidity at the pharynx for nose breathing (95%) was higher than for mouth breathing (75%). For hot air breathing (48 +/- 2 degrees C), the PH2O and relative humidity of inspired gas at the pharynx was lower for the CF group than for the normal group. Also, the CF group had a higher airway surface temperature at the airway openings on inspiration. These data suggest that when the rate of evaporation is sufficiently high, the rate-limiting step may be water transport through the mucosal tissue and/or secretions. At least for the upper airways, this rate limitation is more evident for CF patients than for normal subjects. ER -