title: A modification of the pressure-flow technique for measuring breathing of cold air and its effect on nasal cross-sectional area.
abstract: The purpose of this article was to develop a method based on the pressure-flow technique for measuring cold air breathing and to observe the immediate reactions of breathing function to cold air inhalation in 40 subjectively healthy adults. The pressure-flow technique was used to measure airflow rate and oral/nasal pressure and to calculate the smallest cross-sectional area of the nasal airway. The equipment was modified to allow measurements both at room temperature and with cooled air by connecting the nasal mask to a freezer with a two-valve cylinder and tubing. Nasal cross-sectional area showed a significant decrease from 42.3 mm2 at room temperature to 37.6 mm2 with cooled air. Correspondingly, the airflow rate changed from 411 ml/s to 369 ml/s, whereas the differential pressure remained about the same, 1.2 and 1.3 cm H2O, respectively. The interindividual variation was fairly large. The results suggest that the breathing of cold air seems to cause changes in nasal cross-sectional area and airflow rate. In general, the cross-sectional area diminishes, the change being quantitatively more pronounced in subjects with an initially large area.
authors.affiliation: Department of Oral Development and Orthodontics, University of Kuopio, Finland.
authors.forename: M T
authors.initials: MT
authors.lastname: Laine
authors.forename: J A
authors.initials: JA
authors.lastname: Huggare
authors.forename: P
authors.initials: P
authors.lastname: Ruoppi
mesh_terms: D000328:Adult; D000388:Air; D000399:Air Pressure; D000403:Airway Resistance; D003080:Cold Temperature / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008297:Male; D008838:Microcomputers; D008875:Middle Aged; D009297:Nasal Mucosa / Q000033:anatomy & histology / Q000098:blood supply*; D015508:Nasal Obstruction / Q000209:etiology*; D012123:Pulmonary Ventilation; D015203:Reproducibility of Results; D012129:Respiratory Function Tests / Q000295:instrumentation