Adaptation of Ventilation to "Buffeting" in Vehicles

Short exposures to buffeting in a vehicle driving over rough terrain can induce an increase in the frequency of respiration resulting in hyperpnea (deep, rapid, or labored respiration) and hypocapnia (low carbon dioxide, CO2, levels in the blood). This article reports on a study undertaken to investigate the adaptation to buffeting-induced hyperpnea. The authors monitored ventilation and cardiovascular function in nine healthy young adults prior to, throughout and after a 30-minute simulation of buffeting. This simulation was designed to mimic a mild off-road ride in a 4x4 vehicle or a ride in an emergency ambulance. All subjects had a consistent elevation of respiratory frequency throughout motion. End-tidal CO2 decreased during the first 5 minutes of buffeting due to a transient increase in minute ventilation. Elevation of respiratory frequency was facilitated by shortening of inspiration without change in expiratory time. Tidal volume was maintained which resulted in an increase in mean inspiratory flow during buffeting. At later stages of motion there was a partial return to normal for mean inspiratory flow, minute ventilation and end-tidal CO2 because of a slight reduction in tidal volume whilst inspiratory time remained shortened. Salivary cortisol levels were unaffected by motion, suggesting that the hyperpnea was not secondary to non-specific stress. Although the hypocapnia would probably be inconsequential in healthy normal subjects, if might have significant effects if experienced by an already-compromised patient during emergency transport. The authors conclude by hypothesizing that the cause of elevated respiratory frequency during buffeting could be due to mechanical action on the torso, vestibular-respiratory drive or a protective reinforcement of the torso.

  • Availability:
  • Authors:
    • Green, David Andrew
    • Golding, John Foster
    • Mandip, Aulukh
    • Faldon, Mary Catherine
    • Murphy, Kevin Graeme
    • Bronstein, Adolfo Miguel
    • Gresty, Michael Andrew
  • Publication Date: 2008-12

Language

  • English

Media Info

  • Media Type: Print
  • Features: Figures; Photos; References;
  • Pagination: pp 346-351
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 01149248
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Jan 24 2010 8:23AM