title: Adaptation of ventilation to 'buffeting' in vehicles.
abstract: OBJECTIVE
  Short exposures to buffeting in a vehicle driving over rough terrain induce an increase in the frequency of respiration resulting in hyperpnoea and hypocapnia. The present study investigates the adaptation to buffeting-induced hyperpnoea.
  
  
  METHODS
  We monitored ventilation and cardiovascular function in nine healthy young adults prior to, throughout and post a 30 minute simulation of buffeting.
  
  
  RESULTS
  All subjects had a consistent elevation of respiratory frequency throughout motion. End-tidal CO(2) 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 CO(2)because of a slight reduction in tidal volume whilst inspiratory time remained shortened. Salivary cortisol levels were unaffected by motion, suggesting that the hyperpnoea was not secondary to non-specific stress.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Division of Neuroscience and Psychological Medicine, Imperial College London, Charing Cross Hospital Campus, London, W6 8RF, UK.
authors.forename: David Andrew
authors.initials: DA
authors.lastname: Green
authors.forename: John Foster
authors.initials: JF
authors.lastname: Golding
authors.forename: Mandip
authors.initials: M
authors.lastname: Aulakh
authors.forename: Aulukh
authors.initials: A
authors.lastname: Mandip
authors.forename: Mary Catherine
authors.initials: MC
authors.lastname: Faldon
authors.forename: Kevin Graeme
authors.initials: KG
authors.lastname: Murphy
authors.forename: Adolfo Miguel
authors.initials: AM
authors.lastname: Bronstein
authors.forename: Michael Andrew
authors.initials: MA
authors.lastname: Gresty
mesh_terms: D000222:Adaptation, Physiological; D000328:Adult; D001334:Automobile Driving; D001794:Blood Pressure / Q000502:physiology; D002245:Carbon Dioxide / Q000097:blood; D045853:Exhalation / Q000502:physiology; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D006854:Hydrocortisone / Q000032:analysis; D006935:Hypercapnia / Q000097:blood / Q000209:etiology / Q000503:physiopathology*; D016857:Hypocapnia / Q000097:blood / Q000209:etiology / Q000503:physiopathology*; D001239:Inhalation / Q000502:physiology; D008297:Male; D018986:Motor Vehicles; D012123:Pulmonary Ventilation / Q000502:physiology*
chemical_list: D002245:Carbon Dioxide; D006854:Hydrocortisone
references.citation: Am J Physiol Regul Integr Comp Physiol. 2002 Mar;282(3):R689-94
references.pmid: 11832387
references.citation: J Appl Physiol (1985). 2002 Dec;93(6):2044-52
references.pmid: 12391116
references.citation: Clin Auton Res. 2006 Aug;16(4):281-5
references.pmid: 16832596
references.citation: Clin Chem. 2003 Jan;49(1):203-4
references.pmid: 12507989
references.citation: J Appl Physiol (1985). 2004 Oct;97(4):1219-26
references.pmid: 15155713
references.citation: Acta Physiol Scand. 1992 Apr;144(4):409-18
references.pmid: 1534959
references.citation: N Engl J Med. 2002 Jul 4;347(1):43-53
references.pmid: 12097540
references.citation: Aviat Space Environ Med. 2003 Mar;74(3):220-7
references.pmid: 12650268
references.citation: J Psychosom Res. 2007 May;62(5):595-6
references.pmid: 17467415
references.citation: Aviat Space Environ Med. 1976 Jan;47(1):9-16
references.pmid: 1247443
references.citation: Respir Physiol Neurobiol. 2007 Nov 15;159(2):115-26
references.pmid: 17660051
references.citation: Neurosci Lett. 2001 Jan 26;298(1):17-20
references.pmid: 11154825
references.citation: Brain. 1997 Sep;120 ( Pt 9):1659-73
references.pmid: 9313647
references.citation: Anesthesiology. 1993 Feb;78(2):251-9
references.pmid: 8439019
references.citation: Clin Exp Pharmacol Physiol. 2002 Jan-Feb;29(1-2):112-7
references.pmid: 11906468