Effects of bronchoconstriction, minute ventilation, and deep inspiration on the composition of exhaled breath condensate.
BACKGROUND
Exhaled breath condensate (EBC) is composed of droplets of airway surface liquid (ASL) diluted by water vapor. The goal of this study was to determine if the composition of EBC is affected by changes in airway caliber, minute ventilation, or forceful exhalation, factors that may differ among subjects with asthma in cross-sectional studies.


METHODS
In a group of subjects with asthma, we measured the effects of the following: (1) a series of three deep-inspiration and forceful-exhalation maneuvers; (2) a doubling of minute ventilation; and (3) acute bronchoconstriction induced by methacholine on EBC volume, dilution of ASL, and concentration of cysteinyl leukotrienes (CysLTs).


RESULTS
With the exception of an increase in EBC volume with increased minute ventilation, there were no significant changes in the volume, dilution, or levels of CysLTs in EBC introduced by each of these factors. The CIs surrounding the differences introduced by each factor showed that the maximum systematic errors due to these factors were modest.


CONCLUSIONS
These results indicate that changes in airway caliber, minute ventilation, or breathing pattern among subjects with asthma do not significantly alter the measurements of mediator concentrations in EBC.
Debley
Jason S
JS
Department of Pediatrics, Division of Pulmonary Medicine, University of Washington, Seattle, WA 98195, USA.
Ohanian
Arpy S
AS
Spiekerman
Charles F
CF
Aitken
Moira L
ML
Hallstrand
Teal S
TS
D000328:Adult; D001249:Asthma / Q000378:metabolism* / Q000503:physiopathology; D001944:Breath Tests / Q000379:methods; D016084:Bronchoconstriction / Q000502:physiology*; D045853:Exhalation / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D001239:Inhalation / Q000502:physiology*; D015289:Leukotrienes / Q000032:analysis*; D008297:Male; D012123:Pulmonary Ventilation / Q000502:physiology*; D013147:Spirometry
D015289:Leukotrienes
Am J Respir Crit Care Med. 2003 Dec 15;168(12):1500-5
14512268
Am J Respir Crit Care Med. 2002 Mar 1;165(5):663-9
11874811
Thorax. 2003 Jun;58(6):505-9
12775861
J Appl Physiol (1985). 2007 May;102(5):1969-75
17303703
Proc Am Thorac Soc. 2004;1(1):42-6
16113411
Am J Respir Crit Care Med. 2000 Jan;161(1):309-29
10619836
Respir Med. 2008 May;102(5):720-5
18249106
Respiration. 2007;74(2):142-5
16804290
Am J Physiol Lung Cell Mol Physiol. 2009 Jun;296(6):L987-93
19304910
Eur Respir J. 2007 Apr;29(4):676-81
17135230
Pediatr Pulmonol. 2006 Jan;41(1):87-94
16292777
Am J Respir Crit Care Med. 2001 Feb;163(2):413-9
11179115
Eur Respir J. 1995 Nov;8(11):1966-71
8620970
J Allergy Clin Immunol. 2004 Feb;113(2):257-63
14767439
Lung. 2004;182(4):241-50
15636196
Am J Respir Crit Care Med. 2003 Nov 1;168(9):1129-32; author reply 1130-1
14581290
Pediatr Pulmonol. 2004 Mar;37(3):273-5
14966822
Thorax. 2004 Aug;59(8):694-8
15282391
Eur Respir J. 2005 Aug;26(2):319-38
16055882
Am J Respir Crit Care Med. 2002 Nov 15;166(10):1345-9
12406853
Clin Exp Allergy. 2008 Apr;38(4):557-65
18352973
Eur Respir J. 2008 May;31(5):934-42
18184682
Am Ind Hyg Assoc J. 1987 Nov;48(11):948-9
3425555
J Aerosol Med. 1997 Summer;10(2):105-16
10168531
Int J Chron Obstruct Pulmon Dis. 2007;2(1):71-6
18044068
J Allergy Clin Immunol. 2007 Nov;120(5):1216-7
17655919
Eur Respir J. 2008 Oct;32(4):1124-6
18827164
Respir Med. 2009 May;103(5):750-6
19110408
Respir Med. 2007 Jun;101(6):1331-7
17125983
Eur Respir J. 2005 Sep;26(3):523-48
16135737
J Allergy Clin Immunol. 2002 Jul;110(1):28-34
12110814