Perception of dyspnea during exacerbation and histamine-related bronchoconstriction in patients with asthma.
BACKGROUND
Numerous studies have been performed concerning the perception of dyspnea during changes in airway caliber provoked in the laboratory setting, but studies of asthma exacerbation are scarce.


OBJECTIVE
To investigate whether the perception of dyspnea during histamine-induced bronchoconstriction might be used to identify patients with asthma who sense dyspnea poorly during exacerbation.


METHODS
The perception of dyspnea in 50 patients (45 female, 5 male) with asthma was evaluated at admission with exacerbation and during a stable period. Perceived intensity of dyspnea was estimated using a modified Borg scale. The perception of dyspnea in the stable period 4 to 6 weeks after exacerbation was measured with the histamine challenge test. Perception parameters were defined as the change in Borg score divided by the change in forced expiratory volume in 1 second (FEV1) as a percentage of the baseline FEV1 (deltaBorg/deltaFEV1) and as the Borg score at 20% decrease (PS20Histamine) or increase (PS20Exacerbation) in FEV1.


RESULTS
The perception of dyspnea during asthma exacerbation was unrelated to the perception of dyspnea during histamine-induced bronchoconstriction (for deltaBorg/deltaFEV1, beta = .08, P = .50; for PS20, beta = -.11, P = .40). The kappa value for the agreement of poor perceivers at exacerbation and during the stable period was -0.21 (P = .10). However, the intensity of dyspnea caused by histamine-induced bronchoconstriction was lower than that caused by asthma exacerbation (PS20: 1.6 +/- 1.1 vs 2.8 +/- 2.5, respectively, P = .004; deltaBorg/deltaFEV1: 0.08 +/- 0.05 vs 0.21 +/- 0.28, respectively, P = .001).


CONCLUSIONS
The perception of dyspnea during asthma exacerbation is not correlated with the perception of dyspnea during histamine-induced bronchoconstriction. Therefore, the perception of dyspnea during histamine-induced bronchoconstriction cannot be used to identify the asthmatic patients who perceive dyspnea poorly.
Ekici
Mehmet
M
Kirikkale University Faculty of Medicine, Department of Pulmonary Medicine, Turkey. mehmetekici_@hotmail.com
Ekici
Aydanur
A
Kara
Turkan
T
Keles
Hatice
H
Karlidag
Ali
A
Altunkaya
Volkan
V
Bulcun
Emel
E
D000328:Adult; D000368:Aged; D001249:Asthma / Q000150:complications* / Q000523:psychology*; D001985:Bronchial Provocation Tests; D016084:Bronchoconstriction / Q000502:physiology*; D004417:Dyspnea / Q000209:etiology* / Q000523:psychology*; D005260:Female; D006632:Histamine; D018494:Histamine Agents; D006801:Humans; D008297:Male; D008875:Middle Aged; D010465:Perception
D018494:Histamine Agents; D006632:Histamine