Simplified eucapnic voluntary hyperventilation challenge

doi:10.1016/0091-6749(84)90304-X

Journal of Allergy and Clinical Immunology

Volume 73, Issue 5, Part 2, May 1984, Pages 676-679

https://doi.org/10.1016/0091-6749(84)90304-X Get rights and content

Abstract

A simplified scheme for eucapnic voluntary hyperventilation (EVH) is described that requires only that a source of dry gas containing 5% CO₂, 21% O₂, and 74% N₂ be hyperventilated at 40 L/min or greater. Refrigeration or measurement of end tidal CO₂ is not required. When the ventilation pattern of a standardized treadmill exercise challenge in a group of exercise-sensitive asthmatics breathing dry air was matched according to this EVH procedure, the magnitude of the resultant bronchospasm and the exclusive nature of the postchallenge refractory period were similar, since patients in both cases were still fully responsive to methacholine. It is concluded that such an EVH challenge may be used to reproduce the bronchial heat and water fluxes that occur with exercise challenge as well as the consequential challenge-specific refractoriness that follows.

References (8)

H Chai et al.
Standardization of bronchial inhalation challenge procedures
J Allergy Clin Immunol
(1975)
PM O'Byrne et al.
Asthma induced by cold air and its relation to nonspecific bronchial responsiveness to methacholine
Am Rev Respir Dis
(1982)
HA Menkes
Airways reactivity and the need for a simple test (editorial)
Am Rev Respir Dis
(1980)
EC Deal et al.
Role of respiratory heat exchange in production of exercise-induced asthma
J Appl Physiol
(1979)

There are more references available in the full text version of this article.

Cited by (30)

Approach to the Patient with Exercise-Induced Bronchoconstriction
2014, Middleton's Allergy: Principles and Practice: Eighth Edition
Accuracy of eucapnic hyperpnea or mannitol to diagnose exercise-induced bronchoconstriction: A systematic review
2011, Annals of Allergy, Asthma and Immunology
Citation Excerpt :
The search identified 5,318 citations. Ten cross-sectional studies were included (see e-Fig 1 in online supplement): 7 (138 participants) examined EVH,18-24 and 3 (423 participants) focused on mannitol.25–27 Seven studies18–24 compared EVH with a standardized ECT.
Exercise challenge testing is the typical method for diagnosing exercise induced bronchoconstriction; however, alternate tests have been developed.
The purpose of this paper was to summarize the current literature comparing eucapnic voluntary hyperpnea and mannitol with standard exercise challenge testing to determine whether either test is a suitable alternative to standard exercise testing for the diagnosis of exercise-induced bronchoconstriction.
Using valid systematic review methods, a comprehensive search strategy to avoid publication bias, we identified 10 studies that compared exercise challenge testing with either eucapnic voluntary hyperpnea or mannitol.
For the 7 diagnostic cross-sectional studies that examined eucapnic voluntary hyperpnea, the sensitivity and specificity values were heterogeneous, ranging from 25 to 90% for sensitivity and 0 to 71% for specificity. In the 3 diagnostic cross-sectional studies that evaluated mannitol, the sensitivity and specificity ranged from 58 to 96% and 65 to 78%, respectively. For most studies, a representative spectrum of participants being tested was not used.
Given the heterogeneity in sensitivity and specificity of eucapnic voluntary hyperpnea studies and the relatively small number of studies that have examined mannitol, insufficient evidence is available to conclude that either of these tests are suitable alternatives to exercise challenge testing to detect exercise-induced bronchoconstriction. Additional research is required.
Bronchial responsiveness to eucapnic hyperventilation and methacholine following exposure to organic dust
2002, Chest
Citation Excerpt :
After spirometry, a eucapnic hyperventilation test was performed. Dry, room temperature air with 5% carbon dioxide was hyperventilated through a low-resistance, one-way valve in standing position (Ailos Asthma Test; Ailos; Karlstad, Sweden).1415 The target ventilation was 35 × FEV1 × 0.75, which was maintained for 4 min.
Inhalation of dust in a swine confinement building causes an intense airway inflammatory reaction in the airways and increased bronchial responsiveness to methacholine. The aims of the present study were to investigate whether exposure to organic dust also influences bronchial responsiveness to an indirect stimulus, and to assess the duration of increased postexposure bronchial responsiveness.
Twenty-two healthy nonatopic, nonsmoking subjects were exposed to dust for 3 h in a swine confinement building. Lung function was assessed, and either a methacholine bronchial provocation (n = 11) or a challenge with eucapnic hyperventilation of dry air (n = 11) was performed before exposure and at 7 h, 1 week, 2 weeks, and 4 weeks after exposure.
Vital capacity and FEV₁ decreased 3% and 6%, respectively (p < 0.001), and airway resistance increased 15% (p < 0.05) after exposure. The median provocative dose of methacholine causing a 20% decline in FEV₁ fell from 1.38 mg (25th to 75th percentiles, 0.75 to 7.20 mg) before exposure to 0.18 mg (0.11 to 0.30 mg) after exposure (p = 0.004). Corresponding values for the dose-response slope were 15.3%/mg (2.88 to 25.3%/mg) and 100.2%/mg (2.1 to 27.3%/mg), respectively (p = 0.01). Bronchial responsiveness to eucapnic hyperventilation was not affected by the exposure: FEV₁ fell 4.3% (− 7.2 to − 1.8%) before and 4.8% (− 6.7 to − 1.6%) after exposure (p = 0.72). One week after exposure, the bronchial responsiveness to methacholine was normalized.
The bronchial responsiveness to methacholine but not to dry air increases after exposure to swine house dust. Thus, exposure to organic dust induces increased bronchial responsiveness with different characteristics from that frequently found in asthma.
Airway dehydration: A therapeutic target in asthma?
2002, Chest
Citation Excerpt :
Furthermore, clinicians have long recommended swimming as the exercise least troublesome to asthmatic patients because of the humidity of the inspired air, a phenomenon that is supported by comparative studies of diverse sporting activities.21,22,23 Eucapnic voluntary hyperventilation maneuvers, designed to simulate exercise-induced bronchoconstriction in the laboratory, demonstrate that airway fluid loss has a similar bronchoconstrictor effect to histamine.6,7,8,9 Other workers demonstrate the release of histamine, a potent bronchoconstrictor, and other proinflammatory bronchoconstrictor mediators, including cysteinyl-leukotrienes,24 from mast cells and other airway cells under hyperosmolar conditions.25,26,27
Airway dehydration triggers exercise-induced bronchoconstriction in virtually all patients with active asthma. We are not aware of any investigations of airway dehydration in patients with naturally occurring asthma exacerbations. We wish to investigate whether airway dehydration occurs in acute asthmatic patients in the emergency department, and its functional significance.
In a pilot study on 10 asthmatic patients and 10 control subjects in the emergency department, respiratory rate was counted manually, and relative humidity of expired air was recorded using an air probe hygrometer. In parallel laboratory studies carried out over 2 consecutive days, 19 asthmatics and 10 control subjects were challenged initially with dry air, and on the second day with humidified air. FEV₁ and humidity measurements were made immediately before and after the tachypnea challenges.
In the emergency department, the asthmatic group was more tachypneic (p < 0.0001) and their expired air was drier (p < 0.0001) than the control group. Following a dry-air tachypnea challenge in the laboratory, which caused dehydration of the expired air in all subjects, half of the asthmatics, but none of the control subjects, demonstrated a fall of > 10% in FEV₁ from baseline. This bronchoconstriction was prevented by humidifying the inspired air; tachypnea with no water loss did not affect lung function in asthmatic subjects.
Dehydration of the expired air is present in asthmatic patients in the emergency department. The bronchoconstriction triggered by dry-air tachypnea challenge in the laboratory can be prevented by humidifying the inspired air. Airway rehydration merits further investigation as a potential adjunct to acute treatment of asthma exacerbations.
Exercise-induced asthma in children: A comparative study of free and treadmill running
1998, Annals of Allergy, Asthma and Immunology
Exercise in one of the most common precipitating factors of acute asthmatic crises in childhood. Although it has been described as more frequent among children, this is probably due to their more abundant physical activity. Nevertheless, it also occurs at other ages.
The aim of this study is to assess possible differences in postexercise spirometry after treadmill and free running provocation tests.
We compared the results obtained in a treadmill test performed by 30 asthmatic children and 30 healthy children with the results obtained with these same children in a free running test, keeping similar environmental conditions (temperature and humidity), exercise intensity (assessed by heart rate), and airway status at the time of the test.
Seventy-three percent of the patients had positive treadmill tests and 63.3% had positive free running tests. For the spirometric parameters studied, there were no significant differences in the percent decrease in postexercise performance after either of the provocation tests. For FEV₁, which is the most sensitive diagnositc parameter, the sensitivity was 53.3% in treadmill running and 56.7% in free running, with a specificity of 100% in both tests.
If environmental conditions, exercise intensity, and airway status are controlled at the time of the test, treadmill and free running can be used indistinctly as asthma-inducing exercises.
Eucapnic voluntary hyperventilation as a bronchoprovocation technique: Development of a standardized dosing schedule in asthmatics
1996, Chest
A variety of dosing schedules have been reported for the hyperventilation method of bronchoprovocation testing. To evaluate the effect of challenge technique on the bronchoconstrictive response, we had 16 subjects perform eucapnic voluntary hyperventilation (EVH) with dry, room temperature gas using four different dosing schedules. The hyperventilation challenge dosages included the following: (1) a target minute ventilation ( ${\dot{V}}_{E}$ ) of 20×FEV₁ for 6 min; (2) a target ${\dot{V}}_{E}$ of 15×FEV₁ for 12 min; (3) an interrupted challenge with a target ${\dot{V}}_{E}$ of 30×FEV₁ for 2 min repeated 3 times; and (4) a target ${\dot{V}}_{E}$ of 30×FEV_i for 6 min. Challenges 2, 3, and 4 gave identical absolute ventilatory challenges (identical factor FEV₁×minutes) but at different ${\dot{V}}_{E}$ dosages or time. Challenges 1 and 4 were of identical length, but different target ${\dot{V}}_{E}$ . The mean postchallenge fall in FEV₁ was 16.6±10.9%, 11.0±8.1%, 19.6±9.9%, and 26.7±11.3% for challenges 1, 2, 3, and 4, respectively. The response to an identical EVH challenge (FEV₁×30 for 6 min) was reproducible when performed on separate days. We conclude that the challenge technique used for hyperventilation testing will have a significant impact on the bronchoconstrictive response and must be taken into account when interpreting study results. Tests may be quantitatively comparable over a narrow range of challenge time and ${\dot{V}}_{E}$ . We recommend that a 6-min uninterrupted EVH challenge using dry, room temperature gas at a target ${\dot{V}}_{E}$ of 30×FEV₁ be adopted as the “standard” challenge.

View all citing articles on Scopus

View full text

Simplified eucapnic voluntary hyperventilation challenge

Abstract

J Allergy Clin Immunol

Am Rev Respir Dis

Airways reactivity and the need for a simple test (editorial)

Am Rev Respir Dis

Role of respiratory heat exchange in production of exercise-induced asthma

J Appl Physiol