Reversible Volume Changes of Trapped Gas in Nonspecific Bronchoprovocation Tests

Waßermann, Klaus; Pothoff, G.; J, Bahra; Hilger, H. H.

doi:10.1378/chest.101.4.970

Cited by 12 publications

(3 citation statements)

References 14 publications

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“…A larger percent change (e.g., 45%) is therefore required for a positive test. It is not necessary to measure total lung capacity (TLC) during MCT, because TLC usually does not change (130)(131)(132). A decrease in vital capacity reflects an increase in residual volume.…”

Section: Spirometry and Other End-point Measuresmentioning

confidence: 99%

Guidelines for Methacholine and Exercise Challenge Testing—1999

Ro¹,

Casaburi²,

Al³

et al. 2000

Am J Respir Crit Care Med

2,108

455

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This statement provides practical guidelines and suggestions for methacholine and exercise challenging testing. Specifically, it reviews indications for these challenges, details factors that influence the results, presents brief step-by-step protocols, outlines safety measures, describes proper patient preparation and procedures, provides an algorithm for calculating results, and offers guidelines for clinical interpretation of results. The details are important because methacholine and exercise challenge tests are, in effect, dose-response tests and delivery of the dose and measurement of the response must be accurate if a valid test is to be obtained. These guidelines are geared to patients who can perform good-quality spirometry tests; they are not appropriate for infants or preschool children. They are not intended to limit the use of alternative protocols or procedures that have been established as acceptable methods. We do not discuss the general topic of bronchial hyperresponsiveness (BHR). 100 mg 100 mg 6.25 ml A: 16 mg/ml 3 ml of dilution A 9 ml B: 4 mg/ml 3 ml of dilution B 9 ml C: 1 mg/ml 3 ml of dilution C 9 ml D: 0.25 mg/ml 3 ml of dilution D 9 ml E: 0.0625 mg/ml * Schedule obtained from Methapharm (Brantford, ON, Canada). * This list is provided to simplify access to some sources of equipment. It is not a complete list of all possible sources of acceptable equipment.

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Section: Spirometry and Other End-point Measuresmentioning

confidence: 99%

Guidelines for Methacholine and Exercise Challenge Testing—1999

Ro¹,

Casaburi²,

Al³

et al. 2000

Am J Respir Crit Care Med

2,108

455

View full text Add to dashboard Cite

show abstract

“…Methacholine might cause air-trapping with a concomitant increase in residual volume (RV) and a decrease in FEV1 [28]. The increase in RV resulting from dynamic airway collapse by methacholine may increase the load on inspiratory muscle [29], and reduce the extent of muscle force needed to overcome the airway resistance of obstruction.…”

Section: Effect Of Ncpap On Bronchoconstriction In Asthma and Stable mentioning

confidence: 99%

Differential effects of nasal continuous positive airway pressure on reversible or fixed upper and lower airway obstruction

Wang¹,

Lin²,

Huang³

et al. 1996

Eur Respir J

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Our study was to assess whether there were differential effects of nasal continuous positive airway pressure (nCPAP) on different kinds of obstruction in either upper or lower airways in patients with chronic obstructive pulmonary disease (COPD). nCPAP (6 cmH 2 O for ten minutes) was applied to 7 patients with reversible extrathoracic upper airway obstruction (RUAO) and 3 patients with fixed extrathoracic upper airway obstruction (FUAO). Eighteen stable asthmatics, receiving methacholine challenge to induce a more than 20% reduction in FEV1, were randomly investigated for the effect of nCPAP or sham pressure on reversible lower airway obstruction. Nine stable COPD patients were enrolled to study the effect on irreversible lower airway obstruction. Maximal expiratory and inspiratory flow volume curves and dyspnoea scores were obtained before and after immediate withdrawal of nCPAP.In the RUAO group, nCPAP significantly improved stridor and dyspnoea scores, decreased the ratio of FEF50/FIF50 from 2.05±0.25 to 1.42±0.16, and increased peak inspiratory flow (PIF) as well as forced inspiratory vital capacity by 26±8% and 9±4%, respectively. In expiratory phase, there was no significant change in pulmonary functions. In asthmatics, nCPAP significantly reversed methacholine-induced bronchoconstriction increasing forced vital capacity by 10±3%, FEV1 by 15±4% and PIF by 32±11%. nCPAP significantly increased the response to bronchodilators. The improvement in airflow rate persisted for at least 5 min after nCPAP withdrawal and was highly correlated with the response to bronchodilators. There was no significant effect of nCPAP on airflow rate in COPD patients. Subjective dyspnoea score changes paralleled the pulmonary function improvement.We conclude that there are differential effects of nCPAP on airflow rates in patients with different nature of airway obstruction. Patients with airway obstruction caused by structural changes may not benefit from the use of nCPAP in improving airflow rates. Eur Respir J. 1996, 9, 952-959.

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“…6 Since mast cells are believed to play a predominant role in atopic asthma, the bronchial response to AMP may be a more direct marker of allergic airway inflammation than direct bronchoconstrictors. 7,8 On the other hand, it has long been appreciated that during bronchoconstriction induced by acetylcholine or methacholine, residual volume (RV) increases 9,10 and forced vital capacity (FVC) decreases 11 significantly. The conventional explanation for why the FVC decreases during induced bronchoconstriction is that change in the smooth muscle tone causes an increase in air trapping.…”

Section: Introductionmentioning

confidence: 99%

Effects of allergen exposure on methacholine and AMP-induced air trapping in pollen-sensitive subjects

López

Prieto

Pérez

et al. 2011

Respiratory Medicine

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Although the air trapping induced by both methacholine and AMP is significantly greater in subjects with pollen allergy than in healthy controls, natural allergen exposure is associated with a selective increase in airway sensitivity without concomitant changes in bronchoconstrictor-induced air trapping. These findings suggest that the information provided by the bronchoconstrictor-induced change in FEV1 and FVC is not equivalent and may be complementary.

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Reversible Volume Changes of Trapped Gas in Nonspecific Bronchoprovocation Tests

Cited by 12 publications

References 14 publications

Guidelines for Methacholine and Exercise Challenge Testing—1999

Guidelines for Methacholine and Exercise Challenge Testing—1999

Differential effects of nasal continuous positive airway pressure on reversible or fixed upper and lower airway obstruction

Effects of allergen exposure on methacholine and AMP-induced air trapping in pollen-sensitive subjects

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