5. Bronchial provocation testing and pharmacospirometry Flashcards
What are bronchial provocation testing and pharmacospirometry used for?
They are specialized tests that may help distinguish bronchial asthma from other causes of obstructive lung disease.
What is the methacholine challenge test used for?
It is indicated in patients with suspected airway hyperresponsiveness (e.g. asthma). It is based on the dose of methacholine that results in at least 20% reduction in FEV1, which points to the diagnosis of airway hyperresponsiveness (e.g. asthma).
What should be kept at hand during the methacholine challenge test?
Medications that reverse bronchospasm (e.g. epinephrine, atropine) should be kept at hand during the methacholine challenge test because the test may trigger a life-threatening attack.
What is pharmacospirometry/bronchodilator reversibility test?
It is a test that utilizes spirometry to assess possible reversibility of bronchoconstriction in a disease (aka difference between COPD and asthma)
What is the procedure for pharmacospirometry/bronchodilator reversibility test?
Initial spirometry is performed to assess native respiratory status (FEV1 and airway resistance), and then a dose of fast-acting bronchodilator medication is administered.
What is the purpose of initial spirometry in asthma diagnosis?
To assess native respiratory status (FEV 1 and airway resistance).
What is the mechanism of action of fast-acting bronchodilator medications?
They relax the smooth muscles in the airways, allowing for easier breathing.
What is the recommended wait time before repeating spirometry in asthma diagnosis?
15 minutes.
What is a positive response in spirometry during reversibility test?
An increase in FEV 1 greater than 200mL, indicating asthma.
What is a false positive in spirometry during asthma diagnosis?
A small patient with pulmonary fibrosis or restrictive lung disease, who will have measurably lower FEV 1 than healthy average-sized adults.
