Ch. 9 Flashcards
(39 cards)
What are specialized testing?
Standard tests performed under special conditions to evaluate a response to a condition or medication.
Specialized testing are used in pts who have:
• A normal PFT but still have respiratory symptoms
• uncertain results of bronchodilator testing
• used to identify and characterize hyper-responsiveness in airways or (AHR).
• asses changes in hyper activity or to assess severity if symptoms
• for those at risk of environmental or occupational exposure to antigens and toxins
Bronchial challenge?
• Used to identify and characterize hyper responsiveness in airways
the less gas it takes to evoke a negative response the more hyperactive the airway is
Direct stimulus:
• methcholine
• histamine
• prostaglandins
• leukotrienes
works directly on parasympathetic muscle to cause bronchoconstriction
Indirect stimulus:
• mannitol
• adenosine
• exercise
• EVH
• beta blockers
• hypertonic saline
indirectly stimulate bronchoconstriction via intermediary cells.
Methcholine & histamine tests chemicals that _______ pts response to ________.
Increase ; bronchial smooth muscle
Eucapnic Voluntary hyperventilation
Uses cold air or room temp gases and causes heat and water loss form airway.
Metacholine challenge
• The lower dose needed to illicit a bronchospasm the more hyper responsive the airway.
• Stimulates parasympathetic response
What is the metacholine challenge used for?
Pt who cannot tolerate repeated spirometry testing
When FEV1 is reduced by ______ it’s considered a what test?
Positive
AKA PC20 provocative concentration
Metacholine test is considered _______ if dose of MC reaches ______ with 20% reduction in FEV1
Negative ; 16mg/dL
______ pts will experience a change in airway w/inc concentrations
ALL
The lowest dose needed to stimulate a response the more ______ the pt is?
Hyperresponsive
For testing the pt must be _______?
Asymptomatic
How long do you withhold antihistamines?
48hrs
The delivered dose of Metacholine is standardized by using a fixed number of of _______ breaths for each dose.
5
What are the 2 types of test we use?
• 5 breath dosimeter (most common)
• 2 min tidal breathing method
What is the highest dose for both of the tests?
16mg/dL
Range 0.016-16mg-dL
5 breath dosimeter test
• Dosing starts at 0.016 and is increased x4 for each step until you reach max dose of 16 mg/mL.
• Can be prepared in advance and stand in fridge (must be room temp at time of use)
• delivers a constant volume of drug with a fixed volume of aerosol on each breath
What does a patient do during the five breath dosimeter test?
• Patient takes 5 breaths of 1st concentration
• spirometry is repeated after each dose
• Test is repeated until FEV1 decreases 20% or until the max concentration of metacholine is reached
If at any time during the 5 breath dosimeter test if the FEV1 decreases greater than or equal to 20% test is _______?
Complete
After the 5 breath dosimeter test a _____ is given to reverse bronchospasm.
Bronchodilator
After the 5 breath dosimeter test spirometry is repeated after ______ min?
10
2 minute tidal volume breathing test
• duration is 2 min
• dosage starts at 0.031 mg/mL and inc x 2 for each step up to max dose of 16mg/mL
• can be prepared ahead of time and refrigerated but must be given at room temp
• a filter is used on the expiratory side to prevent medical lien release into room
• bronchodilator is given to reverse bronchospasm
