Pulmonary Studies Flashcards
what are some indications for a pulmonary function test?
- evaluate respiratory symptoms
- evalute/monitor lung disase
- evaluate/monitor response to treatment
- evaluate for disability
- pre-surgical eval.
- baseline numbers prior to pulm. toxic medications (amioderone, mitrofuantonin, methotrexate)
- screening smokers at age 45
what are teh 3 key components of pulmonary funtion testing
- spirometry
- diffusion capacity
- lung volume meaurements
what is spirometry?
what are the measurements obtained and what do they mean
- measures the amount and rate of inhalation and exhalation
pt. will forcefully inhale to max and then forciable exhale as much as they can
- these results in FVC: forced expiratory capactiy –> how much the pt. can blow out
low indicates restrciction –> cant blow out
normal levels calculated based one height, weight and gender
80-120% of predicted is normal levels
- FEV1 calculated: forced expiratory volume in 1 second
- *low levels indicate obstructive diseases to exhaling
- normal levles withint 80-120% of predicted*
if the FVC is low… what are some conditions which would show this
FVC low –> so we think of disease processes which dont allow the lungs to take in as much air as they should – their capacity is decreased – RESTRICTIVE DISEASES
- pulmonary fiberosis
- scoliosis or kyphosis
- lung cancer, scarring
- sarcoidosis/asbestosis
if FEV1 is low… what conditions could have created this?
FEV1 decreased from expected means the air is not able to be exhaled as it should be – think of OBSTRUCTIVE diseases
- asthma
- emphysema
- COPD
explain the FEV1/FVC ratio and what it means
- there are normal ratios depending again on wt., ht., gender to determine what is normal
- if it is low – we think of obstructive diesase since the FEV1 is on top and a smaller lower value indicates a problem
asthma and COPD may show this
how is spirometry and bronchodilators used for asthma? whats the criteria of reversibility?
- bronchcodilators can be used to meausre the amount of reversibility of the decreased FEV1/FVC
- can induce bronchoconstriction (methacholine) first to get a decreased read –> followed by a bronchodilator to reduce the spasms
- want to see a reversibility of >12% and > .2L for the FEV1 or FVC
what are flow volume loops? when are they used and what do they show??
- obstructive will look like what? restrictive?
- a graph of spirometry results –> graphed measurement of the inhalation and exhalation
- the only way to find a functional airway obstruction (like a trauma)
obstructive: disease graphs will look like a much steeper drop fo the exhale (but a lot of residual air remains)
restrictive: much short – the arent able to take in as much air so the graph is short and tall
THERE IS NOT TIME COMPONENT ON A FLOW LOOP GRAPH!!!!!!!
what is a flow time graph? what does it show
- time and expiration
- the FEV1 and FVC can be seen on this chart
- volume exhaled and time to exhale
- so normal is highest, then restrictive since you can get as much in, the obsturtive will have least steep curve since they have a slower exhale
how is lung volume tested? (2 ways)
think of residual capacity
- body plethysmography - where the chamber detects the changes in pressure based on how much you breath in and out
- nitrogen washout test/helium dilation – the amount that is released of these indicates the residual volume
what is PEF? how is it different than FEV1? when is the measurement used
what is green zone? yellow? red?
peak expiratory flow rate (PEFR)
- < 80% predicted may indicate an obstruction
- can be used during tracking of asthma pts. to assess how their treatment is working
- essentiall the same as a FEV1 but easier to obtain
Zones
- green: 80+% of baseline/predicted
- yellow: 50-80%
- red: < 50% (call provider)
what are the following other spirometry measurements?
1. FET
2. FEF 25-75
3. MIP/MEP
-FET : forced expiratory time –> total duration of the exhale (normal < 5 seconds)
-FEF 25-75%: the volume exhaled in the middle of exhaltion most sensitive for obstruction dz. but difficult to interpret
-MIP/MEP: max. inspiratory & expiratory pressure will be low with neuromusk. disorders
what is a diffusion capactiy test? what is the common test conducted? what does it indicate ? what conditions have a decreased DLCO?
- measures the gas exchange ability of the lungs
- the surface area functioning for gas exchange, air perfusion and blood perfusion within the lungs
Commonly its a DLCO test –> a small amount of CO is inahled and in a single breathe– by a blood test can indicate the amount they absored
> 80% is a normal reading
low DLCO when…
- fiberosis, or other alveolitis
- restrictive lung disease
- emphysema (damanged beds)
- PE, Pulm. HTN
- anemia
- aminoderone med.
what is a diffusion capactiy test? what is the common test conducted? what does it indicate ? what conditions have a decreased DLCO?
- measures the gas exchange ability of the lungs
- the surface area functioning for gas exchange, air perfusion and blood perfusion within the lungs
Commonly its a DLCO test –> a small amount of CO is inahled and in a single breathe– by a blood test can indicate the amount they absored
> 80% is a normal reading
low DLCO when…
- fiberosis, or other alveolitis
- restrictive lung disease
- emphysema (damanged beds)
- PE, Pulm. HTN
- anemia
- aminoderone med.
what is the GOLD classifcations? what are they used for?
COPD measuring the FEV1 in those with a FEV1/FVC ratio less than .7
GOLD 1: FEV1 > 80% predicted
GOLD 2: FEV1 50% - 80% predicted
GOLD 3: FEV1 30% - 50% predicted
GOLD 4: FEV1 < 30% predicted
