lecture 3: pulm function test Flashcards by Emily Pereira

what are 3 reasons for performing pulm function tests

1) Diagnossi (allegrgies, resp infections, chronic disease ex: COPD)
2) Presurgery screening (for lung function)
3) Assess treatment of current condition

=quick way to assess pulm health

How well did you know this?

Not at all

Perfectly

what are 3 different methods of measurement for pulm fucntion test

1) plethysmography (measures changes in pressure)
2) gas dilution test (ex: nitrogen washout, helium dilution)
3) Spirometry (measures changes in vol)

How well did you know this?

Not at all

Perfectly

what are some factors that affect PFT results

age
height
sex
ethniticty

How well did you know this?

Not at all

Perfectly

explain how age can affect PFT results

increase age=decrease elasticity of lungs

=decreaese PFT values

How well did you know this?

Not at all

Perfectly

explain how height can affect PFT values

if you have a larger height= larger PFT values

larger lung size

How well did you know this?

Not at all

Perfectly

explain how sex can affect PFT values

males have larger PFT values than females

How well did you know this?

Not at all

Perfectly

explain how ethnicity can affect PFT values

there are anthropometric differences across ethnicities that will affect it

How well did you know this?

Not at all

Perfectly

what are the indications for before doing PFT

1) no smoking within 1 hour of test
2) no alchohol consumption within 4 hours of test
3) no vig exercise 30 minutes before test
4) no large meals within 2 hours of test (stom will take more space)

How well did you know this?

Not at all

Perfectly

what are the 4 static luung valomes

tidal vol
inspiratory reserve volume
expiratory reserve volume
residual volume

How well did you know this?

Not at all

Perfectly

explain tidal volum

the volume of air inhaled/exhaled during a nromal breath
=without concious effort

(normally 200-500 ml but can increase to more than 3L)

How well did you know this?

Not at all

Perfectly

does IRV decreaese or icnrease with exrcise and why

it decreases because tidal volume increases

How well did you know this?

Not at all

Perfectly

explain inspiratory reserve volume

the vol of air that can be maximally inhaled at the end of a normal tidal inspiration
(end todal to max inhale)

normally approx 1900 in fem
3000 in men

How well did you know this?

Not at all

Perfectly

explain Expiratory reselve volume

the vol of air that can be maximally exhaled after a normal tidal exhalation
(end tidal to max exhale)

normal: 700 ml in fem
1100 in males

How well did you know this?

Not at all

Perfectly

does ERV increase or decrease with exrecise and why

it decreases bceause tidal vol increases

How well did you know this?

Not at all

Perfectly

what is residual vol

vol of gas remaining in the lungs after a forced/maximal exhalation

How well did you know this?

Not at all

Perfectly

what is the function of residual vol

The residual lung volume is important for helping pulmonary function since it allows the gas exchange between the blood and the alveoli to be uninterrupted even between breaths

prevents fluctuations and variations of the gases and present in the blood and their concentrations during the entire breathing cycle

the residual volume allows the alveoli to remain open between breaths, to allow for continual gas exchange at all times

How well did you know this?

Not at all

Perfectly

what are the 4 lung capacites

inspiratory capacity
function residual capaicty
vital capacity
total lung capcitty

How well did you know this?

Not at all

Perfectly

explain inspirtaoty capcity

Inspiratory capacity (IC): The maximum volume that can be inhaled from the end of a normal resting exhalation (IC = VT + IRV).

How well did you know this?

Not at all

Perfectly

explain functional residual capacity

Functional residual capacity (FRC): The volume of gas remaining in the lungs at the end of a normal resting exhalation (FRC = ERV + RV).

How well did you know this?

Not at all

Perfectly

explain vital capacity

Vital capacity (VC): The greatest volume of gas that can be exhaled by maximal effort after a maximum inhalation (VC = IRV + VT + ERV).

How well did you know this?

Not at all

Perfectly

explain total lung capacity

Total lung capacity (TLC): The volume of gas in the lungs at the time of maximal inhalation. It is the sum of VC and RV (TLC = IRV + VT + ERV + RV).

How well did you know this?

Not at all

Perfectly

how do you mark off the volumes and capacities on a graph

1) choose the smallest tidal vol before maneuver (but not the first one right before test)
(from end of tidal to end of inhale)

How well did you know this?

Not at all

Perfectly

in the lung volumes tset, each box is how many liters

0.1 L

how do you measure inspiratory server volume off graph

from the end of the tidal inhale all the way to the max inspiration

how do you measure expiratory server volume off graph

measure from end of the tidal breath to end of expiration

how do you calculate RV

usually just estimated at 1 L

what does the forced expirations test measure

dynamic lung volume (allows us to observe air flow, compliance of chest and lungs)

what are the 3 exhale cirtearia inn the forced expirations test

1) exhale needs to be quick 2) exhale should be fprceful 3) exhaule sould be held as long as possible (at least 6 seconds)

what are the variables we are measureing in the forced expirations test

1) forced expiratory volume in 1 sec 2) forced vital capacity 3) FEV1/FVC

how many times is the forced expiration test completed and how do you know which test to choose

done 3 times but choose the one with the longest duration for exhale

explain how to mark the graph for forced expiration test

1) mark time 0 (where exhale begins) =start where dramatic downslope starts 2) mark 1 sec over to establish FVC 3) mark from the max (the beg of exhale) all the way down to lowest point in exhalation

what is considered a normal FEV1.FV ration

greater than 0.7

what is considered a low FEV1/FVC ratio

less than or equal to 0.70

how do you calculate % preduced FVC

FVC measured/FVC predicted

if someone has a normal ratio, and a predicted FVC that is greater or equal to 0.8, what does that indicate

indicates normal FEv1 and normal FVC

if someone has a normal ratio, and a predicted FVC that is less than 0.8, what does that indicate

that the FVC only is reduced (restrictive) =difficult to expand the lungs (it is a volume limitation)

if someone has a low ratio, and a predicted FVC that is less than 0.8, what does that indicate

both FEv1 and FVC are reduced, you have mixed disorders

if someone has a low ratio, and a predicted FVC that is equal or greater than 0.8, what does that indicate

only fev1 is reduced =obstructive =limiated to flow (harder to expty lungs)

know the forced expiration interpretation chart

what is the main symptoms shared between obstructive and restrictive breathing disorders

dyspnea

how can you calculate the severity of the obstruction

calculate the % predicted FEv1 | %FEV1 meaured/predicted

explain obstructive lung disordderes

they have an airflow limitation caused by some sort of obstruction (sometimes inflammation of airways) =cannot exhale/push out air quickly =bad Fev1

give some examples of obstructuve lung dieases

``` COPD Emphysema Bronchitis Asthma cystic fibrosis ```

epxlain resisttrictive lung disorders

difficult to expand lungs(volume limitation) | =lungs cannot expand well due to compliacne issues (sometimes scar tisse and inflammation)

what are some examples of restrictive lung disorders

Obseity scoliosis neuromuscular disease intersitial lung disease

If a subject’s VC is in the normal range for his/her | age, size and gender, the subject likely has no BLANK

Pulm disease

what is FEV1

the forced expiratory volume in 1 second (FEV1 – volume that the subject is able to exhale in the first second of the FVC maneuver, expressed in L

wha t is FVC

volume of gas that is expired by maximal effort after a maximum inhalation, expressed in L)

explain what happens to FEV and FVC in airway obstructions

In conditions where the airways are obstructed (i.e., such as in asthma and chronic obstructive pulmonary disease (COPD), which includes emphysema and chronic bronchitis) the FVC is normal (> 80%). However, the rate of expiratory flow (and thus the FEV1) is reduced (< 80%)

explain what happens to FVC and FEV1 in restrictive diseases

In conditions where the lung volume is reduced (i.e., restrictive diseases such as pulmonary fibrosis, scoliosis, and tuberculosis) the FVC is compromised (< 80%). However, the FEV1/FVC ratio may be normal or even greater than normal due to the normal FEV1 value

what is the def of MVV (max voluntary ventilation)

It is defined as the maximum volume of air that can be exhaled over a specified period of time =largst amount of air that can move in and out of lung in one minute)

the MVV test provides information on what

measures respirtatory muscle stregnth | =provides info on airway resistance, lung elasticity, lung compliace, and respiratory muscle mechanics

what is the goal in terms of breaths/min and vol for the MVV test

90 breaths/min | about 50% of VC

how do you extract data for MVV test

mark off center (start of exhale of first maneurveer) =measureeing all of the exhale volumes up until the last one (do not inlclue last one that has normal breath) sum all the volumes and measure the time from begining of first exhale to end of last exhale =calcualte MVV

what does it mean if the MVV graph has a downward trend

person is breathing out more than they are breathinging in | =respiratory muscle fatigue/increase work of breathing

what does it mean if MVV graph has upward slope

indicates air trapping | not exhaling as much as inhaling

what is the MVV interpresation equation and the norm values

MVV measured / (40 * FEV1 measured) if ration < 0.80, this indicates MVV is low relative to FEV1, which suggests disease or poor effort