Lung Volumes And Capacities -Rogers Flashcards
Spirometry
Measuring breathing to know how much you inhale and exhale
Tidal volume and how much is normal
Normal volume you breath in and out (quiet breathing)
*= 500mL
Inspiratory Reserve Volume
The extra volume you breath in during deep inhale (not including tidal volume in)
Can change with lung compliance (flexibility of wall) + posture
Inspiratory capacity
Deep inhale volume including tidal volume in
Residual Volume
Normal amount
Volume in lung left after deep exhale
Double tidal volume = 1000mL
Changes with disease, cant be seen on spirometry
= if reached its wind knocked out from you
Expiratory reserve volume
Normal amount
Volume of air moving out from lung after deep exhale not including tidal volume out
(Expiration capacity would include tidal volume out)
= double tidal volume = 1000mL
Vital Capacity
Total volume of air from deepest inhale to deepest exhale
Total Lung Capacity
Total amount of volume of air inhaled deeply and exhaled deeply including the reserved volume still left in the lungs
= ERV + IRV + TV + RV
Can not be seen on spirometry
Functional Residual Capacity
Volume of deep exhale (not including tidal volume out) to the end of residual volume = expiratory reserve volume + reserve volume
* volume left in lung during normal Tidal volume exhale
= not seen on spirometry
Biggest part of TLC
IRV
What is similar to FVC
Vital capacity
What decreases FVC (VC) and RV
Age
Reduction in FCV happens when
Laying on back
Other factors effecting volumes in lungs
Body size, sex, ethnicity, obesity, pulmonary disease
Obesity causes what to lung volumes
Decrease all volumes (esp ERV + FRC)
No decease in Tidal volume
Age and lung volume
OLD and YOUNG
YOUNG
OLD = decreased Vital capacity and ERV, increased RV
Increase in FRC(due to higher increased RV)
(SAME TLC IN BOTH)
Posture and lung volume
Seated vs supine (lowest)
Seated = HIGHER TLC HIGHER VC RV is the same (Also higher FCV, ERV, little lower IC)
Obesity and lung volume
LOWER FRC and ERV
Everything else is same
= LOWER TLC AND VC*
Emphysema
Alveoli destroyed (and loose capillaries) ballon (stretchy and flexible) becomes a trash bag = emphysema fills lungs up easily , HARD time blowing out
Emphysema and lung volume
HIGHER TCL* AND RV*
LOWER VC* AND ERV
Emphysema is what type of lung problem
Obstructive
Fibrosis is what type of lung problem
Restrictive
Fibrosis
Thickening of the alveoli tissue (alveoli is more like a balloon in water or whoopee cushion = hard to get air in, hard to push, however ones done air gets out with harder force)
= hard to expand lung cavity
Fibrosis lung volume
DECREASE TLC* and RV* and VC*
How to measure RV
Helium dilution
Do a He dilution inhalation
Change in concentration of known volume = FRV*
TLC = FRV + Inhalation capacity
RV = FRV - ERV
How to measure RV
Body plethysmography
Enclosed box that patient sits inside
P in lungs change causes P in box to change
USE P1V1=P2V2*
How to measure RV
Nitrogen Washout technique
Determine dead space by
1. patient breathing in 100% O2
2. All expired gas is collected until N2 = 0
3. V (expired) x (N2% in expired air) = 80% is normal air N2 percentage
= RV
Pulmonary Dead Space
How to measure it
TV = V(a) +V(d) V(a) = volume doing gas exchange in alveoli V(d) = volume not doing gas exchange in conducting airways (dead space)
Pulmonary dead space is what
Air volume that is part of the tidal volume inhaled and exhaled and is not participating in gas exchange (stays in conducting airway)
Physiological Dead Space
How to calculate it
= Anatomical Dead space + Alveolar Dead space
* measure with CO2 pressure
Anatomical dead space
And amount in normal
Air in conducting airways (never gets to alveoli)
Usually 1mL per body weight lb (so mine is 118mL)
Alveolar Dead Space
And Normal amount
Should be 0mL
Air left in the alveoli after breathing out or in not doing gas exchange
So normally physiologic dead space = anatomical dead space
Alveolar dead space in smoker
Can increase physiological dead space due to increased destruction of alveoli causing increased alveolar dead space
*also increases in emphysema I think
