Respiratory function tests quiz Flashcards
what do respiratory rates measure?
how much air is moved in a given amount of time
what is MVR?
minute volume of respiration: total volume of air moved per minute
what is the equation for finding MVR? the units of MVR?
TV x BPM = MVR in L/min
what is a con of relying on MVR?
it contains the volume of air within the conducting zone (trachea, bronchi, etc.) which is approx. 0.150 L
what is AVR?
alveolar ventilation rate: volume of usable air moved per minute
what is the equation of finding AVR? the units of AVR?
(TV - 0.150) x BPM = AVR in L/min
what is percent effective ventilation?
the percent of air actually being used for external respiration (within alveoli and pulmonary capillaries)
what is the equation of finding percent effective ventilation?
Kent takes 8 breaths in 12 seconds. His tidal volume is 0.650 L. Calculate Kent’s MVR
Kent takes 8 breaths in 12 seconds. His tidal volume is 0.650 L. His conducting zone volume is average. Calculate Kent’s AVR
would the percent effective ventilation go up or down with panting/hyperventilation?
value goes down with panting (rapid shallow breaths)
value goes up with hyperventilation (big breaths)
what is FEV? what does it measure?
forced expiratory volume: measures how fast a max inhale can be exhaled
what is FVC?
forced vital capacity: max air forcibly exhaled after a max inhale
how to calculate FEV 1, 2, and 3?
what are the expected ranges of FEV 1, 2, and 3?
1 = 66-83%
2 = 75-94%
3 = 78-97%
what would you expect if FEV values were lower than expected? why?
COPD
because patients have difficulty exhaling, so exhaling volume would be low
sketch FEV inverted graph
what is MVV? what does it measure?
maximal voluntary volume: measures how much air moved per minute when breathing as fast and deep as possible (hyperventilating)
what is the equation for MVV? units for MVV?
Christian counted 21 breaths in 12 seconds. His average volume per breath was 1.857. calculate his MVV.
Gail took 11 breaths in 12 seconds. Average volume of each breath was 1.846 L.
Jared took 30 breaths in 12 seconds. Average volume of each breath was 0.385 L.
Calculate both MVV.
which was hyperventilating and which was likely panting? why?
Gail was hyperventilating because his MVV was around 100 L/min or more
Jared was panting because he had increased number of breaths and a lower MVV.
what is the expected MVV?
around 100 L/min
sketch MVV graph.
what did we do in the FEV experiment?
3 normal breaths
one big inhale
deep exhale for 3 seconds
all is done seated and sat upright
