PULMONARY FUNCTION TESTS

PULMONARY FUNCTION TESTS (PFT)



What66is66the66primary66function66of66the66lungs?66-66answer--
1.66Oxygenation66of66mixed66venous66blood.
2.66Removal66of66carbon66dioxide66from66mixed66venous66blood.

Primary66function66depends66on66the66integrity66of66466things:66-66answer--1.66Airway
2.66Pulmonary66vasculature
3.66Respiratory66muscles
4.66Respiratory66control66mechanism

PFTs66help66determine66766things:66-66answer--
1.66Presence66of66disease66or66abnormal66lung66function.
2.66Extent66of66dysfunction.
3.66Extent66of66impairment/disability
4.66Progression66of66disease.
5.66Nature66of66physiological66disturbance.
6.66Effect66or66course66of66therapy.
7.66Aid66clinical66prognosis.

Common66PFTs66-66answer--1.66Spirometry
2.66Diffusing66capacity
3.66Body66plethysmography
4.66Bronchial66provocation
5.66Maximal66inspiratory/expiratory66pressure
6.66Exercise66testing
7.66Arterial66blood66gasses

Spirometry66-66answer--Measures66air66flow66and66volumes.

Flow/volume66relationship66-66answer--
Peak66flow66reaches66its66maximal66level66somewhere66near66total66lung66capacity.

As66lung66volume66decreases,66resistance66increases66due66to66intrathoracic66airway66n
arrowing.

How66air66flows66-66answer--
Air66flows66from66higher66to66lower66pressure.66There66is66a66balance66between66forces:
66pressures66trying66to66collapses66and66structures66trying66to66keep66airways66open.