08.19 - PFTs (Freire) - Questions Flashcards
Post-bronchodilator response is positive if
Incr in FEV1 of 200 cc (and 12%), or 15% from basal FEV1
The MVV Maneuver tests
Max respiration in L/min
How to perform MVV Maneuver
Deep breaths as hard and fast as possible for 12 seconds
Internal consistency check for MVV Maneuver
40 times FEV1
If both obstructive and restrictive have decr VC, how differentiate?
Obstructive defined by FEV1/FVC <70%
VC is reduced in (3)
Chest Pain; Fatigue; Poor Effort
TLC is reduced in (4)
Diseases of Thorax; Inspiratory Muscles; Pleural Dz; Loss of functioning alveoli
Hyperinflation and air trapping increases __ volume
Residual Volume
Dynamic Hyperinflation
Air Trapping and Hyperinflation become more profound as RR increases with exercise
__ corresponds more strongly to dyspnea than FEV1
IC
Real way that medication helps patients with COPD and Hyperinflation
Limits dynamic hyperinflation and air stacking.
Compliance in Asthma
Same as normal
Compliance in Emphysema
Increased
Compliance in Fibrosis
Decreased
What differentiates asthmatics form COPD in PFTs
Increased compliance in COPD
FEV1/FVC in Fibrosis
Very high –> Hyperflows
A normal SVC excludes
a significant restrictive disorder
Flow velocities are __ for each given instanteous volume in Restrictive
higher (>elastic recoil)
Which component of Expiration on Flow-Volume loop is effort-independent
Terminal portion –> Driven only by elastic recoil
Can dx central airway disorders by
Flow-Volume Loop
Inspiratory phase of flow-volume loops give the ___ component of central airways
Extra-Thoracic
If fixed obstruction is present, it will show on ___ and ____
inspiratory and expiratory portion of FV Loop
Co is used to measure DL b/c
it has high affinity for Hb; Found in low concentration in blood
Which method of DLCO is simple and standardized
Single Breath
DLCO with blood in lung
Higher than actual
DLCO in Pulmonary HTN
Higher than actual
Bronchoprovocation with Methacholine is considered positive if
FEV1 decrease of 20%
