Spirometry Flashcards
fixed extrathoracic airway obstruction when
FEF50/FIF50 >1
at ___, inspiration/expiration flow rate should be about equal
50% VC
hallmark of restrictive defect
reduced total lung cpacity
significant response to bronchodilator
when FVC or FEV1 increases at least 12% and 200ml
low FEV1 FVC implies ___ process
obstructive
(restrictive and normal flow have not-low ratios)
normal range FEV1/FVC
normal VC
0.70-0.87
normal vc within 80% of predicted
if FEV1/FVC ratio low…
FEV1% of expected classification
FEV1>99% expected = phyiologic variant
FEV1 70-99% mild
FEV1 60-69% moderate
FEV1 50-59 moderately severe
FEV1 34-49 severe
FEV1
restrictive lung disease
sarcoidosis, collagen vascular disease
pulmonary fibrosis
pneumonectomy
plearal effusion
chest wall disease (kyphosis, nm disorder)
extrathoracic conditions (obesity(
process of air into alveoli (pressure differentials)
thorax expands> pleural more sub-atm >
> increase transpul pressure >
>lungs expand>
>alveolar pressure = atm >
air flows into alveoli
in emphysema, lung tissue is ___ compliant
more
restrictive disease = ____ flow rate curve
normal shape, skinnnier (less volume)
___ outside of 95% Confidence interval is low
FEV1/FVC
TLC classifications for restrictive defect
% predicted TLC =70%-to LLN Mild
60-69% Moderate
(if lung volumes cannot be measured, grade FVC using the obstructive FEV1 classes)
satisfactory duration of exhalation for spirometry
6sec
cystic firosis, pulmonary parenchymal disease (emphysema) obstuctive or restrictive?
obstructive
