15 Pulmonary mechanics ad spirometry

Question 0

Inspiratory capacity

Answer 0

from tidal exhalation to maximal inspiration

Question 1

Inspiratory reserve

Answer 1

From max tidal to maximal inspiration

Question 2

Vital capacty

Answer 2

Maximal inspiration to maximal expiration

Question 3

FRC

Answer 3

Whats left in the lung after tidal expiration

Question 4

Expiratory reserve

Answer 4

tidal expiration to full expiration

Question 5

Determinants of lung flow

Answer 5

flow = (pAlv-pAtm)/ airway resistance)

Remember resistance changes at different parts of lung and varies with level of inflation (more inflation = less resistance

Question 6

Resistance across lung

Answer 6

Highest at medium sized bronchi, almost nonexistent in alveoli

Question 7

PFT indication

Answer 7

• Diagnostic: Symptoms, signs, abnormal lab results
• Assess effects of disease
• screenings- smokers, occupatinal exposures, preoperative rsk, disability, prognosis

Question 8

FEV1

Answer 8

How much volume in first second of expiration

Question 9

forced vital capacity

Answer 9

Full amount able to blow out given all the time in the world

Question 10

Intrathoracic Vs extrathoracic

Answer 10

Expiration assess intrathoracic

inspiration assess extrathoracic

Question 11

Obtructive pulmonary disease Flow volume curve

Answer 11

• slower rise to peak
• Lower expiratoryflow
• scalloping of curve from slowing effect on restricted lower airways

Question 12

Resttrictive disease flow/volume curve

Answer 12

Less volume, skinnier curve, fast expiration, no scalloping

Question 13

Lung cancer curve

Answer 13

cant gert a peak flow- no scalloping

Question 14

How to tell id there is restrictiveor obstructive process

Answer 14

look at FEV1/FVC ratio

• Normal (100% of predicted) is either normal or restrictive
• Low ratio indicates obstructive prcess

Question 15

Normal spirometry

Answer 15

*FEV1/FVC is normal
and
*VC is normal 80% or greater of predicted.

Question 16

Obstrucive FEV1 grading in low FEV1/FVC

Answer 16

FEV1 >99 - physiologic
70-99 Mild
60-69 Moderate
50-59 moderrate/severe
34-49 Sever
<34 very severe

Question 17

Bronchodilator response criteria

Answer 17

FVC or FEV1 increases 12% and 200mls

Question 18

Obstructive pulmonary diseases

Answer 18

Tumors and FB in large airwaus
Asthma, chronic bronchitis, CF in pepheral airways
Emphysema in parenchyma

Question 19

Restrictive disease

Answer 19

Sarcoidosis,collagen vasc diseas, pulmonary fibrosis
pneumonectomy
Pleural effusion
Kyphosis and NMJ disorders
Obesity

Question 20

Restrictive defect criteria

Answer 20

Normal FEV1/FVC and DCR. FVC
Reduced TLC

70% to lower limit normal - mild
60-69% mild restrictivve defect
<60% moderately severe

Question 21

Accepttability/repeatablility

Answer 21

Acceptability:

• No artifacts
• PEF reached with <5% of volume or less than .15L, and in less than 120ms

Repeatability:
Two largest FVC within .2L?
Same with FEV1s?

test up to 8 times, keep top 3