Pulmonary Function Testing and Implications for Physical Therapists

Question 1

Spirometry

Answer 1

Assesses the mechanical properties of the respiratory system by measuring expiratory volumes and flow rates

• Requires maximal inspiratory and expiratory effort
• Reported in absolute values and as predicted percentage of normal

Question 2

What is considered a significant response to a beta agonist?

Answer 2

> 12% increase in the FEV1 (absolute improvement in FEV1 of at least 200 ml) or FVC

Question 3

Define: FEV1

Answer 3

Forced expiratory volume 1- the volume of air that is forcefully exhaled in one second

Question 4

Define: FVC

Answer 4

Forced vital capacity- the volume of air that can be maximally forcefully exhaled

Question 5

Define: FEV1/FVC

Answer 5

Ratio of FEV1 to FVC- expressed as a percentage

Question 6

Define: FEF 25-75

Answer 6

Forced expiratory flow- the average forced expiratory flow during the mid (25-75%) portion of FVC

Question 7

PEF

Answer 7

Peak expiratory flow rate- the peak flow rate during expiration

Question 8

3 Criteria for Spirometry Test Acceptability

Answer 8

1. Lack of artifact caused by coughing, glottic closure, or equipment problems
2. Satisfactory start to the test without hesitation
3. Satisfactory exhalation with 6 seconds of smooth continuous exhalation and/or a plateau in the volume time curve of at least one second or a reasonable duration of exhalation with a plateau

Question 9

Variable Effort

Answer 9

Failure to demonstrate the normal early peak showing that the patient failed to expire maximally when instructed to do so

Question 10

Early Glottic Closure

Answer 10

Abrupt cessation of flow during expiration, visible as a sharp downslope on the expiratory flow volume curve

Question 11

Coughing

Answer 11

Sudden sharp spikes in the decreasing limb of the flow volume curve

Question 12

FVC minimum duration

Answer 12

• Adult- 6 sec
• Child- 3 sec
• OR plateau in the volume-time curve
• *SUBJECT CANNOT OR SHOULD NOT CONTINUE TO EXHALE**

Question 13

FVC End of Test Criteria

Answer 13

• subject cannot or should not continue further exhalation OR
• the volume time curve shows an obvious plateau OR
• The forced exhalation is of reasonable duration

Question 14

FVC maximum number of maneuvers

Answer 14

8

Question 15

FVC Maneuver UNacceptability

Answer 15

1. Unsatisfactory start of expiration
2. Back extrapolated volume of greater than 5% of FVC or 150 mL whichever is greater
3. Coughing that interferes with the measurement of FEV1 and/or FVC
4. Early termination of expiration
5. Valsalva maneuver
6. A leak
7. An obstructed mouthpiece, no glottis closure
8. Effort that is not maximal throughout

Question 16

FVC and FEV1

Answer 16

Reproducibility the largest and second largest FVC and/or FEV1 must not vary by more than 200 mL

Question 17

Interpreting Spirograms

Answer 17

Predicted FEV1-->
>80%= normal
<80%= What is FEV1/FVC?-->
>80%= Restriction
<80%= Obstruction; What is the predicted FVC?
>80%= Pure Obstruction
<80%= Can't R/O concurrent restriction