Pulmonary Function Tests (PFT)

Question 1

indications of PFT

Answer 1

1. Respiratory sign and symptoms
2. monitoring of patient with lungs disease for response to treatment and disease progression
3. investigating of further complications
4. surveillance of pulmonary transplant
5. investigating patient at risk of pulmonary disease
6. preoperative evaluation

Question 2

contraindication of PFT

Answer 2

1.myocardial infraction within previous month
2. abdominal, eye, thoracic surgery or aneurysm
3.unstable angina
4. hemodynamic unstability
5. pneumothorax
6. recent hemoptysis

Question 3

TLC (Total Lung Capacity)

Answer 3

the total amount of air in the lungs at maximal inspiration.

Question 4

FRC (Functional Residual Capacity):

Answer 4

the volume of the lungs at which the outward recoil of the resting chest wall is counter-balanced by the inward recoil of the lungs. It is the volume of air that remains in the lungs after expiration of a normal breath.

Question 5

RV (Residual Volume)

Answer 5

amount of air left in the lungs after maximal expiration.

Question 6

FVC – Forced Vital Capacity

Answer 6

The amount of air that can be forcefully expelled, beginning with the lungs completely full. This volume is expressed in Liters

Question 7

FEV1 – Forced Expiratory Volume in 1 second

Answer 7

Volume of air exhaled in the first second of the FVC. This volume is expressed in Liters

Question 8

spirometry

Answer 8

most useful and basic test,
It measure the inhaled or exhaled air against time during force maneuver

Question 9

instructions prior to spirometry use

Answer 9

1. dont drink alcohol 4 hours prior to use
2. dont smoke 1 hour prior to use
3. dont eat heavy meal 2 hour prior
4. dont wear tight clothes
5. remove dentutres
6. should not have MI one month
7. bring medications
   8- dont exercice 30 min before

Question 10

problems or meds that affect result

Answer 10

abdominal/ chest pain, oral/ facial pain, stress incontinence , dementia, physical deformities or medical condition

meds: corticosteriod and bronchodilator

Question 11

Performance of Spirometry

Answer 11

Attach nose clip
inhale air forecefully
put the mouthpiece in mouth and close with lips
exhale as long as fast as u can
repeat 3 times

Question 12

Obstructive Disorders

Answer 12

Airflow is blocked or limited by airway, making it difficult to breath out
example:
asthma, emphysema, bronchitis, cystic fibrosis, bronchiectasis

Question 13

Restrictive Disorders

Answer 13

Characterized by reduced lung volumes / decreased lung compliance (stiff or unable to expand fully)
Examples:
Interstitial Fibrosis
Cystic Fibrosis
Scoliosis
Obesity
Lung Resection
Neuromuscular diseases
Cardiovascular dis.
Trauma/chest wall dysfunction

Question 14

spirometry Normal values vary and depend on:

Answer 14

height
gender
ethnicity
age

Question 15

two types of curves

Answer 15

force volume curve
volume time curve

Question 16

PEFR
Definition
use
results
works

Answer 16

definition: rate at which air expelled forcefully From lung
use: management of asthma
in acute asthmatic attack to check severity of attack
to check trends of disease progression or success
result: % of best previous value if previous not avalible predicted value
works: take 3 reading and the best one noted on peak flow chart
if reading percent less than 50% oral steriod are given

Question 17

PEFR AND SEVERITY
moderate
acute sever
life threatening

Answer 17

moderate 50-77
acute sever 33-50
life threatening <33

Question 18

Bronchodilator Testing

Answer 18

for diagnosis of asthma, presence of reversible airway obstruction has to be confirmed
to check change in airway following admn of bronchodilator like salbutamol nebulizer 2.5mg
positive response is 12% increase in fev1 to the base line ( pre bronchodilator)

Question 19

Arterial blood gases (ABGs)

Answer 19

for acid base status of lungs 3 mechanism
1- buffering system: h+ ions and proton and proteins in blood
2- respiratory system: carbonic and bicarbonate buffer system,
3- renal system: excretion or retention of h+, bicarbonate and na, k, cl-

Question 20

Partial Pressure Of Oxygen (PAO2, PO2)

Answer 20

normal value: 75-100mm hg tor
below normal value: hypoxic in anemia, emphysema
hypoventilation, pulmonary edema, embolism
increase: polycythemia, high dose of o2

Question 21

Drugs which may increase PaCO2:

Answer 21

aldosterone, ethacrynic acid, metolazone, thiazides, hydrocortisone, prednisone, sodium bicarbonate.

Question 22

Drugs which may decrease PaCO

Answer 22

acetazolamide, dimercaprol, methicillin, nitrofurantoin, tetracycline, triamterene.

Question 23

S & S of hypercarbia / hypercapnia

Answer 23

acidotic state.
Headache, dizziness, and decreasing levels of consciousness.

Question 24

S & S of hypocarbia / hypocapnia

Answer 24

alkalotic state
Tingling of fingers, muscle twitching, lightheadedness, and dizziness.

Question 25

Oximetry

Answer 25

monitor the oxygen saturation of arterial blood.
Oximetry measures the percentage of oxygen being carried by the hemoglobin.
Normal Value: ≥95%

Question 26

Oximetry performance

Answer 26

To perform this measurement, a light-emitting sensor is attached to a site such as the finger or wrist.
The sensor emits beams of light through the skin tissue.
A light-detecting sensor then records the amount of light absorbed by the oxygenated hemoglobin.

Question 27

FEV1% Degree of severity
* mild
* moderte
* moderete severe
* severe
* very severe

Answer 27

• mild: >70
• moderte: 69-60
• moderete severe: 59-50
• severe: 49-35
• very severe: <35