Pulmonary Function Tests Flashcards
What is spirometry?
A pulmonary function test useful in managing patients with respiratory disease or respiratory weakness due to neurological impairment.
It aids diagnosis, monitors treatment response, and guides further treatment decisions.
What are contraindications for spirometry?
- Aneurysm
- Hemoptysis of unknown origin
- Pneumothorax
- Unstable cardiovascular status, recent myocardial infarction or pulmonary embolism
- Acute disorders affecting test performance (e.g., nausea, vomiting)
- Recent thoracic or abdominal surgical procedures
- Eye surgery
- Pleural Effusion
- Post-MI
These conditions can lead to complications during the spirometry test.
What lung volumes can spirometry measure?
All lung volumes except residual volume.
Residual volume is measured using other techniques.
What are the indications for performing spirometry?
- Investigation of pulmonary disease symptoms/signs
- Monitoring known pulmonary disease progression and treatment response
- Investigation of diseases with potential respiratory complications
Examples include interstitial fibrosis, COPD, asthma, and neuromuscular diseases.
What is Functional Residual Capacity (FRC)?
The amount of air remaining in the lungs at the end of normal exhalation, calculated as RV + ERV, normal value is about 1800 – 2200 mL.
FRC is reduced in restrictive disorders and indicates hyperinflation when in comparison to TLC.
What is Total Lung Capacity (TLC)?
The maximum volume of air the lungs can accommodate, normal value is about 6000 mL (4-6 L).
TLC is the sum of all primary lung volumes (TV, IRV, ERV, RV).
What does a FEV1/FVC ratio of less than 70% indicate?
It suggests an obstructive pathology.
This indicates that FEV1 is reduced more than FVC.
What does Peak Expiratory Flow (PEF) measure?
The maximal flow that can be exhaled when blowing out at a steady rate.
It is an important measure in assessing respiratory function.
What is the normal value range for FEV1?
80%-120%.
This indicates the expected range for a healthy individual.
What is the procedure for performing spirometry?
Calibration of the equipment is necessary, and patient positioning should be upright sitting with feet flat on the floor.
Proper positioning ensures accurate measurements.
What is the acceptable quality for a spirometry maneuver?
An explosive start with a back-extrapolation volume <150 mL, maximal inspiration and expiration, no glottis closure, and no coughs during the first second.
Quality is crucial for obtaining reliable results.
What is Residual Volume (RV)?
The volume of air remaining in the lungs after maximal exhalation, normal adult value is about 1200 mL.
RV cannot be measured directly by spirometry.
What is Tidal Volume (TV)?
The amount of air inhaled or exhaled during one respiratory cycle, normal adult value is approximately 300-500 mL.
TV reflects the function of respiratory centers and mechanics of the lung.
What is Inspiratory Reserve Volume (IRV)?
The amount of air that can be forcibly inhaled after a normal tidal volume, normal adult value is 1900-3300 mL.
IRV is typically unused but engaged during deep breathing.
What is Expiratory Reserve Volume (ERV)?
The volume of air that can be exhaled forcibly after normal tidal volume, normal adult value is 700-1200 mL.
ERV can be reduced in conditions like obesity and after abdominal surgery.
True or False: Lung volumes are also known as respiratory volumes.
True.
They refer to the volume of gas in the lungs at a given time during the respiratory cycle.
