Respiratory System 4 Flashcards
What is spirometry?
This is a test used to assess pulmonary function
It provides information about lung volumes and capacities
This information can be used to identify patients with obstructive diseases, restrictive diseases or normal lung function
What is tidal volume?
The volume of air inhaled or exhaled with each normal breath
What is inspiration reserve volume(IRV)?
The volume of air inhaled at the end of a normal tidal inspiration
What is expiratory reserve volume(ERV)?
The volume of air within the lungs that can be exhaled after the end of a tidal exhalation
What is the residual volume?
The air remaining in the lungs after a maximal expiration (this volume of gas cannot be expelled, and cannot be measured by spirometry)
What are functional Residual Capacity( FRC)?
The total volume of air remaining in the lungs at the end of a tidal exhalation
What is the function of total lung capacity(TLC) ?
The volume of air in the lungs at the end of a maximal inspiration
What is a vital capacity(VC)?
The volume of air exhaled from maximal inspiration to maximal exhalation; maximum expiration. When done with force this volume is termed the forced vital capacity (FVC)
What is forced expiratory volume in 1 second (FEV1)?
The volume of air exhaled in the first second of a FVC second
What is an obstructive disorder?
- Expiratory flow rate is significantly decreased resulting in decreased FEV 1 and FVC
- The FEV1/FVC ratio is low
What is a restrictive diso4der?
- Lung inflation is decreased resulting in decreased FEV 1 and FVC
- The FEV1/FVC ratio is normal or increased
What is Forced expiratory flow (FEF25-75)?
Forced expiratory flow
- Represents the expiratory flow rate over the middle half of the FVC (between 25% and 75%)
- Small airway obstruction may be present even when the FEV1/FVC % is above the lower limit of normal
- FEF25-75 has the greatest sensitivity for the detection of early airflow obstruction
How much is FEV 1 normally?
Normally FEV 1 should be about 80% of total volume expired(FVC)
FEV1/FVC ratio= 4.5 L/5.5 L*100= 80%
Differentiate restrictive and obstructive in the flow/volume loop
Obstructive loop- scooped out appearance common in emphysema
Restrictive loop- steep expiratory limb
Differentiate restrictive and obstructive pulmonary diseases
Obstructive- expiratory flow rate is decreased,
Restrictive- lung inflation is decreased
Obstructive- airway occlusion, air trapping
Restrictive- intrinsic- lung tissue, extrinsic- chest wall, pleura or neuromuscular
Give examples of obstructive diseases
- Obstructive Bronchitis
- Emphysema
- Asthma