Respiratory Diseases Flashcards
What are restrictive pulmonary diseases?
Due to reduced total lung capacity (TLC), but airflow and airway resistance are normal
What happens during intrinsic lung disease; chronic and acute? How can it lead to restrictive pulmonary disease?
Lung tissue (parenchyma) is destroyed, which reduces lung volume.
Acute; air spaces become filled with inflammatory exudates and debris
Chronic; Inflammation with scarring and fibrosis (interstitial fibrosis) destroys air spaces, thereby reducing lung volume.
Large parts of the lung parenchyma cannot function for gaseous exchange.
What happens in extrinsic disorders of the muscles of respiration?
The chest walls, connective tissue, pleura or the nerve supply that impair movement during inspiration. The inability of the chest to expand for whatever reason mechanically restricts ventilation, and respiratory failure ensues.
What are examples of restrictive pulmonary diseases?
Pneumothorax, pulmonary embolism, adult respiratory distress syndrome (ARDS) and pulmonary fibrosis
What is atelectasis?
A collapse of lung tissue with loss of volume causing a failure of the lungs to expand. Occurs when tiny air sacs (alveoli) become deflated or possibly filled with alveolar fluid.
What is atelectasis commonly caused by?
Acutely –> foreign bodies
Chronically –> tumours
May also be caused when compression, for example due to pleural effusion or pneumothorax, opposes inflation
Is atelectasis obstructive or restrictive?
Obstructive –> obstruction of airways prevents air inflating alveoli
What does this obstruction in atelectasis cause?
Air in this distal region is absorbed and the alveoli collapse. Secretion then accumulate and may become infected
What happens if the lung remains collapsed in atelectasis?
Irreversible fibrosis occurs
What is salbutamol?
Bronchodilator –> Medication that opens up the medium and large airways in the lungs
B-adrenoreceptor agonist
What is salbutamol used to treat?
Asthma, COPD etc
How can asthma and COPD be distinguished?
Measurements of FEV1 and PEFR made before and after inhalation of a bronchodilator
Asthma –> FEV1 and PEFR will be restored to normal as constriction is reversible
COPD –> very small improvement as constriction is irreversible
