Respiratory Flashcards
(158 cards)
Definition of chronic bronchitis
Inflammation of bronchial tubules, with a productive cough for 3/12 for at least 2 years
Give 3 risk factors for chronic bronchitis
Air pollutants
Dust and silica
Genetic factors
Which ratio is particularly low in chronic bronchitis?
FEV1 to FVC ratio
How is the total lung capacity usually affected in chronic bronchitis and why?
High due to air trapping
What type of cells line the airways?
Ciliated pseudostratified columnar epithelial cells- with goblet cells
Give the two layers that make up the lamina propria
Basement membrane and loose connective tissue
Give the two layers of the submucosa
Smooth muscle and connective tissue
How is mucous made and secreted?
Made by goblet cells, secreted by bronchial mucinous glands
How does exposure to irritants and chemicals affect the cilia?
They become shorter and less mobile which makes it more difficult for them to move mucous
How does exposure to irritants and chemicals affect the bronchial mucinous glands and goblet cells?
Hypertrophy and hyperplasia
What is the Reid Index and what value indicated chronic bronchitis
Thickness of glands/ thickness of wall
chronic bronchitis >40%
Give 5 Signs and Symptoms of chronic bronchitis
Wheeze Crackles (rales) Hypoxemia Hypercapnia Cyanosis
How can pulmonary HTN occur as a result of COPD? What does this eventually lead to?
Blood vessels vasoconstrictor in areas with decreased gas exchange to shunt blood
In chronic bronchitis, this is a large proportion of the lung
Increases pulmonary vascular resistance
Increased work from R side of heart leads to right sided heart failure (Cor-Pulmonale)
How would you treat chronic bronchitis?
Reduce risk factors Manage associated illnesses Supplemental oxygen Medication: Bronchodilators Inhaled steroids Antibiotics
Give examples of the following which could be used for COPD:
Bronchodilators
Inhaled steroids
Salbutamol, salmeterol (Beta-2 agonists)
Ipratropium, tiotropium (anticholinergics)
Beclomethasone dipropionate
How does smoking lead to emphysema?
It causes an inflammatory reaction which leads to the release of immune cells and the release of proteases (elastase and collagenases) which break down structural proteins in the connective tissue layer of the alveoli
Use Bernoulli’s principle to explain why the airways collapse during exhalation in a patient with emphysema
Fluid moves at a higher velocity with a lower pressure
Low pressure pulls airways inwards
Since there is a loss of elastin, airways can no longer withstand this pressure during exhalation
How does a loss of elastin affect compliance in emphysema?
Increased compliance, therefore inhalation causes easy expansion and the lungs hold on to air rather than expelling it during exhalation
How does a loss of elastin affect area available for gas exchange in emphysema?
Reduced SA available for gas exchange since a loss of elastin leads to a breakdown of alveolar septa and therefore neighbouring alveoli form larger air spaces
Describe the characteristics of centriacinar emphysema
Most common
Seen with cigarette smoking
Damages proximal alveoli
Typically affects upper lobe of lungs
Describe the characteristics of panacinar emphysema
Associated with alpha-1 antitrypsin deficiency
Entire acinus affected equally
Typically affects lower lobes of the lungs
What is the usual purpose of alpha-1 antitrypsin and why can a deficiency lead to emphysema?
It is a protease inhibitor which protects against unintended damage
Deficiency means no inhibition and therefore damaged air sacs
Describe the characteristics of paraseptal emphysema
Affects distal alveoli
Affects peripheral lung tissue near interlobular septa
Ballooned alveoli can rupture and cause a pneumothorax
Give 5 symptoms of emphysema
Dyspnoea Exhaling slowly through pursed lips (increases airway pressure and prevents collapse) Weight loss Hypoxaemia Cough with some sputum