Week 8: Respiratory Disorders Flashcards
What is COPD?
Chronic Obstructive Pulmonary Disorder refers to long-term pulmonary disorders characterised by air flow resistance. Includes asthma, chronic bronchitis, and emphysema.
What are the predisposing factors of COPD?
Smoking (most important) impairs ciliary action and macrophage function
Recurrent or chronic respiratory infections.
Allergies.
Hereditary factors like alpha1-protease inhibitor deficiency.
Define Asthma
Chronic reactive airway disorder that can present as an acute attack. Causes episodic airway obstruction resulting from bronchospasms, increased mucus secretion, and mucosal edema.
What is the pathophysiology of Asthma?
Muscles surrounding the bronchial tubes tighten (bronchospasm), narrowing air passages. Airflow is further interrupted by increased mucus secretion and swelling of the bronchial tubes.
What characterises genetically induced asthma?
Sensitivity to specific external allergens like pollen, animal dander, house dust, mold, food additives, and cockroach allergen.
What characterises environmentally induced asthma?
Reaction to internal, nonallergenic factors, often occurring after a severe respiratory tract infection. Other factors include irritants, emotional stress, fatigue, endocrine changes, temperature and humidity variations, and exposure to noxious fumes.
List the signs and symptoms of Asthma
Mild: cough, wheezing, chest tightness, or difficulty breathing < twice/week or 3-6 times/week.
Moderate persistent: daily symptoms.
Severe persistent: continual symptoms.
What is status asthmaticus?
A severe acute asthma attack unresponsive to conventional treatment. Symptoms include marked respiratory distress, wheezing or absent breath sounds, pulsus paradoxus, and chest wall contractions.
Define Chronic Bronchitis
A form of COPD, is inflammation of the bronchi caused by irritants or infection. Hypersecretion of mucus and chronic productive cough last for 3 months of the year and occur for at least 2 consecutive years.
What is the pathophysiology of chronic bronchitis?
Prolonged inhalation of irritants leads to excessive mucus production, obstructing small airways. This causes resistance and severe V/Q imbalance, decreasing arterial oxygenation. Chronic hypoxia leads to increased RBC production, causing polycythemia.
List the signs and symptoms of chronic bronchitis
Productive cough, dyspnea, cyanosis, use of accessory muscles, and pulmonary hypertension.
Define Emphysema
A form of COPD, characterised by abnormal, permanent enlargement of the acini accompanied by destruction of the alveolar walls.
What is the cause and pathophysiology of emphysema?
May be caused by alpha1-protease inhibitor deficiency or cigarette smoking. Recurrent inflammation leads to the release of proteolytic enzymes, causing irreversible enlargement of air spaces distal to the terminal bronchioles. Destruction of alveolar walls results in loss of elasticity and breakdown of fibrous and muscle tissues, making the lungs less compliant.
List the signs and symptoms of emphysema
Dyspnea on exertion (initial symptom), barrel-shaped chest, prolonged expiration, and decreased breath sounds.
Define Cor Pulmonale
Hypertrophy and dilation of the right ventricle that develops secondary to a disease affecting the structure or function of the lungs.
What is the pathophysiology of Cor Pulmonale?
Restrictive, obstructive, and primary vascular disorders lead to hypoxic constriction of pulmonary blood vessels and obstruction of pulmonary blood flow, increasing pulmonary resistance.
List the early signs and symptoms of Cor Pulmonale
Chronic productive cough, exertional dyspnea, wheezing, fatigue, and weakness.
List the late signs and symptoms of Cor Pulmonale
Dyspnea at rest, tachypnea, orthopnea, dependent edema, distended neck veins, hepatomegaly, tachycardia, and weight gain.
Define Pulmonary Oedema
Accumulation of fluid in the extravascular spaces of the lung.
What is the pathophysiology of pulmonary oedema?
Diminished left ventricle function causes blood to pool, increasing capillary hydrostatic pressure and pushing fluid into the lungs.
List the early signs and symptoms of pulmonary oedema
Dyspnea on exertion, paroxysmal nocturnal dyspnea, orthopnea, cough, mild tachypnea, increased blood pressure, dependent crackles, and tachycardia.
List the late signs and symptoms of pulmonary oedema
Labored, rapid respiration, diffuse crackles, frothy, bloody sputum, increased tachycardia, arrhythmias, cold, clammy skin, diaphoresis, cyanosis, falling blood pressure, and thready pulse.
Define ARDS
A form of pulmonary edema that can quickly lead to Acute Respiratory Failure (ARF).
What is the aetiology of ARDS?
Common causes include shock, sepsis, and trauma. Other causes include anaphylaxis, aspiration of gastric contents, diffuse pneumonia, drug overdose and inhalation of noxious gases.
