Respiratory Disorders Flashcards
Asthma: Aetiology and Pathophysiology
characterised by airway constriction and/or inflammation
exposure to triggers, such as allergens, medications, stress, physical exertion, environmental factors can lead to obstruction of airflow during expiration
Exercise-induced Asthma
constriction of the bronchi due to exercise
manifests within 5-20 mins of physical activity
caused by increased breathing rates and loss of heat and water from the respiratory tract
leads to airway hyperresponsivity making breathing more difficult
Occupational Asthma
results from exposure to workplace substances and/or environmental conditions
can be allergen induced or non-allergen induced
allergen induced: due to allergens like dust and pollen
non allergen induced: due to irritants like smoke, fumes and gases
Asthma: clinical manifestations
high pitched, end-expiratory wheeze
dyspnea
non productive cough (dry cough)
chest tightness
hypoxia (not enough oxygen) -> activates SNS –> increases heart and breathing rates
nasal congestion
severe attacks –> excessive bronchoconstriction
respiratory muscle fatigue, and silent chest
severe signs include cyanosis and significant anxiety due to SNS activation
Asthma: Diagnosis
taking a thorough history to identify triggers and environmental factors (pet cohabitation, home routine cleaning, and any presence of mould)
physical exam with chest observation and auscultation
pulse oximetry from the start of an acute episode of asthma
chest x-rays and arterial blood gas analysis helps to rule out other conditions and assess respiratory changes
allergy testing and sputum analysis
Asthma: Management
apply high flow oxygen
position patient upright in high fowlers o semi-fowlers position
administer short acting beta 2 agonist (opens airways quickly and stops asthma) through nebulization
create a calm environment to reduce SNS activity
use corticosteroids (inhaled or oral) to control inflammation and bronchial hyperresponsiveness
educate on controlling environmental exposures
monitor physical activity and encourage indoor exercises
stop smoking and avoiding exertion in high pollution conditions
recommend avoiding certain drugs like aspirin and NSAIDS which can exacerbate Asthma symptoms
Chronic Obstructive Pulmonary Disorders (COPD)
characterised by irreversible airflow limitation
causes breathing difficulties
Chronic Bronchitis:
a productive (wet) cough lasting at least 3 months for two consecutive year
often coexists with emphysema due to shared risk factors like smoking
one of the most prevalent forms of COPD
Chronic Bronchitis: Clinical Manifestations
frequent productive cough
dyspnea and wheezing
signs of upper respiratory tract infections
increased breathing and heart rates during acute episodes
chronic issues: heart-related complications , pulmonary hypertension, peripheral oedema, R sided HF
can cause cyanosis in severe cases
Chronic Bronchitis: Diagnosis
through medical history and physical exam.
pulse oximetry to assess blood oxygen saturation
blood tests for additional info, especially for patients presenting fever symptoms
for patients with purulent productive cough, a sputum culture is typically advised
chest x-rays for chronic gas trapping and signs of heart failure
pulmonary function tests showing obstructive pattern
arterial blood gas analysis in severe cases for acidosis (acid in the blood) and gas levels
Chronic Bronchitis: Management
Focus on symptom relief and preventing acute exacerbations.
Use of bronchodilators and mucolytics.
Supplemental oxygen during hypoxic episodes.
Beta-2 agonists (a bronchodilator) to reduce wheezing and dyspnoea.
Staying well-hydrated to reduce secretion viscosity.
Avoid expectorant agents in acute bronchitis - they tend to increase mucus production
Quitting smoking is crucial.
Corticosteroids for inflammation reduction.
Antibiotics for secondary bacterial infections.
Emphysema: Background
Incurable condition often linked to smoking.
Leads to enlargement of terminal bronchioles and alveoli damage.
Results in loss of lung elasticity.
Emphysema: Aetiology and Pathophysiology
Arises from the imbalance of the enzyme that protects the alveoli
Destroys elastin and collagen, reducing lung elastic recoil and alveolar pressure.
Alveolar spaces become permanently enlarged.
Smoking initiates or worsens damage by triggering inflammation.
Emphysema: Risk factors
Exposure to tobacco smoke, occupational dusts, pollution.
Male gender.
Age over 50 years.
Frequent respiratory infections.
Low socioeconomic status.
Poor nutrition.
Respiratory comorbidities
Emphysema: clinical manifestations
Gradual progression, often unnoticed until significant respiratory compromise.
Symptoms include frequent URIs, dyspnea, wheezing, tachypnoea, productive coughing.
Dyspnea initially during exertion, progressing to minimal effort.
Chronic gas trapping leads to barrel chest appearance.
Weight loss and fatigue due to chronic dyspnoea and increased respiratory effort.
Seasonal exacerbations can cause severe respiratory dysfunction.
Depression common due to social isolation and decreased mobility
Emphysema: Diagnosis
Detailed history and physical examination.
Blood tests for arterial blood gas (ABG) analysis and full blood count.
ABG analysis may show respiratory acidosis progressing to metabolic alkalosis, low blood oxygen, and high blood carbon dioxide levels.
X-rays reveal long lung fields and flattened diaphragm.
Lateral chest X-rays over time show barrel chest development.
Sputum samples and respiratory function tests reveal obstructive pattern in FEV1 (forced expiratory volume in 1 second)
Emphysema: Management
Focuses on slowing disease progression and preventing exacerbations.
Key interventions include:
Stopping smoking.
Annual flu vaccinations.
Minimizing exposure to pollutants and passive smoking.
Oxygen therapy and diuretics.
Intermittent positive pressure ventilation in severe cases.
Managing weight loss and muscle wasting through diet and exercise.
Addressing osteoporosis risks, especially with corticosteroid use.
Pulmonary Fibrosis: Aetiology and Pathophysiology
Condition where lung tissue becomes scarred and damaged, leading to breathing difficulties.
Damage from prolonged exposure to toxins like silica dust and asbestos fibres.
Can develop from medical conditions like dermatomyositis (muscle weakness and skin rash), scleroderma (hardening and thickening of skin), and pneumonia.
Certain chemotherapy drugs and medications can contribute to lung damage.
Lung tissue becomes thicker and stiffer, hindering lung function and causing shortness of breath.
Idiopathic pulmonary fibrosis has unknown causes, possibly linked to viruses, smoking, and genetics.
Key risk factors include:
Older age and male gender
Smoking habits.
Exposure to pollutants in work environments (e.g., mining, farming).
Previous cancer treatments.
Genetic predispositions.
Pulmonary Fibrosis: Clinical Manifestations
Symptoms vary but often include:
Shortness of breath.
Persistent dry cough.
Fatigue and unexplained weight loss.
Muscle and joint aches.
Clubbing of fingers and toes.
Progression and severity differ among individuals.
Acute exacerbations can cause sudden, severe increases in symptoms like breathlessness
Pulmonary Fibrosis: Diagnosis
Thorough physical exam and review of medical and family history.
Imaging tests: chest X-rays, CT scans, echocardiograms.
Pulmonary function tests, pulse oximetry, exercise capacity tests, and arterial blood gas analysis.
Invasive tests: lung biopsy, bronchoalveolar lavage, blood tests for liver and kidney function.
Pulmonary Fibrosis: Management
Treatment aims to alleviate symptoms and enhance life quality.
Medications and therapies, including antibiotics and corticosteroids, during acute exacerbations.
Mechanical ventilation for severe cases.
Lung transplantation for certain individuals.
Pulmonary Fibrosis: Complications
Possible complications include:
Pulmonary hypertension.
Right-sided heart failure.
Respiratory failure.
Lung cancer.
Pulmonary blood clots.
Pneumothorax.
Lung infections.
Acute Bronchitis: Aetiology and Pathophysiology
Primarily caused by viral infections following an upper respiratory tract infection.
Bacterial infections can also cause acute bronchitis (more susceptible in individuals with chronic lung conditions e.g. emphysema)
Infection triggers an inflammatory response, increasing mucus production.
Leukocytes damage the ciliated epithelium in the bronchi, overwhelming the mucociliary escalator.
Leads to coughing fits and potentially bronchospasm, further obstructing the bronchi
