PBL Topic 2 Case 3 Extra Flashcards
Identify two conditions associated with COPD
- Emphysema
- Chronic Bronchitis
What is the main cause of COPD in developed countries?
- Smoking
- Which accounts for 90% of cases in developed countries
What is the main cause of COPD in developing countries?
- Smoke from biomass fuels
Outline the pathophysiology of COPD
- Increased numbers of goblet cells
- Inflammation with infiltration of CD8 cells
- Scarring, thickening and fibrosis of the airways
- Ulceration and squamous cell metaplasia replacing columnar cells
What is emphysema?
- Loss of elasticity
- Air trapping (enlargement of air spaces)
Outline the two abnormalities of Va/Q in emphysema
- Obstruction results in unventilated alveolar
- Va/Q approaching zero
- Resulting in serious physiologic shunt
- Destruction of alveolar walls results in inadequate perfusion
- Va/Q approaches infinity
- Resulting in serious physiologic dead space
Identify three types of emphysema
- Centri-acinar emphysema
- Pan-acinar emphysema
- Irregular emphysema
Describe centri-acinar emphysema
- Emphysema centred around the respiratory bronchioles
Describe pan-acinar emphysema
- Emphysema that affects the entire acinus
Which type of emphysema is associated with a1-Antitrypsin deficiency?
- Pan-acinar emphysema
Describe the ‘pink puffer’
- Individuals are breathless but not cyanosed
- Individuals are typically thin
- Normal PaCO2
Describe the ‘blue bloater’
- Individuals are cyanosed but rarely breathless
- Individuals are oedematous peripherally
- High PaCO2
Explain why ‘blue bloaters’ are not typically breathless
- Patients become insensitive to CO2
- Patients then become dependent on low O2 to drive their ventilation
Explain why oxygen administration should be avoided in ‘blue bloaters’
- Patients are dependent on low O2 to drive their ventilation
- Oxygen therapy increases O2
- Thus reducing their respiratory drive
Outline the symptoms of COPD
- Productive cough with sputum
- Frequent infective exacerbations with purulent sputum
- Wheeze and breathlessness
- All of which are worsened by cold, foggy weather and atmospheric pollution
Outline the signs of COPD
- Hyper-inflated ‘barrel’ chest
- Pursed lip breathing
- Raised JVP, peripheral oedema
Outline a sign of COPD that can be detected using auscultation
- Reduced breath sounds
- Wheeze
Outline a sign of COPD that can be detected using percussion
- Cardiac apex not palpable
- Loss of cardiac dullness
Outline the pathophysiology of Cor Pulmonale
- Fluid overload due to hypoxic kidney
- Pulmonary valve incompetence
- Tricuspid incompetence
Outline the clinical features of Cor Pulmonale
- Elevated jugular venous pressure
- Peripheral oedema
- Ascites
- Liver swelling
- Parasternal heave
- Loud pulmonary second sound
When is COPD diagnosed?
- Spirometry demonstrating airflow obstruction
- FEV1 is less than 80% predicted
- FEV1/FVC ratio is less than 70%
How is hyperinflation tested for in COPD?
- Helium dilation technique
- Low gas transfer factor
How is respiratory failure diagnosed?
- PaO2 < 8 kPa
- PaCO2 > 7 kPa
Explain why pulmonary hypertension occurs in respiratory failure
- Constriction of pulmonary arterioles
- Due to alveolar hypoxia and hypercapnia
What are the targeted oxygen saturations in respiratory failure? How do these differ in patients with COPD?
- 94% - 98%
- In COPD: 88% - 92%
In nocturnal hypoxia, during which phase of sleep is PaO2 particularly affected?
- During the REM phase of sleep
- PaO2 may fall as low as 2.5 kPa
Outline the pathophysiology of nocturnal hypoxia
- Inhibition of intercostal and accessory muscles
- Shallow breathing in REM sleep
- An increase in upper airway resistance because of a reduction in muscle tone
Explain why patients with nocturnal hypoxia suffer from daytime sleepiness
- Each episode is terminated by arousal of sleep
- This occurs hundreds of times per night
- So the amount of sleep is reduced
Explain why sleeping tablets should never be given in patients with nocturnal hypoxia
- Sleeping tablets will further reduce respiratory drive
Identify the treatment used in nocturnal hypoxia
- Non invasive positive pressure ventilation
- Administered with BiPAP
Outline how BiPAP works
- Inspiratory to provide inspiratory assistance
- Expiratory to prevent alveolar closure,
- Improves ventilation during sleep
- Allows respiratory muscles to rest at night.
Outline the treatment of COPD
- Smoking cessation
- Pulmonary rehabilitation
- Bronchodilators e.g. salbutamol and ipratropium
- Corticosteroids
- Antibiotics
- Oxygen therapy
Outline three examples of surgery used as additional measures in COPD
- Surgical bullectomy
- Lung volume reduction
- Single lung transplantation
How is prognosis of COPD calculated?
- BODE Index
- B = BMI
- O = Airflow obstruction
- D = Dyspnoea
- E = Exercise capacity
What is bronchiectasis?
- Mucociliary transport is impaired
- Resulting in frequent infections
- Resulting in dilated airways that are inflamed, thickened and irreversibly damaged
Identify two different causes of bronchiectasis
- Congenital defect such as cystic fibrosis
- Destructive infection such as tuberculosis
Identify 6 clinical features of bronchiectasis
- Clubbing
- Crackles
- Breathlessness
- Sputum
- Halitosis
- Haemoptysis
What will a CXR show in bronchiectasis?
- Thickened, dilated bronchi
- Cysts containing fluid
What will a sputum culture show in bronchiectasis?
- Staphylococcus aureus
- Pseudomonas aeruginosa
- H. influenza
- Anaerobes
Why are sinus x-rays carried out in bronchiectasis?
- 30% of bronchiectasis patients have rhinosinusitis
Why are serum immunoglobulins investigated in bronchiectasis?
- 10% of patients have IgA deficiency
Outline the treatments used in bronchiectasis
- Postural drainage
- Flucloxacillin for Staphylococcus aureus
- Ceftazidime for Pseudomonas aeruginosa
- Blood transfusion, embolisation and surgical resection for haemoptysis
Identify three complications of bronchiectasis
- Pulmonary Tuberculosis
- Pneumonia
- Pneumothorax
What is Pneumonia?
- Inflammation of the substance of the lungs
Outline the three classifications of Pneumonia
- Community-Acquired
- Hospital-Acquired
- Immunocompromised Hosts
What type of person is most likely to be affected by CAP?
- Those at the extremities of age
Which organism is responsible for causing CAP?
- Pneumococcus
Identify two examples of drugs given in mild CAP infections
- Amoxicillin
- Clarithromycin
What is Roflumilast?
- Phosphodiesterase Type 4 Inhibitor
What is Carbocysteine?
- Antimucolytic
