6 - Asthma and COPD Flashcards
What is the pathophysiology of asthma?
- Chronic reversible airway obstruction that responds to bronchodilators
- Increased airway responsiveness and narrowing to stimuli
- Airway narrowing: bronchial muscle contraction, mucosal swelling due to mast cells and basophils releasing mediators, increased mucus production
What are the signs and symptoms of asthma?
Symptoms: Intermittent dyspnea, wheeze, nocturnal cough, sputum
Signs: tachypnea, audible wheeze, hyperinflated chest
What are some differentials for a wheeze apart from asthma>
If a patient presents with asthmatic like symptoms, what are some questions you need to ask in the history?
- Triggers: e.g cold air, exercise, pets, smoking, NSAIDs
- Diurnal variation: worse at night?
- Exercise tolerance
- Disturbed sleep?
- Other atopic diseases?
- Job?
- Days per week off school or work?
When is asthma classified as mild, moderate, severe, life threatening and near fatal?
What does PEF depend on?
- Age
- Gender
- Height
What is the emergency management for acute asthma?
- Aim for sats of 94-98% with oxygen. If <92% ABG needed
- 5mg Salbutamol NEB and repeat after 15 minutes
- 40mg oral prednisolone or IV hydrocortisone
How do you initially diagnose asthma?
What investigations should you do if a patient is having an acute episode of asthma?
- PEF
- Sputum culture and ?Blood culture
- FBV, U+Es, CRP
- ABG
- CXR to exclude infection or pneumonthorax
What investigations can you do for a patient with chronic asthma?
- PEF monitoring (diurnal variation with >20% variability on >3days in 2 weeks)
- CXR may have hyperinflation
- Spirometry (obstructive pattern, ratio<70% with bronchodilator reversibility)
- Skin prick test to identify allergens
- Metacholine or Histamine challenge
What is the criteria that needs to be fulfilled for a safe discharge after an asthma exacerbation?
What factor means a patient with asthma will be responsive to steroids?
Eosinophillia
Apart from asthma, what are some diseases that cause eosinophilia?
What are some common asthma triggers?
- Smoking
- URTI
- Pollen
- Pets
- Exercise
- Cold air
- Aspirin and beta blockers
- Stress
- Occupational exposures
What is the general management of asthma in a primary care setting?
- Avoid triggers
- Stop smoking
- PEF monitoring
- Self management plan for emergencies
- BTS pharmacological management
- Treat correct inhaler technique
What is the pharmocological management of asthma using the BTS guidelines?
Start at step most appropriate to severity, moving up or down. Can move down after >3months of control
1st: SABA reliever when needed
2nd: Add low dose ICS
3rd: Add LABA with the ICS or LTRA or oral theophylline
4th: Increase ICS
5th: Add regular oral prednisolone with specialist input
What signifies poor asthma control?
- 3 or more days a week with symptoms
- 2 or more days a week with use of a rescue SABA inhaler
- 1 or more nights a week with awakening due to asthma
Need to check inhaler technique, inhaler adherance, smoking and self management plan
How do beta-agnonists help asthmatics and what are the side effects of these?
Relax bronchial smooth muscle within minutes by increasing cAMP
SE: tachyarrhythmias, hypokalaemia, tremor, paradoxical bronchospasm
How do inhaled corticosteroids help asthma and what are the side effects of these?
Act over days to decrease bronchial mucosal inflammation
Used inhaled to minimise systemic effects
SE: usual steroid side effects, oral thrush so rinse mouth adter use
How does aminophylline help asthmatics and what are some side effects of this?
Metabolised to theophylline. Inhibits phosphodiesterase so decreases bronchoconstriction.
Used as prophylaxis at night
SE: arrhythmias, GI upsets, seizures
Monitoring: theophylline levels, ECG monitoring
How do LTRA help asthmatics?
Block the effects of leukotrienes by antagonising the CystLT1 receptor
What is the definiton of COPD and what are the causes of it?
Progressive airflow obstruction that is not reversible
Chronic bronchitis + Emphysema
Causes: smoking, alpha antitrypsin deficiency, industrial exposure e.g soot
What is the definiton of chronic bronchitis and emphysema?
Chronic Bronchitis: Cough and sputum production on most days for 3 months in 2 successive years
Emphysema: Enlarged air spaces with destruction of alveolar walls and loss of elasticity. Visualised on CT and diagnosed histologically
What is the pathophysiology of COPD?
- Mucous gland hyperplasia
- Loss of cilia function
- Emphysema
- Chronic inflammation and fibrosis of small airways
What are the signs and symptoms of COPD?
Symptoms: cough, sputum, dyspnea, wheeze
Signs: barrel chest, use of accessory muscles, hyperinflation, decreased chest expansion, hyperresonant
What are some complications of COPD?
- Pneumothorax due to ruptured bullae
- Polycythemia
- Acute exacerbations
- Cor pulmonale
- Lung carcinoma
What investigations can you do if you suspect COPD and what will the results be?
- FBC: increased PCV
- CXR: hyperinflation with flat diaphragm, large pulmonary arteries
- CT: bronchial wall thickening, scarring, air space enlargement
- ECG: right ventricle hypertrophy
- ABG: low O2 and hypercapnia
- Spirometry: obstructive pattern (FEV1/FVC <70%)
What healthcare professionals are involved in the MDT team for COPD patients?
The severity of COPD needs to be known for therapy and prognosis. How is the severity of COPD assessed?
BODE index
- Looks at BMI, airflow obstruction, dyspnea and exercise capacity
- Predicts severity and number of exacerbations
GOLD
- Mild, moderate, severe and very severe based on post bronchodilator FEV1% oredicted
How is chronic COPD managed in general ?
- Confirm diagnosis with spirometry
- Smoking cessation
- Pulmonary rehabilitation
- Pharmacology
- Diet and weight loss if high BMI
- Pneumococcal and flu vaccine
- Depression screening
- LTOT if appropriate
- Lung volume reduction if appropriate
What is the inhaled pharmacological treatment for COPD?
1st: offer all patients SABA or SAMA
2nd: if non-asthmatic features LABA/LAMA, if asthmatic features LABA/ICS. If giving LAMA stop SAMA. Continue SABA
3rd: Triple therapy of LABA/LAMA/ICS. Use if 1 severe exacerbation (hospitalisation) or 2 moderate exacerbations (abx/steroids needed) in a year
Apart from LABA, LAMA, SABA and ICS, what can be offered to COPD patients?
Prophylactic abx: Can give azithromycin to non-smokers on all treatments with 4 or more exacerbations a year. Do sputum culture and sensitivity, LFTs and ECG (long QT) before starting. Review every 3-6 months
Roflumilast: phosphodiesterase type-4 inhibitor, used in addition to bronchodilator therapy with chronic bronchitis
Mucolytics: patients with chronic cough and sputum
Modified release theophylline: only if cannot use inhaled therapy
LTOT: see future flashcard
What patients with COPD qualify for long term oxygen therapy and why is this offered?
- Given if pO2 consistently below 7.3kPa or below 8kPa with Cor Pulmonale. Do 2 separate ABGs
- Must be non-smokers and not be a CO2 retainer. Also used for terminally ill patients
- Give continuous pO2 for at least 16hours a day for 3 year survival improvement of 50% as long term hypoxia can cause renal and cardiac damage
What is pulmonary rehabilitation used for in COPD patients?
Many COPD patients avoid physical activity because of breathlessness.
6-12 week programme to increase exercise and break cycle.
Mix of supervised exercise, unsupervised home exercise, nutritional advice and disease education
What COPD patients are offered lung volume reduction surgery?
Need CT to see if candidate:
- Recurrent pneumothoraces
- Isolated bullous disease
Can also be offered endobronchial valve and transplant
What are the goals of pulmonary rehabilatation for COPD patients?
- Alleviate symptoms
- Improve exercise tolerance
- Restore functional capabilities
- Peer support
- Disease education
How is a COPD exacerbation managed?
- Salbutamol and Iptratropium Bromide NEB
- Controlled oxygen therapy
- PO prednisolone
- Abx if evidence of infection
- IV aminophylline if nebulisers didn’t work
- Consider physiotherapy and NIPPV
What interventions improve prognosis/mortality for patients with COPD?
- Smoking cessation
- Lung reduction surgery
- LTOT
What are some drugs that can cause a cough?
- ACEi
- Beta blockers
- NSAIDs/Aspirin
- Methotrexate (pulmonary fibrosis)
What are some common causes of dry cough?
What is an idiopathic cough and when can this diagnosis be made?
Cough lasting >3 weeks in association with normal clinical exam, normal CXR and high resolution CT scan, normal lung function tests, negative methacholine inhalation test, normal PEF, normal sputum differential eosinophil count (<2%), and no GORD
What features may help differentiation a case of CAP from TB?
COME BACK TO
What are some differentials for acute asthma?
- Acute bronchitis
- Pneumonia
- Foreign body
- PE
What is controlled oxygen?
- Avoiding unneccessary over oxygenation
- ABG if sats<92%
What is included in an asthma self-management plan?
- What to do normally
- What to do if it gets worse
- When to seek help
How does oral prednisolone vary for a COPD and an Asthma exacerbation?
COPD 30mg
Asthma 40mg
What is included in the COPD care bundle?
When should you do an ABG in asthma?
Only when sats fall below 92%!!!!
When should you use IV salbutamol in acute asthma?
- Airway obstruction so cannot use nebuliser
- Tracheostomy making nebuliser difficult
Why is the half life of salbutamol important?
Peak onset of action 40 minutes after administration so do not need to give back to back if no response initially!
Can put them into acidosis
How should a primary pneumothorax be treated?
How should a secondary pneumothorax be treated?
How is an iatrogenic pneumothorax treated?
What discharge advice should you give a patient after a pneumothorax?
