COPD Flashcards
What is COPD?
- COPD is characterised by Airflow Obstruction.
- The airflow obstruction is usually progressive, not fully reversible and does not change markedly over several months.
What can cause COPD?
The disease is caused by long term exposure to toxic particles and gases but predominantly caused by smoking.
What occurs in COPD to the respiratory System?
- Mucous gland hyperplasia
- Loss of Cilial function
- Emphysema
- Chronic inflammation and fibrosis of small airways
What occurs as a result of Respiratory System changes in COPD?
- Airflow limitation is due to loss of elasticity, inflammation and scarring which cause small airway narrowing, and mucus secretion blocking airways.
- Each of these causes air trapping, leading to hyperinflation of lungs, V/Q mismatch and increase work of breathing and breathlessness
What is emphysema?
- Alveolar wall destruction causes irreversible enlargement of air spaces distal to the terminal bronchioles.
- This leads to expiratory airflow limitation and air trapping.
- The lung capacity also increases.
What is the effect of COPD on the O2 in blood?
- V/Q mismatch due to damage and mucus plugging of smaller airways from chronic inflammation as well as rapid closure of smaller airways in expiration due to loss of elastic support.
- Mismatch lead to fall in arterial O2 and increased work of respiration.
What is the effect of COPD on the CO2 in blood?
- V/Q mismatch affect CO2 less.
- Increasing alveolar ventilation to correct hypoxia.
- PaCO2 increases when patient fail to maintain respiratory effort.
- In short term, the effect is stimulation of respiration but in longer term patient become insensitive to CO2 and comes to depend on hypoxaemia to drive ventilation
- Such patient appear less breathless and retain fluid as well as increase erythrocyte production due to renal hypoxia.
- They become bloated, cyanosed and plethoric.
- Administration of oxygen to stop hypoxaemia can make situation worse due to decreased respiratory drive
What are the causes of COPD?
- Smoking
- Inherited α-1-antitrypsin deficiency
- Industrial exposure, e.g. soot
- Infections
What are symptoms of COPD?
- Productive white or clear sputum
- Wheeze
- Breathlessness. Can be severe in advanced cases with onset upon mild exercise such as putting on clothes
- Smoker’s cough
- Colds seem to ‘settle on the chest’ and frequent infective exacerbations occur with purulent sputum
- Systemic effect include hypertension, osteoporosis, depression, weight loss, and reduced muscle mass with general weakness
What can affect the symptoms in COPD?
Symptoms can be worsenedd by cold or damp weather and atmospheric pollution
What are the examination signs for COPD?
Mild disease
- There may be quiet wheezes throughout chest or nothing
Severe Disease
- Patient is tachypnoiec with prolonged expiration.
- Acccesory muscle of respiration are used and possible intercostal indrawing on inspiration, pursing of lips on expiration
- Chest expansion is poor, lungs are hyperinflated and loss of normal carida and liver dullness on percussion
- Patients responsive to CO2: usually breathless and rarely cyanosed
- Patient’s unresponsive to CO2: often oedematous and cyanosed but not breathless.
What can present with hypercapnia induced by COPD?
- Bounding pulse
- Peripheral vasodilation
- Course flapping tremor.
- Severe hypercapnia can cause confusion and drowsiness
What are some investigations for COPD?
- Lung function tests
- Chest X-ray
- High Resolution CT
- Alpha-1 Antitrypsin (Genotype worth measuring in premature disease or lifelong non-smokers)
- Haemoglobin level and Packed cell volume
- Blood Gases
- ECG: P wave tall
- Echocardiogram
What are some lung function tests findings in COPD?
- Peak Expiratory Flow Rate is low
- FEV1:FVC ratio reduced
- CO gas transfer low in significant emphysema
What are CXR findings in COPD?
Can be normal but classic features can be:
- Overinflation of lung with low flattened diaphragms and sometimes the presence of large bullae.
- Blood vessels may be pruned with large proximal vessels and relatively little blood visible in peripheral lung fields
Why are Haemoglobin levels and Packed cell volumes measured?
Can be elevated as result of persistent hypoxaemia
What are management principles in regards to COPD management?
- COPD care bundle
- Smoking cessation
- Annual influenza vaccination
- Single dose of polyvalent pneumococcal polysaccharide vaccine
- Pulmonary Rehabilitation
- Drug Therapy
- Diet
- Lung reduction surgery in select cases
What is Pulmonary Rehabilitation?
MDT 6-12 week programme of:
- Supervised exercise
- Unsupervised home exercise
- Nutritional advice
- Disease education
Why do patient require Pulmonary Rehabilitation?
- COPD patient with COPD avoid exercise and physical activity
- May lead to vicious cycle of increasing social isolation and inactivity leading to worsening of symptoms
- Pulmonary Rehabilitation aims to break this cycle
- Pulmonary rehabilitation to all people who view themselves as functionally disabled by COPD (usually Medical Research Council [MRC] grade 3 and above)
What is the treatment progression of drug therapy for patients with COPD for dilation of airway?
Bronchodilators
-
1st line: SABA and SAMA
- If no asthmatic features/features suggesting steroid responsiveness, add a long-acting beta2-agonist (LABA) + long-acting muscarinic antagonist (LAMA)
- If asthmatic features/features suggesting steroid responsiveness, add LABA and ICS If patients remain breathless or have exacerbations offer triple therapy i.e. LAMA + LABA + ICS.
- NICE recommends combined inhalers
- Recommendation of theophylline only after trials of short and long-acting bronchodilators or to people who cannot used inhaled therapy
What are the criteria for determining if a patient has asthmatic/steroid responsive features?
- Any previous, secure diagnosis of asthma or of atopy
- A higher blood eosinophil count
- Substantial variation in FEV1 over time (at least 400 ml)
- Substantial diurnal variation in peak expiratory flow (at least 20%)
How are corticosteroid initiated in COPD?
- Used in moderate/severe COPD.
- Trial of corticosteroids always indicated.
- Prednisolone 30 mg daily for 2 weeks and then inhaled corticosteroids given.
- Should measure to check if airflow limitation improved before prescribing inhaled
What other medications are given in COPD?
- Antibiotics given in acute episodes
- Mucolytic Agents considered in patients with chronic productive cough and continued if symptoms
- Diuretics
- Phosphodiesterase type 4 inhibitors
Why is long term oxygen therapy helpful and how is it utilised?
- Extended periods of hypoxia cause renal and cardiac damage (can be prevented by LTOT)
- Patients who receive LTOT should breathe supplementary oxygen for at least 15 hours a day. Oxygen concentrators are used to provide a fixed supply for LTOT.
What would indicate assessment for LTOT is needed?
- Very severe airflow obstruction (FEV1 < 30% predicted). Assessment should be ‘considered’ for patients with severe airflow obstruction (FEV1 30-49% predicted)
- Cyanosis
- Polycythaemia
- Peripheral oedema
- Raised jugular venous pressure
- Oxygen saturations less than or equal to 92% on room air
How is the need for LTOT assessed?
- Done by measuring arterial blood gases on 2 occasions at least 3 weeks apart in patients with stable COPD on optimal management.
What are indications based on test results for giving LTOT?
- Offer LTOT to patients with a pO2 of < 7.3 kPa or
- To those with a pO2 of 7.3 - 8 kPa and one of the following:
- Secondary polycythaemia
- Peripheral oedema
- Pulmonary hypertension
What are considerations to make when giving LTOT?
- Patients must be non-smokers and not retain high levels of CO2. The risks of burns and fires, and the increased risk of these for people who live in homes where someone smokes (including e‑cigarettes)
- O2 needs should be balanced with loss of independence and reduced activity which may occur
- Risk of falls from tripping over the equipment
What are complications of COPD?
- Respiratory Failure
- Pulmonary hypertension
- Cor pulmonale
What are features of Cor Pulmonale and treatment?
- Features include
- Peripheral oedema
- Raised jugular venous pressure
- Systolic parasternal heave, loud P2
- Use a Loop Diuretic for oedema, consider long-term oxygen therapy
- ACE-inhibitors, calcium channel blockers and alpha blockers are not recommended by NICE
How can Antitrypsin deficiency be treated?
- Antitrypsin replacement
- Weekly or monthly infusions of α1 -antitrypsin have been recommended for patients with serum levels <310 mg/L and abnormal lung function.
What are some conditions that need to be treated as a result of COPD?
-
Secondary polycythaemia.
- This requires venesection if the PCV is >55%.
- Heart failure
-
Pulmonary hypertension.
- This can be partially relieved by the use of oral β-adrenergic agonists, such as salbutamol (4 mg three times daily), but the long-term value is unknown.
-
Sensation of breathlessness
- This can be reduced by either promethazine 125 mg daily or dihydrocodeine 1 mg/kg by mouth.
How does Air Travel have to be managed in COPD?
Patients whose saturation drops below 85% within 15 minutes should be advised to contact their airline to request supplemental oxygen during their flight.
What are investigations to consider in COPD exacerbations?
- Arterial blood gases
- Chest X-ray
- Electrocardiogram
- Full blood count and urea and electrolytes
- Theophylline level on admission (if the patient is on theophylline)
- Sputum microscopy and culture if purulent
- Blood cultures if pyrexial
What are the types of COPD exacerbations?
- Infective (Change in sputum volume / colour or Fever, Raised WCC +/- CRP)
- Non-infective
What is the management of an exacerbation of COPD?
- ABCDE approach
- Oxygen with aim for SaO2 88-92% being guided by ABGs.
- Start with Nasal Cannula NEBs – Salbutamol and Ipratropium
- If the response to nebulised bronchodilators is poor consider IV aminophylline
- Steroids: Prednisolone 30mg STAT and OD for 7 days
- Antibiotics if raised CRP / WCC or purulent sputum CXR
- Consider NIV if Type 2 respiratory failure and pH 7.25-7.35
- If pH <7.25 consider ITU referral
- Chest Physiotherapy
