COPD Flashcards
What is copd
- is a non-reversible, long term deterioration in air flow through the lungs caused by damage to lung tissue.
- almost always the result of smoking
- The damage to the lung tissues causes an obstruction to the flow of air through the airways making it more difficult to ventilate the lungs and making them prone to developing infections
what is the presentation of copd
- chronic shortness of breath
- cough
- sputum production
- wheeze
what investigations to diagnose copd?
• Clinical presentation • Spirometry: FEV1/FVC ratio <0.7 • Chest X-ray: o Hyperinflation o Bullae: if large, may mimic pneumothorax o Flat hemidiaphragm o Important to exclude lung cancer • FBC: exclude secondary polycythaemia • BMI
what is the MRC dyspnoea scale
- Grade 1 – Breathless on strenuous exercise
- Grade 2 – Breathless on walking up hill
- Grade 3 – Breathless that slows walking on the flat
- Grade 4 – Stop to catch their breath after walking 100 meters on the flat
- Grade 5 – Unable to leave the house due to breathlessness
what is FEV1 and FVC
- The overall lung capacity is measured by forced vital capacity (FVC)
- ability to quickly blow air out is measured by the forced expiratory volume in 1 second (FEV1).
how do you assess severity of copd
Post-bronchodilator FEV1/FVC FEV1 (of predicted) Severity < 0.7 > 80% Stage 1 - Mild** < 0.7 50-79% Stage 2 - Moderate < 0.7 30-49% Stage 3 - Severe < 0.7 < 30% Stage 4 - Very severe
what other investigations do you do?
- Chest x-ray to exclude other pathology such as lung cancer.
- Sputum culture to assess for chronic infections such as pseudomonas.
- ECG and echocardiogram to assess heart function.
- CT thorax for alternative diagnoses such as fibrosis, cancer or bronchiectasis.
- Serum alpha-1 antitrypsin to look for alpha-1 antitrypsin deficiency. Deficiency leads to early onset and more severe disease.
- Transfer factor for carbon monoxide (TLCO) is decreased in COPD. It can give an indication about the severity of the disease and may be increased in other conditions such as asthma.
what is the long term management of stable copd
- stop smoking
- one off pneumococcal + annual influenza
- pulmonary rehab (grade 3+)
Stage 1: SABA or SAMA
Stage 2 (if no asthmatic features): SABA as required, LABA + SAMA regularly
Stage 2 (if asthmatic features): SABA/SAMA as req., LABA + ICS regularly
Stage 3: SABA as req., LABA+LAMA+ICS regularly
what abx prophylaxis do you give for stable copd. what is the associated risk? how do you investigate?
azithromycin
long QT
ECG
What are additional options for severe copd management (5)
- Nebulisers (salbutamol and/or ipratropium)
- Oral theophylline
- Oral mucolytic therapy to break down sputum (e.g. carbocisteine)
- Long term prophylactic antibiotics (e.g. azithromycin)
o ECG to exclude QT prolongation – azithromycin can cause - Long term oxygen therapy at home
o used for severe COPD that is causing problems such as chronic
o hypoxia, polycythaemia, cyanosis or heart failure secondary to pulmonary hypertension (cor pulmonale).
o can’t be used if they smoke due to fire hazard.
what are the most common causes of copd exacerbations (bacterial and viral)
Bacterial: o Haemophilus influenza
o Streptococcus pneumoniae
o Moraxella catarrhalis
Viral: Human rhinovirus
how do you manage copd exacerbations (4)
• Prednisolone 30mg once daily for 5 days
• Increase frequency of inhalers or home nebulisers
• Antibiotics if there is evidence of infection (Amoxicillin or doxycycline)
Physiotherapy can help clear sputum
how do you manage severe copd exacerbations
- IV aminophylline
- Non-invasive ventilation (NIV)
- Intubation and ventilation with admission to intensive care
- Doxapram can be used as a respiratory stimulant where NIV or intubation is not appropriate
what is the target for 02 therapy in copd
- If retaining CO2 aim for oxygen saturations of 88-92% titrated by venturi mask
- If not retaining CO2 and their bicarbonate is normal (meaning they do not normally retain CO2) then give oxygen to aim for oxygen saturations > 94%
what might you see in FBC in copd and what is it due to
secondary polycythaemia due to chronic hypoxia
What factors improve survival in patients with copd?
smoking cessation - the single most important intervention in patients who are still smoking
long term oxygen therapy in patients who fit criteria
lung volume reduction surgery in selected patients
what determines criteria if patients have asthmatic features of copd
- any previous, secure diagnosis of asthma or of atopy
- a higher blood eosinophil count - note that NICE recommend a full blood count for all patients as part of the work-up
- substantial variation in FEV1 over time (at least 400 ml)
- substantial diurnal variation in peak expiratory flow (at least 20%)
what are features of cor pulmonale? (4)
management?
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
When should LTOT be considered?
o Very severe airflow obstruction (FEV1 <30% predicted, consider for 30-49%) o Cyanosis o Polycythaemia o Peripheral Oedema o Raised jugular venous pressure o Oxygen saturations = 92%
What assessment is done?
who is given LTOT?
• Assessment done by: measuring ABG 2x 3 weeks apart • Offer to: p02 <7.3kPa • or 7.3-8.2 kPa with: o secondary polycythaemia o peripheral oedema o pulmonary htn
What risk assessments are done for LTOT
• Risk assessment: falls from tripping over equipment, risk of burns and fires, increased risk of these for people living in homes where people smoke
When should you use NIV (BiPAP) in COPD?
- in severe cases
- where there is respiratory acidosis pH 7.25-7.35
- following full medical treatment
i. e Type 2 respiratory failure
what should you do if severe copd exacerbation with pH <7.25
- trial NIV
but should also be considered for invasive ventilation
