COPD Flashcards
What is COPD?
COPD is a non-reversible, long-term deterioration in airflow through the lungs caused by damage to lung tissue.
COPD patients are susceptible to exacerbations that worsen lung function. What triggers these exacerbations?
Infections (Infective Exacerbations)
What kind of patient presentations suggest COPD?
Long-term smoker presenting with chronic shortness of breath, cough, sputum production, wheeze and recurrent respiratory infections, particularly in winter
Differential diagnoses that can be considered while investigating COPD include
- lung cancer
- heart failure
- fibrosis
Does COPD cause clubbing?
No
Would you expect to see hemoptysis or chest pain among COPD patients?
It is unusual and should be further investigated
List out the MRC Dyspnoea scale grades from NICE
1 - Breathless on strenuous exercise
2 - Breathless on walking up hill
3 - Breathlessness that slows walking on the flat
4 - Stop to catch their breath after walking 100 meters on the flat
5 - Unable to leave the house due to breathlessness
How’d you diagnose COPD?
Clinical presentation and spirometry
The severity of airflow obstruction can be graded using FEV1. List the stages.
1 - FEV1 > 80% of predicted
2 - FEV1 50-79% of predicted
3 - FEV1 30-49% of predicted
4 - < 30% of predicted
Additional investigations that can be conducted to help with COPD diagnosis and management include:
- Chest X-Ray
- Full blood count
- Body Mass Index
- Sputum Culture
- ECG and echocardiogram
- CT Thorax
- Serum alpha-1-antitrypsin
- Transfer factor for carbon monoxide (TLCO)
What is the purpose of chest X-Ray in COPD diagnosis?
To exclude other pathology (i.e. lung cancer)
What is the purpose of full blood count in COPD diagnosis?
For polycythaemia or anaemia. Polycythaemia (raised haemoglobin) is a response to chronic hypoxia.
What is the purpose of BMI in COPD diagnosis?
Baseline to later assess weight loss (e.g. cancer or severe COPD) or weight gain (e.g. steroids)
What is the purpose of sputum culture in COPD diagnosis?
To assess for chronic infections such as pseudomonas
What is the purpose of CT thorax in COPD diagnosis?
Alternative diagnoses such as fibrosis, cancer, or bronchiectasis
What is the purpose of TLCO in COPD diagnosis?
Decreased in COPD. It can give an indication about the severity of the disease and may be increased in other conditions such as asthma
Step 1 of Long-term COPD management
Short-acting bronchodilators such as::
- Beta-2 agonists (salbutamol or terbutaline)
- Short-acting muscarinic (ipratropium bromide)
Step 2 of Long-term COPD management if the patient does not have asthmatic or steroid-responsive features
Combine LABA and LAMA (i.e. Anoro Ellipta, Ultibro Breezhaler, or DuaKlir Genuair)
Step 2 of Long-term COPD management if the patient has asthmatic or steroid-responsive features
Combine LABA and ICS (i.e. Fostair, Symbicort, or Seretide)
Step 2 of Long-term COPD management if the patient has asthmatic or steroid-responsive features and LABA + ICS does not work
Add LAMA to the LABA and ICS combination (i.e. Trimbo, or Trelegy Ellipta)
Long-term Management options for severe cases include
- Nebulizers (Salbutamol and/or ipratropium)
- Oral theophylline
- Oral mucolytic therapy to break down sputum (e.g. carbocisteine)
- Long term prophylactic antibiotics (e.g. azithromycin)
- Long term oxygen therapy at home
At which point of COPD is long-term oxygen therapy used?
During severe COPD that is causing problems such as chronic hypoxia, polycythaemia, cyanosis or heart failure secondary to pulmonary hypertension (cor pulmonale)
Why can you not use oxygen therapy when the patient is smoking?
Oxygen plus cigarettes is a fire hazard
An exacerbation of COPD presents as
acute worsening of symptoms such as cough, shortness of breath, sputum production and wheeze
COPD exacerbation is triggered by
viral or bacterial infections
CO2 makes blood acidotic by
breaking down into carbonic acid (H2CO3)
Raised bicarbonate indicates
chronic retention of carbondioxide and the kidneys respond by producing more bicarbonate to balance the acidic CO2 and maintain a normal pH
What happens to bicarbonate production by the kidneys during a COPD exacerbation?
The kidneys can’t keep up with the rising level of CO2 so they become acidotic despite having a higher bicarbonate
List and explain the 3 types of respiratory failures
- Low pO2 indicates hypoxia and respiratory failure
- Normal pCO2 with low pO2 indicates type 1 respiratory failure
- Raised pCO2 with low pO2 indicates type 2 respiratory failure
Other investigations that can be conducted to confirm a COPD exacerbation diagnosis
- Chest x-ray to look for pneumonia or other pathology
- ECG to look for arrhythmia or evidence of heart strain (heart failure)
- FBC to look for infection (raised white cells)
- U&E to check electrolytes which can be affected by infection and medications
- Sputum culture if significant infection is present
- Blood cultures if septic
What would happen to the respiratory drive of someone who is prone to retaining carbondioxide and is given too much oxygen?
It can depress their respiratory drive slowing down their breathing rate and effort therefore leading to increased carbondioxide retention.
How can oxygen be provided to someone who is prone to retaining carbondioxide?
Carefully balanced to optimise their pO2 whilst not increasing their pCO2. This is guided by oxygen saturations and repeat ABGs.
General rule regarding target oxygen saturations in COPD is:
- 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%
Typical treatment for a COPD exacerbation if patient is well enough to remain at home
- Prednisolone 30mg once daily for 7-14 days
- Regular inhalers or home nebulisers
- Antibiotics if there is evidence of infection
Typical treatment for a COPD exacerbation if patient is in hospital
- Nebulised bronchodilators (e.g. salbutamol 5mg/4h and ipratropium 500mcg/6h)
- Steroids (e.g. 200mg hydrocortisone or 30-40mg oral prednisolone)
- Antibiotics if evidence of infection
- Physiotherapy can help clear sputum
Treatment options in severe COPD exacerbation cases not responding to first line treatment
- 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
