Resp II Flashcards
What are the 5 grades of the MRC dyspnoea scale? [5]
- Grade 1: Breathless on strenuous exercise
- Grade 2: Breathless on walking uphill
- Grade 3:Breathlessness that slows walking on the flat
- Grade 4: Breathlessness stops them from walking more than 100 meters on the flat
- Grade 5: Unable to leave the house due to breathlessness
mMRC ≥2
What investigations would you conduct for COPD? [7]
Spirometry:
- FEV1/FVC < 70%
Pulse ox:
- low oxygen saturation
- In patients with chronic disease, an oxygen saturation of 88% to 90% may be acceptable.
CXR:
- hyperinflation
- bullae
- flat hemidiaphragm
COPD Assessment Test (CAT) or Modified British Medical Research Council (mMRC)
- mMRC ≥2 or CAT score ≥10 indicates higher symptoms burden
FBC
- polycythaemia (raised haemoglobin due to chronic hypoxia),
- anaemia
- infection & WBC count
BMI:
- weight loss occurs in severe disease
Serum alpha-1 antitrypsin
- look for alpha-1 antitrypsin deficiency
What are common ECG changes might you see in COPD patients? [4]
- Rightward deviation of the P wave and QRS axis
- Low voltage QRS complexes, especially in the left precordial leads (V4-6)
- With development of cor pulmonale, right atrial enlargement (P pulmonale) and right ventricular hypertrophy
- Arrhythmias including multifocal atrial tachycardia
State how the different severity scores for COPD are calculated [4]
The severity can be graded using the forced expiratory volume in 1 second (FEV1):
Stage 1 (mild):
- FEV1 more than 80% of predicted
Stage 2 (moderate):
- FEV1 50-79% of predicted
Stage 3 (severe):
- FEV1 30-49% of predicted
Stage 4 (very severe):
- FEV1 less than 30% of predicted
If the FEV1 is greater than 80% predicted but the post-bronchodilator FEV1/FVC is < 0.7 then this is classified as Stage 1 - mild. Symptoms should be present to diagnose COPD in these patients
Describe the stepwise approach to treating COPD
First line treatment:
- SABA (salbutamol) or SAMA (e.g ipratropium bromide)
The next stage depends on whether the patient has asthmatic features / features suggesting steroid responsiveness
If NONE: use a combination:
- Add LABA AND LAMA regularly
If ASTHMATIC features:
- Add LABA & ICS regularly
Next stage for both:
- Use LABA AND LAMA AND ICS
What are the determinants that decide if COPD is asthmatic or steroid responsive? [4]
- Previous diagnosis of asthma or atopy
- Variation in FEV1 of more than 400mls
- Diurnal variability in peak flow of more than 20%
- Raised blood eosinophil count
Label A-E
When is oral theophylline indicated for COPD treatment? [1]
NICE only recommends theophylline after trials of short and long-acting bronchodilators or to people who cannot used inhaled therapy
Which antibiotic is given as oral prophylactic antibiotic therapy in some COPD patients? [1]
azithromycin prophylaxis is recommended in select patients
Explain which further tests would you need to conduct if giving azithromycin prophylaxis? [4]
ECG:
- can cause QT prolongation
LFTs:
- Can cause liver injury
CT scan:
- to exclude bronchiectasis
Sputum culture:
- exclude atypical infections and tuberculosis
Name a long-term risk of azithromycin use [1]
Long-term azithromycin use is associated with clinically significant hearing loss
Name an example and describe the MoA of phosphodiesterase-4 (PDE-4) inhibitors in COPD
roflumilast:
- antiinflammatory and immunomodulatory effects in the pulmonary system due to increased levels of intracellular cyclic AMP
When are roflumilast / PDE-4 inhibitors indicated in COPD treatment? [2]
FEV1 < 50%
AND
Ptx has two or more exacerbations in previous twelve months despitre triple therapy (LAMA; LABA & ICS)
A 62-year-old man presents to his general practitioner (GP) with symptoms of exertional breathlessness, wheeze and cough. He has a 30 pack-year smoking history.
As part of the patient’s work-up, spirometry is requested:
FEV1/FVC ratio 0.61
Given the likely diagnosis, which of the following would be an appropriate first-line treatment?
Ipratropium
Formoterol
Salmeterol
Tiotropium
Beclometasone
Ipratropium
SAMA or SABA is first line COPD
What are the most common causes of cor pulmonale? [5]
COPD (the most common cause)
Pulmonary embolism
Interstitial lung disease
Cystic fibrosis
Primary pulmonary hypertension
Explain the physiological reasons of what can happen to CO2 levels when treated with oxygen in COPD patients? [2]
Many patients retain CO2 when treated with oxygen (oxygen induced hypercapnia)
Due to:
Increased V/Q mismatch (most important)
- COPD ptx optimise gas exchange by hypoxic vasoconstriction leading to altered Va/Q ratios
- Excessive oxygen administration overcomes this, leading to increased blood flow to poorly ventilated alveoli, and thus increased Va/Q mismatch and increased physiological deadspace
The Haldane effect:
- deoxygenated Hb binds CO2 with greater affinity than oxygenated Hb
- Thus: oxygen induces a rightward shift of the CO2 dissociation curve (Haldane effect)
What pO2 level is LTOT therapy given to COPD without any other factors? [1]
What pO2 levels [1] and other conditions [3] mean that LTOT is given to COPD factors?
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
Which of the following is not an indication for long-term oxygen therapy (LTOT) in patients with stable chronic obstructive pulmonary disease (COPD)?
PaO2 = 7.3-8.0 kPa with secondary polycythaemia
PaO2 = 7.3-8.0 kPa with anaemia
PaO2 = 7.3-8.0 kPa with pulmonary hypertension
PaO2 < 7.3 kPa
PaO2 = 7.3-8.0 kPa with peripheral oedema
PaO2 = 7.3-8.0 kPa with anaemia
NICE recommends that LTOT should be considered in patients with stable COPD who do not smoke and are on optimal medical therapy in the following circumstances:
PaO2 < 7.3 kPa
PaO2 7.3-8.0 kPa with secondary polycythaemia
PaO2 7.3-8.0 kPa with peripheral oedema
PaO2 7.3-8.0 kPa with pulmonary hypertension (eg. loud P2, RVH on ECG)
What indicates COPD patients to start LTOT? [1]
LTOT if 2 measurements of pO2 < 7.3 kPa
Which bacterial [3] and viral infections [3] most commonly cause acute exacerbations of COPD?
Bacterial infections:
- Haemophilus influenzae
- Moraxella catarrhalis,
- Streptococcus pneumoniae
Viral infections:
* Rhinovirus
* influenzae
* respiratory syncytial virus
Describe which investigations do NICE recommend for all patients admitted with COPD acute exacerbations of COPD? [5]
Blood tests to establish a baseline:
* Full blood count
* Urea and electrolytes
* Theophylline levels if the patient is on it
Serial arterial blood gases (ABGs) to monitor for the development of Type 2 respiratory failure
* A PaO2 of < 7 kPa and a pH level of < 7.35 are indications that the patient should continue to be managed in hospital
Chest X-ray
* overt changes such as opacification and oedema should prompt a reconsideration of the diagnosis
ECG
* helps to exclude acute ischaemia and/or comorbid cardiac dysfunction
Microbiological investigations:
* Sputum sample for microscopy and culture if sputum purulent
* Blood cultures if pyrexia present
Treatment of acute exacerbations of COPD:
1 Supplemental oxygen titrated to achieve target saturations of 88-92%
2 Repeat ABG measurements every 30-60 mins
3 Pharmacological managment:
- SABA &/or SAMA initially via inhaler or nebuliser
- LABA, LAMA & ICS continued
- 5-day course of oral prednisolone
- IV theophylline if response inadequate
- Abx (if evidence of infection)
4 Patients with persistent hypercapnia and respiratory acidosis despite optimal medical management need to be started on NIV
5 Escalate to invasive mechanical ventilation
State three ways in which supplemental oxygen can be given in treatment of acute excaerbation of COPD [3]
A 24% Venturi mask at 2-3 L/min
A 28% Venturi mask at 4 L/min
Nasal cannulae at 1-2 L/min
