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
BTS recommends that NIV is indicated if WHICH features are present 60 minutes after optimal supplemental oxygen and bronchodilation have been given in COPD? [3]
BTS recommends that NIV is indicated if the following features are present 60 minutes after optimal supplemental oxygen and bronchodilation have been given:
Acidosis - pH < 7.35
Hypercapnia - pCO2 > 6.5
Respiratory rate > 23
Which Abx [3] are commonly used in treating acute exacerbations of COPD and why [2]?
penicillin e.g. amoxicillin
macrolides e.g. clarithromycin
tetracyclines e.g. doxycyclin
Due to their effectiveness against Haemophilus influenzae and Streptococcus pneumoniae
Acute exacerbation of COPD
Which features of a decompensating a patient would indicate moivng to invasive mechanical ventilation? [5]
- Imminent respiratory arrest
- Severe respiratory distress
- Failure of NIV - persistent acidosis (pH < 7.25) and tachypnoea (RR > 35)
- Persistent or worsening acidosis (pH < 7.15)
- Depressed consciousness (GCS < 8)
A 73-year-old man presents to the emergency department with a 3-day history of increased dyspnoea and cough. He has a past medical history of severe COPD and uses a Trimbow inhaler daily.
He is admitted and treated for an acute exacerbation with prednisolone 30 mg daily for 5 days and nebulisers. This is his fourth exacerbation in the past 3 months.
What option is most appropriate to reduce the risk of future exacerbations?
Amoxicillin
Carbocisteine
Doxycycline
Long-term oxygen therapy
Roflumilast
Roflumilast
Oral PDE-4 inhibitors such as roflumilast reduce the risk of COPD exacerbations in patients with severe COPD and a history of frequent COPD exacerbations
When is NIV indicated in acute exacerbations of COPD? [1]
NIV should be considered in all patients with an acute exacerbation of COPD in whom a respiratory acidosis (PaCO2>6kPa, pH < 7.35 ≥7.26) persists despite immediate maximum standard medical treatment
What are the presenting features of an acute exacerbation of asthma? [5]
- Progressively shortness of breath
- Use of accessory muscles
- Raised respiratory rate (tachypnoea)
- Symmetrical expiratory wheeze on auscultation
- The chest can sound “tight” on auscultation, with reduced air entry throughout
Describe what is meant by brittle asthma [2]
*Type 1:
- wide PEF variability (>40% diurnal variation for >50% of the time over a period >150 days) despite intense
therapy
*Type 2:
- sudden severe attacks on a background of apparentlywell-controlled asthma
Describe what is meant by moderate exacerbation of asthma [6]
- Increasing symptoms
- Speech normal
- PEF >50-75% best or predicted
- No features of acute severe asthma
- RR < 25 / min
- Pulse < 110 bpm
Describe what is meant by an acute severe exacerbation of asthma [4]
Any one of:
* PEF 33-50% best or predicted
* respiratory rate >25/min
* HR > 110bpm
* inability to complete sentences in one breath
Admit – if persisting symptoms
What is a pneumonic for life-threatening exacerbation of asthma?
33-92 CHEST:
- PEF < 33%
- sats < 92%
- Cyanosis or confusion
- Hypotension
- Exhaustion
- Silent chest
- Tachy or bradychardia
Describe what is meant by a near fatal exacerbation of asthma [1]
Raised PaCO₂ (>6kPa) and/or need for mechanical ventilation.
It typically correlates with an FEV1 around 20% of predicted or less.
D
Describe the treament algorithm / management plan for acute asthma
ABC
Oxygen:
- High flow
- Aim sats >92
IV fluids
Reassess
- Every 15mins with PEFR
Therapys:
Oxygen
Salbutamol
Hydrocortisone/Prednisolone
Ipratropium bromide
Theophylline
! Magnesium sulphate
What dose salbutamol would you give? [1]
How is it delivered? [1]
How often? [1]
2.5-5mg every 10 minutes
Nebulised with oxygen
Which ICS would you give in acute asthma? [2]
What dose? [2]
How is it delivered? [1]
How often? [1]
Hydrocortisone
-IV 100-200mg QDS
prednisolone
- PO 40mg OD
Acute asthma
What dose ipratropium bromide would you give? [1]
What is the MoA? [1]
How is it delivered? [1]
How often? [1]
Ipratropium bromide
- Nebulised with oxygen
- Muscarinic antagonist: Bronchodilator
- 500 micrograms every 4-6 hours
Acute asthma
What dose Magnesium sulphate would you give? [1]
What is the MoA? [1]
How is it delivered? [1]
How often? [1]
Magnesium sulphate
1.2 – 2 grams over 20 minutes IV
Bronchodilator
What dose theophylline would you give? [1]
What is the MoA? [1]
How is it delivered? [1]
How often? [1]
Theophylline
Inhibit phosphodiesterase and increase cAMP – smooth muscle dilation
Life-threatening
Senior guidance
What is the treatment plan for Mild asthma attacks? [5]
- Inhaled beta-2 agonists (e.g., salbutamol) via a spacer
- Quadrupled dose of their inhaled corticosteroid (for up to 2 weeks)
- Oral steroids (prednisolone) if the higher ICS is inadequate
- Antibiotics only if there is convincing evidence of bacterial infection
- Follow-up within 48 hours
What is the treatment plan for moderate asthma attacks? [3]
- Consider hospital admission
- Nebulised beta-2 agonists (e.g., salbutamol)
- Steroids (e.g., oral prednisolone or IV hydrocortisone)
What indications would be for intubation in life-threatening asthma? [5]
There are few indications apart from coma and arrest.
However, findings such as severe fatigue, cardiovascular compromise and pneumothorax may be useful in decision making about mechanical ventilation
Describe side effects of salbutamol tx [3]
Serum potassium needs monitoring with salbutamol treatment, which causes potassium to be absorbed from the blood into the cells, resulting in hypokalaemia
- tachycardia (fast heart rate)
- lactic acidosis.
What is the follow up plan when discharing acute asthma exacerbations? [3]
o Follow up within 48 hrs
o < 30 days post discharge by GP/nurse specialist
o under specialist supervision indefinitely for near-fatal asthma and
at least 1 yeat for severe asthma attack
A 35-year-old lady with a history of asthma is brought to the Emergency Department with an acute asthma attack. She has previously been admitted to the intensive therapy unit (ITU) with the same problem. Treatment is commenced with high-flow oxygen and regular nebulisers.
Which of the following is a feature of life-threatening asthma?
Normal PaCO2
Peak expiratory flow rate < 50% of predicted or best
Pulse rate 105 bpm
Respiratory alkalosis
Unable to complete full sentences
Normal PaCO2
What indicates life-threatening asthma? [1]
Why? [1]
A normal PaCO2 in an acute asthma attack indicates exhaustion and should, therefore, be classified as life-threatening
Explain why in acute asthma, a pH of < 7.35 is particularly alarming [1]
A pH less than 7.35 likely represents carbon dioxide retention in a tiring patient and is an ominous sign in acute asthma.
