Respiratory V (Bronchiectasis; Respiratory Failure) Flashcards
Define what is meant by bronchiectasis [1]
Bronchiectasis is the abnormal dilation of bronchi due to the destruction of the elastic and muscular components of the bronchial wall
Which inherited diseases can cause bronchiectasis? [4]
- (Alpha-1-antitrypsin deficiency)
- Connective tissue disorders (e.g., rheumatoid arthritis)
- Cystic fibrosis
- Yellow nail syndrome
Describe the classic triad of yellow nail syndrome [3]
- Yellow fingernails
- Bronchiectasis
- Lymphoedema
TOM TIP: Yellow nail syndrome is characterised by yellow fingernails, bronchiectasis and lymphoedema. Patients are stable and have good clinical signs, making it a good choice for OSCEs. As it is rare, examiners will score high marks if you can combine these features and name the diagnosis.
Describe the pathophysiology of bronchiectasis [7]
Cole’s ‘vicious cycle hypothesis:
A deficit in mucociliary clearance +/- immune function
→
Microorganism acquisition, colonisation and infection
→
Chronic inflammation
→
Dilation and thickening of bronchi
→
Bronchial wall oedema and increased mucus production
→
More infections
→
Further inflammation and damage.
Describe the three morphological types of bronchiectasis [3]
Tubular/cylindrical:
- most common type
- the morphology is of smooth uniform dilatation of the bronchi with loss of normal tapering. **
- This type is associated with the ‘signet ring sign**’ due to an increased bronchoarterial ratio and the ‘tram-track sign’ due to parallel bronchial walls.
Varicose:
- relatively uncommon, the bronchi are irregular with dilatation interspersed with areas of constriction.
Cystic:
- associated with cystic fibrosis, dilated bronchi that are cyst like and filled with either air or fluid.
Describe the classical symptoms of bronchiectasis [5]
- Shortness of breath
- Chronic productive cough: may produce large amounts of purulent sputum and sometimes haemoptysis
- Recurrent chest infections
- Weight loss
- Fever
- Chest pain
- GORD
Describe the classical signs of bronchiectasis [5]
- Scattered crackles throughout the chest that change or clear with coughing
- Scattered wheezes and squeaks
- Sputum pot by the bedside
- Oxygen therapy (if needed)
- Weight loss (cachexia)
- Finger clubbing
- Signs of cor pulmonale (e.g., raised JVP and peripheral oedema)
When taking a history and examining the patient, it is also important to consider other systems of the body too, as these may reveal co-morbid conditions associated with the development of bronchiectasis
.
Which do these include? [4]
Joints:
- RA
GI:
- IBD
- Cystic fibrosis
- GORD
Describe what CT [7] and CXR [2] would reveal when investigating for bronchiectasis? [2]
High resolution chest CT
- Test of choice
- Thickened & dilated airways
- May show fluid-filled cysts; these represent superimposed infection and warrant a course of systemic antibiotics.
- Tram line or signet ring appearance
- Bronchoarterial ratio > 1: the internal airway lumen is larger than the adjacent pulmonary artery (signet ring sign)
- Lack of tapering: bronchi should taper in diameter as they travel distally from the lung hila to the periphery
- Bronchus visible within 1cm of pleural surface: normal, non-dilated airways cannot usually be seen within 2cm of the pleura
CXR:
- the majority of X-rays will be abnormal in those with bronchiectasis but findings are non-specific and further imaging is required.
- They are also useful for ruling out other possible causes such as TB or malignancy
Sputum culture is used to identify colonising and infective organisms. The most common infective organisms are? [2]
Haemophilus influenza
Pseudomonas aeruginosa
Asides from imaging investigations, describe what else you would investigate for bronchiestasis [7]
Sputum culture
- Most commonly Haemophilus influenzae and Pseudomonas aeruginosa
FBC:
- may reveal high eosinophil count in bronchopulmonary aspergillosis
specific IgE or skin prick test to Aspergillus fumigatus
serum alpha-1 antitrypsin phenotype and level
serum immunoglobulins
- to identify individual immunoglobulin deficiencies as underlying aetiology
Rheumatoid factor
Serum HIV antibody
Describe most common pattern seen on post-bronchodilator spirometry in bronchiectasis
Post-bronchodilator spirometry: most commonly an obstructive pattern is seen, although mixed, restrictive, and normal results are also possible.
How would you distinguish between bronchiectasis and:
- COPD [2]
- Asthma [2]
COPD Differences:
- Sputum more likely to be clear (except during infection)
- Smoking stronger RF
Asthma:
- Dysopnea more associated with triggers
NB: Both diseases can co-exist with bronchiectasis
TOM TIP: The key features to remember with bronchiectasis are [4]
TOM TIP: The key features to remember with bronchiectasis are finger clubbing, diagnosis by HRCT, Pseudomonas colonisation and extended courses of 7-14 days of antibiotics for exacerbations.
Describe the treament algorithm for bronchiestasis for the initial presentation? [5]
initial presentation
1ST LINE: exercise and improved nutrition.
- Including vitamin D supplementation
- Higher BMI has beneficial outcomes
- Excercise is considered form of airway clearance
PLUS –
airway clearance therapy (ACT):
- maintenance of oral hydration; percussion, breathing, or coughing strategies
- positioning and postural drainage; positive expiratory pressure devices; and oscillatory devices
- recommended for 15 to 30 minutes, 2 or 3 times daily
PLUS –
self-management plan
CONSIDER –
inhaled bronchodilator:
- salbutamol inhaled
CONSIDER –
mucoactive agent
- hypertonic saline
BMJ BP
acute exacerbation: mild to moderate underlying disease if is first or new presentation of Pseudomonas aeruginsoa
1ST LINE –
short-term oral antibiotic:
- For adults, prescribe amoxicillin 500 mg three times a day for 7–14 days
PLUS –
increased airway clearance
PLUS –
continued maintenance therapy:
- Healthy diet & exercise
- Higher BMI
- Nebulised bronchodilators
- Nebulised hyperosmolar agents, such as hypertonic saline,
Describe how treatment for bronchiectasis would be escalated in a stepwise manner if they were suffering ≥ 3 exacerbations in one year despite following the initial management?
3 or more exacerbations per year despite maintenance therapy
1ST LINE –
reassess physiotherapy ± mucoactive treatment
PLUS –
continued maintenance therapy
- Azithromycin 500 mg three times a week, or
- Azithromycin 250 mg daily, or
- Offer a minimum of 6 months treatment, but up to 1 year may be required.
CONSIDER –
long-term antibiotic
CONSIDER –
surgery:
- Surgical resection is considered in patients with localised disease whose symptoms are not controlled by optimal medical treatment
- Complete resection of the bronchiectatic area is associated with the best results
CONSIDER –
treatment of respiratory failure
BTS sugget what criteria for a lung transplantation for bronchiestasis? [3]
BTS specify the following criteria for lung transplantation:
* Aged 65 years or less and
* FEV is < 30% predicted with significant clinical instability
or
* Rapid progressive deterioration despite optimal medical management
A patient is diagnosed with bronchiestasis. Subsequent sputum sampling diagnoses them the infective agent as Streptococcus pneumoniae. What is the approriate first line treatment
- Co-amoxiclav 625 mg three times daily
- Amoxicillin 500 mg three times daily
- Flucloxacillin 500 mg four times daily
- Doxycycline 100 mg twice daily PLUS rifampicin (for adults)
- Ciprofloxacin 500 or 750 mg twice daily
Amoxicillin 500 mg three times daily
When giving long term antibiotic therapy to those with bronchiestasis, if people have concurrent Pseudomonas aeruginosa infection, first-line therapy is []
inhaled colistin.
A patient is diagnosed with bronchiestasis. Subsequent sputum sampling diagnoses them the infective agent as Haemophilus influenzaebeta lactam negative. What is the approriate first line treatment
- Co-amoxiclav 625 mg three times daily
- Amoxicillin 500 mg three times daily
- Flucloxacillin 500 mg four times daily
- Doxycycline 100 mg twice daily PLUS rifampicin (for adults)
- Ciprofloxacin 500 or 750 mg twice daily
A patient is diagnosed with bronchiestasis. Subsequent sputum sampling diagnoses them the infective agent as Haemophilus influenzae. What is the approriate first line treatment
- Co-amoxiclav 625 mg three times daily
Amoxicillin 500 mg three times daily
- Flucloxacillin 500 mg four times daily
- Doxycycline 100 mg twice daily PLUS rifampicin (for adults)
- Ciprofloxacin 500 or 750 mg twice daily
A patient is diagnosed with bronchiestasis. Subsequent sputum sampling diagnoses them the infective agent as Haemophilus influenzae (beta-lactamase positive). What is the approriate first line treatment
- Co-amoxiclav 625 mg three times daily
- Amoxicillin 500 mg three times daily
- Flucloxacillin 500 mg four times daily
- Doxycycline 100 mg twice daily PLUS rifampicin (for adults)
- Ciprofloxacin 500 or 750 mg twice daily
Co-amoxiclav 625 mg three times daily
A patient is diagnosed with bronchiestasis. Subsequent sputum sampling diagnoses them the infective agent as Pseudomonas aeruginosa. What is the approriate first line treatment
- Co-amoxiclav 625 mg three times daily
- Amoxicillin 500 mg three times daily
- Flucloxacillin 500 mg four times daily
- Doxycycline 100 mg twice daily PLUS rifampicin (for adults)
- Ciprofloxacin 500 or 750 mg twice daily
A patient is diagnosed with bronchiestasis. Subsequent sputum sampling diagnoses them the infective agent as Pseudomonas aeruginosa. What is the approriate first line treatment
- Co-amoxiclav 625 mg three times daily
- Amoxicillin 500 mg three times daily
- Flucloxacillin 500 mg four times daily
- Doxycycline 100 mg twice daily PLUS rifampicin (for adults)
- Ciprofloxacin 500 or 750 mg twice daily
A patient is diagnosed with bronchiestasis. Subsequent sputum sampling diagnoses them the infective agent as Klebsiella. What is the approriate first line treatment
- Co-amoxiclav 625 mg three times daily
- Amoxicillin 500 mg three times daily
- Flucloxacillin 500 mg four times daily
- Doxycycline 100 mg twice daily PLUS rifampicin (for adults)
- Ciprofloxacin 500 or 750 mg twice daily
A patient is diagnosed with bronchiestasis. Subsequent sputum sampling diagnoses them the infective agent as Klebsiella. What is the approriate first line treatment
- Co-amoxiclav 625 mg three times daily
- Amoxicillin 500 mg three times daily
- Flucloxacillin 500 mg four times daily
- Doxycycline 100 mg twice daily PLUS rifampicin (for adults)
- Ciprofloxacin 500 or 750 mg twice daily
Which vaccines are recommonded for bronchiestasis? [2]
Vaccines (e.g., pneumococcal and influenza)
[] is the usual choice for infective exacerbations caused by Pseudomonas aeruginosa
Ciprofloxacin is the usual choice for exacerbations caused by Pseudomonas aeruginosa
How long are the extended course of Abx for infective exacerbations? [1]
Extended courses of antibiotics, usually 7–14 days
Cardiac tamponade
This CXR causes hypoxia due to which underlying mechanism
V/Q mismatch
Shunt
Diffusion limitation
Hypoventilation
Increased dead space
This CXR causes hypoxia due to which underlying mechanism
V/Q mismatch
This CXR causes hypoxia due to which underlying mechanism
V/Q mismatch
Shunt
Diffusion limitation
Hypoventilation
Increased dead space
Pneumothorax causing V/Q mismatch
Define Type 1 & Type 2 respiratory failure [2]
Type 1 respiratory failure (T1RF): is characterised by hypoxaemia (PaO2 < 8 kPa) and a normal or low CO2.
Type 2 respiratory failure (T2RF): is characterised by hypoxaemia (PaO2 < 8 kPa) and hypercapnia (PaCO2 > 6.5 kPa).
Describe what is meant by low and high V/Q mismatch in hypoxia [2]
State what could cause each [2]
Hypoxaemia usually caused by:
Low V/Q:
- alveoli with poor ventilation compared to perfusion
- Caused by: airway disease or interstitial lung disease where ventilation is reduced
- Therefore, hypxoxia induced v/c occurs and redirects blood to better ventilated areas
High V/Q:
- Poor perfusion c.f ventilation
- Caused by: PE
What is a shunt (with regards to hypoxia)? [1]
How does this occur in pathological conditions? [1]
Blood entering the left side of the heart without first having travelled through pulmonary capillaries and participating in gaseous exchange.
This can be thought of as an extreme version of V/Q mismatch (V/Q = 0)
In pathological conditions this occurs due to pulmonary arteriovenous malformations
State 4 conditions that cause pulmonary shunts [4]
pneumonia
ARDS
pulmonary oedema
alveolar collapse
What is meant by diffusion limitation (causing hypoxia?)
Describe two pathophysiological causes of diffusion limitation [2]
Diffusion limitation refers to the impairment of gaseous exchange across the alveolocapillary membrane.
Causes:
Reduced surface area:
- reduced surface area of alveoli due to pathological destruction limits the amount of lung tissue available for gaseous exchange.
Alveolocapillary membrane changes:
- inflammation and fibrosis of the alveolocapillary membrane impairs diffusion across it.
State common causes of diffusion limitation [3]
Emphysema
Lung fibrosis
Oedema
State 6 causes of hypoventilation [6]
Respiratory depressants (e.g. opiates, alcohol)
Neurological disorders (e.g. ALS, GBS, Myasthenia gravis)
Myopathies
Chest wall disease (e.g. kyphoscoliosis)
Exacerbation of COPD
Severe asthma attack
Describe what is meant by increased dead space causing hypoxaemia [1]
Areas of the lung that are ventilated but not perfused and therefore do not contribute to gaseous exchange.
(It can be thought of as an extreme V/Q mismatch and the opposite of a shunt)
Name two pathologies that cause increased dead space [2]
emphysema (COPD) and interstitial lung disease destroying pulmonary capillaries
What is the most common cause of T1RF? [1]
V/Q mismatch
State 5 main causes of hypoxaemia [5]
V/Q mismatch
Shunt
Diffusion limitation
Hypoventilation
Increased dead space
Describe how T1RF can present [1]
Why is this clinically significant when investigating T1RF? [1]
Can be acute or chronic; but can‘t differentiate between the two on an ABG
State common consequences of chronic T1RF [5]
These indicate oxygen treatment
Polcythaemia (increase in RBC)
Development of cor pulmonale
Peripheral oedema
Poor sleep
Fatigue
Pulmonary hypertension
State 5 common causes of T1RF [6] (and the cause of hypoxia)
Diffusion abnormality:
- Pulmonary fibrosis
- Emphysema in COPD
V/Q mismatch: reduced V
- Pneumonia
- Pulmonary oedema
- Pneumothorax
V/Q mismatch: reduced Q
- Pulmonary embolism
Low inspired oxygen
Hypxoxia = increased V
More CO2 exhaled
Hypoxia but not hypercapnic
T2RF is seen in conditions that cause what changes to alveoli? [1]
T2RF is seen in conditions that result in alveolar hypoventilation.
Describe the difference between acute and chronic T2RF presentation
Acute T2RF:
- Significant hypoxaemia
- New respiratory acidosis with normal bicarbonate
- Electrolyte disturbances
- CV instability
- LOC
- Cardiac arrest
Chronic T2RF:
- Increase in bicarbonate levels in setting of chronic respiratory acidosis
Remember T2RF is caused by alveolar hypoventilation
How do acute and chronic T2RF present with regards to blood gases?
Acute:
- New respiratory acidosis with normal bicarbonate
Chronic:
- Increase in bicarbonate levels in setting of chronic respiratory acidosis
What are common causes of acute T2FR? [5]
Exacerbations of obstructive lung disease:
* COPD (most common)
* Severe asthma
* Cystic fibrosis
* Bronchiectasis
Respiratory depressants (e.g. opiate overdose)
Acute T2RF: failure of ventilation
What are common causes of chronic T2FR? [5]
Obstruction to airways:
* COPD
* Severe asthma
Hyperexpanded lungs:
- COPD
Thoracic cage problems:
- Kyphoscoliois
- Obesity
Weakness of resp. muscles
* Chronic neurological disorders (e.g. motor neuron disease)
* Chronic neuromuscular disorders (e.g. myopathies)
What type of hypoxia does scoliosis cause? [1]
Hypoventilation (get smaller diaphragm working)
Which of the following would this CXR cause hypoxaemia?
V/Q mismatch
Shunt
Diffusion limitation
Hypoventilation
Increased dead space
Lobar pneumonia causing V/Q mismatch
Out of which of the following would this CXR cause hypoxaemia?
V/Q mismatch
Shunt
Diffusion limitation
Hypoventilation
Increased dead space
Diffusion abnormality: patient has sarcoidosis
Out of which of the following would this CXR cause hypoxaemia?
V/Q mismatch
Shunt
Diffusion limitation
Hypoventilation
Increased dead space
Hypoventilation: patient has TB
Out of which of the following would this CXR cause hypoxaemia?
V/Q mismatch
Shunt
Diffusion limitation
Hypoventilation
Increased dead space
Hypoventilation: lobar collapse
Out of which of the following would this CXR cause hypoxaemia?
V/Q mismatch
Shunt
Diffusion limitation
Hypoventilation
Increased dead space
Diffusion limitation:
Pulmonary fibrosis
Out of which of the following would this CXR cause hypoxaemia?
V/Q mismatch
Shunt
Diffusion limitation
Hypoventilation
Increased dead space
Hypoventilation: COPD
Can be T1 or T2RF
Out of which of the following would this cause hypoxaemia?
V/Q mismatch
Shunt
Diffusion limitation
Hypoventilation
Increased dead space
Hypoventilition: motor neuron disease - can’t use muscles / diaphragm to breathe
Out of which of the following would this CXR cause hypoxaemia?
V/Q mismatch
Shunt
Diffusion limitation
Hypoventilation
Increased dead space
VQ mismatch: pneumothroax
Out of which of the following would this cause hypoxaemia?
V/Q mismatch
Shunt
Diffusion limitation
Hypoventilation
Increased dead space
Morbid obesity: hypoventilation
Out of which of the following would this CXR cause hypoxaemia?
V/Q mismatch
Shunt
Diffusion limitation
Hypoventilation
Increased dead space
Shunt: eisenmenger syndrome
Hypoventilaton:
State pathologies that cause
Obstruction to airways [2]
Hyper-expanded lungs [1]
Thoracic cage problems [2]
Weakness of respiratory muscles [2]
Obstruction to airways
- COPD
- Asthma
Hyper-expanded lungs:
- COPD
Thoracic cage problems
- Kyphoscoliosis
- Thoracoplasty
- Obesity
Weakness of respiratory muscles
- MND
- MD
V/Q mismatch:
State causes for:
- Area of lung perfused but not ventilating (airspaces filled with fluid [2]; lung collapsed [2] )
- Area of lung ventilated, but not perfused (2)
Area of lung perfused but not ventilating:
- airspaces filled with fluid: pneumonia; pulmonary oedema
- lung collapsed: pneumothorax; lung collaspe
Area of lung ventilated, but not perfused: PE; shock
Explain why diffusion abnormalities cause hypoxia but not hypercapnia [2]
In diffusiin abnormalities: ventilation is normal, but a barrier to the transer of oxygen from alveoli to blood stream
- Hypoxia leads to increased ventilation
- More CO2 is exhaled
- Creates hypoxia but not hypercapnia
Explain why hypoventilation causes T2RF [1]
Hypoxia from hypoventilation increases ventilation
Unable to increase ventilation
Causes hypoxia AND hypercapnia
Which of the following causes hypercapnia
V/Q mismatch
Shunt
Diffusion limitation
Hypoventilation
Increased dead space
Which of the following causes hypercapnia
V/Q mismatch
Shunt
Diffusion limitation
Hypoventilation
Increased dead space
How do you treat Acute T1RF? [3]
Give oxygen (60-100% via a mask)
Treat underlying cause (pneumonia; PE; pulmonary oedema; non-severe asthma)
Consider CPAP if hypoxia continues
How do you manage acute T2RF? [4]
Controlled oxygen:
- 0.5 - 2l/min via nasal cannulae
- 24 to 28% masks using venturi valves
Regular ABG to monitor CO2 levels
Consider non-invasive ventilation (BIPAP) if pH and CO2 dont improve
Go over BIPAP - is this correct?
Why does NIV (BIPAP) help to treat acute T2RF? [2]
In acute T2RF:
- Hypoxia causes increase in ventilation
- Unable to increase ventilation
- NIV helps to increase ventilation
When [5] and where [2] is NIV indicated?
Acute T2RF: COPD exacerbations
- Inpatient
Chronic T2RF: At home
- Kyphoscoliosis
- Neuromuscular
- Obesity hypoventilation syndrome
- COPD
What shifts oxygen haemoglobin to the right? [5]
What happens to oxygen release when this happens? [1]
Shift to right:
* Increased CO2
* Decreased pH
* Increased temperature
* Increased 2,3 DPG
* Exercise
When moves to right, becomes easier to release (Bohr Shift)
What are the five causes of tissue hypoxia? [5]
Hypoxaemic hypoxia: due to hypoventilation, ventilation/perfusion (V/Q) mismatch, or pulmonary shunts
Circulatory hypoxia: due to inadequate cardiac output
Anaemic hypoxia
Histotoxic hypoxia: inability of the tissue to use oxygen (e.g. cyanide poisoning)
Oxygen affinity hypoxia: decreased oxygen delivery to tissue (i.e. haemoglobin holds onto oxygen)
Name an AE of oxygen therapy? [1]
Can cause vasoconstriction
When should nasal cannulae not be used? [1]
Do not use if the patient mainly breathes through their mouth
Simple face masks deliver what oxygen flow between what range? [1]
What oxygen concentration does this cause? [1]
Delivers oxygen between 5-10L/min
Creates variable oxygen conc between 35-60%
What oxygen flow rate does a non-rebreather mask deliver? [1]
What FiO2 does this equate to? [1]
Delivers up to 15L/min, which approximately equates to 70-90% FiO2 (does not deliver 100% FiO2 as some room air will escape into the mask due to the mask not being perfectly adherent to the face)
What is high flow nasal cannulae? [1]
Why is it particularly useful? [2]
High-flow nasal cannula (HFNC) therapy is an oxygen supply system capable of delivering up to 100% humidified and heated oxygen at a flow rate of up to 60 liters per minute.
Can provide PEEP 7.4cm H20 (PEEP: Positive end-expiratory pressure; stops airways from collapsing due to pressure)
Explain the physiology of why delivering oxygen to COPD patients is different to normal patients [2]
COPD patients are used to being in a hypercapnic state, so their respiratory drive becomes determined by oxygen levels: aka they rely on their hypoxic drive (Normally respiratory drive, is detected in the carotid body by the levels of pCO2)
If give oxygen, you reduce the ventilatory drive and may become hypercapnic
Can cause CO2 retention leading to narcosis / respiratory arrest
What % of COPD patients are CO2 retainers? [1]
5-15%
