Respiratory Flashcards
What are the characteristics of asthma symptoms (wheeze, breathlessness, chest tightness and cough)?
Worse at night and early morning
In response to exercise, cold air, and allergen exposure
In response to aspirin or beta blockers
Occur apart from colds
What is the pathophysiology behind asthma?
Reversible obstructive airway inflammation and bronchial hyper-responsiveness
Describe the wheeze of asthma.
High pitched
Polyphonic
Expiration
What should a GP do if there is a high probability of asthma?
Move to a trial of treatment and reassess in 2-3 months
How is asthma diagnosed?
Spirometry: changes in PEFR or FEV1 10 minutes after bronchodilator
>12% improvement in lung function
What is the treatment of asthma?
1) SABA
2) ICS + SABA
3) LTRA, ICS + SABA
4) LABA, ICS + SABA
5) MART
6) MART, ↑dose ICS within the MART
7) MART, ↑dose ICS/theophylline
How do short acting beta agonists such as salbutamol or terbutaline work?
Act on beta-2 adrenoreceptor –> smooth muscle relaxation –> dilation of bronchial passages
How do inhaled corticosteroids such as beclomethasone dipropionate or budesonide work?
Reduce chronic inflammation and decreases reactivity of the airways
What are the indications of an inhaled corticosteroid?
Beta agonist being used >2 times per week
Symptoms disturb sleep >1 week
Exacerbation in last 2 years
All children with new diagnosis should be started on ICS.
How do leukotriene receptor antagonists such as Montelukast work?
What are leukotrienes?
Block the action of leukotriene D4 in the lungs –> decreases inflammation and relaxes smooth muscle
Leukotrienes are an immune molecule which promote bronchoconstriction, inflammation, microvascular permeability, and mucous secretion.
How do long acting beta agonists such as salmeterol and formoterol have a longer lasting effect?
Addition of a long lipophilic side chain that binds to an exosite on adrenergic receptors, allowing the active part of the molecule to continuously bind and unbind.
What is the condition characterised by partially reversible obstructive lung disease, associated with an abnormal inflammatory response of the lungs to noxious particles or gases?
COPD
Define airflow obstruction in COPD.
Reduced post bronchodilator FEV1/FVC ratio (less than 0.7)
What are the symptoms of COPD?
Asymptomatic in early stages
Exertional dyspnoea, chronic cough, regular sputum production, frequent winter bronchitis, wheeze.
What are the signs of COPD?
Cachexia Hyperinflated chest Pursed lip breathing Use of accessory muscles Paradoxical movement of lower ribs Wheeze/quiet breath sounds Peripheral oedema Cyanosis Raised JVP
What is the main respiratory drive in COPD?
Hypoxia (rather than PaCO2)
How is COPD diagnosed?
Stage 1 mild: FEV1 >80% predicted
Stage 2 moderate: FEV1 50-79% predicted
Stage 3 severe: FEV1 30-49% predicted
Stage 4 very severe: FEV1 <30% predicted (or less than 50% with respiratory failure)
What other investigations are required in COPD?
CXR
FBC
BMI
Alpha-antitrypsin if early onset, family history, or minimal smoking
Which vaccinations do COPD patients receive?
Pneumococcal and influenza
What is the management of stable COPD?
1) SABA/SAMA (salbutamol or ipratropium)
* assess steroid responsiveness*
2) YES: ICS + LABA (+SABA) NO: LABA + LAMA (+SABA)
3) LABA + LAMA + ICS (+SABA)
What is a SAMA?
Short acting antimuscarinic
Ipratropium
What is a LAMA?
Long acting antimuscarinic
E.g. tiotropium or glycopyrronium bromide
What are the indications for oxygen in COPD?
FEV1<30% Cyanosis Polycythaemia Peripheral oedema Raised JVP Saturations <92%
What is the management of an exacerbation of COPD?
Increase dose/frequency of SABA
Prednisolone 30mg OD 7-14d
Salbutamol/ipratropium nebs
What are the most common causes of infective exacerbations of COPD?
Rhinovirus
Influenza
Adenovirus
Bacterial - Hib, strep pneumoniae
If bacterial exacerbation of COPD is suspected (purulent sputum, signs of consolidation), which antibiotics should be prescribed?
Amoxicillin
Doxycycline
What is the cause of cystic fibrosis?
Mutation in the CF transmembrane conductance regulator (CFTR) gene on chromosome 7
Delta F508 mutation
What is the pathophysiology of CF?
CFTR: ATP responsive chloride channel so does not absorb chloride ions, which remain in the lumen and prevent sodium absorption.
High sodium sweat, pancreatic insufficient, reduce mucociliary clearance in the airway
What are the symptoms of CF
Recurrent LRTI with chronic sputum production Bowel obstruction with meconium ileus Rectal prolapse Nasal polyps Bronchiectasis Male infertility
Why are males with CF infertile?
Congenital bilateral absence of vas deferens
What are the signs of CF?
Finger clubbing
Crackles and wheeze
FEV1 shows obstruction
How is CF diagnosed?
Immunoreactive trypsinogen on Guthrie test
Sweat testing chloride >60mmol/L, lower sodium (pilocarpine)
Molecular genetic testing
ard X-Ray/CT - opacification of the sinuses
Stool elastase for pancreatic insufficiency
How is CF treated?
Twice daily chest physiotherapy
Regular physical exercise
Prophylactic antibiotics
How are the following treated in CF:
1) Nasal polyps
2) Pancreatic insufficiency
3) Thickened mucus
1) nasal steroids/polypectomy
2) pancreatic enzymes
3) rhDNAse or mannitol dry powder
What are the indications of azithromycin in CF?
As an immunomodulator: deteriorating lung function, repeated exacerbations
What are the complications of CF?
Bronchiectasis
Cor pulmonale
When does respiratory failure occur?
Disease of the heart or lungs leads to hypoxia +/- hypercapnia
What is Type 1 respiratory failure and what are the causes?
Hypoxia <8kPa and normal/low PaCO2
COPD, pneumonia, p.fibrosis, asthma, PE, ARDS, bronchiectasis
What is Type 2 respiratory failure and what are the causes?
Hypoxia <8kPa and hypercapnia (PaCO2>6kPa)
COPD, asthma, myasthenia, polio, head/neck injuries, pulmonary oedema
What are the symptoms of respiratory failure?
S+S of underlying cause Confusion and reduced GCS Tachycardia and arrhythmias from hypoxia and acidosis Cyanosis Polycythaemia if long standing hypoxia
How is respiratory failure diagnosed?
ABG
CXR
FBC
How is respiratory failure treated?
ICU and resuscitation
oxygen (unless patients rely on their hypoxic drive. elevation of PaO2 may reduce ventilation rate so Co2 rises dangerously)
Assisted ventilation
What is a pneumothorax?
Collection of air in the pleural cavity resulting in collapse of the lung on the affected side
What is a tension pneumothorax?
Pleural pressure > alveolar pressure
Air passes through the valve on inspiration, but cannot escape on exhalation
What are the causes of primary pneumothoraces?
Rupture of subpleural bleb and bullae
Penetrating chest wound
Lung biopsy
Thoracic endometriosis
What are the signs and symptoms of tension pneumothoraces?
Sudden pain, dyspnoea, sweating, cyanosis, hypotension
Trachea deviated away from collapse, hyperresonance on percussion, reduced breath sounds
How is a pneumothorax diagnosed?
Erect CXR in inspiration
What is the treatment of a tension pneumothorax?
Tension: needle decompression mid clavicular line, 2nd IC space.
What is the treatment of a normal pneumothorax (if short of breath)?
<1cm: admit, give oxygen, review in 24h
1-2cm: aspirate
>2cm: insert chest drain (anterior/mid axillary line, 5th IC space)
What is the safe triangle of chest drain insertion?
Latissimus dorsi, pectoralis major, line superior to the nipple, and apex at the axilla.
What are the types of pulmonary fibrosis?
Replacement fibrosis secondary to lung damage
Focal fibrosis in response to irritants
Diffuse parenchymal lung disease which occurs in IPF and EAA.
What are the s+s of idiopathic pulmonary fibrosis?
Dyspnoea Persistent dry cough Bilateral inspiratory crackles Clubbing Systemically unwell, weight loss Extra-articular features such as arthralgia
How is IPF diagnosed?
High resolution CT - pattern of usual interstitial pneumonia - honeycombing, basal predominance, reticular pattern
CXR, spirometry, gas transfer
What is the treatment of IPF?
Physiotherapy and oxygen
Pirfenidone
Nintedanib
What is nintedanib?
Intracellular tyrosine kinase inhibitor
antifibrotic and anti-inflammatory
What is extrinsic allergic alveolitis?
Diffuse granulomatous inflammation of parenchyma and airways in people who have been sensitised by repeated inhalation of antigens in dusts.
Hypersensitivity reaction
Name three types of EAA and the allergen.
Farmer’s lung: mouldy hay
Bird fancier’s lung: avian proteins
Cheese worker’s lung: mouldy cheese
How does EAA present?
Acute: starts 4-8h post exposure, resolve within days. flu-like, tight chest, dry cough, dyspnoea, anorexia, crackles
Chronic: gradual decrease in exercise tolerance, cyanosis, clubbing, hypoxia, PHTN.
How is EAA diagnosed?
High resolution CT
LFTs (restrictive if acute, mixed if chronic)
CXR
Inhalation challenge
How is EAA treated?
Oxygen
Avoid allergen
Corticosteroids
In pleural effusions, how are transudates and exudates differentiated?
Transudates: protein <30g/L
Exudates: protein >30g/L
If pleural protein is 25-35g/L, apply Light’s criteria
What are the causes of bloody pleural fluid (>1%)?
Malignancy
Trauma
PE
Give some examples of transudate pleural effusions.
Heart failure Cirrhosis Hypoalbuminaemia Peritoneal dialysis Nephrotic syndrome
Give some examples of exudate pleural effusions.
Pneumonia
Malignancy
Autoimmune disease
TB
What are the symptoms of alpha-antitrypsin deficiency?
Cirrhosis and HCC in adults
Cholestasis in children
Basal emphysema (COPD=apical emphysema)
What occurs if a COPD patient is given too much oxygen?
Acute respiratory acidosis on top of chronic resp acidosis with metabolic compensation
What are the symptoms of sarcoidosis?
Bilateral hilar lymphadenopathy Cough Low grade/swinging fever Erythema nodosum Facial palsies Ocular problems Parotid enlargement Hypercalcaemia
When stepping down asthma treatment, how should you reduce the dose of inhaled steroids?
By 25-50% at a time
What is atelectasis?
Common post-operative complication in which basal alveolar collapse can lead to respiratory difficulty
What occurs in lung function tests in obstructive lung disease and give examples?
FEV1 reduced
FVC reduced/normal
FEV1:FVC reduced
Asthma, COPD, bronchiectasis
What occurs in lung function tests in restrictive lung disease and give examples?
FEV1: reduced/normal
FVC: reduced
FEV1:FVC: normal/increased
IPF, ARDS, kyphoscoliosis.
What is the name of the condition characterised by permanent dilatation and thickening of the airways, secondary to chronic infection or inflammation?
Bronchiectasis
Why does bronchiectasis develop?
Post-infective: TB, pneumonia, measles Immunodeficiency Cystic fibrosis Ciliary dyskinetic syndrome e.g. Kartagener's syndrome Lung cancer
How is bronchiectasis diagnosed?
CXR: tramlines
CT: tramlines and signet ring signs
What are the features of Kartagener’s syndrome?
Dextrocardia/situs inversus
Bronchiectasis
Recurrent sinusitis
Subfertility
What are the types of lung cancer?
Small cell: 15%, worse prognosis
Non-small cell: usually squamous or adenocarcinoma
Which lung cancer is not related to smoking?
Alveolar cell carcinoma/adenocarcinoma
What are the signs and symptoms of lung cancer?
Persistent cough Haemoptysis Dyspnoea Chest pain Weight loss and anorexia Fixed monophonic wheeze Clubbing Hoarseness
What extra features are associated with small cell lung cancer?
Ectopic ADH (hyponatraemia) or ACTH (Cushing’s, hypokalaemic alkalosis) secretion
How does squamous cell carcinoma of the lung result in hypercalcaemia?
Associated with parathyroid hormone related protein secretion
What is acute respiratory distress syndrome?
Non-cardiogenic pulmonary oedema
Increased permeability of alveolar capillaries leading to fluid accumulation in the alveoli
What are the causes of ARDS?
Sepsis, pneumonia Massive blood transfusion Trauma Smoke inhalation Acute pancreatitis
How is occupational asthma diagnosed?
Peak flow diary = home and work
What are the components of the CURB score?
1 point for:
Confusion (new, or abbreviated mental test score (AMTS) <8) Blood urea nitrogen >7mmol RR>=30 Systolic BP<90, or diastolic BP<=60 Age >=65
What is Lambert-Eaton myasthenic syndrome?
What are the symptoms?
Paraneoplastic syndrome associated with small cell lung cancer of the lung
Difficulty walking and muscle tenderness from autoimmune destruction of calcium channels on the presynaptic motor neurone terminal.
Which organisms cause atypical pneumonia (dry cough)
Legionella pneumophilia
Mycoplasma pneumonia
Chlamydia psittaci
Coxiella burnetti
What are the symptoms of atypical pneumonia?
Dry cough and dyspnoea
Type 1 respiratory failure
Nausea, vomiting, diarrhoea
SIADH - hyponatraemia
Transient hepatitis (raised aminotransferases)
Rashes (erythema multiforme, rose spots)
Confusion, drowsiness (presents like meningo-encephalitis)
How may atypical pneumonia be treated?
Rifampicin
Erythromycin
Tetracycline
Treat as CAP until culture confirms diagnosis i.e. amoxicillin and macrolide
What is the respiratory aspect of management of Guillain Barre syndrome?
4-6 hourly spirometry
Any significant reduction in FEV1 = assisted ventilation
What results suggest a COPD patient is a chronic CO2 retainer?
Elevated serum bicarbonate - partial compensation for respiratory acidosis
Hyperventilation leading to hypoxia may lead to…
Respiratory alkalosis
Lymphoid =
Myeloid =
leucocytes
Everything else - neutrophils basophils
2 pharmacological treatments to maintain sobriety.
Antabuse (disulfiram) - makes you feel sick when you drink
Acamprosate - stops cravings
What are the differentials for nocturnal cough?
Asthma
Congestive cardiac failure
Sinusitis with post nasal drip
Gastro-oesophageal reflux
