Respiratory Flashcards
Asthma
paroxysmal and reversible obstruction of airways - involves bronchospasm and excessive production of secretions
Asthma patho
narrowing of airway, SM contraction, airway wall thickening by cellular infiltration, inflammation, secretions
Eosinophilic - associated with allergy, subset of atopic/non-atopic
Non-eosinophilic - later onset, overlaps with smoking, obesity, neutrophils instead of eosinophils
RFs
FHx, atopy, low SES, inner city environ, obesity, premature, viral infections in early childhood, smoking
Asthma Px
symptoms intermittent SOB wheeze cough (often nocturnal) sputum chest tightness
signs tachypnoea audible wheeze - widespread, polyphonic hyperinflated chest hyper-resonant percussion note reduced air entry
Levels of acute asthma atttack
Moderate
increasing symptoms
PEF >50-75%
no features of severe attack
Severe cannot complete sentences HR >110 RR >25 PEF 33-50% predicted
Life-threatening silent chest confusion exhaustion cyanosis bradyacardia PEF <33% Sats <92% hypotension
Near fatal
PaCO2 increase
Asthma DDx
COPD
later disease, smokers
more relentless progressive SOB with wheeze, less diurnal variation
winter symptoms, sputum production
fibrosis - would have crackles
bronchiolitis, bronchiectasis, CF, PE, bronchial obstruction, CCF, pneumothorax, PO, viral infections…
Asthma Ix
Blood count - eosinophils
Atopy/allergy (SPT, RAST)
CXR
Spirometry / peak flow
Reduced FEV1, FEV1/FVC <70%
PEFR reduced, >20% variability
FeNO test
level of NO in breath - measure of inflammation
BDR test (bronchodilator reversibility) see if obstruction gets better with bronchodilator medication
Direct bronchial challenge
see if breathing worsens worsens with provocation agent (methacholine/histamine)
Asthma Mx
Stop smoking, avoid precipitants, wt loss, monitor PEF
BTS guidelines
1 - SABA (salbutamol)
2 - ICS (beclometasone)
3 - LABA (salmeterol), maybe leukotriene receptor antagonist, theophylline
4 - higher dose ICS, with previous therapy
5 - oral prednisolone
omalizumab - anti-IgE Mab for persistent allergic asthma
Acute attack Assess severity - PEF, ability to speak, RR, HR, sats O2 Salbutamol Ipratropium if severe Hydrocortisone/prednisolone Reassess every 15 mins ECG Magnesium sulfate if not responding
Bronchiectasis
permanent dilatation and thickening of bronchi and bronchioles after chronic inflammation
Bronchiectasis patho
diffuse/local
characterised by chronic cough, excessive sputum, bacterial colonisation, recurrent acute infections
Main orgs - H.influenzae, Strep.pneumoniae, Staph.aureus, Pseudomonas aeruginosa
Results from chronic pulmonary inflammation, scarring, mucociliary transport mechanism impaired, impairment of immune function
Causes - congenital, post-infection, other (bronchial obstruction, allergic bronchopulmonary aspergillosis (ABPA), RA, UC)
Bronchiectasis Px
signs
finger clubbing
coarse inspiratory crepitations
wheeze (asthma, COPD, ABPA)
symptoms persistent cough SOB copious purulent (khaki coloured) sputum intermittent haemoptysis chest pain
Bronchiectasis DDx
CF, asthma, TB, pneumonia, cancer
Bronchiectasis Ix
Sputum culture, bloods
CXR - cystic shadows, thickened bronchial walls, abnormal dilatation
HRCT - dilated, thickened bronchi, signet ring sign
Spirometry - obstruction
Bronchoscopy
Serum Igs, CF sweat test, SPT, RAST
Bronchiectasis Mx
Healthy diet, stop smoking
Airway clearance techniques - postural drainage, chest physio
ABs
P.aeruginosa - ciprofloxacin
H.influenzae - amoxicillin, co-amoxiclav, doxycycline
S.aureus - flucloxacillin
Salbutamol
Anti-inflammatory - eg azithromycin
Surgery - if disease is localised, or to control haemoptysis
Bronchiectasis Cx
pneumonia, pleural effusion, pneumothorax, haemoptysis
COPD
progressive respiratory disorder characterised by airflow obstruction - airway/parenchymal damage
obstruction = FEV1/FVC <0.7
Resp drive normally PaCO2 driven, but in COPD, hypoxia can be a strong drive, so resp drive can be reduced if hypoxia is corrected
COPD patho
Small airways disease - chronic bronchitis
airway inflammation, fibrosis, luminal plugs, increased airway resistance, cough, sputum production
Parenchymal destruction - emphysema
loss of alveolar attachments, decrease of elastic recoil, alveolar wall destruction
Vascular changes
V/Q mismatch, low PaO2, high PaCO2, pul HTN may result
A1AT deficiency
A1AT is a protease inhibitor, normally protects tissues from enzymes from inflammatory cells (neutrophil elastase -> loss of recoil)
Causes
smoking, air pollution, occupational exposure
RFs
male, older, asthma, A1AT deficiency, low SES, HIV
COPD Px
signs tachypnoea use of accessory muscles of resp (might lean forward) hyperinflation (barrel shaped chest) decreased expansion resonant/hyper-resonant percussion note expiration through pursed lips quiet breath sounds cyanosis cor pulmonale, peripheral oedema, raised JVP cachexia
symptoms SOB cough sputum wheeze minimal diurnal variation wt loss
PP vs BB
PP - increased alveolar ventilation, normal PaO2, breathless, not cyanosed
BB - decreased alveolar ventilation, low PaO2, high PaCO2, cyanosed, not breathless, resp centres insensitive to CO2, rely on hypoxic drive
COPD DDx
Asthma, HF, other causes of SOB, PE, pneumonia, lung cancer, bronchiectasis, TB
COPD / asthma? age usually younger in asthma smoking history - in most with COPD SOB variable in asthma nocturnal symptoms more common in asthma persistent productive cough common in COPD, not asthma
COPD Ix
Spirometry - FEV1/FVC < 0.7, FEV1 < 80%
CXR - hyperinflation, flat hemidiaphragms, large central pulmonary arteries, bullae
CT - bronchial wall thickening, scarring, air space enlargement
ECG - cor pulmonale
ABG - decreased PaO2 +/- hypercapnia
FBC - identify anaemia / polycythaemia
MRC SOB scale, NICE COPD severity classification
COPD Mx
Stop smoking, influenza and pneumonia vaccines, pulmonary rehab
Bronchodilators SABA - salbutamol LABA - salmeterol, formoterol SAMA - ipratropium LAMA - tiotropium Theophylline - bronchodilator, suppresses airway response to stimuli
ICS - beclometasone, fluticasone
Combination therapy of above
Oxygen therapy
NIV (non-invasive ventilation)
Phosphodiesterase t4 inhibitors - anti-inflammatory - eg roflumilast
Mucolytics
Surgery - bullectomy, lung volume reduction surgery, transplant
OVERALL
- SABA / SAMA
- If steroid responsive / asthmatic = add LABA + ICS
- If not steroids responsive / non-asthmatic = add LABA + LAMA
- Oral theophylline
- Long term oxygen therapy
Do not prescribe LAMA and SAMA together, if started on LAMA, remove SAMA
COPD Cx
Acute exacerbation, infection secondary polycythaemia (not enough O2 reaching tissues, EPO increases) resp failure pneumothorax lung carcinoma reduced QoL
COPD acute exacerbation
acute worsening of symptoms
commonly viral cause, also bacterial, air pollutants
Tx - nebulised bronchodilators, O2, steroids, ABs, aminophylline/theophylline, doxapram (respiratory stimulant drug), NIV
CF
autosomal recessive multi-organ disease, resp problems, pancreatic insufficiency, characterised by thickened secretions
CF patho
mutations in CFTR gene (chromosome 7) - chloride channel exporting Na and Cl
defective -> not enough Cl secretion, increased Na absorption, less water secreted -> thickened secretions
(in sweat gland, cannot reabsorb Cl, thus Na also not reabsorbed)
- High sodium sweat
- Pancreatic insufficiency - dehydration of secretions, they stagnante in ducts
- Biliary disease - concentrated bile, plugging, local damage
- GI disease - highly viscous secretions, intraluminal water deficiency
- Resp disease - dehydration of airway surfaces, reduced mucociliary clearance, favours bacteria, inflammatory lung damage
RFs - FHx
CF Px
Neonates
failure to thrive, meconium ileus, rectal prolapse
Respiratory cough thick mucus wheeze recurrent infections bronchiectasis, airflow limitation sinusitis nasal polyps spontaneous pneumothorax haemoptysis, SOB
Alimentary thick secretions reduced pancreatic enzymes pancreatic insufficiency - DM, steatorrhoea distal intestinal obstruction syndrome reduced bicarb malabsorption cholesterol gallstones, liver cirrhosis peptic ulcers, malignancy
Others male infertility females can conceive, often develop secondary amenorrhea as disease progresses salty sweat clubbing osteoporosis bilateral coarse crackles cyanosis FEV1 - obstruction
CF Ix
Sweat test - high sodium and chloride
Genetic testing
CXR, thorax CT
Lung function tests, spirometry
Sputum micro, swab (common orgs - H.influenzae, S.aureus, P.aeruginosa, E.coli, K.pneumoniae)
Bloods
CF Mx
Stop smoking, good nutrition
Chest Postural drainage, chest physio ABs, for infection and prophylaxis Mucolytics - dornase alfa Bronchodilators
GI
pancreatic enzyme replacement
ADEK vitamin supplements
Ursodeoxycholic acid for impaired liver function
Tx CF-related diabetes
Advanced lung disease - O2, diuretics, ventilation, transplant
CF Cx
Resp disease - infection, bronchiectasis, cor pulmonale, death`
Extrinsic allergic alveolitis
diffuse granulomatous inflammation of lung parenchyma - response to organic antigens
aka hypersensitivity pneumonitis
EEA patho
allergic reaction to inhaled antigen (eg fungal spores, avian proteins)
acute and subacute - pneumonitis
chronic - fibrosis, emphysema, permanent damage
T3 HYPERSENSITIVITY - inflammation through activation of complement via classical pathway
Associations:
Farmer’s lung, pigeon fanciers lung, cheese-workers lung, malt-workers lung, humidifier fever, hot tubs
EAA Px
Acute fever rigors myalgia dry cough SOB crackles (no wheeze) chest-tightness
subacute
less severe as acute, gradual onset, can present as recurrent pneumonia
chronic
cyanosis, clubbing, wt loss, increasing SOB, T1 resp failure, cor pulmonale
EEA DDx
infection, connective tissue disorder, pulmonary fibrosis, asthma, drug-induced ILD
EEA Ix
Take good history
CXR - fibrotic shadow in upper zone (upper zone mottling)
HRCT
FBC - WCC, ESR increased
PFTs - reversible restrictive defect, reduced gas transder
Bronchoalveolar lavage - analysis of lymphocyte count
EEA Mx
Acute
remove antigen
O2
oral prednisolone
Chronic
avoid allergen exposure
long term prednisolone
EEA Cx
Spontaneous pneumothorax, pulmonary fibrosis, emphysema, resp failure
Goodpasture’s syndrome
autoimmune disease - acute glomerulonephritis and pulmonary alveolar haemorrhage
GP syndrome patho
circulating anti-GBM ABs - ABs against an intrinsic antigen to BMs of kidney and lung
RFs - genetics, exposure to organic solvents, hydrocarbons, smoking, infection
GP syndrome Px
upper RTI symptoms - sneezing, nasal discharge, nasal congestion, runny nose, fever
signs
anaemia (from persistent intrapulmonary bleeding)
acute glomerulonephritis
tachypnoea, SOB, inspiratory crackles, cyanosis, HTN
massive pulmonary haemorrhage -> resp failure
symptoms cough intermittent haemoptysis tiredness chills, fever, N+V, wt loss, chest pain
GP syndrome DDx
idiopathic pulmonary haemosiderosis, SLE, RA
GP syndrome Ix
anti-GBM ABs in blood
CXR - transient patchy shadows - due to haemorrhage, often in lower zones
Kidney biopsy
GP syndrome Mx
Some patients spontaneously improve
Tx shock
Immunosuppression - methylprednisolone, cyclophosphamide, azathioprine, then oral prednisolone
Plasmapheresis - remove blood, clean to remove ABs, insert back
GP syndrome Cx
resp failure, AKI, CKD
Granulomatosis with polyangiitis (GPA)
multisystem disorder characterised by necrotising granulomatous inflammation and vasculitis of small/medium vessels
GPA patho
ANCA-associated - anti-neutrophil cytoplasmic AB
neutrophils activated inappropriately, ROS production, neutrophil degradation, inflammation and granuloma formation
most commonly presents with lesions in upper resp tract, lungs, kidneys
sinuses, eyes, skin may also be affected
GPA Px
rhinorrhoea (nasal congestion), then nasal mucosal ulceration - ‘saddlenose’ deformity
signs
renal disease - glomerulonephritis with crescent formation, proteinuria, haematuria
skin purpura, peripheral neuropathy, arthritis/arthralgia
symptoms cough pleuritic pain haemoptysis fever
GPA DDx
Churg-Strauss syndrome, GP syndrome, SLE, RA with systemic vasculitis
GPA Ix
Bloods - c-ANCA positive, also p-ANCA, raised ESR, CRP
CXR - nodular masses of pneumonic infiltrates with cavitation
CT - maybe diffuse alveolar haemorrhage
Biopsy of affected tissue
Urinalysis - proteinuria/haematuria, if yes consider renal biopsy
GPA Mx
Prednisolone, cyclophosphamide, rituximab
azathioprine, methotrexate
plasma exchange
surgery - nasal deformity, AKI (renal transplant)
GPA Cx
AKI, resp failure, chronic conjunctivitis, nasal septum perforation
Influenza
acute resp illness due to infection with influenza virus
Influenza patho
Droplet infection and contact
Three serotypes
- A - more frequent, major outbreaks
- B - less severe
- C - mild, like common cold
Antigens
H - haemagglutinin (15) - facilitates virus entry into host cell
N - neuraminidase (9) - facilitates virion release from infected cell
Antigenic drift - mutations to surface antigens
Influenza Px
1-4 day incubation fever dry cough sore throat coryzal symptoms - catarrhal inflammation of nose headache malaise myalgia anorexia conjunctivitis eye pain +/- photophobia
complications pneumonia chronic lung disease exacerbation croup otitis media D+V myositis encephalitis Reye syndrome - encephalopathy + fatty degenerative liver failure
