Respiratory medicine Flashcards
Define Acute respiratory distress syndrome
Acute lung damage leading to non-cardiogenic pulmonary oedema
It’s due to diffuse alveolar damage with hyaline membrane formation, endothelial disruption and leakage of fluid into the alveoli from pulmonary capillaries
The Berlin criteria are used to determine if a pt has ARDS, they need to have all of the following:
1) Acute onset <1wk
2) CXR showing bilateral opacities
3) Decreased ratio of arterial to inspired O2 concentration (PaO2/FiO2) <300
Causes of Acute respiratory distress syndrome
Common:
- Sepsis
- Pneumonia
- Aspiration
- Pancreatitis
- Major trauma
Other:
- Fat embolism
- Drowning
- Burns
- TRALI
- Drug overdose
- DIC
Acute respiratory distress syndrome features
- Severe dyspnoea
- Tachypnoea
- Confusion and presyncope secondary to hypoxia
- Appear in respiratory distress
- Critically unwell
- Diffuse crepitations on auscultation
Acute respiratory distress syndrome investigations
- Resp viral swabs = COVID19, influenza
- Sputum, blood and urine cultures = septic screen
- ABG
- Serum amylase = pancreatitis is a common cause
- CXR = bilateral alveolar infiltrates w/out features of HF (cardiomegaly and Kerley B lines)
- CT chest
Acute respiratory distress syndrome management
- Identify and treat underlying cause
- Intubation and ventilation on ICU
Define Asbestosis
Chronic fibrotic lung disease that typically manifests 10-20 years following exposure to asbestos fibres
Asbestosis features
Symptoms:
- Progressive dyspnoea manifesting over months-years
- Dry cough
- WL
- Fatigue
Signs:
- Bilateral fine end-expiratory crepitations, predominantly basal
- Finger clubbing
- Cyanosis
Asbestosis investigations
- Exposure Hx
- PFTs = reduced FVC and TL w/ normal FEV1/FVC
- CXR = bilateral shadowing, often at the bases
- High resolution CT = may show honeycombing, traction bronchiectasis and parenchymal bands esp in the lower zones
Asbestosis management
No specific treatment to reverse the lung damage - aim for supportive therapy and reducing the risk of LC:
- Smoking cessation
- Pulmonary rehab
- O2 therapy if significant hypoxaemia
- Influenza and pneumococcal vaccines
Define Aspiration pneumonia
Inflammation of the lungs after an irritating substance is inhaled (commonly gastric or oesophageal secretions)
This causes pneumonitis, and may lead to infection caused by the normal flora found in the oropharynx entering the LRT
Causes of Aspiration pneumonia
- Swallowing difficulties = stroke, bulbar palsy, oesophageal strictures, MS, achalasia
- Impaired consciousness = seizures, GA, alcohol/drug intoxication
- Tracheooesophageal fistulae
Aspiration pneumonia features
- Cough - may be productive of purulent sputum
- SOB
- Chest pain
- Fever
- Malaise
Aspiration pneumonia investigations
- Sputum culture
- Bloods
- CXR = look for consolidation - more likely to be right sided due to the more vertical orientation of the right main bronchus
Aspiration pneumonia management
- Initial abx as per local guidelines - BTS suggest co-amoxiclav
- Supportive care
Asthma pathophysiology
Type 1 hypersensitivity reaction leading to inflammation
This inflammation leads to airway hyperresponsiveness which in turn causes bronchospasm, mucus hypersecretion and airway obstruction
Over time in severe asthma, airway remodelling mediated by fibroblasts causes chronic obstruction and thickening of smooth muscle
Asthma investigations
- Spirometry w/ bronchodilator reversibility testing for all pts >5
- FeNO testing in adults to confirm eosinophilic airway inflammation = +ve if >40 parts per billion
If there is diagnostic uncertainty following the tests, pts may be asked to monitor their peak flow twice a day for 2-4 wks and keep a dairy, this is to assess peak flow variability - variability >20% is +ve
If still uncertain then can do direct bronchial challenge testing = histamine or metacholine is inhaled to trigger bronchoconstriction, airway hyperresponsiveness is assessed by looking at the concentration of the triggering medication required to causes a 20% decrease in FEV1 - 8mg/mL or less is +ve
Management ladder for chronic asthma
1) SABA (salbutamol) +/- low dose ICS (betamethasone) for pts using their SABA 3x a week or more
2) Add a leukotriene receptor antagonist e.g. Montelukast
3) Add LABA e.g. salmeterol
4) Low dose ICS + maintenance and reliever therapy inhaler (MART) +/- LTRA
- MART = combination inhaler of beclomethasone + formoterol (Fostair) which can be used as both a reliever therapy and maintenance treatment
5) Increase ICS dose and refer to secondary care
6) High dose ICS, oral corticosteroids
7) Biologics e.g. omalizumab which targets IgE
Grading of acute asthma exacerbation severity
Moderate:
- PEFR >50% of predicted or best
- No features of severe/life-threatening asthma
Severe:
- PEFR 33-50% of predicted or best
- HR >110
- Resp rate >25
- Unable to complete sentences in one breath
- Accessory muscle use
Life-threatening:
- PEFR <33% of predicted or best
- O2 sats <92% or cyanotic
- Altered consciousness/confusion
- Exhausted/poor resp effort
- Cardiac arrhythmia
- Hypotension
- Silent chest
Acute asthma management
- ABCDE
- Titrate O2 to maintain sats 94-98%
- Nebulised salbutamol (10 puffs outside of hospital)
- Add ipratropium bromide if no response
- Give prednisolone 40-50g orally, or IV hydrocortisone if pt unable to swallow
- Consider IV magnesium sulphate and/or aminophylline if no response to nebulisers
- If pt continues to deteriorate then intubation and ventilation in ICU
Follow pt up 2 wks after an acute attack
Chronic asthma management ladder in paediatrics
Under 5’s:
1) SABA
2) 8 week trial of moderate paediatric dose ICS if symptoms >3x a week or disturb sleep
4) If symptoms reoccur w/in 4 wks then paediatric low dose ICS, if reoccur after 4 wks repeat the trial
5) Add LTRA
6) Refer to secondary care
5-16:
1) SABA
2) Add paediatric low dose ICS
3) Add LTRA
4) Swap LTRA for LABA
5) Swap to MART inhaler e.g. Fostair
6) Refer to secondary care
What are the 2 types of pneumococcal vaccine?
1) Pneumococcal polysaccharide vaccine = 1 off dose that covers 23 variants - revaccinated every 5 years
2) Pneumococcal polysaccharide conjugate vaccine = part of the childhood vaccination schedule, 2 doses are given at 12 weeks and 1 year - covers 13 serotypes
Who is given the Pneumococcal polysaccharide vaccine?
Pts aged 65+ and pts aged 2+ in an at risk group:
- Splenic dysfunction or asplenia
- COPD
- Chronic HF
- CKD stage 4/5
- Chronic liver disease
- DM requiring medication
- Immunosuppressed pts
- Cochlear implant
- Pts at risk of CFS leak
- Pts exposed to metal fumes at work (e.g. welders)
Causes of Bilateral hilar lymphadenopathy
- Inflammation = sarcoidosis
- Infective = TB, mycoplasma, histoplasmosis
- Malignancy = lymphoma (HL more common than NHL), carcinoma
- Pneumoconiosis = silicosis, berylliosis
Define Bronchiectasis
A chronic lung disease where inflammation and obstruction causes damage to the bronchial walls leading to their permanent dilation
The damage may affect the whole lung or only one lobe
Causes of Bronchiectasis
- Idiopathic (40%)
- Previous severe LRTI (most common identifiable cause)
- Immunodeficiency = HIV, CVID
- Defective mucocilliary clearance = CF, PCD
- AI = RA, SLE, IBD
- Airway obstruction = inhaled foreign body, bronchial carcinoma, severe COPD/asthma
- Chronic aspiration
- Congenital defects of the large airways = Marfan’s, tracheobronchomegaly
Bronchiectasis features
Symptoms:
- Productive cough lasting at least 8 weeks
- Copious production of purulent sputum
- Dyspnoea
- Haemoptysis
- Chest pain
- Fatigue
- WL
Signs:
- Coarse crackles on auscultation
- Wheeze
- Rhonchi = snoring sound caused by secretions in the large airways
- Finger clubbing
Bronchiectasis investigations
- Sputum culture
- Spirometry
- Bloods
- CXR = increased lung markings, tram-track opacities and ring shadows
- High-resolution CT = diagnostic -shows lack of tapering of airways, increased ratio of bronchi to adjacent pulmonary arteries, bronchial wall thickening and impacted mucus
- Investigate underlying cause
Bronchiectasis management
Conservative:
- Pt education on sputum clearance chest exercises
- Smocking cessation
- Pulmonoral rehan
- Influenxa and pneumococcal vaccines
Medical:
- Treat infectious exacerbations
- Long-term abx prophylaxis should be considered in pts w/ 3+ exacerbations per year, or exacerbations causing significant morbidity - these should be tailored to sputum cultures
- Treat comorbidities
Surgical:
- Lung resection in severe localised disease
- Lung transplant in severe diffuse cases
COPD GOLD gradeing system
Grade 1) Mild COPD = FEV1 >80% of predicted, FEV1/FVC <0.7
Grade 2) Moderate COPD = FEV1 50-79% of predicted , FEV1/FVC < 0.7
Grade 3) Severe COPD = 30-49% of predicted, FEV1/FVC <0.7
Grade 4) Very severe COPD = FEV1 <30% of predicted or <50% w/ resp failure or RHF, FEV1/FVC <0.7
COPD features
Symptoms:
- SOB worse w/ exertion
- Reduced exercise tolerance
- Chronic productive cough
- Recurrent LRTI
- Wheeze
Signs:
- Wheeze or crackles on auscultation
- Accessory muscle usage
- Pursed lip breathing
- Cyanosis
- Hyperinflation of the chest
- Cachexia
- Raised JVP and pulmonary oedema (indicates cor pulmonale)
COPD investigations
- Spirometry = FEV1/FVC <0.7
- Bloods = look for polycythaemia (chronic hypoxia) or anaemia (of chronic disease)
- CXR = hyperinflation, flattened hemidiaphragms, bullae
Chronic COPD management
Conservative:
- Smoking cessation
- Annual influenza and 1 off pneumococcal vaccines
- Pulmonary rehab
Medical:
- SABA or SAMA (ipratropium) inhaler for all pts who’s activates are limited by breathlessness
- Next step depends on if they have features of asthma or steroid responsiveness - if they do then add LABA (formoterol) and ICS, if not then add LABA and LAMA (tiotropium)
- Then all 4 inhalers = SABA/SAMA + LABA + LAMA + ICS
- Oral mucolytics
- Prophylactic abx = azithromycin 3x a week
- Long-term O2 therapy for at least 15 hrs a day if they meet the criteria (in another flash card)
Surgical = Lung volume reduction surgery = removal of emphysematous areas of the lung so the healthy lung can expand:
- Surgical resection
- Bronchoscopic insertion of a one-way valve in one of the larger airways to collapse the diseased lung
why
How are COPD pts assessed for long-term O2 therapy?
Pts should be referred if:
- Oxygen saturations <92% in air or cyanosis
- FEV1 <30% predicted (consider referring if <49%)
- Polycythaemia
- Peripheral oedema or raised jugular venous pressure (suggesting cor pulmonale)
Pts are assessed to ensure they are medically optimised and their COPD is stable (not recovering from a recent exacerbation) and to ensure they dont smoke (O2 is a fire hazard)
Pts then have 2 ABGs in air at least 3 weeks apart and the following pts are offered LTOT:
- PaO2 below 7.3kPa
- PaO2 7.3-8kPa w/ any of; secondary polycythaemia, peripheral oedema or pulmonary HTN
Acute exacerbation of COPD management
- If clinically well = increase in usual inhaler usage, 30mg prednisolone for 5 days, oral abx if bacterial suspected
- If unwell then admit for IV steroids and abx
Causes of Croup
- Parainfluenza virus (most common)
- Adenovirus
- RSV
- Rhinovirus
- Influenza
These viruses causes inflammation of the subglottic and laryngeal mucosa which partially obstruct the airways - leads to resp distress and stridor
Croup management
Depends on severity:
- No stridor or chest recessions = treat at home w/ single dose of oral dexamethasone 0.15mg/kg
- Stridor or chest recessions or systemically unwell = admit, O2 therapy, oral dex/prednisolone or nebulised budesonide
- Nebulised adrenaline for temporary symptomatic relief
- Anaesthetics +/- ENT input if concerns regarding airway
Cystic fibrosis features
Resp:
- Bronchiectasis (chronic productive cough, dyspnoea)
- Frequent LRTIs
- Chronic sinusitis
- Nasal polyps
- Increased incidence of pneumothoraces
GI:
-Meconium ileus
- Distal intestinal obstruction syndrome = SBO due to thickened secretions
- Rectal prolapse
- Pancreatic insufficiency = DM and steatorrhea
- Cirrhosis and portal HTN
- Gallstones
- Failure to thrive
- Prolonged neonatal jaundice
Reproductive:
- Congenital absence or blockage of vas deferens = obstructive azoospermia
- Thickened cervical mucus and menstruation disruption due to malnutrition can impact female fertility
MSK:
- Finger clubbing
- Osteopenia/porosis due to malnourishment
- Short stature
- Non-specific joint and muscle pain
Cystic fibrosis investigations
- Heel pick test at birth
- Chloride sweat testing = if sweat Cl level >60mmol/L
- Genetic testing
Cystic fibrosis management
Conservative:
- Pt education
- Airway physio = twice daily airway clearance ant home
- Dietitian input
Medical:
- Orkambi (CFTR modulator) can be given to pts w/ 2 copies of the F508 gene
- Other precision medication used for 1 copy
- Dornase alpha daily nebuliser = is a mucoactive agent which reduces the viscosity of the mucus and makes sputum clearance easier
- Creon and insulin for pancreatic insufficiency
- Flucloxacillin should be given from diagnosis till ages 3-6 as prophylaxis against infections
- Oral azithromycin can be used as an immunomodulator in pts w/ declining lung function or frequent exacerbations - oral steroids 2nd line
Surgical:
- Organ transplant - lung or liver
Differentials for haemoptysis
Bleeding from the trachea or bronchi:
- Malignancy
- Bronchitis
- Bronchiectasis
- Airway trauma
Bleeding from the lung parenchyma:
- Pneumonia = rust coloured in pneumococcal, red current jelly coloured in klebsiella
- TB
- Lung abscess
- Granulomatosis w/ polyangiitis
- Goodpasture’s syndrome
Vascular bleeding:
- PE
- AV malformation
- Mitral stenosis (due to pulmonary venous HTN)
- Iatrogenic
Causes of Horner’s syndrome
Central lesions:
- Vertebral artery dissections
- Ischaemic stroke (lateral medullary syndrome)
- Syringomyelia above T1 (can be bilateral)
- Demyelination
- Neoplasm of the brainstem
Preganglionic:
- Cervical rib
- Pancoast’s tumour (apical LC that invades the surrounding soft tissue)
- Thyroid or mediastinal tumour
- Iatrogenic (birth trauma)
Postganglionic:
- Carotid artery dissection
- Cavernous sinus thrombosis
- Injury of the superior cervical ganglion
- Cluster headache
- Neoplasms of the nasopharynx, pituitary or skull base
Serotypes of Influenza
- Influenza A = capable of causing pandemics and epidemics, no animal reservoir
- Influenza B = capable of epidemics only, animal hosts includes pigs and birds
- Influenza C = only found in cattle
Influenza features
Incubation period of 1-4 days and pts can remain infectious for 7-21 days
- Fever
- Non-productive cough
- Myalgia
- Headache
- Malaise
- Sore throat
- Rhinitis
Influenza management
- Largely supportive
- If w/in 48hrs and pt at great risk of complications - can give Tamiflu (neuraminidase inhibitor)
Causes of Interstitial lung disease
Upper zone predominant (BREAST):
- Bronchopulmonary aspergillosis
- Radiotherapy
- Extrinsic allergic pneumonitis
- Ankylosing spondylitis
- Sarcoidosis/silicosis
- TB
Lower zone predominant (RAIDS):
- RA
- Asbestosis
- Idiopathic pulmonary fibrosis (most common)
- Drugs (amiodarone, nitrofurantoin, bleomycin, methotrexate, phenytoin)
- Scleroderma/SLE
Define Idiopathic pulmonary fibrosis
A progressive, fibrotic lung disease of unknown cause that is more common in males and smokers
Imaging usually shows interstitial pneumonitis, and there is characteristic basal honeycombing on high resolution CT scan
Median survival of 3yrs from diagnosis
Define Hypersensitivity pneumonitis
A hypersensitive reaction in the lungs due to inhalation of specific environmental agents - e.g. chemicals, agricultural dusts, plants, animals and fungal proteins
One-off exposure can cause acute onset flue-like symptoms, but repeated exposure results in ongoing inflammation - this leads to interstitial fibrosis
Define Farmers lung
A type of hypersensitivity pneumonitis triggered by mould spores of hay or straw
Interstitial lung disease features
Symptoms:
- Dry cough
- SOB
- Reduced exercise tolerance
- Fatigue
- WL
- Anorexia
Signs:
- Cyanosis
- Clubbing
- Cachexia
- Fine end-inspiratory crackles that don’t clear on coughing - location depends on the type of ILD
Interstitial lung disease investigations
Bloods:
- FBCs may show eosinophilia in hypersensitivity pneumonitis
- U&E, LFTs, bone profile
- CRP
- AI screen
- Serum precipitins to specific antigens
- Serum ACE if suspecting sarcoid
Imagine:
- CXR = usually shows reticular and nodular shadowing
- Bilateral hilar lymphadenopathy = sarcoidosis
- HRCT = gold standard - typical findings are honeycombing, ground-glass changes and traction bronchiectasis (where contracting fibrosis pulls the bronchioles apart)
Other:
- Spirometry = FEV1/FVC >0.7, decreased total lung capacity, decreased TLCO
- Bronchoscopy to find predominant cells in the lung
- Lung biopsy
Idiopathic pulmonary fibrosis management
2 antifibrotic drugs available:
- Pirfenidone = reduces fibroblast proliferation
- Nintedanib = tyrosine kinase inhibitor
Other:
- Early palliative care
- Smoking cessation
- LTOT
- Lung transplant
Hypersensitivity pneumonitis management
- Potential for reversal if causative agent can be identified and removed
- Trial steroids if symptoms still persist
- Immunosuppression (cyclophosphamide, azathioprine) if those don’t work
Types of Lung cancer
- Small cell (from neuroendocrine cells)
- Non-small cell = SCC (basal epithelial cells), adenocarcinoma (alveolar type 2 cells), large cell (variety of epithelial cells)
Lung cancer features
Symptoms:
- Persistent cough
- Haemoptysis
- Dyspnoea especially on exertion
- Chest pain
- WL
- Recurrent chest infections, or infections resistant to treatment
- Anorexia
Signs:
- Cachexia
- Finger clubbing
- Lymphadenopathy (supraclavicular, persistent cervical)
- Lung collapse due to obstructive tumour
- Malignant pleural effusions
Paraneoplastic syndromes:
- Cushing’s syndrome (SCLC)
- SIADH (SCLC)
- Lambert-Eaton syndrome (SCLC)
- Humoral hypercalcaemia of malignancy (SCC) = release of PTHrP that mimics PTH and causes hypercalcaemia
- Hypertrophic pulmonary osteoarthropathy (adeno) = a periosteal reaction of bones which causes clubbing and arthritis especially affecting the wrists and ankles
Lung cancer investigations
2WW referal criteria:
- Aged 40+ w/ unexplained haemoptysis
- CXR findings suspicious for LC
Urgent CXR w/in 2wks for pts 40+ who have any of these symptoms and have smoked, or have 2 symptoms and have never smoked:
- Cough
- Fatigue
- SOB
- Chest pain
- WL
- Anorexia
Chest X-ray findings:
- Lung mass
- Consolidation
- Bulky hilum (indicative of SCC which arises centrally)
- Lobar collapse (SCC)
- Pleural effusion
Other:
- Biopsy
- PET-CT
- Spirometry
Lung cancer management
Conservative:
- MDT approach
- Smoking cessation
- Advanced care planning
Medical:
- Chemo = palliative for most SCLC, and stage 3/4 NSCLC - can also be adjuvant or neoadjuvant
- Immunotherapy = pembrolizumab or atezolimab - palliative in NSCLC
- Targeted therapies for pts w/ specific mutations
- Radiotherapy = can be curative (early NSCLC) or palliative
Surgical:
- Lobectomy = standard in early stages
- Wedge resection = for very small tumours
- Pneumonectomy may be required depending on size and location of tumour
- All pts should have the mediastinal and hilar lymph nodes sampled and resected if suspicious
Define Lung nodule
A rounded opacity in the lung that measure under 3cm in diameter (>3cm is a mass)
They are the most common incidental finding on CXR and CT
Causes of Lung nodules
- Inflammatory = granulomas, RA nodules
- Infectious = abscess, small focus of pneumonia, TB, fungal
- Neoplastic = LC, mets, carcinoid tumour, lymphoma, benign neoplasm (pulmonary hamartoma)
- Congenital = lung cyst, AV malformation, pulmonary sequestration (accessory lung formation), bronchial atresia w/ mucus plugging
- Other = infarcted lung due to PE, localised haemorrhage
Causes of Lung abscesses
- Aspiration = most common, usually mixed infections w/ anaerobes
- Necrotising pneumonia = Staph A, Klebsiella, Pseudomonas and Proteus infections
- TB
- Bronchial obstruction = secondary to inhaled foreign body or malignancy
- Infective endocarditis = from right sided vegetations
- Contiguous spread = from a liver abscess or empyema
Lung abscess features
Symptoms - non-specific:
- Fevers
- Productive cough
- SOB
- Lethargy
- Night sweats
- WL
- Haemoptysis
- If near pleura = chest pain
Signs:
- Clubbing
- Localised dullness to percussion
- Reduced air entry over the abscess
Lung abscess investigations
- Sputum MC&S
- Bloods +/- cultures
- CXR = shows a round lesion w/ an air-fluid level - right lobe is most common due to aspiration
- CT chest
- Bronchoscopy
- Pus MC&S
Lung abscess management
- Broad spectrum abx (co-amoxicilin) IV for 2-3 weeks, then switch to an oral agent based on microbiology and local guidelines for 4-8 weeks
- Supportive care
- Chest physio
- Can do surgery if poor response to therapy, or concurrent empyema = open drainage, percutaneous drainage or via bronchoscopy
Define Empyema
A collection of pus w/in the pleural cavity
Usually due to pneumonia, but can be caused by thoracic surgery or trauma, TB or lung abscesses
Empyema management
- Thoracentesis
- IV Abx
Define Obstructive sleep apnoea
A condition where the upper airway becomes completely or partially obstructed during sleep causing apnoea’s (temporary stoppage of breathing) or hypopnea’s (decreased airflow during breathing) episodes
These episodes cause O2 desaturation which causes brief arousal from sleep - this can happen 100s of times a night
This leads to overall poor sleep quality
Obstructive sleep apnoea risk factors
- Obesity
- Male
- Older age
- Decreased muscle tone = alcohol excess, sedative meds, muscular dystrophy, neuromuscular disorders
- Anatomical defects = retrognathia, macroglossia
- Large neck circumference
- Adenotonsillar hypertrophy
- Sleeping supine
- Down’s syndrome
Obstructive sleep apnoea features
- Unrefreshing sleep
- Daytime sleepiness
- Snoring, apnoea’s, gasping/chocking during sleep
- Difficulty concentrating
- Morning headaches
Obstructive sleep apnoea investigations
- Screening questionnaires = STOP-Bang or Epworth sleepiness scale
- Polysomnography (definitive) = sleep study at a specialist clinic
Obstructive sleep apnoea management
Conservative:
- Advice on sleeping supine
- WL support
- Smoking cessation
Medical:
-CPAP therapy (1st line)
Surgical:
- If oropharyngeal obstructions then can remove via surgery
Define Pleural effusion
A collection of fluid in the pleural cavity >10-20ml (normal serous volume) - this can impede respiration as the lungs cannot fully expand
There are 2 types:
1) Transudates (protein <25g/L) = changes in oncotic and hydrostatic pressure cause fluid to leak from the vasculature
2) Exudates (protein >35g/L)= where inflammation leads to increased microvascular permeability and drainage of pleural fluid may be impaired
Causes of Pleural effusion
Transudative:
- HF
- Nephrotic syndrome
- Cirrhosis
- Hypoalbuminaemia
Exudative:
- Pneumonia
- Malignancy
- TB
- PE
- RA
- SLE
- Pancreatitis
- Trauma
What are Light’s criteria?
A way to distinguish effusions - if any of the following are true than the effusion is an exudate:
- The ratio of pleural to serum protein > 0.5
- The ratio of pleural to serum LDL > 0.6
- The pleural fluid LDL is greater than 2/3 of the upper limit of the normal serum value
Pleural effusion features
Symptoms:
- Asymptomatic
- SOB
- Dry cough
- Pleuritic chest pain
Signs:
- Reduced chest expansion on the affected side
- Dullness to percussion over the effusion
- Reduced or absent breath sounds over the effusion
- Loss of vocal resonance over the effusion
- Large effusions may cause tracheal deviation away from the effusion
- Resp distress
Pleural effusion investigations
- CXR (1st line) = shows blunting of the costophrenic angle, or a white-out of a lung
- CT w/out contrast
- Pleural tap should be done on all suspected exudative effusions, as well as transudative that have failed to respond to treatment
- Aspirate is then sent for MC%S, cytology and biochemistry
- Paired serum protein and LDL should be sent
Pleural effusion management
Conservative:
- Symptom management
- O2
Medical:
- Abx for infection
- Diuretics if secondary to HF
Interventional:
- US guided pleural aspiration for symptomatic relief
- Chest drain for empyema’s, haemothorax’s and larger effusions
- For rapidly recurrent effusions = indwelling drain or pleurodesis (irritant injected into pleural space sealing it shut via a fibrotic reaction)
Surgical:
- Thoracotomy for recurrent effusions
Define Pneumocystis pneumonia (PCP)
An infection caused by the fungus Pneumocystis Jirovecii
Only affects pts who are immunocompromised
Which people are at risk of getting Pneumocystis pneumonia
- HIV w/ a CD4 count <200
- Steroids or other immunosuppressive medications
- Previous organ transplant
- Congenital immunodeficiencies
- Severe malnutrition
- Comorbid lung disease
- Haematological malignancies
Pneumocystis pneumonia features
Symptoms:
- Fever
- Dry cough
- Exertional breathlessness - pts classically desaturate on exertion
- Chest pain
Signs:
- Chest may be clear, end-inspiratory crackles or wheeze
Pneumocystis pneumonia investigations
Bedside:
- O2 on exertion (desaturate)
- ABG
- Sputum sample - silver staining is used to confirm PCP
Bloods:
- FBC
- CRP
- LFTs
- U&Es
- HIV testing
- CD4 count if HIV +ve
Imaging:
- CXR = bilateral hilar interstitial infiltrates (10% have normal Xray)
- HRCT = if CXR normal and PCP suspected
- Bronchoscopy w/ bronchoalveolar lavage = if sputum -ve to gain a resp sample for staining
Pneumocystis pneumonia management
- Supportive
- Mild disease - OPT treatment
- Moderate-severe = inpatient
- High dose co-trimoxazole is 1st line
- Steroids in all pts w/ moderate or severe = either oral prednisolone or IV hydrocortisone
Define Pnuemonia
An inflammatory condition of the lung parenchyma caused by infection
The alveoli become filled w/ inflammatory cells and microorganisms, leading to consolidation - this impairs gas exchange
Which organisms cause Pnuemonia?
Typical community aquired:
- Streptococcus pneumonia (most common)
- Haemophilus influenzae
- Moraxella catarrhalis
Atypical community aquired:
- Mycoplsama pneumoniae
- Legionella pneumophilia
- Chylmydophilia psittaci
Hospital acquired (>48hr after admission):
- Pseudomonas aeruginosa
- Staphylococcus aureus
- Any of the above (less common)
Typical Pnuemonia features
Symptoms:
- Fever
- Malaise
- Rigors
- Cough productive of purulent sputum
- Pleuritic chest pain
- Haemoptysis
Signs:
- Tachypnoea
- Tachycardia
- Hypotension
- Cyanosis
- Pyrexia
- Dullness to percussion over consolidated area
- Increased vocal resonance over consolidated area
- Bronchial breathing over the consolidated area
- Pleural rub may be heard due to inflammation of the adjacent pleura
Staphylococcal pneumonia features
- Bilateral cavitating bronchopneumonia
- More common in IVDU, or as a super added bacterial infection in influenza
Klebsiella pneumonia features
- Cavitating pneumonia affecting he upper lobes
- Presents w/ red-currant sputum
- Gram -ve anaerobic rod
- Increased risk in immunocompromised, elderly and alcohol excess
Mycoplasma pneumonia features
- Flu-like symptoms = arthralgia, myalgia, dry cough, headache
- Primarily in younger pts
- Associated w/ AI haemolytic anaemia caused by cold agglutinins
- May cause erythema multiforme, SJS, GBS and meningoencephalitis
Legionella pneumonia features
- Fever, myalgia and malaise followed by dyspnoea and a dry cough
- Caused by Gram -ve coccobacillus
- Occurs in those exposed to contaminated water
- Causes hyponatraemia and deranged LFTs
Chlamydophila psittaci pneumonia features
- An intracellular bacteria acquired from contact w/ infected birds
- Lethargy, arthralgia, headache, anorexia, dry cough, fever
What is the CURB-65 score?
Classification system for CAP to determin management:
- Confusion
- Urea > 7
- RR > 30 breaths/min
- BP < 90 systolic, or <60 diastolic
- 65 and older
Score of 0-1 requires home treatments, 2 should be considered for admission, 3-5 should be admitted and considered for ITU referral
Pneumonia investigations
Bedside:
- Sputum for microscopy, culture and sensitivity
- ABG
- Urinary legionella and pneumococcal antigens
Bloods:
- Cultures if febrile
- FBC/CRP
- U&Es to look for AKI
- LFTs - deranged in Legionella
- Mycoplasma serology if suspected
- HIV testing in pts with recurrent pneumonias
Imaging:
- CXR = consolidation, parapneumonic effusions
Pneumonia management
Conservative:
- O2
- IV fluids
- Analgesia
- Resp support
Medical:
- CURB-65 of 0-1 = oral amoxicillin TDS for 5 days
- CURB-65 2 or more = IV co-amox and clarithromycin
- Abx should be tailored to sensitivities when those are returned
All pts would be followed up with a repeat CXR 6-8 wks after recovery to screen for underlying cancer - this could have been masked on initial imaging by consolidation
Define Pneumothorax
A collection of air in the pleural cavity which may cause collapse of the underlying parenchyma
Pneumothorax classifications
Can be either spontaneous or traumatic
Spontaneous can be further divided into:
- Primary = pts w/ no underlying lung disease
- Secondary = in pts w/ underlying lung disease
Tension pneumothorax occurs when the defect in the pleura creates a one-way valve effect whereby air can enter the pleural space but cannot leave
Pneumothorax features
Symptoms:
- Sudden onset SOB
- Pleuritic chest pain
- Dry cough
- Tachyapnoea
- Small ones may be asymptomatic and picked up incidentally on imaging
Signs:
- Unilateral reduced expansion
- Unilateral hyper-resonance to percussion
- Reduced or absent breath souds
- Reduced tactile vocal fremitus
Signs of tension:
- Tracheal deviation away from the pneumothroax
- Tachycardia
- Hypotension
- Distended neck veins
Pneumothorax investigations
- If tension suspected = immedtate needle decompression w/out delay for imaging
- Erect PA CXR for other pts
- CT chest in high risk pts w/ an unclear CXR
Tension pneumothorax management
Emergency decompression by inserting a large-bore cannula into the second intercostal space in the midclavicular line
Insertion into the 5th intercostal space in the mid-axillary line in traumatic cases
Primary/secondary pneumothorax management
- Sypmtomatic pts w/ large pneumothorax > 2cm, or pts w/ high-risk features (signigicant hypoxia, bilateral, underlying lung disease, >50 w/ smoking hx, haemopneumothorax) = chest drain and admission for monitoring
- Symptomatic pts w/ large pneumothorax but not high risk = conservative, ambulatory device or needle decompression (pts choice)
- <2cm = conservative management
Ambulatory device = one-way valves inserted under local which allow air to leave but not re-enter
All pts should be followed up 2-4 wks later w/ a repeat CXR - pts shouldn’t fly until 7 days after chest imaging has confirmed resolution + shouldn’t scuba dive for life
What is a provoked PE?
A PE that is associated with a major risk factor w/in the last 3 months
Risk factors:
- Immobility
- Pregnancy or recent childbirth
- Oestrogen-containing medication
- Obesity
- Older age
- Malignancy
- Thrombophilia’s
- Recent surgery
- Smoking
- IVDU
- Personal/family Hx
Pulmonary embolism features
Symptoms:
- Classic triad = sudden onset SOB, pleuritic chest pain, haemoptysis
- Pre/Syncope can indicate a massive PE
- Small PE’s may be asymptomatic
Signs:
- Tachypnoea
- Tachycardia
- Hypoxia
- Crackles
- Low-grade pyrexia
- Massive PE’s = hypotension, cyanosis, signs of RHF
What are the criteria of the Wells score?
3 points for:
- Clinical signs and symptoms of DVT
- PE is most likely diagnosis
1.5 points for:
- Tachycardia
- Immobility > 3 days or major surgery w/in 1 month
- Previous PE/DVT
1 point for:
- Haemoptysis
- Current malignancy
Score of 4 or less = PE unlikely, do a D-dimer - low D-dimer excludes a PE, high should be investigated further
Score of more than 4 = PE likely, do a CTPA or V/Q scan
Pulmonary embolism investigations
Bedside:
- Wells score
- ECG = normal or sinus tachycardia - classic S1Q3T3 (deep S wave in lead 1, pathological Q waves in lead 3 and inverted T waves in lead 3) is seen in < 20% of pts
Bloods:
- D-dimer = not specific, but has a 95% negative predictive value
- U&Es = need to assess renal function before CTPA
- Coagulation baseline screen
Imaging:
- CXR = typically normal but can have Fleischner sign (enlarged pulmonary artery), Hampton’s sign (peripheral wedge shaped opacity), Westermark sign (regional oedema)
- CTPA = gold standard, will show filling defects in the pulmonary vasculature
- V/Q scan = if severe renal impairment or contrast allergy
- LL US doppler
- Unprovoked PE’s should have a full work up to look for malignancy
Pulmonary embolism management
Medical:
- LMWH or DOAC immediately if there is a high clinical suspicion of PE
- Unprovoked PE = 6+ months of DOAC
- Provoked PE = 3 months of DOAC
- Massive PE (hypotension for > 15 min) = thrombolysis w/ IV bolus of Alteplase
Surgical:
- Embolectomy in pts w/ massive PE but contraindicated for thrombolysis
- Catheter-directed thrombolysis in pts w/ a high risk of bleeding
- IVC filter in Pts with recurrent DVTs despite treatment, or who cannot be anticoagulated
Define Pulmonary hypertension
Pulmonary arterial pressure of > 15mmHg at rest
Normal range = 11-20
Causes of Pulmonary hypertension
- Pulmonary arterial HTN = idiopathic, familial, associated w/ other diseases or drugs
- Chronic lung disease = COPD, ILD, bronchiectasis or OSA
- Chronic thromboembolic disease
- Chronic hypoventilation = kyphosis, scoliosis, NMD
- Left heart disease = LHF, mitral stenosis
- Multifactorial = sarcoidosis, myelofibrosis, glycogen storage diseases
Pulmonary hypertension classification
WHO classifies pts into 5 groups:
1) Pulmonary arterial HTN
2) Secondary to LH disease
3) Secondary to chronic pulmonary disease and/or hypoxia
4) Due to chronic thromboembolic disease
5) Other causes
Pulmonary hypertension features
Symptoms:
- Progressive SOB
- Fatigue
- Syncope
- Fluid overload w/ ascites and peripheral oedema (late sign)
Signs:
- Raised JVP
- Parasternal heave
- Loud P2
- Presence of S3 sound
- Pansystolic murmur due to tricuspid regurgitation - occurs due to RV becoming pressure and volume overloaded
- End-diastolic murmur indicative of pulmonary regurgitation - due to high pulmonary pressures
Pulmonary hypertension investigations
Right heart catheterisation = gold standard diagnostic test
Pulmonary hypertension management
Medical:
- O2
- Diuretics
- Manage underlying condition
- CCBs e.g. nifedipine
- PDE-5 inhibitors e.g. sildenafil
- Prostacyclin analogues e.g. iloprost
- Endothelin receptor antagonists e.g. bosentan
- Soluble guanylate cyclase stimulators e.g. riociguat
Aim of these meds is to reduce pulmonary vascular resistance
Surgical:
- Thrombo-arterectomy or pulmonary balloon angioplasty for chronic embolic disease
- Atrial septoplasty = hole made between atria to reduce right sided pressure
- Heart-lung transplant
What is normal PaCO2 on ABG?
4-6kPa
What is normal pH on ABG?
7.35-7.45
Define Type 1 respiratory failure
Hypoxaemia (PaO2 < 8kPa) w/ low or normal levels of Co2 in the arterial blood
Define Type 2 respiratory failure
Hypoxaemia (PaO2 < 8kPa) w/ hypercapnia (PaCO2 > 6.5kPa)
Causes of Type 1 respiratory failure
Due to problems w/ oxygenation though multiple pathologies:
- V/Q mismatch (most common) = an imbalance between ventilation and perfusion in the lungs leading to inefficient oxygenation - low V/Q occurs when alveoli are not sufficient ventilated, a high V/Q occurs when there is limited blood flow to the lungs
- Diffusion limitation = impaired gas exchange across the membranes due to either inflammation/fibrosis or decreased alveolar SA (emphysema) - CO2 is more soluble than O2 and thus this doesn’t cause hypercapnia
- Shunting = when blood passes through the lungs w/out undergoing gas exchange - may be a physiological response to V/Q mismatch as if there are alveoli w/ very poor ventilation the blood will not be sent to them - may cause hypercapnia and T2RF
Causes of Type 2 respiratory failure
Due to a problem w/ ventilation through multiple pathologies:
- Increased dead space = dead space is ventilated but not perfused so there is no gas exchange
- Reduced minute ventilation = either from conditions that decrease RR or conditions that reduce tidal volume
Respiratory failure management
- O2 therapy - pts at risk of CO2 retention should aim for target sats of 88-92% - this is because of the vasoconstrictive properties of O2 therapy which can worsen V/Q mismatch and dead space, decreasing CO2 clearance
- Severe T1RF = CPAP - splints open the airways to increase oxygenation
- Severe T2RF = BiPAP - improves ventilation
Define Sarcoidosis
A multi-system disease that is characterised by the formation of non-caseating granulomas around the body
This leads to scarring in the organs
Sarcoidosis features
Pulmonary:
- Dry cough
- Dyspnoea
- Reduced exercise tolerance
- Chest pain
- Clubbing
- Fine crackles
Dermatological:
- Erythema nodosum
- Lupus pernio (red/purple plaques and nodules on the face)
- Hyper/hypopigmentation
Neurological:
- Meningitis
- Peripheral neuropathy
- Bilateral facial nerve palsy
- Seizures/encephalopathy
Ocular:
- Uveitis
- Keratoconjunctivitis sicca
- Glaucoma
Cardiac:
- Arrhythmias
- Restrictive cardiomyopathy
- Syncope
Abdominal:
- Hepatomegaly
- Splenomegaly
- Renal stones
Systemic:
- Fatigue
- WL
- Arthralgia
- Low-grade fevers
- Lymphadenopathy
- Enlarged parotids
Sarcoidosis investigations
Bedside:
- ECGs = look for hypercalcaemia
- LFTs
- Ophthalmological exam
Bloods:
- FBCs
- LFTs
- Renal function
- Bone profile
- ESR
- Serum ACE = is elevated in around 60%
Imaging:
- CXR = used to stage
- HRCT = assess for pulmonary fibrosis
Other:
- Biopsy = used for confirmation
- Bronchoalveolar lavage = classically find raised lymphocytes and elevated CD4:CD8 ratio
What are the CXR stages of Sarcoidosis?
Stage 1 = bilateral hilar lymphadenopathy (BHL)
Stage 2 = BHL w/ peripheral infiltrates infiltrates
Stage 3 = peripheral infiltrates alone
Stage 4 = pulmonary fibrosis
Sarcoidosis management
Conservative:
- Smoking cessation
- No active treatment needed in many cases
Medical:
- High dose steroids (prednisolone) weaned down to a lower maintenance dose (1st line)
- If that doesn’t work or is contraindicated - immunosuppressants (methotrexate, mycophenolate, azathioprine)
- 3rd line is biologics e.g. infliximab
Surgical:
- Lung transplant in severe fibrosis
Medical management for smoking cessation
Nicotine replacement therapy:
- Reduces craving and withdrawl symptoms
- Multiple formulations = patches, gums, sprays, lozenges
- Common side effects = nausea, dizziness, vivid dreams, palpitations
- Should be started on the day of quiting
- Combo NRT is the most effective = patch for background cravings and a short-acting preperation (e.g. mouth spray) for breakthrough cravings
Bupropion:
- Inhibits the reuptake of dopamine and noradrenaline
- Tablet taken OD for 6 days then BD for 7-9 weeks
- Should be started 7-14 days before the quit date
- Side effects = insomnia, hypersensitivity reactions, rarely seizures
- Contraindicats = epilepsy (decreases seizure threshold), eating disorders, bipolar, brain tumours, benzo/alcohol withdrawl, pregnancy and breastfeeding
Varenicline:
- Partial nicotinic receptor agonist
- Taken as an oral med which is uptitrated over the first week
- Start 7-14 days before the quit date, continued for 12 weeks
- Side effects = suicidal thoughts, depression, hallucinations, nausea and headaches
- Contraindicated in pregnancy and end-stage renal disease
Only 1 of these should be perscribed at any one time
What is a restrictive picture on spirometry?
- Both FVC and FEV1 are reduced (<80% predicted)
- FEV1/FVC is normal (>0.7)
What is an obstructive picture on spirometry?
- FEV1 is reduced (<80% predicted)
- FVC is normal or reduced (but to a lesser extent that FEV1)
- FEV1/FVC is reduced (<0.7)
TB features
Systemic:
- NS
- Fevers
- WL
- Malaise
- Non-tender lymphadenopathy (most commonly cervical and supravlavicular)
Resp:
- Chronic productive cough
- Haemoptysis
- SOB
- Collapse or pleural effusion
Neuro:
- Meningitis
- Focal neuro signs
- Decreased consciousness
MSK:
- Pott’s syndrome = spinal TB - back pain, spinal deformity and neuro deficits
- Arthritis
- Osteomyelitis = cold abscesses with swelling and erythema but no change in temp
- Psoas abscess = triad of fever, limp and back pain
GUM:
- Renal TB = haematurai and flank pain
- Epidydimo-orchitis
- Salpingitis
GI:
- Ileocaecal TB can cause SBO
- Peritoneal TB = ascities
- Intestinal TB can mimic IBD = abdo pain and bloody diarrhoea
Pericardial:
- Pericardial effusions
- Constrictive pericarditis
Cutaneous:
- Erythema nodosum
- Lupus valgaris = painful nodular skin lesions on the face
- Miliary TB may spread to the skin
- Scrolfuloderma = direct invasion of the skin by a TB-infected lymph node or osteomyelitis - forms ulcer and fistulating tracts
Adrenals:
- TB-mediated adrenal destruction (Addison’s)
TB investigations
Screening:
- Mantoux = induration of >5mm is +ve for TB exposure
- Interferon-gamma release assay (IGRA) test = blood test for WC activity against TB antigens
Bedside:
- Sputum sample for MC&S - take 3 early morning samples, can take weeks to grow
- Early morning urine sample for MC&S for genitourinary TB
Bloods:
- FBC, U&E, LFT, CRP
- Mycobacteria blood culture = takes weeks to grow
- HIV test should be offered
Imaging:
- CXR may show = cavitating lesions, pleural effusion, mediastinal or hilar lymphadenopathy, parenchymal infiltrates esp in the upper lobes, Miliary TB (tiny nodules throughout the lung fields)
- Joint aspiration or spinal XR for MSK involvement
- CT head for CNS TB
- US of lymphadenopathy
- Echo
- LP
TB management
Latent:
- 3 months of isoniazid, rifampicin and pyridoxine, or
- 6 months of isoniazid and pyridoxine
Active:
- 2 months of isoiazid, rifampicin, ethambutol and pyrazinamide
- The 4 more months of just isoniazid and rifampicin
Side effects of TB medication
Rifampicin:
- Red/orange discolouration of bodily fluids
- CYP450 induction (i.e. reduces effectiveness of other medications such as the combined oral contraceptive pill)
-Hepatotoxicity
Isoniazid:
- Peripheral neuropathy (prevented by co-administration of pyridoxine)
- Hepatotoxicity
- CYP450 inhibition
Pyrazinamide:
- Arthralgia
- Hyperuricaemia (may cause gout)
- Hepatotoxicity
Ethambutol:
- Retrobulbar neuritis causing colour blindness and loss of visual acuity
-Visual side effects are more common in chronic kidney disease so dose adjustment may be required
