Flashcards in Respiratory Deck (325)
What is a defining feature of asthma?
Reversible air flow limitation - usually with a bronchodilator
What are the possible classifications of an asthma diagnosis?
What immune profile suggests atopy?
Which immune profile strengthens the case for the hygiene hypothesis?
Th1 vs Th2
Which immune cells are seen in asthma?
CD4+ T lymphocytes
Neutrophils (especially in severe asthma)
Which immune cells are particularly seen in severe asthma?
What histological features are seen in asthma?
Thickened basement membrane
New vessel formation
Mucus gland hypertrophy
Which conditions can result in airflow obstruction?
Inhaled foreign body
Large airway stenosis
How can airflow obstruction be tested for?
Which test is no use if there is no suspected airflow obstruction?
What is the differential diagnosis in the event of no airflow obstruction?
Vocal cord dysfunction
Which white blood cell is commonly raised in asthma?
Which drugs may stimulate an asthma attack?
Aspirin in 2-3 percent of asthmatics
What is the identifying feature in bronchiectasis?
Chronic productive cough
How is bronchiectasis diagnosed?
High resolution CT
What is the most common cause of cough with no obvious cough?
What feature of a cough indicates acid reflux?
Cough is excessive relative to other asthma symptoms
Is acid reflux cough always with dyspepsia?
In what percentage of asthmatics is aspirin an irritant?
What clinical features are associated with aspirin induced asthma?
What features are commonly seen on the FBC of someone with an exacerbation of asthma?
Raised eosinophils and neutrophils
What test may be done to investigate the specific trigger of a patients asthma?
Specific IgE finger prick testing
What is the airway responsiveness test?
What are the methods for primary prevention of asthma?
Avoid tobacco smoking
Is it worth avoiding pathogens for primary asthma prevention?
What are the risk factors for near fatal asthma?
Heavy use of beta 2 agonists?
3+ asthma medications
How is acute asthma classified?
Which patients can be discharged within 1hr?
PEF>75% after 1hr unless risk factors or living alone
What are the features of a moderate asthma exacerbation?
PEF>50-75% best or predicted
No features of acute severe asthma
What are the features of acute severe asthma?
RR greater than or equal to 25/min
HR greater than or equal to 110 bpm
Cannot complete sentences in one breath
What are the features of life threatening asthma?
Any one of:
What are the clinical features of life threatening asthma?
Feeble respiratory effort
Feeble respiratory effort
Describe type 1 brittle asthma?
Wide PEF variability (>40% diurnal variation for more than half of the time over 150 days)
Describe type 2 brittle asthma
Sudden severe attacks on a background of otherwise well controlled asthma
What is near fatal asthma?
Raised PaCO2 and/or requiring mechanical ventilation with raised inflation pressures
What is the principle of near fatal asthma management?
Bronchodilators to keep the patient alive/ steroids decrease inflammation
Which bronchodilators should be used in near fatal asthma?
Salbutamol or tetrabutaline nebs via spacer
Ipratropium if concerned
Which bronchodilator should be used if life threatening asthma becomes near fatal?
For how longs should steroids be given in acute exacerbations of asthma?
What steroids can be given in severe asthma?
Prednisolone 40 or 50 od OR
Hydrocortisone 100 or 200mg qds
How is acute asthma attack managed?
O2 - aim for SaO2 >92%
iv fluids for rehydration and to correct electrolytes
How does FEV1 and FVC change in obstructive disease?
FEV1 and FVC reduced so FEV1/FVC reduced
How does FEV1 and FVC change in restrictive disease?
Both FEV1 and FVC reduced but FEV1 not reduced as much so FEV1/FVC normal or raised
What is tidal volume?
Air expired or inspired in a single breath
What is inspiratory reserve volume?
Additional volume of air that can be inspired after tidal volume
What is expiratory reserve volume?
Additional volume that can be expired after tidal volume
What is the vital capacity?
Maximum volume of air that can be exhaled following max inspiration (IRV+TV+IRV)
How can lung volume be measured?
How is gas transfer measured?
CO single breath technique
How does the helium method work?
Helium acts as a tracer that mixes with air
What environmental factors are linked to lung cancer?
Coal and tar oils
Which oncogenes may be present in lung cancer?
KRAS, MYC family, EGFR and ALK mutations
Which tumour suppressor genes are relevant to lung cancer?
Where can autocrine growth factors be derived from?
What percentage of lung cancers are small cell (oat cell) tumours?
What types of non small cell lung cancers are there and what is their incidence?
Squamous cell carcinoma (20-30%)
Large cell carcinoma (10-15%)
What are distinctive features of SCLC?
May respond to chemo
Often nodal spread
Early aggression - often inoperable
What are features of squamous cell tumours?
Typically in smokers
High serum calcium due to PTH-rp
What are the features of large cell lung cancer?
The clinical picture of adenocarcinoma in situ may resemble which other disease?
Which paraneoplastic syndromes are linked to SCLC?
Dermatomyositis (more common is SCLC)
Which paraneoplastic syndrome may be present in squamous cell carcinoma?
Hypercalcaemia due to PTH-rp
When should an urgent respiratory referral be made?
CT/CXR suggests cancer including pleural effusion or slow removal of consolidation
High suspicion with normal CT/CXR
Persistent haemoptysis in smokers/ex-smokers older than 40 years of age OR signs of SVCO obstruction or strider
Why should an MRI be done?
To look for pan coast tumours
What is the ideal pathway in the diagnosis of lung cancer?
Patient presents to GP or A&E
Refer to respiratory
Respiratory physician requests CT
CT given with report to team
Bronchoscopy/ CT biopsy/ EBUS
Histology and PET report
Decide on chemo/ radio/ surgery
What are the symptoms of pleuritic disease?
Pleuritic chest pain
Shoulder pain and heaviness
What is an exudate fluid?
More that 30g/l protein in the fluid
What is a transudate fluid?
Less that 30g/l protein in the fluid
When should Light's criteria be used to differentiate between transudate and exudate?
If the fluid is between 25g/l and 35g/l
What is Light's criteria?
The fluid is an exudate if:
Pleural fluid/serum protein > 0.5
Pleural fluid LDH/ serum LDH > 0.6
Pleural fluid LDH > 2/3 of upper limit of serum LDH
What can lead to an exudate fluid?
What conditions can lead to a transudate fluid?
Left ventricular failure
Cirrhotic liver disease
What is a pleural infection?
How should pleural effusion be investigated? (After CXR)
Diagnostic pleural tap
What other investigations should be done after a pleural tap when investigating pleural effusion?
What is the most cause of community acquired pleural infection?
What is the second most common cause of community acquired pleural infection?
What is the third most common cause of community acquired pleural infection?
What is the most common cause of hospital acquired pleural infection?
Staph - MRSA (25%) and S.aureus (10%)
How should a pleural infection be managed?
First line- antibiotics
Seconds line- chest tube drainage
Third line- intrapleural fibrinolytics (not routinely used)
If still doesn't resolve refer to surgeons for VATS/thoracotomy and decortication/open thoracic drainage
What is a mesothelioma?
Malignant tumour of the serosal surfaces
What is the average latency period of mesothelioma?
What is the prognosis after mesothelioma diagnosis?
Poor 9-12 months
What causes a mesothelioma?
What signs and symptoms are seen in mesothelioma?
Dull ache in chest
Weight loss and fatigue
Chest wall invasion
What are the first line investigations in suspected mesothelioma?
CXR and CT thorax
What further investigations may be done when investigating mesothelioma?
Pleural fluid analysis (cytology and colour)
What histological subtypes may be seen in mesothelioma?
Epitheloid - 50% - better prognosis
Which histological subtype of mesothelioma is the most common and results in the best prognosis?
How can pleural effusions be managed?
Drainage (pleurodesis if recurrent)
What is the role of radiotherapy in mesothelioma management?
Reduce chest wall invasion risk?
Which chemotherapy agents should be used in mesothelioma?
Cisplatin + pemetrexed/ gemcitibine
What CXR findings may one see in mesothelioma?
What is bronchiectasis?
Permanent dilation of the bronchi and bronchioles with necrosis of their walls
What causes bronchiectasis?
Obstruction or childhood viral pneumonia
What is a key clinical finding in bronchiectasis?
Foul smelling pus
How is bronchiectasis diagnosed?
High resolution CT scan
Why does foul smelling pus occur in bronchiectasis?
Air ways become sac like and fill with pus
What are the characteristics of the fluid in pulmonary oedema?
Pink and granular with haemosiderin-laden macrophages (heart failure cells)
What process occurs in long standing pulmonary oedema?
Resolution or 'brown induration'
What causes ARDS?
Diffuse alveolar damage and build up of oedema due to injury to alveolar capillary endothelium
What does histology show in ARDS?
Oedema and fluid
Fibrinous membranes lining alveoli
Proceeds to severe scarring
Why is ARDS life threatening?
Rapidly developing respiratory insufficiency
Which type of PE is immediately life threatening?
Large saddle emboli - lodges are in the bifurcation of the pulmonary trunk
What shape of infarct appears in the lungs in the event of a normal PE?
Does pulmonary circulation normally have a high or low resistance?
What can cause pulmonary hypertension?
Left heart valvular disease
What complication arises from pulmonary hypertension?
Right ventricular hypertrophy - chronic cor pulmonale
Which type of lung disease does occupational lung disease normally cause?
What are the features of coal workers pneumocosis?
Progressive massive fibrosis
In what jobs is silicon exposure common?
Which disease are due to silicon?
Which conditions are linked to asbestos exposure?
Lung, stomach and colon cancer
Which lung disease are due to organic dusts?
Bird breeder's lung
Which habit typically causes chronic bronchitis and emphysema?
What is centriacinar emphysema?
Central and proximal parts of the respiratory bronchioles affected and the distal parts are spared
This type is seen in smokers
What is paracinar emphysema?
Uniform dilation of acini from respiratory bronchiole to alveoli
Seen in alpha 1 anti trypsin deficiency
Which type of emphysema is seen in alpha 1 anti trypsin deficiency?
What is paraseptal emphysema?
Peripheral along large margins
Occurs adjacent to scarring/collapse/fibrosis
Predisposition to spontaneous pneumothorax in young adults
Which type of emphysema predisposes young adults to pneumothorax?
What is irregular emphysema?
Irregular involvement of acini - linked to scarring
What is the pathogenesis of emphysema?
Smoking and congenital alpha 1 anti trypsin deficiency leads to antielastase
Smoking and emphysema leads to elastic damage
Compare chronic bronchitis to emphysema?
Productive cough for longer than 3m in 2 consecutive years
Mucous gland hypertrophy and hypersecretion +/- infection
Hypoxia, hypercapnia and cyanosis prone
Permanent dilation of airways distal to terminal bronchiole
Elastic destruction leading to loss of elastic recoil
Tendency to hyperventilate but ABG normal
What is the pathogenesis of lung cancer?
1. Normal respiratory epithelium (pseudo stratified columnar, ciliated, mucous secreting)
2. Turns to stratified squamous
3. Turns to squamous dysplasia
4. Becomes carcinoma
What causes hypercapnia?
What can cause type 1 respiratory failure?
Low inspired oxygen
V/Q mismatch - reduced Q e.g PE
Diffusion abnormality e.g pulmonary fibrosis or emphysema in COPD
What can cause type 2 respiratory failure?
Thoracic cage problems e.g. obesity, thoracoplasty and kyphoscoliosis
Hyperexpanded lungs e.g. COPD
Obstructive airway disease e.g. COPD or asthma
Weakness of respiratory muscles e.g. MND, DMD
What is CPAP?
Continuous positive airway pressure that pushes air into lungs during expiration
It can expand collapsed portions of lung that are underventilated
What improvements are seen with CPAP?
Improves V/Q mismatch
Keeps airway open in sleep apnoea
What is not improved with CPAP?
Why should too much O2 not be given in type 2 respiratory failure?
It will worsen hypoventilation so will worsen hypercapnia
How should oxygen be given in type 2 respiratory failure?
0.5 to 2.0l via nasal cannula with or 24 to 28% with Venturi mask
What is the target saturation in respiratory failure?
88 to 92 percent
What is non-invasive ventilation?
Delivers high pressure during inspiration to improve ventilation
Useful in hypoventilation and type 2 respiratory failure
What are the consequences of type 2 respiratory failure?
Secondary polycythaemia leading to stroke
What are the complications of chronic hypoxia?
How should acute type 1 respiratory failure be managed?
High flow oxygen
60 to 100 percent oxygen via mask
Keep sats above 95 percent
Treat underlying cause
When should CPAP be considered in type 1 respiratory failure?
How is sleep apnoea diagnosed?
Home sleep study
What is the definition of obstructive sleep apnoea?
Repetitive episodes of partial or complete upper airway obstruction during sleep
What is apnoea?
Complete stop in airflow for 10s
What is hypopnoea?
Reduction in airflow by 50 percent or by 30 percent for at least 10s with desaturation of at least 4 percent
What is the AHI? (Same as Sleep Disturbance Index)
Number of apnoeas or hypopnoeas per hour of the study
What are the classifications of the AHI?
0 to 5 is normal
5 to 15 is mild
15 to 30 is moderate
30 plus is severe
What BMI is linked to OSA?
Greater than 30
What are the relevant risk factors for OSA?
Obesity - narrows the upper airway
Neck circumference > 16.5
Male - longer pharyngeal airway
Which system conditions are linked to OSA.
Type 2 DM
Which scale is associated with OSA?
Epworth sleepiness scale
Which features in the history are suggestive of OSA?
Planned or unplanned naps
Witnessed by partner
When should CPAP be used?
Moderate or severe OSA
When should mandibular splints be advised?
Mile to moderate sleep apnoea
Intolerance to CPAP
What is the aetiology of sarcoidosis?
Exaggerated immune response
Kveim antigen - mycobacterial catalase peroxidase (Kat G)
Which gene is linked to acute sarcoidosis lasting less than 2 years with a better prognosis?
Which genes are linked to chronic sarcoidosis?
Which gene is associated with a better response to anti TNF in sarcoidosis?
Which IL variants may occur in sarcoidosis?
IL 12 and IL 23
Which other genes are linked to sarcoidosis?
ATNXA11 and XAF1
What is the main age range for sarcoidosis?
25 to 45 years
Is SACE raised in sarcoidosis?
Is tuberculin raised in sarcoidosis?
Which CXR features are typically seen in sarcoidosis?
Bilateral hilar lymphadenopathy
What are the clinical features of sarcoidosis?
80 percent of cases are asymptomatic
Thirst and polyuria (due to high calcium)
How should asymptomatic sarcoidosis be monitored?
Monitor lung function and SACE
How should symptomatic sarcoidosis be managed?
How is TB diagnosed?
What antibiotics are given in TB?
Why does pyrazinamide need to be given with isoniazid?
To prevent antibiotic induced peripheral neuropathy
What percentage of TB strains are resistant to isoniazid and rifampicin?
Which immune cells are linked to post-primary TB?
CD4 and CD8
What is the mechanism of isoniazid?
Bacteriacidal acting on the cell wall
How does rifampicin work?
Bacteriostatic on cell wall
How does pyrazinamide work?
Bacteriostatic of FAS11
How does ethambutol work?
Bacteriostatic on cell wall
What is the second line investigation in someone presenting with TB symptoms?
Mantoux test if under 35
CXR if over 35
What type of granuloma is seen in TB?
What type of granuloma is present in sarcoidosis?
Non caseating granuloma
What is the pathophysiology of primary pneumothorax?
Air leaks from subpleural blebs and Bullard
Which are bullae?
Air filled blisters in the visceral pleura
What conditions can lead to secondary pneumothorax?
COPD- 60 percent
Connective tissue disease e.g. Marfans
What are the clinical features of pneumothorax?
Acute pleuritic chest pain +\- shortness of breath
Reduced chest expansion
Subcutaneous emphysema - bubble and crack
Quiet breath sounds
How is a small pneumothorax defined?
Less than 2cm on CXR
How is large pneumothorax defined?
More than or equal to 2cm on CXR
How should a small pneumothorax be managed?
Conservatively with high flow oxygen and let it reabsorb (happens at a rate of 1.25%)
When should a pneumothorax be medically managed?
If the rim is greater than 2cm with or without breathlessness
How should a large pneumothorax be medically managed?
Aspirated with 16-18G cannula up to 2.5l of air this is considered successful if the rim is now less than 2cm and breathing has improved. If the aspiration is not successful a chest drain can be done (the patient should be admitted).
How should a chest drain be managed?
Underwater seal and drainage
Do not lift above waist to prevent retrograde flow of fluid or air
Do not clamp if bubbling or a tension pneumothorax will develop
What are the clinical signs of a tension pneumothorax?
Trachea and mediastinum deviate away
How should a tension pneumothorax be managed?
Needle decompression with a large bore (14G) needle in the mid clavicular line 2nd intercostal space
What is a PE?
Thrombi from a distant site
What percentage of post operative deaths are due to PE?
What is the most common cause of maternal death?
What percentage of thrombi are formed in the deep veins of the lower limb and pelvis?
In which veins do thrombi develop?
Deep veins of the lower limb and pelvis
What is the pathophysiology of PE?
Thrombi formed in the deep veins of the pelvis and lower limb
Platelet aggregation around venous valve sinuses
Clotting cascade activated
What is Virchow's triad?
Injury to vessel wall
What can cause PE?
How is a PE diagnosed?
What test should be done in the event of a chronic PE?
V/Q scan (lower radiation)
What should be done prior to PE management?
What are the components to the Wells score?
Clinical DVT (3 points)
PE most likely diagnosis (3 points)
HR over 100 (1.5 points)
Immobilisation for 3 days or surgery in the last 4 weeks (1.5 points)
Previous DVT/PE (1.5 points)
Haemoptysis (1 point)
Malignancy with treatment in the last 6m (1 point)
How should a wells score be graded?
Score over 4 - consider imaging
Score under 4 - rule out PE with a normal D-dimer
What findings may show on an ECG with PE?
RV strain (anterior T wave inversion)
S1 Q3 T3
What is the medical management of PE?
Anticoagulation with LMWH or warfarin
What is the interventional radiology management for PE?
Inferior vena cava filter
What is the surgical management if PE?
Embolectomy (if life threatening)
Pulmonary thromboendarterectomy (chronic PE)
What are the presenting features of a large PE?
Hypotension, collapse and cardiac arrest
Acute right heart strain
Right heart failure
What are the features of acute right heart strain?
Splitting of 2nd heart sounds
What are the features of right heart failure?
Low cardiac output
What are the presenting signs of a PE?
New onset AF
Reduced chest movement due to pain
Low grade fever
What are the presenting symptoms of COPD?
Regular sputum production and frequent chest infections
Frequent winter bronchitis
How is COPD diagnosed?
Post bronchodilator spirometry- not much change in FEV1
What are the stages of COPD?
Stage 1 - mild - 80 percent with symptoms
Stage 2 - moderate - 50-79 percent
Stage 3 - severe - 30-49 percent
Stage 4 - very severe - below 30 percent ( or less than 50 percent with respiratory failure)
Why is it necessary to do a CXR when diagnosing COPD?
To rule out other causes
What further investigations should be done in COPD? After CXR
ABG for respiratory failure and acidosis
FBC to look for anaemia or polycythaemia
Which genetic factor may cause COPD or emphysema in younger patients?
Alpha 1 anti trypsin deficiency
What is the first line management in COPD?
Reduction in risk factors such as the pneumococcal and influenza vaccine
Chest physiotherapy if needed
Short acting antimuscarinic (Ipratropium) or beta 2 agonist (salbutamol) PRN
Which bacteria is most likely to cause an acute exacerbation of COPD?
How should mild to moderate COPD be managed?
Inhaled long acting muscarinic (tiotropium) or beta 2 agonist
How should severe COPD be managed?
Combination long acting beta 2 agonist and corticosteroids (budesonide + formoterol) or tiotropium
If severe COPD remains symptomatic, what is the second line treatment?
Tiotropium + inhaled steroid + long acting beta 2 agonist
(Consider steroid trial, home nebs and theophylline)
How can pulmonary hypertension in COPD be managed?
Assess the need for long term oxygen therapy
Treat oedema with diuretics
What theoretically can cause asthma?
Genetics - there is an inheritable component
Which non-pharmacological treatments have been proven effective in asthma?
What is the first step in asthma treatment (mild intermittent asthma)?
Short acting beta agonist PRN e.g. salbutamol, terbutaline
What is the second step in asthma management (regular preventer therapy)?
Inhaled steroid 200-800 mcg but 400mcg is a good starting dose e.g. beclamethasone, budenoside, fluticasone
What is the third step in asthma management? (Initial add on therapy)
Add LABA e.g. Salmeterol or formoterol
if there is not a full benefit from LABA increase inhaled steroid dose to 800mcg
If no response to LABA increase inhaled steroids to 800mcg and try leukotriene antagonist or SR theophylline
What is the fourth step in asthma management? (Persistent poor control)
Consider trials of increasing inhaled steroids to 2000mcg
Add fourth drug e.g. Leukotriene receptor agonist, SR theophylline, beta 2 agonist tablets
What is step 5 in the management of asthma?
Daily steroid tablets
Consider ways to minimise steroid use
Refer to respiratory
What has shown to decrease asthma mortality?
Increased corticosteroid use
Give an example of a leukotriene receptor antagonist
What is the mechanism of action of theophylline?
What are the indications for anti-IgE therapy?
On maximum inhaled therapy
Impaired lung function
Frequent exacerbations especially due to allergy
Raise IgE but less than 700iu/litre
How does Anti IgE therapy work?
Monoclonal antibody that decreases free IgE
Give an example of anti IgE therapy
How is anti IgE therapy given?
2-4 weekly subcutaneous injections
What is upper airways disease?
Asthma +\- sinusitis or rhinitis (often coexist)
What factors can precipitate asthma?
Dust/ house mites
Which lung diseases show a restrictive pattern?
What is the vital capacity?
Maximum volume of air that can be exhaled following a maximal inspiration (VC = IRV + TV + ERV)
What is the inspiratory capacity?
Volume of air that it is possible to inspire at the end of a normal quiet expiration? (IC = TV + IRV)
What is the residual volume?
Volume of air remaining in the lungs and airways at the end of a maximal expiration?
What is the functional residual capacity?
Volume of air contained in the lungs at the end of a quiet tidal volume expiration (FRC = RV + ERV)
What is the total lung capacity?
The volume of air contained in the lungs at the end of a maximal inspiration (TLC = RV+ERV+TV+IRV)
What is Lambert Eaton syndrome? (Can be paraneoplastic in SCLC)
Myaesthenic autoimmune disease where the immune system attacks the neuromuscular junction
In TNM staging what is a T1a tumour?
Small peripheral tumour which can be removed surgically
What grade is given to a large invading tumour?
What is an N1 tumour?
Hilar lymph node involvement
What is an N2 tumour?
Mediastinal lymph node involvement
What is an N3 grade cancer?
Contractural lymph node involvement
What is a grade M1a lung cancer?
Metastatic pleural effusion
What is a grade m1b tumour?
Mets at common sides such as liver, lungs, adrenals, brain, bones
What are the complications of radiotherapy?
Why may palliative radiotherapy given in lung cancer?
To relieve pain and to stop haemoptysis and neurological problems through brain and spinal mets
What is the survival advantage when giving chemo in lung cancer?
Which chemotherapy agents are given in small cell lung cancer?
Pemetrexed and cisplatin
What other agents may be combined with chemo in lung cancer?
EGFR antagonists such as endotinib
What palliative treatments can be given in lung cancer?
Endobronchial laser to relieve obstruction, breathlessness and haemoptysis
Stenting to relieve breathlessness
Endobronchial radiotherapy (brachytherapy)
Why type of fluid do disease affecting local factors in the lung produce?
What type of fluid do diseases affecting systemic factors produce?
Which diseases affect local factors in the lung and what conditions do they produce?
Increased capillary permeability - trauma, malignancy, inflammation, infection, pancreatitis
Increased pleural permeability - inflammation, malignancy and PE
Decreased lymphatic drainage - malignancy and trauma
Increased negative pleural pressure - atelectasis, mesothelioma
Which systemic factors affecting the lung are affected by which disease?
Increased capillary hydrostatic pressure - heart failure
Increased pulmonary interstitial fluid - heart failure
Decreased intravascular oncotic pressure - hypoalbuminaemia, cirrhosis
Increased flow from other cavities - peritoneal dialysis, liver cirrhosis
What is the progression of a pleural infection?
Simple parapneumonic effusion to complicated parapneumonic effusion to empyema
What are the characteristics of the fluid produced in simple parapneumonic effusion?
Clear, sterile fluid with normal pH, glucose and LDH that resolves with LDH
Chest drain not usually required
What are the characteristics of the fluid produced in a complicated parapneumonic effusion?
Fibrinopurulent stage, fluid infected but not purulent. pH 1000iu/l, gram stain may be positive
Chest drain needed
What is the characteristic of the fluid in empyema?
Pus in the pleural space, free flowing or multiloculated, fluid gram stain may be positive. Fibroblasts may have cause a thickened pleura.
What is the incidence of pneumonia?
5 - 11 cases per 1000 adults
What is the 30 day mortality of pneumonia?
What are symptoms of pneumonia?
Sweating, fevers, shivers, aches, pain, fevers
What are the signs of pneumonia?
New and focal chest signs
Radio graphic changes - new radio graphic shadowing with no other explanation
Do most cases of pneumonia have an unidentified pathogen?
What is the most common pathogen in pneumonia?
When should healthcare associated pneumonia be considered?
Inpatient longer than 48hrs or 10 days post discharge or living in nursing home
Which pathogens are common in HAP?
H. Influenza, Gram negative bacilli, S.aureus all increased due to aspiration
Which pathogens are less likely in HAP?
Legionella and unknown pathogens
Which pathogens are more common in the elderly?
M. pneumonia and legionella
How does alcohol influence pneumonia?
Increased risk of most pathogens
Aspiration most likely
How does diabetes influence pneumonia?
Increased risk of bacteraemic pneumococcal pneumonia
What impact does COPD have on pneumonia?
H.influenza and M.catarrhalis more likely
Increased symptoms but same mortality
Which bacteria is almost unseen in HAP?
Which can disrupt filtration and increase deposition in the upper airways?
What can affect the cough reflex leading to increased chance of aspiration?
Neurological conditions e.g. stroke
What can reduce mucocilliary clearance?
What can damage and reduce alveolar macrophages?
What reduces humoral and cellular immunity?
What can negatively affect the oxidative metabolism of neutrophils?
What are the components of the CURB65 score?
Confusion AMTS less than 8
Urea equal to or greater than 7mmol/l
Respiratory rate greater than 30
BP systolic less than 90/ diastolic less than or equal to 60
65 - age 65 plus
How does the CURB65 score influence pneumonia treatment?
0-1 treat at home - amoxicillin 500mg tds oral
2 short admission - amoxicillin 500mg tds oral
3 plus admit - urgent senior review amoxicillin 500mg tds oral + clarithromycin 500mg bd oral
4-5 admit into ITU/HDU - coamoxiclav 1.2g tds IV and clarithromycin 500mg bds IV
If legionella expected give levofloxacin
What does the trachea consist of?
C shaped cartilage
What do the bronchi consist of?
Discontinuous cartilage plates and mutinous glands
What do the bronchioles consist of?
No cartilage or mucous glands
Terminal bronchioles are less than 2mm in diameter
Gas exchange occurs in the terminal bronchioles
What do the alveolar ducts consist of?
Flat epithelium, no glands or cilia
What do the alveolar sacs consist of?
No glands or cilia
What does Eisenmeger syndrome consist of?
Right to left shunt via VSD
Hypertrophic right ventricle
Patent ductus arteriosus
What are the defence mechanisms of the lung?
Particles bigger than 10 microns held in the upper airway
3-10 microns held in tracheobronchial mucus (mucocilliary action)
Which age group does lobar pneumonia typically affect?
Previously healthy males aged 20-50
What is the pathophysiology of lobar pneumonia?
Congestion (24hrs) - vessels engorged, oedema in alveoli, heavy red lung
Red hepatisation (2-4d) - outpouring of neutrophils and RBCs into alveoli, red, solid, airless liver like lung
Grey hepatisation (4-8d) - fibrin and macrophages replace neutrophils and RBCs. Grey, solid and airless lung.
Resolution (8-10d) - gradual return to normal
What is a serious complication of lobar pneumonia?
Lung abscess or empyema especially with Klebsiella or Staph aureus
What is the most common type of pneumonia?
What are the 4 typical clinical settings where bronchopneumonia occurs?
Chronic debilitating illness
Secondary to viral infection
What is the pathophysiology of bronchopneumonia?
Bilateral, basal and patchy progressing to grey/red spots of consolidation and microscopically acute inflammatory infiltrate in bronchioles and alveoli
What CXR findings are present in bronchopneumonia?
Focal opacities, clinical signs are less pronounced, usually patchy bilateral basal distribution.
Which pathogens are typically responsible in bronchopneumonia?
Staph, strep viridians, pneumococcus, haemophilia, pseudomonas, coliforms
What is atypical pneumonia?
What are the clinical signs of interstitial pneumonia?
Patchy or extensive
Congested and subcrepitant lungs
Secondary bacterial infection
More generalised symptoms rather than local
Usually mild and self limiting
Possible DAD (diffuse alveolar damage)
What are predisposing conditions to interstitial pneumonia?
Malnutrition, alcoholism, debilitating illness
What is the pathogenesis of interstitial pneumonia?
Intra alveolar proteinaceous material forming hyaline membranes in the case of DAD
What is found on histology with interstitial pneumonia?
Inflammation restricted to alveolar septa and interstitial pneumonia
No/minimal alveolar exudate
What pathogens may be present in interstitial pneumonia?
Viruses: influenza A and B, RSV, adenovirus, rhinovirus, rubeola, varicella
Which pathogens cause TB?
What is the pathogenesis of TB?
Cell mediated hypersensitivity central to development of characteristic destruction through caseating necrosis and cavitation
Macrophages phagocytose but cannot kill bacteria so they multiply, lyse and infect other cells
T cell mediated immunity 2-3 weeks post infection:
CD4 mediated IFN gamma secretion intracellular killing and granuloma formation
CD8 mediated lysis of macrophages and killing
CD4-/CD8- mediated lysis of macrophages and caseation and necrosis; bacilli killed in an anoxic, acidic environment
What is primary TB?
Represents first reponse to tubercle bacili
What is the pathophysiology of primary TB?
Ghon complex (typically 1cm focus in midzone with draining lymph node) that leads to fibrosis and calcification
What is the pathophysiology of secondary TB?
Reinfection or reactivation, sometimes progressive primary TB
Bacteria relocate to high oxygen areas of the lung
Usually apical granuloma 3cm at presentation
Which type of hypersensitivity is relevant to primary TB?
Type IV (delayed type)
What can be seen on histology with TB?
Granulomas with caseous necrosis
Langhans giant cells
What does a Ziehl-Neelsen stain reveal with TB?
Characteristic acid-fast bacilli
What are the complications of pulmonary TB?
Progressive fibrocavitary TB - gradually destroys lung through necrosis, cavitation and fibrosis
Miliary TB - blood bourne dissemination within lung or throughout the body, seed like foci consisting of granulomas in meninges, bone marrow, liver or any other organ
Which patients get fungal pneumonia?
Which fungi is responsible for fungal pneumonia in HIV patients?
Pneumocystis carinii (PCP)
What is the human response to primary TB?
No pre existing immunity
Often outside lung
Children and elderly
HIV co infection
What is the human response to post primary TB?
Pre existing immunity
Cavities with TB biofilm
Surprisingly well tolerated
Young adults effected
Immunocompetent with CD4 and CD8 involvement
What are the side effects if isoniazid?
Liver damage - raised ALT
What are the side effects of rifampicin?
Liver damage - raised bilirubin
Flu like syndrome
What are side effects of pyrazinamide?