Respiratory Flashcards
What are the two broad types of lung cancer?
Small cell (20%)
Non-small cell (80%)
Name 3 types of non-small cell lung cancers
Adenocarcinoma
squamous cell carcinoma
Large-cell carcinoma
What is mesothelioma
Lung malignancy affecting mesothelial cells of the pleura
associated with asbestos inhalation
What are some presenting features of lung cancer?
Shortness of breath
Cough
Haemoptysis
Finger clubbing
Recurrent pneumonia
Weight loss
Lymphadenopathy – often supraclavicular nodes are the first to be found on examination
What are some extrapulmonary manifestations of lung cancer?
recurrent laryngeal nerve palsy
Phrenic nerve palsy
Superior vena cava obstruction
Horner’s syndrome
SIADH
Cushing’s
Hypercalcaemia
Limbic encephalitis
Lambert-Eaton myasthenic syndrome
How does superior vena cava obstruction present?
facial swelling
difficulty breathing
distended neck and upper chest veins
What is Pemberton’s sign?
raising the hands over the head causes facial congestion and cyanosis - sign of SVC obstruction
What is the triad of Horner’s syndrome?
Ptosis
Anhidrosis
Miosis
What are the referral criteria for offering a CXR within two weeks?
over 40
Clubbing
Lymphadenopathy (supraclavicular)
recurrent or persistent chest infections
Thrombocytosis
Chest signs of lung cancer
What findings on x-ray are suggestive of lung cancer?
Hilar enlargement
Peripheral opacity (a visible lesion in the lung field)
Pleural effusion (usually unilateral in cancer)
Collapse
When is pneumonia classed as hospital acquired?
develops after more than 48 hours in a hospital
What type of bacteria is associated with aspiration pneumonia
Anaerobic bacteria
What are some presenting symptoms of pneumonia?
Cough
Sputum production
Shortness of breath
Fever
Feeling generally unwell
Haemoptysis
Pleuritic chest pain
Delirium
What are some characteristic chest signs of pneumonia on auscultation?
Bronchial breath sounds
Focal coarse crackles
Dullness to percussion
What are the aspects of CURB-65?
C – Confusion
U – Urea > 7 mmol/L
R – Respiratory rate ≥ 30
B – Blood pressure < 90 systolic or ≤ 60 diastolic.]
65 – Age ≥ 65
How should you interpret a CURB-65 score?
Score 0/1: Consider treatment at home
Score ≥ 2: Consider hospital admission
Score ≥ 3: Consider intensive care
Predicts mortality. NICE state 0/1 is low risk (under 3%), 2 is intermediate risk (3-15%), and 3-5 is high risk (above 15%)
What are the 2 most common causes of bacterial pneumonia?
Streptococcus pneumoniae (most common)
Haemophilus influenzae
What rarer cause of pneumonia is more common in patients with cystic fibrosis or bronchiectasis?
Pseudomonas aeruginosa (both)
(Staphylococcus aureus in patients with cystic fibrosis)
What is a rarer cause of pneumonia in immunocompromised or those with chronic pulmonary disease?
Moraxella catarrhalis
How can Legionnaires’ disease present and how is it investigated?
symptoms of pneumonia + hyponatraemia (due to SIADH)
urine antigen test
What is the rash that mycoplasma pneumoniae may cause?
erythema multiforme
What type of atypical pneumonia is associated with exposure to bodily fluids of animals?
Coxiella burnetii
What atypical pneumonia is contracted through contact with infected birds?
Chlamydia psittaci
Name 4 causes of atypical pneumonia
Legions – Legionella pneumophila
Psittaci – Chlamydia psittaci
M – Mycoplasma pneumoniae
C – Chlamydophila pneumoniae
Qs – Q fever (coxiella burnetii)
What type of fungal pneumonia is more common in patients with HIV and how is it treated?
Pneumocystis jirovecii
co-trimoxazole
What investigations may be done in a patient admitted to hospital with pneumonia?
Chest x-ray
Full blood count (raised white cell count)
Renal profile (urea level for the CURB-65 score and acute kidney injury)
C-reactive protein (raised in inflammation and infection)
Patients with moderate or severe infection will also have:
Sputum cultures
Blood cultures
Pneumococcal and Legionella urinary antigen tests
How is mild community-acquired pneumonia treated?
5 days of oral antibiotics
refer to local guidelines e.g. amoxicillin, doxycycline, clarithromycin
State 5 complications of pneumonia
Sepsis
Acute respiratory distress syndrome
Pleural effusion
Empyema
Lung abscess
Death
What are the normal paO2 values?
10.7-13.3 kPa
What are the normal PaCO2 values?
4.7-6.0 kPa
What is a normal pH?
7.35-7.45
What is a normal lactate?
0.5-1
What is the FiO2 of room air?
21%
What is the approximate FiO2 with 2L via nasal cannula?
28%
What would a ABG show in type 1 respiratory failure?
Low PaO2
Normal PaCO2
What would a ABG show in type 2 respiratory failure?
Low PaO2
Raised PaCO2
What would an ABG show in respiratory acidosis?
pH below 7.35
raised PaCO2
What does a raised bicarbonate level suggest?
Patient is chronically retaining CO2
What would an ABG show in respiratory alkalosis?
raised pH
low PaCO2
Name 2 conditions that would cause respiratory alkalosis
Hyperventilation syndrome
Pulmonary embolism
What would an ABG show in metabolic acidosis?
low pH
low HCO3
What is the normal range of HCO3 (bicarbonate) ?
22-26 mmol/L
State some possible causes of metabolic acidosis
DKA
Renal failure
Rhabdomyolysis
Diarrhoea
Renal tubular acidosis
What would an ABG show in metabolic alkalosis?
raised pH
raised HCO
State some causes of metabolic alkalosis
Vomiting
Conn’s syndrome
Liver cirrhosis
heart failure
loop diuretics
thiazide diuretics
order the different types of respiratory support from least to most intensive
Oxygen therapy
High-flow nasal cannula
Non-invasive ventilation
Intubation and mechanical ventilation
Extracorporeal membrane oxygenation (ECMO)
Acute respiratory distress syndrome presents as an acute onset of:
Collapse of the alveoli and lung tissue (atelectasis)
Pulmonary oedema (not related to heart failure or fluid overload)
Decreased lung compliance (reduced lung inflation when ventilated with a given pressure)
Fibrosis of the lung tissue (typically after 10 days or more)
What are the clinical signs of acute respiratory distress syndrome?
Acute respiratory distress
Hypoxia with an inadequate response to oxygen therapy
Bilateral infiltrates on a chest x-ray
How is acute respiratory distress syndrome managed?
Respiratory support
Prone positioning (lying on their front)
Careful fluid management to avoid excess fluid collecting in the lungs
Positive end-expiratory pressure is added by:
High-flow nasal cannula
Non-invasive ventilation (NIV)
Mechanical ventilation
What is IPAP and EPAP in NIV?
IPAP (inspiratory positive airway pressure) is the pressure during inspiration – where air is forced into the lungs
EPAP (expiratory positive airway pressure) is the pressure during expiration – stopping the airways from collapsing
When is FEV1 reduced?
airflow obstruction
When is FVC reduced ?
Restricted lung capacity
What spirometry value can be used to diagnose obstructive lung disease?
FEV1:FVC ratio of less than 70%
What will spirometry show in restrictive lung disease?
FEV1 and FVC are equally reduced
FEV1:FVC ratio greater than 70%
State 4 types of restrictive lung disease
Interstitial lung disease, such as idiopathic pulmonary fibrosis
Sarcoidosis
Obesity
Motor neurone disease
Scoliosis
Describe the technique needed for peak flow tests
stand tall, take a deep breath in, make a good seal around the device with the lips and blow as fast and hard as possible into the device. Take three attempts and record the best result.
What are some symptoms of asthma?
Shortness of breath
Chest tightness
Dry cough
Wheeze
What is a key finding on auscultation of asthma?
widespread “polyphonic” expiratory wheeze
State 4 triggers that can exacerbate the symptoms of asthma
Infection
Nighttime or early morning
Exercise
Animals
Cold, damp or dusty air
Strong emotions
Name 2 medications that can worsen asthma
beta-blockers
NSAIDs
What investigations can be done for asthma and what would they show?
Spirometry (FEV1:FVC <70%) with bronchodilator reversibility
Fractional exhaled nitric oxide
others:
Peak flow (variability >20%)
Direct bronchial challenge testing
What are the steps for long term asthma management?
- SABA
- ICS
- LABA (or MART)
- increase ICS or add leukotriene receptor antagonist (montelukast)
What is the peak flow in a moderate asthma exacerbation
50 – 75% best or predicted
What are the clinical features of a severe asthma exacerbation?
Peak flow 33-50% best or predicted
Respiratory rate above 25
Heart rate above 110
Unable to complete sentences
What are the clinical features of a life-threatening asthma exacerbation?
Peak flow less than 33%
Oxygen saturations less than 92%
PaO2 less than 8 kPa
Becoming tired
Confusion or agitation
No wheeze or silent chest
Haemodynamic instability (shock)
How would you manage a mild asthma exacerbation?
Inhaled beta-2 agonists (e.g., salbutamol) via a spacer
Quadrupled dose of their inhaled corticosteroid (for up to 2 weeks)
Oral steroids (prednisolone) if the higher ICS is inadequate
Antibiotics only if there is convincing evidence of bacterial infection
Follow-up within 48 hours
How would you manage a moderate asthma exacerbation?
Consider hospital admission
Nebulised beta-2 agonists (e.g., salbutamol)
Steroids (e.g., oral prednisolone or IV hydrocortisone)
How would you manage a severe asthma exacerbation?
Hospital admission
Oxygen to maintain sats 94-98%
nebulised salbutamol
steroids
Nebulised ipratropium bromide
IV magnesium sulphate
IV salbutamol
IV aminophylline
What electrolyte requires monitoring with salbutamol?
potassium
After an acute asthma attack what management/advice may be given ?
Optimising long-term asthma management
Individual written asthma self-management plan
Considering a rescue pack of oral steroids to start early in an exacerbation
NICE suggest referral to a specialist after 2 attacks in 12 month
What are the presenting symptoms of COPD?
long-term smoker
persistent symptoms:
Shortness of breath
Cough
Sputum production
Wheeze
Recurrent respiratory infections, particularly in winter
Describe the grades of the MRC Dyspnoea scale
Grade 1: Breathless on strenuous exercise
Grade 2: Breathless on walking uphill
Grade 3: Breathlessness that slows walking on the flat
Grade 4: Breathlessness stops them from walking more than 100 meters on the flat
Grade 5: Unable to leave the house due to breathlessness
How is COPD diagnosed?
Clinical presentation + Spirometry (FEV1:FVC<70%)
How is the severity of COPD measured?
Stage 1 (mild): FEV1 more than 80% of predicted
Stage 2 (moderate): FEV1 50-79% of predicted
Stage 3 (severe): FEV1 30-49% of predicted
Stage 4 (very severe): FEV1 less than 30% of predicted
What 2 vaccines should be offered to patients with COPD?
pneumococcal
flu
What is the long term management of COPD?
conservative = stop smoking, pulmonary rehab
1. SABA/SAMA
2. LABA + LAMA (if no asthmatic or steroid-responsive features, if are then LABA+ICS)
3. LABA + LAMA + ICS
When would long-term oxygen therapy be offered to a patient with COPD?
Chronic hypoxia (<92%)
polycythaemia
cyanosis
cor pulmonale
State 4 causes of Cor pulmonale
COPD (the most common cause)
Pulmonary embolism
Interstitial lung disease
Cystic fibrosis
Primary pulmonary hypertension
What is Cor Pulmonale?
right-sided heart failure caused by respiratory disease. The increased pressure and resistance in the pulmonary arteries (pulmonary hypertension) limits the right ventricle pumping blood into the pulmonary arteries. This causes back-pressure into the right atrium, vena cava and systemic venous system
What are some symptoms of Cor Pulmonale?
Shortness of breath
Peripheral oedema
Breathlessness of exertion
Syncope (dizziness and fainting)
Chest pain
What are some signs of Cor Pulmonale ?
Hypoxia
Cyanosis
Raised JVP
Peripheral oedema
Parasternal heave
Loud second heart sound
Murmurs
Hepatomegaly due to back pressure in the hepatic vein
What is the first line medical treatment of an acute exacerbation of COPD?
Regular inhalers or nebulisers (e.g., salbutamol and ipratropium)
Steroids (e.g., prednisolone 30 mg once daily for 5 days)
Antibiotics if there is evidence of infection
if severe:
IV aminophylline
Non-invasive ventilation (NIV)
Intubation and ventilation with admission to intensive care
What are some causes of bronchiectasis?
Idiopathic (no apparent cause)
Pneumonia
Whooping cough (pertussis)
Tuberculosis
Alpha-1-antitrypsin deficiency
Connective tissue disorders (e.g., rheumatoid arthritis)
Cystic fibrosis
Yellow nail syndrome
What is the characteristic triad of yellow nail syndrome?
yellow fingernails
Bronchiectasis
lymphoedema
What are the key presenting symptoms of bronchiectasis?
Shortness of breath
Chronic productive cough
Recurrent chest infections
Weight loss
What are some signs of bronchiectasis on examination?
Sputum pot by the bedside
Oxygen therapy (if needed)
Weight loss (cachexia)
Finger clubbing
Signs of cor pulmonale (e.g., raised JVP and peripheral oedema)
Scattered crackles throughout the chest that change or clear with coughing
Scattered wheezes and squeaks
What are the most common infective organisms in bronchiectasis?
Haemophilus influenza
Pseudomonas aeruginosa
What are the x-ray findings in bronchiectasis?
Tram-track opacities (parallel markings of a side-view of the dilated airway)
Ring shadows (dilated airways seen end-on)
What is the test of choice for establishing a diagnosis of bronchiectasis?
High-resolution CT
What is the general management of bronchiectasis?
Vaccines (e.g., pneumococcal and influenza)
Respiratory physiotherapy
Pulmonary rehabilitation
Long-term antibiotics (e.g., azithromycin) for frequent exacerbations (e.g., 3 or more per year)
Inhaled colistin for Pseudomonas aeruginosa colonisation
Long-acting bronchodilators may be considered for breathlessness
Long-term oxygen therapy in patients with reduced oxygen saturation
Surgical lung resection may be considered for specific areas of disease
Lung transplant is an option for end-stage disease
How should an infective exacerbation of bronchiectasis be managed?
Sputum culture (before antibiotics)
Extended courses of antibiotics, usually 7–14 days
Ciprofloxacin is the usual choice for exacerbations caused by Pseudomonas aeruginosa
Name 4 types of interstitial lung disease
Idiopathic pulmonary fibrosis (the most important to remember)
Secondary pulmonary fibrosis
Hypersensitivity pneumonitis
Cryptogenic organising pneumonia
Asbestosis
What are they key presenting features of interstitial lung disease?
Shortness of breath on exertion
Dry cough
Fatigue
What are the 2 typical findings on examination of a patient with idiopathic pulmonary fibrosis?
Bibasal fine end-inspiratory crackles
Finger clubbing
What does diagnosis of interstitial lung disease involve?
Clinical features
High-resolution CT scan (HRCT) of the thorax (showing a typical “ground glass” appearance)
Spirometry
What are the general management options for interstitial lung disease?
Remove or treat the underlying cause
Home oxygen where there is hypoxia
Stop smoking
Physiotherapy and pulmonary rehabilitation
Pneumococcal and flu vaccine
Advanced care planning and palliative care where appropriate
Lung transplant is an option, but the risks and benefits need careful consideration
What is the prognosis of idiopathic pulmonary fibrosis?
2-5 years
What are the management options for pulmonary fibrosis?
Pirfenidone
Nintedanib
what drugs can cause secondary pulmonary fibrosis?
Amiodarone (also causes grey/blue skin)
Cyclophosphamide
Methotrexate
Nitrofurantoin
What conditions can lead to pulmonary fibrosis?
Alpha-1 antitrypsin deficiency
Rheumatoid arthritis
Systemic lupus erythematosus (SLE)
Systemic sclerosis
Sarcoidosis
What type of hypersensitivity reaction causes hypersensitivity pneumonitis?
III + IV
How is Hypersensitivity pneumonitis diagnosed?
Bronchoalveolar lavage
What are the 2 categories of pleural effusion?
Exudative – a high protein content (more than 30g/L)
Transudative – a lower protein content (less than 30g/L)
What is Light’s criteria used for?
establishing an exudative effusion using protein or lactate dehydrogenase (LDH):
Pleural fluid protein / serum protein greater than 0.5
Pleural fluid LDH / serum LDH greater than 0.6
Pleural fluid LDH greater than 2/3 of the normal upper limit of the serum LDH
State 3 causes of exudative pleural effusion
Cancer (e.g., lung cancer or mesothelioma)
Infection (e.g., pneumonia or tuberculosis)
Rheumatoid arthritis
State 3 transudative causes of pleural effusion
Congestive cardiac failure
Hypoalbuminaemia
Hypothyroidism
Meigs syndrome
What is the main presenting symptom of pleural effusion?
shortness of breath
What are the examination findings of a pleural effusion?
Dullness to percussion over the effusion
Reduced breath sounds
Tracheal deviation away from the effusion in very large effusions
What are the CXR findings with a pleural effusion?
Blunting of the costophrenic angle
Fluid in the lung fissures
Larger effusions will have a meniscus (a curving upwards where it meets the chest wall and mediastinum)
Tracheal and mediastinal deviation away from the effusion in very large effusions
What are the treatment options for a pleural effusion?
Conservative = small effusions
Pleural aspiration
Chest drain
What is an empyema?
infected pleural effusion
What will a pleural aspiration of an empyema show?
pus, low pH, low glucose and high LDH
What is a pneumothorax?
air in the pleural space
state 4 causes of a pneumothorax
Spontaneous
Trauma
Iatrogenic, for example, due to lung biopsy, mechanical ventilation or central line insertion
Lung pathologies such as infection, asthma or COPD
What is the diagnostic investigation for a pneumothorax ?
Erect chest xray
How is a pneumothorax managed?
high risk = chest drain
lower risk (<2cm) = conservative
lower risk (>2cm) = pleural vent ambulatory device, needle aspiration/chest drain
Where is a chest drain inserted?
triangle of safety
5th intercostal space (or the inferior nipple line)
Midaxillary line (or the lateral edge of the latissimus dorsi)
Anterior axillary line (or the lateral edge of the pectoralis major)
state 2 key complications of a chest drain
Air leaks
Surgical emphysema
What are some signs of a tension pneumothorax?
Tracheal deviation away from the side of the pneumothorax
Reduced air entry on the affected side
Increased resonance to percussion on the affected side
Tachycardia
Hypotension
How is a tension pneumothorax managed?
Insert a large bore cannula into the second intercostal space in the midclavicular line
State 5 risk factors for a DVT/PE
Immobility
Recent surgery
Long-haul travel
Pregnancy
Hormone therapy with oestrogen
Malignancy
Polycythaemia
Systemic lupus erythematosus
Thrombophilia
What is used for VTE prophylaxis in hospital?
LMWH
anti-embolic compression stockings
state 2 contraindications to VTE prophylaxis with LMWH
active bleeding
existing anticoagulation e.g. warfarin or DOAC
What are some presenting features of a pulmonary embolism?
Shortness of breath
Cough
Haemoptysis
Pleuritic chest pain
Hypoxia
Tachycardia
Raised respiratory rate
Low-grade fever
Haemodynamic instability causing hypotension
How is a pulmonary embolism diagnosed?
Wells score - likelihood
CT pulmonary angiogram if likely
if unlikely then d dimer followed by CTPA if +ve
Apart form PE state 3 other causes of a raised d dimer
Pneumonia
Malignancy
Heart failure
Surgery
Pregnancy
In patients with contraindication to a CTPA for a suspected PE what other investigation can be carried out?
Ventilation-perfusion (VQ) scan
What is the 1st line medical management of a PE?
1st: apixaban or rivaroxaban
How is a massive PE treated?
continuous infusion of unfractionated heparin and consider thrombolysis
What are the options for long term anticoagulation is patients who have had a PE?
DOAC (e.g. apixaban)
Warfarin (1st line in pts with antiphospholipid syndrome)
LMWH (1st line in pregnancy)
Continue anticoagulation for:
3 months with a reversible cause (then review)
Beyond 3 months with unprovoked PE, recurrent VTE or an irreversible underlying cause (e.g., thrombophilia)
3-6 months in active cancer (then review)
pulmonary hypertension is defined as what?
a mean pulmonary arterial pressure of more than 20 mmHg
What are the 5 causes of pulmonary hypertension?
Group 1 – Idiopathic pulmonary hypertension or connective tissue disease (e.g. SLE)
Group 2 – Left heart failure, usually due to myocardial infarction or systemic hypertension
Group 3 – Chronic lung disease (e.g., COPD or pulmonary fibrosis)
Group 4 – Pulmonary vascular disease (e.g., pulmonary embolism)
Group 5 – Miscellaneous causes such as sarcoidosis, glycogen storage disease and haematological disorders
What are some signs and symptoms of pulmonary hypertension ?
Shortness of breath
Syncope
Tachycardia
Raised JVP
Hepatomegaly
Peripheral oedema
What are the ECG changes seen in pulmonary hypertension?
P pulmonale (peaked P waves)
Right ventricular hypertrophy (tall R waves in V1 and V2 and deep S waves in V5 and V6)
Right axis deviation
Right bundle branch block
What are the xray changes seen in pulmonary hypertension?
Dilated pulmonary arteries
Right ventricular hypertrophy
What are the treatment options for idiopathic pulmonary hypertension?
Calcium channel blockers
Intravenous prostaglandins (e.g., epoprostenol)
Endothelin receptor antagonists (e.g., macitentan)
Phosphodiesterase-5 inhibitors (e.g., sildenafil)
What is the epidemiology of sarcoidosis?
Aged 20-39 or around 60
Women
Black ethnic origin
What are the skin features of sarcoidosis?
erythema nodosum
Lupus pernio (raised purple skin lesion often on cheeks and nose)
How can sarcoidosis affect the lungs?
Mediastinal lymphadenopathy
Pulmonary fibrosis
Pulmonary nodules
What are some systemic features of sarcoidosis?
Fever
Fatigue
Weight loss
What are some liver features of sarcoidosis ?
Liver nodules
Cirrhosis
Cholestasis
What are some eye features of sarcoidosis?
Uveitis
Conjunctivitis
Optic neuritis
What are some heart features of sarcoidosis?
Bundle branch block
Heart block
Myocardial muscle involvement
What are some kidney symptoms of sarcoidosis?
Kidney stones (due to hypercalcaemia)
Nephrocalcinosis
Interstitial nephritis
What are some neurological symptoms of sarcoidosis?
Central nervous system:
Nodules
Pituitary involvement (diabetes insipidus)
Encephalopathy
Peripheral Nervous System:
Facial nerve palsy
Mononeuritis multiplex
What are some bone features of sarcoidosis?
Arthralgia
Arthritis
Myopathy
What is Lofgren’s syndrome?
specific presentation of sarcoidosis with a classic triad of symptoms:
Erythema nodosum
Bilateral hilar lymphadenopathy
Polyarthralgia (joint pain in multiple joints)
State 4 differential diagnosis for sarcoidosis
Tuberculosis
Lymphoma
Hypersensitivity pneumonitis
HIV
Toxoplasmosis
Histoplasmosis
What is the gold standard for diagnosing sarcoidosis
Biopsy with histology
What does histology show in sarcoidosis?
non-caseating granulomas with epithelioid cells.
What two blood tests findings may be raised in sarcoidosis?
Raised angiotensin-converting enzyme (ACE) (often used as a screening test)
Raised calcium (hypercalcaemia)
What is the first line treatment if required for sarcoidosis?
Oral steroids (for 6-24 months) are usually first-line where treatment is required. Bisphosphonates protect against osteoporosis whilst on long-term steroids
2nd: methotrexate
What is the prognosis of sarcoidosis?
Sarcoidosis spontaneously resolves in around half of patients, usually within two years. In some patients, it progresses to pulmonary fibrosis and pulmonary hypertension. Overall mortality is less than 10%.
What causes obstructive sleep apnoea?
collapse of the pharyngeal airway
State 4 risk factors of obstructive sleep apnoea
Middle age
Male
Obesity
Alcohol
Smoking
How does obstructive sleep apnoea present?
Episodes of apnoea during sleep (reported by a partner)
Snoring
Morning headache
Waking up unrefreshed from sleep
Daytime sleepiness
Concentration problems
Reduced oxygen saturation during sleep
What scale is used to assess symptoms of sleepiness associated with obstructive sleep apnoea.
Epworth sleepiness scale
What investigation is used to diagnose obstructive sleep apnoea?
sleep study
What is the management of obstructive sleep apnoea?
manage risk factors
CPAP
Surgery
What is the most common causative organism of an infective exacerbation of COPD?
Haemophilus influenzae
What organism can commonly cause a cavitating pneumonia following an influenza infection?
Staphylococcus aureus
patient presenting with dry cough, erythema multiforme and bilateral consolidation on x-ray - what is the most likely causative organism?
Mycoplasma pneumoniae
