Respiratory S7 (Done) Flashcards
List some of the common microbial flora in the Upper respiratory tract (URT)
Common permanent colonies:
Viridans streptococci
Neseria spp.
Anaerobes
Candida sp
Common transient colonies:
Streptococcus pneumoniae
Strep pyogenes
List the specific defenses of the respiratory system against infection
Muco-ciliary clearance:
Nasal hairs, ciliated columnar epithelium
**Cough and sneezing reflex **
Respiratory mucosal immune system:
Lymphoid follicles in the pharynx and tonsils, alveolar macrophages, secretory IgG and IgA
Give examples of URT infections
Rhinitis (Common cold)
Pharyngitis
Epiglotitis
Laryngitis
Tracheitis
Sinusitis
Otitis media
What are the common features of URTIs?
Most commonly causes by viruses:
Rhinovirus
Coronavirus
Respiratory syncytial virus (RSV)
Can lead to bacterial superinfection:
Esp. Sinusitis and otitis media
Can lead to mastoiditis, meningitis, brain abscess
What are the two common forms of Lower respiratory tract (LRT) infections?
Bronchitis
Pneumonia
Differentiate aetiology of acute and chronic bronchitis
Acute:
Viruses and bacteria
May lead to pneumonia
Chronic:
Not primarily infective
Exacerbations can be infective
Give a brief description of pneumonia
Infection of pulonary parenchyma:
Involves distal airspaces and results in inflammatory exudate
Fluid filled air spaces and consolidation lead to heavy, stiff lungs
Gas exchange impaired resulting in local and systemic effects
By what methods might we classify pneumonia?
Clinical setting (Hospital, community)
Presentation (acute, sub-acute, chronic)
Organism (bacteria, fungi, viral)
By lung pathology (lobar, broncho- or interstitial pneumonia)
What is pneumonitis?
Non-infective inflammatory disease of lung parenchyma
Give examples of common and atypical bacteria implicated in pneumonia
Common:
S. pneumoniae
H influenzae
Kleb pneumoniae
Atypical:
Chlamydia spp.
Mycoplasma
Legionella
Give examples of common viruses implicated in pneumonia
Influenza
Parainfluenza
RSV
Adenovirus
Give examples of common microbiota implicated in:
- Hospital acquired pneumonia*
- Aspirational pneumonia*
- Pneumonia in immunocompromised host*
Hospital:
G-neg enteric bacteria
Pseudomonas
S aureus and MRSA
Aspirational:
Anaerobes and oral flora
Immunocompromised host:
Candida sp
Aspergillus
Viruses (HSV, VZV)
Pneumocystis jirovecii
What are some patient features associated with S pneumoniae infection?
Elderly
Co-morbidities
Acute onset
High fever
Pleuritic pain
What are some patient features associated with H influenza infection
COPD
What are some patient features associated with Legionella infection
Recent travel
Infected aerosol exposure
Smokers
Young
What are some patient features associated with Mycoplasma infection
Young
Prior antibiotics
Extra-pulmonary involvement (haemolysis, skin and joints)
What are some patient features associated with S aureus infection
Post viral
People who inject drugs (PWID)
What is lobar pneumonia?
Confluent consolidation involving a complete lung lobe
Most often due to Strep pneumoniae
Usually community acquired
Acute onset
Describe the pathology of lobar pneumoniae
Disease:
Acute inflammatory response
Exudation is fibrin rich fluid
Neutrophil and macrophage infiltration
Response:
Resolution due to immune system
Antibodies opsonise and lead to phagocytosis of bacteria
What is broncho-pneumonia?
Infection starting in the airways and spreading to adjacent alveoli and lung tissue
Most commonly seen in context of pre-existing disease
What might be the causes of broncho-pneumonia?
Complication of viral infection (influenza)
Aspiration of gastric contents
Cardiac failure
COPD
Describe the appearance of broncho-pneumonia when viewed radiologically
Pathy infiltrates that are not confined to lobar architecture
List the typical organisms causing broncho-pneumonia
Srep pneumoniae
H. influenza
S. aureus
Anaerobes
Coliforms
What is the treatment for typical acute bacterial pneumonia?
Amoxicillin (Mild to moderate)
Co-amoxiclav (severe)
What are the possible outcomes of acute bacterial pneumonia?
Resolution
Organisation of tissue (Fibrous scarring)
Complications:
Lung abscess
Bronchiectasis
Empyema
Describe the investigations and appearance of atypical pneumonia
Investigations:
Sputum stain and G culture
CXR
Urine antigen test (legionella)
Bllod testing for antibodies
Appearance:
Unilateral/bilateral path segmental infiltrates (usually lower lobes)
Describe the typical causative organisms and treatment for atypical pneumonia
Organisms:
Chlamydia pneumoniae
Mycoplasma pneumoniae
Legionella pneumoniae (Notifiable)
Treatment:
Levofloxacillin, Erythromycin, Clarithromycin, Doxycycline
Describe the pathology and appearance of viral pneumonia
Pathology:
Damage to cells lining the airways/alveoli by the virus and immune cells
Fluid fills air spaces and interferes with gas exchange
Severe forms can lead to necrosis/haemorrhage into lung parenchyma
Appearance:
Patchy or diffuse
Ground glass opacity on CXR
What is the definition of hospital acquired pneumonia?
In who is it most common?
Pneumonia occuring 48hrs post-admission
Most common in ITU, post surgical and ventilated patients
What organisms are the likely causes of HAP and how is it treated?
Organisms:
Enteric Gram-neg bacteria (E. coli)
Pseudomonas
Anaerobes
S aureus/MRSA
Treatment:
Broad spectrum antibotics
What conditions predispose aspirational pneumonia?
What are the at risk groups for aspirational pneumonia?
Predisposing conditions:
Alcoholism
Dsyphagia
Epileptics
Drowning
Risk groups:
Eldery in care homes
Drug takers
What are the symptoms of pneumonia?
Fever, Chills, Sweats, Rigor
Cough
Purulent/Rust-coloured sputum
Dyspnoea
Pleuritic chest pain
Maliase, Anorexia, Vomiting
Headache
Myalgia
Diarrhoea
What are the specific chest signs of pneumonia?
Bronchial breath sounds
Crackles
Wheeze
Dullness to percussion
Reduced vocal resonance
List the non-microbiological investigations for pneumonia
CXR
O2 sats and ABG
FBC, WBCC, Platelets
Urea, LFT and CRP
What are the useful markers in assessment of pneumonia disease progression?
WBCC:
>20 or <4 indicate severe disease
CRP:
Assessment of response to treatment
Radiology:
Reliable
Radiological signs can very rarely lag behind clinical characteristics (24-48hrs)
What are the microbiological samples that might be taken during diagnosis/treatment of pneumonia?
Sputum
Nose or throat swabs
Endotracheal aspirates
Broncho-alveolar lavage fluid
Open lung biopsy
Blood culture
Urine (Detect legionella antigens)
Serum
What are the microbiological investigations into pneumonia?
Macroscopy (Mucoid, purulent, blood stained)
Microscopy (Gram stain, acid fast, special stains)
Culture (Bacteria and virus)
PCR (respiratory virus ID)
Antigen detection (Legionella in urine)
Antibody detection (serology)
What is the CURB-65 prognostic index?
Used to assess severity of pneumonia
Criteria:
Confusion (AMT <8)
Urea - >7
RR - >30
BP - <90s or <60d
Age - >65
Add 1 point if yes to any of these
If score is >2 then admission +/- ITU referal advised
What are the principles of pneumonia treatment?
Assess severity and co-morbidities
Give supportive and specific treatment
Broad spectrum antibiotics to cover most organisms
Review patient if change in microbiology resuts or poor response
Follow local guidelines
Describe the antibiotic treatment of pneumonia
1st line:
Penicillin class antibiotics (Amoxycillin)
Severe infection:
Penicillin class + Clavulanic acid (Co-amoxiclav)
Legionella pneumonia:
Levofloxacin
Other atypical organisms:
Tetracyclines or macrolides
Poor response:
Discuss with microbiology
Describe pneumonia prophylaxis
Immunisation:
Flu vaccine - annual to high risk patients
Pneumococcal vaccine (2 vaccines)
Chemoprophylaxis:
Oral penicillin/erythromycin to high risk patients (i.e asplenia, immunodeficient)
In what circumstances should you refer to ITU in a patient with pneumonia?
CURB-65 of >2
Respiratory failure occurs
Rising pCO2
Worsening metabolic acidosis
Hypotension despite fluid resus
Query patient suitability for ITU (E.g. If ITU treats successfully will there be any quality of life?)
What special measures must be taken in the dignosis of pneumonia in the immunocompromised host?
High index of suspicion
Multidisciplinary involvement
Broncho-alveolar lavage and lung biopsies as a more standard method of histological diagnoses (lots of special stains!)
List the likely causes of pneumonia or LRTIs in a cystic fibrosis patient
Early infections:
H influenza
S aureus
Later:
Pseudomonas aeuruginosa
Burkholderia cepecia
What is the common causative organism of pneumocystic pnumonia?
Who are at risk for this infection?
Organism:
Penumocystis jirovecii
Risk groups:
HIV infected
Transplant recievers
Immunocompromised
How is diagnosis of Pseudomonas jirovecci infection made?
What is the reccomended treatment?
Diagnosis:
Induced sputum, broncho-alveolar lavage and lung biopsy used to determine diagnosis histogogically
PCR can be used to confirm P jirovecii
Treatment:
High dose Cotrimoxazole
What is Whooping cough?
What are the symptoms?
What:
Disease of respiratory tract caused by Bordetella pertussis
Symptoms:
Starts off cold-like
Progresses to characteristic ‘whoop’ or vomiting
Can last 2-3 months
Who is at greatest risk of Whooping cough?
How is it spread?
High risk:
<1 year
Transmission:
Droplets
Outline the clinical management of whooping cough and prevention of whooping cough
Diagnosis:
Specimens (Nasal or nasopharyngeal swbs or aspirates)
Culture/PCR
Treatment:
Erythromycin
Prevention:
Childhood vaccination
Vaccination of pregnant mothers
What is the incidence rate of lung cancer and related mortality in the UK?
37,500 new cases per year
33,000 deaths per year
Smoking causes what proportion of lung cancer in:
- Male smokers*
- Female smokers*
- Non smokers*
90%
80%
20%
What proportion of cancer deaths are attributable to smoking?
1/3
What are some risk factors for lung cancer other than smoking?
COPD (3-6x relative risk)
Asbestos
Radon gas exposure (mining or indoor exposure)
Occupational carcinogens (Chromium, nickel, arsenic)
Genetic/familial factors
How is Lung cancer distributed over socio-economic groups?
Higher prevalence in the poorer:
40 per 100,000 in affluent
100 per 100,000 in poorest
Age standardised
What are the symptoms of a primary lung tumour?
Cough
Dyspnoea
Wheezing
Haemoptysis
Chest/Shoulder pain
Weight loss
Lethary/Malaise
What are the possible symptoms of a region lung cancer metastases?
Superior vena caval obstruction
Hoarseness (Left reccurent laryngeal nerve palsy)
Dyspnoea (Phrenic nerve palsy)
Dysphagia
What are some of the possible symptoms of distant lung cancer metastases?
Bone pain/fracture
CNS symptoms (Headache, double vision, confusion)
List the range of paraneoplastic syndromes possible in lung cancer
Endocrine:
Hypercalcaemia
Cushings
SIADH
Neurological:
Encephalopathy
Peripheral neuropathy
Haematological:
Anaemia
Thrombocytosis
Skeletal:
Clubbing
Where are the common sites of metastases for lung cancer?
Local:
Draining nodes
Pleura
Pericardium
Distant:
Brain
Liver
Adrenals
Bone
How is lung cancer first investigated then diangosed and staged?
On first clinical suspicion:
Plain CXR
Diagnosis and staging:
Serum biochemistry (Na+, LFT, Ca2+)
Imaging (CT and PET CT, Isotope bone scan)
Tissue:
- Endobronchial ultrasound*
- CT guided biopsy of lung*
- Biopsy of lymph nodes, pleura and metastatic sites*
What are the major cell types in lung cancer?
Carcinoma:
Non-small cell carcinoma: ~80%
- Squamous cell carcinoma *~40%
- Adenocarcinoma*
- Large cell carcinoma*
Small cell carcinoma ~12%
Rare tumours (E.g. Carcinoid) ~5%
Describe squamous cell carcinoma
Often central tumours
Angulate cells
Eosinophilic cytoplasm
Keratinisation
Intercellular bridges
Keratin pearls
Describe adenocarcinoma
Often peripheral tumour
Columnar/cuboidal cells
Form acini (glands)
Papillary structures
May line alveoli
Some produce mucin
Describe small cell carcinoma
Very cellular tumour
Small nuclei
Little cytoplasm
Nuclear moulding
Often necrosis and lots of mitoses
Describe the local effects of cancer within the lung
Necrosis +/- cavitation
Ulceration (haemoptysis)
Infection (abscess formation
Bronchial obstruction, lung collapse, consolidation
Describe the effects of spread of lung cancer within the thorax
Direct spread or metastasis to pleura/pericardium
Pleural/pericardial effusions
Compression of structures (Superior vena caval obstruction, dysphagia)
Reccurent laryngeal nerve might be effected (Hoarseness)
Phrenic nerve might be affected (Diaphragm palsy/dyspnoea)
What is the role of imaging in lung cancer?
Extensive use through clinical experience
Screening
Diagnosis, staging, trreatment planning
Assessing response to treatment
Assessing complications
Aiding interventions
Checking for recurrence
How is lung cancer staged?
TNM staging I - IV
Describe the difference between a stage I and Stage IV primary lung tumour
TI:
<3cm diameter, operable
TIV:
Large, usually inoperable lung mass
Invades into surrounding structures (Trachea, pleura, bronchi, mediastinum, great vessels)
Describe nodal staging in lung cancer
Nodes with short axis diameter of >10mm considered abnormal
Where abnormal nodes appear determines stage
NI:
Peribronchial
Ipsilateral hilar
N2:
Ipsilateral mediastinal
Subcarinal
N3:
Contralateral mediastinal
Contralateral hilar
Scalene
Supraclavicular
Describe metastases staging in lung cancer
M0:
No metastases
M1a:
Lung nodules, pleural effusion
M1b:
Distant metastases
What radiological investigations would you perform to find/assess bone metastases
X ray
Scintigraphy
Describe scintigraphy of bone and how it’s useful to visualising bone metastases
Scintigrpahy:
Radioiostopes administered and prefferentially taken up by bone
Greatest concentrations will be in areas of greatest cellular activity
Radiation detected by external cameras
Use:
Metastases will appear as areas of bone with higher than normal activity and hence darker
What is the role of ultrasonography in lung cancer?
Guided biopsy (Lung, liver, ribs, peripheral lesions)
Identification of pleural effusion
Identification of chest wall invasion of tumour
What is the role of stenting in lung cancer?
Primary tumours or local metastases can compress and obstruct flow through structures, stenting alleviates this
E.g. Superior vena cava obstruction stenting or airway stenting
What is the role of MRI in lung cancer?
Identification of metastases
What is FDG PET?
FGD is a glucose analogue with a Flourine-18 atom attached
FDG taken up into cells as a marker for glucose uptake
Increased FGD uptake therefore indicates metabolic rate
Flourine 18 emits positrons to allow this to be visualised in a PET scanner
What are overall 5 year and median survival rates for lung cancer?
What factors influnece prognosis?
5 yr survival:
10-15%
Median:
6 months
Prognosis:
Cell type
Stge
Performance ststus (General fitness)
Biochemical markers
Co-morbities
What is the most coomon routes to diagnosis for pateints?
Emergency presentation (~40%)
Screening (~20%)
How does route to diagnosis affect survival rates?
Emergency presentation has a 12% survival rate at 1 year
Screened, two week waiters, GP referral or other outpatients have 40% survival at 1 yr
What are the treatment options for lung cancer?
Surgery:
Normally non-small cell (20-25% operable)
Radiotherapy:
Either radical (potentially curative) or palliative (Symptom control
Combination chemotherapy:
Small cell is potentially curative
Non-small cell gives modest survival increase and symptom control
Combination therapy:
Chemo-radiotherapy (potentially curative)
Biological therapies
Palliative care
Describe non-small cell lung cancer management
Multimodality therapy
Palliative radiotherapy:
For local symptom relief and bony metastases symptom relief
Chemotherapy:
50-60% response rates, modest survival improvement, can be cell type targeted
Combination Chemo-radiotherapy:
Important in locally advanced disease
Targeted agents:
Epidermal growth factor inhibitors
ALK inhibitors
Immunotherapy
Describe small cell lung cancer management
Systemic and rarely operable disease with ~3 month survival untreated
Treatment focus is therefore palliative
85-90% respond to combination chemo, gives approx 1 year added survival if combined with radiotherapy in early stage disease
Death from cerebral metastases common
What and who is involved in supportive treatment for lung cancer?
Focuses on prompt treatment of symptoms
Palliative care involvement from early stage
Nurse specialists have a central role
Specific palliation best done by appropriate clinician for symptoms
What are the problems with lung cancer management and attempts to treat?
Late diagnosis common
Poor prognosis
Very symptomatic
Professional nihlism
Variable standards of care
Lack of public pressure for improvement
What are the effects of public health campaigns and screening regarding lung cancer?
E.g. 3 week cough campaign
Reduced incidence of death from lung cancer in those screened
Shift towards earlier stage diagnosis
