Respiratory - Lung Infections Flashcards
Specifics for resp hx
Age Gender Occupation Smoking hx Asbestos exposure Pets/ birds at home Hx of childhood resp illness
Classification of resp diseases
Airways diseases Lung parenchymal diseases Pleural diseases Pulmonary vascular diseases Lung infections Lung cancer Thoracic oncology
Examples of airway diseases
Asthma
Allergic rhinitis
Examples of lung parenchymal diseases
Emphysema
ILD
What’s included in the conducting airways
Trachea
Bronchi
Bronchioles
Terminal bronchioles
What included in the acinar airways
Transitional bronchioles
Alveolar ducts
Alveolar sacs
What does the control of respiration involve
Higher brain centres, chemoreceptors and other reflexes
Common symptoms to look out for
Breathlessness
Cough
Chest pain
General inspection for resp
Pallor Jaundice Clubbing Cyanosis Oedema Lymphadenopathy Pulse and RR
Common resp ix
Pulse oximetry Lung physiology - LFTs/ PFTs Gas exchange analysis - ABG Radiological modalities - CXR, CT Bronchoscopy Pleural procedures Blood test, sputum test Urine antigens
Lung defence mechanisms
Muco-cillairy apparatus
Alveolar macrophages
Cytotoxic T cells and NK cells: intracellular pathogens
Epidemiology of CF
Most common inherited lethal disease
1 in 2500 babies born have CF
Inheritance of CF
Autosomal recessive inheritance on long arm of chromosome 7
What genes is affected in CF
CFTR gene contains code to create CFTR chloride channel
LOF mutation causes increased Na and Cl in sweat and increased reabsorption of water from resp system –> viscous mucus and dehydration of epithelium
Clinical features of CF
C/c sinusitis Abnormal sweat [Na] and [Cl] Bronchiectasis Liver disease Constipation Male infertility - loss of vas deferens Finger clubbing Pancreatic insufficiency, pancreatitis, DM
The Sweat test
Pads soaked in pilocarpine are placed on skin to stimulate sweat
Sweat is collected then amount of chloride is measure - should be high to get a +ve result
Dx and ix for CF
Clinical assessment and examination Oxygen saturations Resp secretions samples LFT - FEV1, FVC, FEF Infant screening test - trypsinogen
Aims of CF treatment
Prevent or delay serious lung problems
Maintain lung function and clinical stability for long periods
Symptoms associasted w. exacerbation of pulmonary infection
Increased frequency and duration of cough
Increased sputum production
Increased SOB
Decreased exercise tolerance
Decreased appetite
Feeling of increased congestion in the chest
Signs associated w/ exacerbation of pulmonary infection
Increased RR Use of accessory muscles for breathing Fever and leukocytosis Wt loss New infiltrate on CXR
Prophylactic abx given for Staph A
Fluclox
Treatment of Staph A infections
Fluclox
Co-amoxiclav
Mx of Psuedomonas A
Needs combo of nebuliser and systemic abx
Nebulised - 3/12 of nebuliser Colistin OR 1/12 of individual abx
PLUS
Systemic: 3/52 of po Ciprofloxacin (or 3/52 of iV ceftazidime/ Tobramycin)
Treating a/c infections of Aspergillus
Antifungals
Treatment of ABPA
Steroids and antifungals
ABPA
Allergic Bronchopulmonary Aspergillosis
When would we give mucolytics and hydrators
Impaired muco-cilairy clearance
Decreased airway surface liquid volume
Secretions that are difficult to expectorate
Mucus degrading agent used in CF
Dornase alfa
Long-term maintenance therapy is required
Practical issues of dornase alfa
Given via nebuliser
Expensive - hosp prescription
Given at least 30 mins - 1hr before PT
What does hypertonic saline do
Expectorant
Increases thickness of ASL
Promotes coughing
ASL
Airway Surface Layer
Order of inhaled medicines
Bronchodilator
Mucolytics
Airways clearance
Inhaled abx
How is pancreatic insufficiency assessed in CF pts
Clinically
By stool elastase
Dietary mx of CF pts
Start on lifelong PERT
Regular growth monitoring
Fat soluble Vit supplementation - A, D, E, K
Higher caloric needs
Ionising ix of lung
CXR
CT
Nuclear med
Conventional angiography
Non-ionising ix of lung
MRI
Ultrasound
VQ scan
Ventilation/ perfusion scan
Inhaling radioactive material to examine airflow and blood flow in lungs
Usually looking for PE
When are pts most likely to have a PET scan
When they are candidates for surgery - to complete staging
Use of MRI in resp med
Charcterising mediastinal masses
Paravertebral masses (neurogenic tumours)
Monitoring of thoracic aneurysms
Use of ultrasound in resp med
Detects pleural abnormalities
Probe can be placed in IC space
What types of imaging are used in image-guided biopsy or drainage
Ultrasound
CT
Collapse (atelectasis)
Reduction of volume in various parts of lung
Obstruction or compression
AP vs PA CXRs
Cannot see scapula in PA view
Postero-anterior is preferred over antero-posterior
Silhouettes of CXR
Image margins or areas of contrast where structures that are bordering have a clear delineation
Is loss of silhouette shadowing on CXR normal
No
Normal silhouette on CXR
Lung, heart and hemipericardium border
Silhouette sign on CXR
Increased shadowing of interface of lung and heart border
What does the silhouette sign on a CXR indicate
Abnormalily - loss of normal silhouette
Clinical definitions of consolidation
Dull to percussion
Reduced breath sounds
Bronchial breathing
Histopathological definition of consolidation
Filling of the alveolar spaces w/ pus, water, blood, tumour or protein
Air space opacity on CXR
Abnormal density in areas that should normally be aerated in X-ray contrast
Air bronchogram
Part of lung is consolidated - alveoli filled w/ fluid but larger airways are patent
Radiological definition of consolidation
Presence of air bronchogram
Types of loss of lung volume
Lung
Lobar
Segmental
Subsegmental
Diagnosing loss of volume of X-ray
Mediastinal shift - main factor Tracheal deviation Elevation of diaphragm Displaced hilum Rib crowding
Hilar point on CXR
Angle between lower lobe & pulmonary artery and upper lobe & pulmonary vein
Other patterns of consolidation
Diffuse Multifocal Perihilar - Bat's wing Bibasal Peripheral
Contusion
An injury to the lung parenchyma (bruised) leading to haemorrhage and oedema
What is pneumonia caused by
Invasion and overgrowth of pathogens in lung parenchyma
Symptoms of pneumonia
Dyspnoea - harsh breathing sounds Fever Rigours Shaking chills Dry/ productive cough Chest pain Malaise
Pathophysiology of pneumonia
Infection to the lung initiates an infl response
Causing alveolar oedema + exudate formation
Alveoli & resp bronchioles fill w/ serous exudate, blood cells, fibrin bacteria
Consolidation of lung tissues
Pathogen factors affecting infection
Virulence factors
Host factors affecting infection
Innate immunity - physical-mechanical, complement
Phagocytes - macrophages, neutrophils
Cellular immunity - B cells, T cells
Cytokine, chemokine
Environmental factors affecting infection
Travel, occupation Medical devices (ventilators)
Pneumonia classification
Community (CAP)
Hosp (HAP)
Immune compromised
Age group affected in CAP
All ages
Classic infection seen in CAP
Bacterial or viral
When does HAP occur
2-3 days after admission
Who gets immuno-compromised pneumonia
HIV pts
Transplant pts
Cancer pts
1’ immunodeficiency pts
CAP epidemiology
6th leading cause of death in world
Leading cause of death due to infectious diseases
Highest incidence <5yrs and >65yrs - incidence increases w/ age and in winter
Resp tract bacterial pathogens
Strep pyogenes
Strep pneumonia
H. influenza
Bacterial/ viral pathogens causing CAP
Strep pneumonia and H. influenza cause 85% of cases
Moraxella catarrhalis
Influenza - Staph A
Resp viruses
Atypical bacteria causing CAP
Chlamydia psittaci Coxiella birmetoo - Q fever Mycoplasma pneumonia Legionnaire's disease Mycobacterium TB
DDx signs of pneumonia
Sputum
Halitosis
General appearance
Haemoptysis
Most common symptoms of bacterial pneumonia
Productive cough
How can colour of sputum help suggest pathogen
Rust (S. Pneumoniae)
Green (Pseudomonas)
Redcurrant (Klebsiella)
Bad-smelling (anaerobes)
What is a sudden onset on pneumonia symptoms associated with
Bacterial infection
What is slow onset of URTI and wheezing associated w/ in pneumonia
Viral infection
Who gets pneumococcal pneumonia
V young and v elderly
People w/ asplenia or functional asplenia
People w/ other cases of impaired immunity and certain c/c condns
What is lobular pneumonia likely to progress to in pneumococcal pneumonia
Empyema or pleural effusion if treated insufficiently
Empyema
Collection of pus in pleura
How many serotypes are there of pneumococcal pneumonia
90
Vaccines against pneumococcal pneumonia
13-valent pneumococcal conjugate vaccine - intro childhood immunisation in 2010
23-valent pneumococcal polysaccharide vaccine
What months do pneumococcal pneumonia peaks in
Dec and Jan
CURB-65
Tool used to determine whether pts w/ pneumonia should be admitted or not
Confusion Urea >7mmol/l RR > 30 BP < 90/60 mmHg Age > 65
CURB-65 score of 0-1
Low severity
<3% mortality
Treatment at home if 0 or hosp If 1
Ix for CAP
CXR
Sputum culture - viral throat swabs
Hospitilisation
Resp virus PCR and further bloods - CRP/ESR, serology
When do abx need to be started for CAP
Within 4 hrs of admission
Treatment for moderate/severe CAP
Empirical therapy (dual) - penicillin (amoxicillin, tazobactam) and macrolide (clarithromycin) Antivirals --> oseltamovir for 7/7 (but within 3/7 - 5/7 of start of symptoms)
Smoking and CAP
Associated w/ 2x fold increase
Epidemiology of HAP
4th most common HAI
Prevalence 14.1%
Risk factors for HAP
Abx Surgery C/c lung disease Advanced age Immunosuppression Tracheal intubation Mechanical ventilation
Types of HAP
Ventilator associated pneumonia
Aspiration pneumonia
Environmental source
Hosital transmission
Causative organisms of ventilator associated HAP
Pseud aeruginosa Haemophilia Staph A - MRSA E. coli, Kleb pneumoniae, Enterobacter Strep Fungi (Candida spp Aspergillus)
Causative organism of aspiration HAP
Gram -ve organisms
Anaerobes
Strep pneumonia
Initial stages of aspiration HAP
Pneumonitis then further infection by pathogens ensue
Makes course long and characteristic
Examples of humoral immune dysfunction
Complement deficient
Ig deficient
Examples of cellular immune dysfunction
Neutropenia (e.g. chemo)
Lymphopenia (e.g. HIV transplant)
How does low CD4 T cell count increase chances of catching pneumonia
Reactivation of dormant virus (CMV, HSV, etc)
Reactivation of dormant bacteria e.g. TB
Susceptible to intracellular bacteria (TB, atypical mycobacteria)
Susceptible to fungi
How does poor phagocyte function in HIV increase risk of pneumonia
Susceptible pneumococcus
CXR in HIV pneumonia
Ground glass showing
Treatment of HIV pneumonia
Trimethoprim - sulfanethoxazole
CXR in CMV pneumonitis
Ground glass shadows
Treatment of CMV pneumonitis
Ganciclovir
CXR in TB
UL consolidation
Nodular
Symptoms of TB
Productive cough Fever Night sweats Wt loss Erythema nodusum
Treatment of TB
Isoniazid/ Rifampicin/ Pyrazinamide/ Ethambutol for 2/12 then I & R for further 4/12
TB drugs are hepatotoxic for measure LFTs
Atypical mycobacterium
M avid - intracellular complex
Cause of pneumonia in neutropenic pts
Chemo Leukaemia Bone marrow transplant Steroids DM
CXR in invasive aspergillosis
Consolidation
Treatment for invasive aspergillosis
Amphotericin B or caspofungin
Types of samples
Swabs Secretions Invasive samples Blood Urine
Where do we take a swab sample from
Ear
Throat
Pemasal
Types of secretion samples
NPA
Sputum
Types of invasive samples
Aspirates
Washings
Biopsies
Urine sampling for resp pathogens
Antigen detection - Legionella, pneumococcus
Sputum collection for TB culture
Sputum specimenn are essential to confirm dx
Should be from lung secretions
Collect 3 specimen on 3 diff days
What type of sputum is best for TB culture
Spontaneous morning sputum vs induced specimens
Staining mycobacteria
Ziel-Nielsen stain
Auramin stain
AFB
Serology (blood) for resp pathogens
Antibody titre
Ag detection
Primary prevention of infection
Prevent or reduce exposure
Immunisation (pnumococus, influenza)
Secondary prevention of TB
Chemoprophylaxis
Contact tracing
Tertiary prevention of infection
Minimise disability arising from infection
Effective treatment
PT
What does the URT incl
Anterior snares Nasal passages Paranasal sinuses Nasopharynx Oropharynx Portion of larynx ABOVE vocal cords
What does the LRT incl
Portion of larynx beneath viral cords Trachea Bronchi Bronchioli Alveoli
Lab techniques used to identify bacteria
Microscopy - gram stain, immunofluorescence
Bacterial culture or DNA/ PCR sequencing
Antigen detection - EIA/ ELISA
Antibody deduction
Treatment of Strep pneumonia
Penicillin
Macrolides
Does Strep pneumonia affect URT or LRT
LRT
Bacterial causes of bacterial throat infection
Gp A Strep (also Gp C & G)
C. diphtheria
When is Strep pneumonia vaccinated against in children
Pneumococcal vaccine at 2, 4, 12/12
Who do bacterial sore throats primarily affect
School-age children
Less serious complications of Gp A Strep infections caused by Strep progenies
Quinsy
Otitis media/ sinusitis
Mastoiditis
Systemic complications of Gp A Strep infections caused by Strep pyogenes
Scarlet fever
Immune mediated complications of Gp A Strep infections caused by Strep pyogenes
Rheumatic fever
Glomerulonephritis
Rheumatic heart disease
What does Coryne diphtheriae cause
Toxins that destroy epithelium coating resp system
Is C diphtheriae Grame -ve or +ve
Gram +ve bacilli
Complications of C. diphtheriae
Resp obstruction - fatal
Toxic myocardiopathy
Toxic neuropathy
Treatment of C. diphtheriae
Antitoxin
Erythromycin
Prevention of C. diphtheriae infections
Immunisation - DTaP/ IPV/ Hib at 2/3 and 4/12
Close contacts - 7/7 erythromycin
Is H influenzae Gram -ve or +ve
Gram -ve coccobacilli
Treatment for H. influenza infections
Amoxi
Co-amoxiclav
Doxy
Pertussis (whooping cough)
Known for uncontrollable, violent coughing which often makes it hard to breathe
Results in ‘whooping’ sound ad can be v serious
Bacterium causing pertussis
Bordetella pertussis
What does horizontal transmission incl
Direct contact Inidrect contact Droplet Airborne Vector borne
Typical presentation of H. influenza infection
66 M w/ hx of COPD and recurrent LRTIs
Typical presentation of pneumocystis jiroveci
47 F w/ known HIV presents w/ fever and B/L infiltrates in lungs
Typical px of M tuberculosis
37 M Latvian origin prensts w/ R upper lobe cavity
Flu like symptoms
Erytheme multiforme
Typical presentation of RSV
2 F productive cough and wheeze
Typical px of Strep pneumonia
48 M w/ CAP
Most common cause of CAP
Typical px of Pseudomonas
27 M w/ CF and productive cough
What do tetracyclines target
30S subunit
What does penicillin target
Cell wall synthesis
What does Rifampicin target
RNA polymerase
What does Quinolone (Ciprofloxacin) target
DNA gyrase
What does trimethoprim target
Folate synthesis
What do macrolide target
50S subunit
How can bacteria become resistant to abx
Either intrinsically resistant due to inherent structural characteristics or acquired through horizontal and vertical transmission
Why do Gram -ve bacteria have intrinsic resistance
Due to reduced permeability of cell wall
Most common URTI
Common cold - self limiting illness
Causative viruses of the common cold
Rhinoviruses (30-40%) Adenovirus (5-10%) Coronaviruses (10-15%) Influenzavirus (25-30%) Parainfluenzavirus (5%)
Bronchiectasis
Irreversibly damaged bronchi - dilated and thickens
Usually colonised w/ bacteria –> pus formation and mucus hypersecretion
Examples of obstructive airways disease
COPD (c/cbronchitis, emphysema) Asthma Bronchiectasis CF Bronchiolitis
What do obstructive airway diseases affect
Your ability to exhale all the air in the lungs
What does mucus consist of
Musins (5%) and water (95%)
This contributes to 10x expansion
What does mucus production respond to
Stimuli
Approach to mx of bronchiectasis pts
Consider it as possible dx Confirm dx - HRCT Think about underlying cause Assessments - sputum microbiology Structure a mx plan - airway clearance and abx?
When should bronchiectasis be considered in adults
Younger pts Long hx of symptoms No smoking hx Large volumes of purulent sputum Haemoptysis
When should bronchiectasis be considered in children
C/c productive cough Asthma not responding to treatment Episode of severe pneumonia or recurrent pneumonia Localised c/c bronchial obstruction Unexplained haemoptysis
HRCT in bronchiectasis
Signet ring sign - white circle (blood vessel) smaller than black circle (dilated airways)
Tram line appearnce
Clinical features of bronchiectasis
Regular, daily sputum production over long period that is mucoid or purulent in colour
Cough
Social embarrassment related to symptoms
Symptoms seen in a/c exacerbations of bronchiectasis
Increasing sputum volume
Worsening sputum colour
Haemoptysis
Malaise/ tiredness
Examination findings of bronchiectasis
Crackles over affected area
Causes of bronchiectasis
Resp infections Direct damage - foreign body inhalation, GORD Mucocililary disorders Allergic/ infl Immune effects CTD - rhA, SScl
Mucocilliary disorders causing bronchiectasis
Cilliary dyskinesia
CF
Allergic/ infl cause of bronchiectasis
ABPA
Resp infections leading to bronchiectasis
Bacterial pneumonia
Mycoplasma pneumonia
Mycobacterium
Viral
Bacterial pneumonia infections causing bronchiectasis
Bordetella pertussis
Staph A
H influenza
Klebsiella
Viral infections casing bronchiectasis
Measles
Adenoviruses
Influenza
Ciliary defects as a cause of bronchiectasis
Primary ciliary dyskniesia (1 in 30,000)
No real mx
Seen in Kartagener’s syndrome
Kartagener’s syndrome
Inherited disorder of ciliary function
V rare - 1 in 60,000
Triad of features - bronchiectasis, sinusitis, situs invertus
Who is ABPA most likely to occur in
Asthmatics
CF pts
What does ABPA cause
Intense bronchial infl
IgE and IgG antibodies to aspergillus
Secondary immune defects causing bronchiectasis
Lymphoid malignancy
HIV/ AIDS
Primary immune defects causing bronchiectasis
Hypogammaglobulinaemia (early childhood onset)
Common variable immunodeficiency (late childhood/ adult onset)
Humoral immune defects and bronchiectasis
Disorder of antibody production
Low incidence but immune defects important to excl as treatable w/ IV Ig replacements
Common presentation of primary humeral defects
Sepsis (lungs and sinuses)
Ix for bronchiectasis
Bloods Specialist tests Sputum culture - repeated and regular Radiology Lung function
Blood for bronchiectasis
Ig
IgG and Aspergillus-spp IgE/ IgG
RhF and ANA
Specialist tests for CF
CF sweat tests/ genetics
Immunology tests
Imaging for bronchiectasis
CXR
HRCT - tram line, signet sign
Testing lung function for bronchiectasis
Spirometry - obstructive pattern
What pathogens can amoxicillin treat in bronchiectasis
Strep pneumonia
H. Influenza
What pathogens can macrolide treat in bronchiectasis
Strep pneumonia
(M. Catarrhalis)
(H. influenza)
What pathogens can co-amoxiclav treat in bronchiectasis
Strep pneumonia
M. Catarrhalis
H. Influenza
Pseud. aeruginosa
What pathogens can ciprofloxacin treat in bronchiectasis
Strep pneumonia
M. Catarrhalis
H. Influenza
Pseud. aeruginosa
What pathogens can ceftazidime (IV) treat in bronchiectasis
Pseud. aeruginosa
Mx of bronchiectasis
Treat underlying disorders e.g. steroids (ABPA), Ig replacement
PT
Abx
Prophylaxis - po, nebuliser
PT’s role in treating bronchiectasis
Regular BD airway clearance techniques – active cycle, forced expiratory, postural drainage
Treatment of a/c exacerbations of bronchiectasis
Amoxicillin - po
Ciprofloxacin - IV
10 - 14 days at home or in hosp
Common symptoms seen in lung infections
Cough Wheezing Sneezing Facial pain - sinusitis Chest pain Breathless/ SOB Fever Haemoptysis and other red flag symptoms
Main ddx for chest pain
PE Pneumonia Pleurisy PTX MI Aortic dissection
PTX
Pneumothorax
Pleurisy
Infl of pleura (lining of lungs)
Main ddx of SOB
HF
Anaemia
Ddx of c/c cough
Lung cancer CF COPD ACEi GORD Bronchiectasis C/c rhino sinusitis (PND syndrome)
PND syndorme
Post -nasal drip syndrome
Features of Horners syndrome
Ptosis
Miosis
Enophthalmos
Why do we assess for tremors in resp exam
Associated w/ (over)use of beta 2 agonist
What causes asterixis (flapping tremor)
CO2 retention in conditions that result in type 2 resp failure e.g. COPD
When does Horner’s syndrome develop
The sympathetic trunk is damaged by lung cancer affecting apex of lung (Pancoasts tumour)
Why do we look for oral candidiasis in resp exam
Associated w/ steroid inhaler use (local immunosuppression)
Resp causes of displaced apex beat
RV hypertrophy (pulmonary HTN, COPD, ILD)
Large pleural effiusion
Tension PTX
Causes of symmetrical reduced chest expansion
Pulmonary fibrosis (reduced lung elasticity)
Causes of asymmetrical reduced chest expansion
PTX
Pneumonia
Pleural effusion
What does increased vocal resonance suggest
Increased tissue density e.g. consolidation, tumour, lobar collapse
What does decreased vocal resonance suggest
Presence of fluid or air outside lung e.g. pleural effusion, PTX
Special features of empyema
Failure to recover fully w/ abx
Characteristic ‘swinging’ fever
Risk factors for empyema
Trauma
Pneumonia
Immunocompromised status
Treatment of empyema
Urgent drainage
IV abx
Ddx of hameoptysis
PE Pneumonia TB Aspergilloma Bronchiectasis Lung cancer Granulomatous w/ polyangitiis
Sepsis 6
Take lactate, blood cultures, measure urine output
Give fluids, IV abx and oxygen
Side effects of isoniazid
Peripheral neuropathy (give pyridoxine) Liver toxicity
Side effects of rifampicin
Liver toxicity
Turns bodily fluids red/ orange colour
Side effects of ethambutol
Visual disturbances (colour disturbances, loss of acuity) Avoid in CKD