5 Infection of resp systems PNEUMONIA Flashcards
LRT infection !
Examples of different pathogens that cause pneumonia ?
- viruses
- bacteria
- fungi (pneumocystis jirovecii)
- parasites
Pneumonia classified depending on source of infection how ?
- community-acquired pneumonia (CAP)
- hospital-acquired pneumonia (HAP)
Pneumonia diagnosis ? list 3 ways:
1. symptoms and signs of …
2. diagnosis confirmed by ….. which shows …..that’s not due to any other cause
3. different …. strategies for CAP and HAP
1.LRT infection
2. chest X ray showing new shadowing, not due to any other cause
3.management
Pneumonia risk factors that aren’t age, lifestyle, underlying medical conditions & exposure to contaminated resp therpay equipment , water sources or exposure to healthcare setting ?
- impaired cough reflex
- aspiration of naso- or oropharyngeal secretions
- antibiotic therapy
- surgery of head, neck, thorax, or upper abdomen
- intubation / mechanical ventilation
Pneumonia risk factors that are from exposure of ….?
- contaminated respiratory therapy equiment
- contaminated water sources
- healthcare setting
Pneumonia classified by sites how ?
- loba - entire lobe (streptococcus pneumoniae)
- bronchopneumonia - (Descending infection around bronchi and bronchioles, lower lobes )
- interstitial
4 stages of lobar pneumonia ? and the durations of each stage
- congestion (24 - 48 hr)
- red hepatisation (2 - 3 days)
- grey hepatisation (4 - 8 days)
- resolution (day 8 - 4 weeks)
macroscopic features of congestion stage
- partial consolidation of the parenchyma
- red - purple
- lungs are heavy , boggy
microscopic characteristics of congestion stage
- vascular engorgement
- intra-alveolar oedema
- many bacteria / few neutrophils
macropscopic features of red hepatisation
- red-pink, dry, granular, airless
- parenchymal consolidation
- reversible
microscopic characteristics of red hepatisation ?
- fibrin strands replace oedema fluid
- cellular exudate of neutrophils
- extravasation of erthrocytes
- desquamated epithelial cells
- alveolar septa become less prominent
macroscopic features of grey hepatisation
- lung appears grey
- liver-like consistency
microscopic characteristics of grey hepatisation
- lung appears grey
- liver-like consistency (due to fibrin deposition)
- red cell lysis / disintegration / clearance
macroscopic features of resolution
gradual restoration of aeration
part of body e.g. lung / portion lung tissue gradually regains its ability to take in air
microscopic characteristics of resolution stage of lobar pneumonia
- resolution and restoration of pulmonary architecture
- enzymatic fibrinolysis
- macrophages remove neutrophils and debris
community - acquired pneumonia infection acquired where ?
outside of hospitals
In CAP mortality and morbidity increase if patients are ….
transferred to intensive care within 24 - 48hr admission
Why will ~ 10% of patients admitted with CAP will need intensive care admission ?
- severe respiratory failure
- septic shock
- sepsis
symptoms of CAP ? that typically present with signs / symptoms of which tract ?
lower respiratory tract infection
* cough
* dyspnoea (SOB)
* pleuritic chest pain
* mucopurulent sputum
* myalgia (muscle aches and pains)
* fever
onset over hours to days
Management (assessment) of CAP and HAP that are similar ?
Chest x-ray
Full blood count
Oxygen saturations
Blood gas
Urine antigen testing
management (assessment) specific to CAP ?
Sputum gram stain
Sputum culture
Blood culture
Test for influenza
CURB-65
Pneumonia severity index
management (assessment) specific to HAP ?
- CT scan chest
- Chest ultrasound
- Thoracocentesis and pleural fluid culture
Prevention of CAP ?
- Vaccination
- Lifestyle changes
- Good respiratory hygiene
Treatment of CAP ?
- Administration of antibiotics
- Initiate antibiotic treatment within 4 hours of presentation
- Supplement oxygen for patients with oxygen saturation < 94% or 88% for those at risk of CO2 retention
- Consider risk of sepsis
What is CAP mortality risk assessment ?
CURB-65
Confusion
Urea
Respiratory rate
Blood pressure
Age >= 65
How is CURB65 scored ?
1 point for the presence of each crieterion (confusion, urea, respiratory rate, blood pressure, age)
CURB65 cirterion presence for confusion ?
abbreviated mental test score 8 or less , or new disorientation in person , place or time
CURB65 cirterion presence for urea ?
> 7 mmol
CURB65 cirterion presence for respiratory rate ?
> = 30 breaths per minute
CURB65 cirterion presence for blood pressure?
diastolic 60 mmHg or less
systolic less than 90 mmHg
Using the CURB65 score how are patients stratified for risk of death ?
- 0 = low risk , 1% mortality risk
- 1 / 2 = intermediate risk , 1-10% mortality risk
- 3 / 4 = high risk , > 10% mortality risk
How is nosocomial pneumonia defined ? acquired when ?
Hospital-acquired pneumonia
* acute lower respiratory tract infection acquired at least 48 hours of admission
* not present/ incubating on admission
risk factors of nosocomial pneumonia - HAP ?
- endotracheal intubation
- mechanical ventilation (ventilator-associated pneumonia)
- aspiration
symptoms / signs of HAP ?
- Cough with increasing sputum production
- Dyspnoea
- Dever (core temperature > 38.5 )
- Chest pain
- Asymmetrical expansion of the chest
- Diminished resonance
- Raised or lower WBC counts
- Worsening gaseous exchange and increase in O2 requirements
Treatment of HAP ?
Antibiotics
Treatment of HAP , antibiotics include what ?
- Clinical judgement
- number of days hospitalisation
- Severity
- Risk of complications
- Microbiological results
- Risk of adverse events from broad-spectrum antibiotics (e.g. clostridium difficile)
Commonly observed pathogens of CAP and HAP ? (6)
- Streptococcus pneumonia
- Staphylococcus aureus (including MRSA)
- Haemophilius influenzae
- Moraxella catarrhalis
- Klebsiella pneumoniae
- Escherichia coli
how do typical pneumonia and atypical pneumonia differ ?
in terms of causative agents, clinical presentation, severity of symptoms, and radiographic findings
typical pneumonia of CAP ?
- streptococcus pneumoniae
- staphylococcus aureus
- group A streptococcus
- klebsiella pneumoniae
- haemophilus influenzae
- moraxella catarrhalis
- MRSA
- Escherichia coli
- other enterobacteriaceae
atypical pneumonia of CAP ?
- mycoplasma pneumoniae
- chlamydophila pneumoniae
- legionella pneumophilia
- influenza pneumophila
- chlamydophila psittaci
Aetiology of CAP that are common secondary bacterial infections with influenza ?
- streptococcus pneumoniae
- staphylococcus aureus
Name 9 viruses that are involved in aetiology of CAP
- influenza A and B viruses
- SARS-CoV-2
- other coronoviruses
- rhinoviruses
- parainfluenza viruses
- adenoviruses
- respiratory syncytial virus
- human metapneumovirus
- human bocaviruses
Pathogens causing HAP that doesn’t cause CAP ?
Pseudomonas aeruginosa
Acinetobacter species
Serratia species
Candida species
legionella
aspergillus fumigateurs
complications of pneumonia
- acute respiratory distress syndrome (ARDS)
- pleural effusions (swelling of / fluid filling the pleura)
- empyema (infection of fluid filling the pleura)
- pleurisy (inflammation and swelling of pleura)
- lung abscesses
- respiratory failure
- septic shock
- sepsis
- bacteremia
