Lecture 9.1: Pneumonia and Lower Respiratory Tract Infections Flashcards
What is Bronchitis?
An infection of the main airways of the lungs (bronchi), causing them to become irritated and inflamed
What is Bronchiolitis?
Bronchiolitis affects the smaller airways (bronchioles)
What is Pneumonia?
Inflammation in the alveoli/tissue in one or both lungs
What causes Acute Bronchitis? (2)
- Viruses
- Bacteria
What causes Chronic Bronchitis?
- Not primarily infective
- Consequence of repeated infections
- Irritation from smoking
Types of Defences of the Respiratory Tract (3)
- Muco-Ciliary Clearance Mechanisms
- Cough and Sneezing Reflexes
- Respiratory Mucosal Immune System
Defences of the Respiratory Tract: Muco-Ciliary Clearance Mechanisms
- Nasal Hairs
- Ciliated Epithelium
- Goblet Cells
Defences of the Respiratory Tract: Respiratory Mucosal Immune System
- Lymphoid Follicles of the Pharynx and Tonsils
- Alveolar Macrophages
- Secretory IgA and IgG
Predisposing Factors for Pneumonia: INSPIRATION Pneumonic
I: mmunosuppression
N: eurologically impaired cough reflex
S: ecretion retention
P: ulmonary oedema
I: mpaired mucociliary clearance
R: espiratory tract infection (viral)
A: ntibiotics and cytotoxins
T: racheal instrumentation
I: mpaired alveolar macrophages
O: ther
N: eoplasia
Symptoms of Pneumonia (11)
- Cough
- Fever/Chills/Sweats
- Haemoptysis
- Dyspnoea
- Pleuritic Chest Pain
- Malaise
- Anorexia and Vomiting
- Headache
- Myalgia
- Diarrhoea
- Green/Yellow Sputum
Signs of Pneumonia (5)
- Bronchial Breath Sounds
- Crackles
- Wheeze
- Dullness to Percussion
- Increased Vocal Resonance
Classifications of Pneumonia (4)
- By Clinical Setting
- By Presentation
- By Organism
- By Lung Pathology
Classifications of Pneumonia: Clinical Setting (4)
1) Community acquired
2) Hospital acquired (nosocomial)
3) Aspiration Pneumonia
4) Pneumonia in the immunocompromised
patient
Classifications of Pneumonia: Organism (3)
1) Bacterial
2) Viral
3) Fungal
Classifications of Pneumonia: Presentation (3)
1) Acute
2) Sub-Acute
3) Chronic
Classifications of Pneumonia: Lung Pathology (3)
1) Lobar Pneumonia
2) Bronchopneumonia
3) Interstitial Pneumonia
Common Organisms Causing Community-Acquired Pneumonia (5)
- Streptococcus pneumoniae (30%)
- Haemophilus influenzae (13%)
- Klebsiella pneumoniae
- Moraxella cattarhalis
- Currently SARS-CoV-2
Atypical (10% of cases) Organisms Causing Community-Acquired Pneumonia (3)
- Legionella
- Mycoplasma
- Chlamydia spp
What is the Definition of Hospital Acquired Pneumonia? Who does it occur in?
- Occurs within 48hr after admission
- ITU patients, ventilated patients, post surgery
Organisms Causing Hospital-Acquired Pneumonia (9)
- Influenza/parainfluenza
- Respiratory Syncytial Virus
- Adenovirus
- SARS-CoV-2
- Mixed infections (10%)
- Staphylococcus Aureus
- Pseudomonas
- MRSA
- Gram-negative enteric bacteria
What is Aspiration Pneumonia?
Occurs upon aspiration of exogenous material or secretions into lung
What type of organism commonly affects immunocompromised patients?
- Opportunistic pathogens
- High risk of virulent infection with common
organism
What type of patients is Mycoplasma found in?
- Young
prior antibiotics, extra-pulmonary involvement
When are patients at risk of infection with Staphylococcus aureus?
Post-Viral Infection
When are patients at risk of infection with Chlamydia?
Contact with birds
When are patients at risk of infection with Coxiella?
Contact with animals
What conditions put patients at risk of infection with Klebsiella? (2)
- Thrombocytopenia
- Leucopenia
What are some Viral Pneumonia Causing Pathogens? (3)
- Influenza
- Parainfluenza
- Respiratory syncytial virus (RSV)
What are some effects of SEVERE Pneumonia?
- Lung Necrosis
- Haemorrhage in to Lung Parenchyma
- ARDS
- High Mortality
What is SARS-CoV-2? What are the effects of infection?
- RNA Virus
- Most sufferers have mild/moderate disease
- Asymptomatic transmission important
- Some patients develop severe pneumonia and
multi-organ failure
What is Lobar Pneumonia? What pathogen most commonly causes this?
- Consolidation involving a whole lobe
- Streptococcus pneumoniae
What happens in the typical acute inflammatory response in lobar pneumonia? (3)
1) Fibrin Rich Exudate
2) Neutrophil Infiltration
3) Macrophage Infiltration
What parts of the lungs does Bronchopneumonia affect?
- Infection starting in airways
- Spreads to alveoli
- Consolidation is patchy
Pathogens that can cause Bronchopneumonia (4)
- Streptococcus pneumoniae
- Staphylococcus aureus
- Anaerobes
- Coliforms
Complications of Bronchopneumonia (4)
- May leave fibrous scarring
- Lung abscess
- Bronchiectasis (recurrent pneumonia)
- Empyema (pus in pleural cavity)
What Investigations are done for the diagnosis of Pneumonia? (6)
- Chest X-Ray
- Oxygen saturation
- ABGs
- Full Blood Count
- Urea, liver function tests and CRP
- Cultures (blood and sputum)
How are samples for cultures collected?
- Drawing blood
- Cough-up sputum
- Endotracheal aspirates
- Nose and throat swabs
- Bronchoalveolar lavage (BAL)
- Urine for antigens of legionella and
pneumococcus
What does CURB-65 stand for?
- Confusion
- Urea (>7mmol/L)
- Respiratory Rate (>30)
- Blood Pressure (Systolic<90, Diastolic<60)
- Age (more than 65)
What is the 1st-line Antibiotic used to treat Pneumonia?
Penicillin class first choice (amoxicillin)
What Antibiotics are used to treat severe Pneumonia? (2)
Penicillin plus clavulanic acid (co-amoxiclav)
What Antibiotics are used to treat Legionella?
Levofloxacin
What classes of Antibiotics are used to treat “Atypical” Pneumonia? (2)
- Tetracyclines
- Macrolides
What pathogen is Whooping Cough caused by?
Bordetella pertussis
What is Whooping Cough?
A highly contagious bacterial infection of the lungs and airways that causes repeated coughing bouts that can last for two to three months
