S9) Lower Respiratory Tract Infections and Pneumonia Flashcards
Identify 4 common microbial flora of the upper respiratory tract
- Viridans streptococci
- Neisseria sp
- Anaerobes
- Candida sp
Identify 5 less common microbial flora of the upper respiratory tract
- Streptococcus pneumoniae
- Streptococcus pyogenes
- Haemophillus influenzae
- Other: Pseudomonas, Escherichia coli
Identify three defences of the respiratory tract
- Muco-ciliary clearance mechanisms (nasal hairs, ciliated columnar epithelium)
- Cough & the sneezing reflex
- Mucosal immune system (lymphoid follicles, alveolar macrophages, IgA, IgG)
Identify 5 ways in which the respiratory defences can be compromised
- Poor swallowing (muscle weakness, alcohol)
- Abnormal ciliary function (smoking, viral infection)
- Abnormal mucus (cystic fibrosis)
- Dilated airways (bronchiectasis)
- Defects in host immunity (HIV, Immunosuppression)
Identify 5 common upper respiratory tract infections
- Rhinitis
- Pharyngitis
- Laryngitis
- Sinusitis
- Otitis media
Respiratory tract infections are most commonly caused by viruses.
Identify 5 of these
- Rhinovirus
- Coronavirus
- Influenza
- Respiratory syncytial virus (RSV)
When are bacteria common causes for respiratory tract infections?
Bacterial super-infection common with sinusitis and otitis media – can lead to mastoiditis, meningitis, brain abscess
Identify 5 common lower respiratory tract infections
- Bronchitis
- Pneumonia
- Empyema
- Lung abscess
- Bronchiectasis
What is acute bronchitis?
Acute bronchitis is the short-term inflammation of medium-sized airways
Identify 5 typical presentations of acute bronchitis
- Cough
- Fever
- Increased sputum production
- Increased shortness of breath
- Normal CXR
Identify 2 causative organisms of acute bronchitis
- S. pneumoniae
- H. influenzae
How is acute bronchitis treated?
- Bronchodilation
- Physiotherapy
- ± Antibiotics
What is pneumonia?
Pneumonia is a condition resulting from the inflammation of the lung parenchyma (alveoli) and the accumulation of fluid in the air spaces
Identify and describe the four different ways of classifying pneumonia?
- By clinical setting (community acquired, hospital acquired)
- By presentation (acute and chronic)
- By organism (bacterial, viral, fungal)
- By lung pathology (lobar, interstitial or bronchopneumonia)
Describe the pathology of pneumonia
- Acute inflammatory response
- Fibrinous exudate
- Neutrophil infiltration
- Macrophage infiltration
Identify the 5 main causative organisms for Community Acquired Pneumonia (CAP)
- Streptococcus pneumoniae (most common)
- Haemophilus influenzae (common)
- Moraxella catarrhalis
- Staphylococcus aureus
- Klebsiella pneumoniae
Identify 5 symptoms of pneumonia (besides being explictly unwell)
- Fever
- Cough (± sputum)
- Pleuritic chest pain
- Shortness of breath
- Nausea & vomiting
Identify 6 signs of pneumonia seen on examination
- Pyrexia
- Tachycardia
- Tachypnoea
- Cyanosis
- Dullness to percussion (tactile vocal fremitus)
- Crackles
Identify 5 investigations commonly requested for pneumonia
- Full Blood Count
- Urea & Electrolytes
- C Reactive Protein
- Arterial Blood Gases
- Chest X Ray (abnormal)
Which microbiological samples and investigations are requested for pneumonia?
- Sputum / induced sputum
- Blood culture
- Broncho alveolar lavage fluid (BAL)
- Nose & Throat swabs
The CURB-65 score is used to determine the severity of pneumonia.
Which 5 measurements are involved?
- Confusion
- Urea > 7 mmol/l
- RR > 30
- BP <90/60
- Age > 65 years
Score 2-5 = manage as severe
Which 4 considerations are made when determining whether or not a patient needs antibiotic treatment for pneumonia?
- Community vs hospital acquired?
- Severity of illness?
- Personal risk factors
- Ventilator associated?
Community acquired pneumonia is treated with empiric therapy.
Outline this treament for mild-moderate and moderate-severe pneumonia
- Mild-moderate: amoxicillin or doxycycline/erythromycin/clarithromycin
- Moderate-severe: co-amoxiclav and clarithromycin/doxycycline
Describe the outcome of acute bacterial pneumonia in terms of resolution and complications
- Resolution – organisation (fibrous scarring)
- Complications – lung abscess, bronchiectasis, empyema
Identify 5 possible reasons for the failure of antibiotic treatment for pneumonia
- Empyema / abscess
- Proximal obstruction (tumour)
- Resistant organism (incl. Tb)
- Not receiving / absorbing antibiotics
- Immunosuppression
Identify 4 atypical organisms which do not respond to penicillins (cell-wall active antibiotics)
Organisms without a cell wall:
- Mycoplasma
- Legionella
- Chlamydia
- Coxiella
Which antibiotics can be used for pneumonia caused by atypical organisms?
Agents that work on protein synthesis:
- Macrolides (clarithromycin / erythromycin)
- Tetracyclines (doxycyline)
Identify 2 extra-pulmonary features of pneumonia caused by atypical organisms
- Hepatitis
- Hyponatraemia
Viral pneumonia accounts for 10% of pneumonia cases.
Identify 3 effects of viral pneumonia (and arising immune cells)
- Damage to cells lining the airways / alveoli
- Fluid filled air spaces interferes with gas exchange
- Severe viral pneumonia necrosis / haemorrhage into the lung parenchyma
How does viral pneumonia present on a chest X-ray?
Abnormal – patchy or diffused ground glass opacity
Identify 4 causes of viral pneumonia
- Influenza
- Parainfluenza
- Respiratory Syncytial virus (RSV)
- Adenovirus
When does hospital acquired pneumonia commonly occur?
- > 48 hours in hospital
- Often previous antibiotics
- ± Ventilator
Identify 5 causative organisms of hospital acquired pneumonia
- Staphylococcus aureus
- Enterobacteriaciae
- Pseudomonas spp
- Haemophilus influenzae
- Fungi (Candida sp.)
Outline the treatment of hospital acquired pneumonia
- First line: Co-amoxiclav
- Second line/ITU: Pipperacilin / Tazobactam / Meropenem
When is aspiration pneumonia commonly seen?
Aspiration of exogenous material or endogenous secretions into the respiratory tract
Which patient groups commonly present with aspiration pneumonia?
- Neurological dysphagia (strokes)
- Epilepsy
- Alcoholics
- Drowning
Which causative organisms are at play in aspiration pneumonia?
Mixed infection – viridans streptococci & anaerobes
How is aspiration pneumonia treated?
Co-amoxiclav
Identify 4 immunosuppresion patient groups who are vulnerable to pneumonia and other lower respiratory tract infections
- HIV (PCP, TB, atypical mycobacteria)
- Neutropenia (fungi e.g. Aspergillus spp)
- Bone marrow transplant (CMV)
- Splenectomy (encapsulated organisms)
Identify and describe three ways in which pneumonia can be prevented
- Vaccination – flu vaccine and pneumococcal vaccine (high risk patients)
- Chemoprophylaxis – oral penicillin / erythromycin (high risk patients)
- Stop smoking
