Lobar pneumonia Flashcards
How common is it?
In the United Kingdom, the annual incidence rate of pneumonia is approximately 6 cases per 1000 people in individuals aged 18–39 years. For those over 75 years of age, the incidence rate rises to 75 cases per 1000 people.
Who does it affect?
More common in extremes of age (esp. community acquired).
What causes it?
Bacterial:
- S. pneumoniae
- S. aureus
- C. pneumoniae
- H. influenzae
- M. catarrhalis
- C. psittaci (psitticosis - bird fanciers)
- C, burnetti (Q fever)
- K. pneumonia
- P. aeruginosa
Fungal:
- Pneumocystis pneumonia
- Aspergillus
- Candidiasis
- Rare in those who aren’t immunocompromised
Parasitic:
- Mycoplasma pneumoniae
Viral:
- All respiratory viruses
What are the broad classifications for pneumonia?
Community-acquired (CAP): in the community by a person with no underlying immunosuppression or malignancy
Hospital-acquired (HAP) (or other institution)
In a patient whose immune system is compromised (genetic defect, HIV, immunosuppression)
What risk factors are there for CAP (and how can they be reduced)?
Age: <16 or >65 years
Co-morbidities: HIV infection, diabetes, CKD, malnutrition, recent viral respiratory infection
Other respiratory conditions: CF, COPD, bronchiectasis, obstructing lesion
Lifestyle: smoking, excess alcohol, IVDU
Iatrogenic: immunosuppressant therapy
What are the classic symptoms?
Cough: dry or productive, haemoptysis can occur, pneumococcal sputum typically rust-coloured
Breathlessness
Fever: can be as high as 39.5-40, swinging fever suggests empyema
Chest pain: pleuritic
Elderly patients: nonspecific symptoms such as recurrent falls/confusion
What are the extrapulmonary manifestations of pneumonia?
Myalgia, arthralgia and malaise
Myocarditis and pericarditis
Headache, meningioencepalitis (uncommon)
Abdo pain, diarrhoea, vomiting, hepatitis
Herpes simplex reactivation
Erythema multiform/nodosum (in mycoplasma)
Steven-Johnsons (very rare)
What are the signs of pneumonia?
Respiratory:
- Coarse crackles heard in affected lobe
- Bronchial breathing
- Pleural friction rub
- Dullness to percussion over affected lobe
- Increased vocal resonance (increased lung density)
Other:
- Fever
- Tachycardia
- Hypotension
- Tachypnoea
What is the CURB-65 score?
Determines severity of pneumonia
C: confusion present (amts <8/10) U: (plasma) urea level >7mmol/L R: respiratory rate >30/min B: systolic BP <90mmHg; diastolic <60mmHg 65: age >65
1 point for each of the above
Score 0-1: outpatient
Score 2: Admit
Score 3+: often need ICU
What are the differential diagnoses?
Acute exacerbations of asthma or COPD Atelectasis Bronchiectasis Bronchiolitis Bronchitis Foreign Body Aspiration Lung Abscess Respiratory Failure
In children:
- Bronchiolitis
- Croup or Laryngotracheobronchitis
- Epiglottitis
- Reactive Airway Disease
- Respiratory Distress Syndrome
What investigations would you do?
CURB-65 of:
0-1 - none
1-2 - blood cultures, sputum (if no Abx), pneumococcal Ag if suspected (culture if +ve), serology and PCR
2-5 - all above plus Legionella Ag (culture if +ve)
What would you tell the patient and how would you explain the condition to them?
Severe lung infection, may take a long time to feel better again.
How do you think the patient and/or family might be affected by the diagnosis? Will it affect their
ability to work/care for themselves?
Recovery may take a long time and they may be left with lasting sequelae.
What treatment/s (surgical, pharmacological and non-pharmacological) would you discuss with
them? What risks and benefits of treatment are there?
CURB 65 of:
0-1 - oral amoxycillin 500mg tds OR oral clarithromycin 500mg bd OR if penicillin allergic doxycycline 100mg sd (200mg loading)
2-3 - amoxycillin 500-1000mg tds AND clarithromycin 500 bd (doxy if penicillin allergic)
3-5 - IV co-amoxiclav 1.2g tds AND IV clarythromycin 500mg bd (various other options if penicillin resistant
The usual risks associated with Abx which are far outweighed by the risks of untreated pneumonia!
Also: 02, IV fluids, analgesia, chest physio (if required), bronchial wash out (if necessary)
