Pneumonia Flashcards
What is pneumonia?
Pneumonia is characterised by acute inflammation with an intense infiltration of neutrophils in and around the alveoli and the terminal bronchioles. The affected bronchopulmonary segment or the entire lobe may be consolidated by the resulting inflammation and oedema.
What are risk factors for developing pneumonia?
- Age: young and elderly
- Lifestyle: smoking, alcohol
- Preceding viral infections: Streptococcus pneumoniae
- Respiratory: asthma, COPD, malignancy
- Immunosuppression
- Intravenous drug abuse, often associated with Staphylococcus aureus infection
- Aspiration pneumonia
- Hospitalisation - often involving Gram-negative organisms.
What usually causes viral pneumonia?
Streptococcus pneumoniae
What are the main causes of community-acquired pneumonia?
S. pneumoniae, S. aureus, Mycoplasma pneumoniae, Haemophilus influenzae, Chlamydophila pneumoniae and respiratory viruses
What is the presentation of community-acquired pneumonia?
Symptoms: cough, purulent sputum, breathlessness, fever, malaise.
Signs: tachypnoea, bronchial breathing, crepitations, pleural rub, dullness with percussion.
When would you admit someone with community-acquired pneumonia?
NICE CRB65 score of 2 or higher
Confusion
RR > 30
S-BP < 90
Age > 65
How would you manage community-acquired pneumonia?
Patients with suspected CAP should be advised not to smoke and to rest and drink plenty of fluids
Also: oxygen, NSAIDs
Those who fail to improve after 72 hours of treatment should be advised to seek further medical advice
Antibacterials are recommended in all suspected cases of pneumonia, starting as soon as possible
What antibiotic would you give for low-severity community-acquired pneumonia?
five-day course of amoxicillin
clarithromycin, erythromycin (in pregnancy) or doxycycline for patients allergic to penicillin or if atypical pathogen suspected
What antibiotic would you give for high-severity community-acquired pneumonia?
For high-severity CAP a five-day course of co-amoxiclav with clarithromycin or erythromycin (in pregnancy) should be offered. The oral or intravenous route can be used
Levofloxacin orally or IV is an option for patients allergic to penicillin.
What are causes of atypical pneumonia?
M. pneumoniae
C. pneumoniae
Legionella pneumophila
What is a hospital-acquired pneumonia?
This is defined as a new infection of lung parenchyma appearing more than 48 hours after admission to the hospital.
What are the causes of hospital-acquired pneumonia?
Infection occurring less than five days after hospital admission is usually caused by S. pneumoniae.
Infection occurring after this time is usually caused by H. influenzae , methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa and other non-pseudomonal Gram-negative bacteria.
Who is most at risk for hospital-acquired pneumonia?
It occurs mostly in patients who are severely debilitated, immunocompromised or mechanically ventilated.
What investigations would you do for a suspicion of hospital-acquired pneumonia?
FBC with differential white cell count. CRP (to aid diagnosis and as a baseline measure). Renal function and electrolytes. LFTs. Blood cultures. CXR
What are complications following pneumonia?
Pleural effusion Empyema Lung abscess DVT Septicaemia, pericarditis, endocarditis, osteomyelitis, septic arthritis, cerebral abscess, meningitis AKI
What is empyema?
Puss in the pleural space
Explain the anatomy of the pleural membrane?
This is a serous membrane divided into the visceral pleura (lines the lungs) and parietal pleura (lines the internal thoracic cavity).
The potential space between the visceral and parietal pleura contains a small amount of lubricating serous fluid.
The serous fluid allows the visceral and parietal pleura to slide over each other during respiration and creates surface tension between the two layers.