Pneumonia Flashcards
What is pneumonia?
Is it common?
Infection of the lung parenchyma commonly caused by bacterial organism
It is very common, >1 per 300 population with 20-50% ending up hospitalised and 5-10% requiring ITU admission.
Name groups who are at higher risk of pneumonia
Infants and elderly COPD and chronic lung conditions Immunocompromised Nursing home residents Impaired swallow - stroke, MND, surgery Diabetes Congestive heart failure Alcoholics and IVDUs
Describe the pathogenesis of pneumonia
- Pneumococci temporarily colonise pharynx which are micro-aspirated and usually cleared by alveolar macrophages
- In some infections, the macrophages ability to kill becomes overwhelmed so they produce pro-inflammatory response which attracts neutrophils recruited to kill bacteria
- This will result in dead bacteria, dead neutrophils and tissue fluid and inflammatory proteins = inflammatory exudate (pus) in airspaces
- This process is collateral damage to the lung which takes some time to heal
Presentation of pneumonia?
Productive cough Fever, sweat, rigors Sputum (s pneumoniae = rusty coloured sputum) Breathlessness Pleuritic chest pain Weakness and general malaise
Signs you might find in examination of a patient with pneumonia?
- Dull percussion note
- Reduced breath sounds
- Bronchial breathing
- Coarse crepitations
- Increased vocal fremitus
- Tachycardia
- Hypotension
- Confusion
- Cyanosis
Investigations for pneumonia
Bedside
- Obs
- Sputum sample
- Urinary sample
- ECG
Bloods
- FBC: WCC
- U&E
- CRP (higher in bacterial)
- Blood cultures
- HIV test for anyone with pneumonia
Imaging on CXR
- Often diagnostic and shows consolidation. Can access how many lobes are affected, if there is an abscess, any air or fluid in abscess
If a patient with pneumonia presented with vasodilation, reduced blood pressure, impaired oxygen perfusion, tissue hypoxaemia, what would you be worried about?
sepsis
What is the most common causative organism for community acquired pneumonia?
Streptococcus pneumoniae
Pneumonia which has been contracted >48hrs after hospital admission is known as what? What are the common causative organisms?
What patients are more likely to get this type of pneumonia and how do we treat it?
Hospital acquired pneumonia
- Klebsiella, E coli, pseudomonas, s aureus
HAP is more common in elderly, ventilator assisted or post-op patients
Treatment: broad abx and the focus when have results (pipeeracillin tazobactam or merpenam)
How is aspiration pneumonia caused?
Which patients are most at risk of aspiration pneumonia?
- Caused by inhalation of oropharyngeal or gastric contents which brings bacteria found in those environments into the lungs
- Associated with patients who cannot adequately clear their airways (reduced conscious level, neuromuscular disorders etc)
What is the most common cause of CAP?
How will a patient commonly present?
How do we treat CAP caused by this organism?
Strep pneumoniae (gram pos alpha haemolytic strep). Common presentation: cough, pleuritic pain and pyrexia Treat = b-lactams such as amoxicillin.
Which organism typically causes HAP?
Who does it typically affect?
How do we obtain samples?
How is it treated?
Pseudomonas aeruginosa
Typically causes pneumonia in immunocompromised patients (opportunistic) and those with chronic lung disease
Samples via bronchoalveolar lavage
Treatment = cephalosporin and aminoglycoside
Which organism is responsible for causing pneumonia commonly in alcoholics or homeless patients?
What is the characteristic sputum appearance?
Klebsiella pneumophilia
Sputum = red currant jelly appearance
Mycoplasma pneumoniae tends to affect younger patients to cause pneumonia but it also causes extra-pulmonary features. What features may be seen?
Erythema multiforme
Arthralgia
Myocarditis, pericarditis
Haemolytic anaemia
What scoring system do we use to help stratify patients at risk of mortality from pneumonia and determine their best place of care?
CURB65 Confusion Urea >7 Respiratory rate >30 Blood pressure <90sys, <60dia >65
0-1 = outpatient 2 = secondary care 3 = admit and closely monitor 4-5 = ICU
Higher mortality the higher the score
