Community acquired pneumonia is a common disease with a reducing incidence. It usually occurs in children or the elderly, or in people with an underlying pathology.
This type of pneumonia is often a complication of viral respiratory disease such as influenza.
It is particularly common in winter in countries with temperate climates.
Eighty percent of community acquired pneumonia is pneumococcal pneumonia.
Other causes of community acquired pneumonias include haemophilus influenzae, staphylococcal aureus, atypical pneumonias (e.g. due to mycoplasma pneumoniae), mycobacterium tuberculosis, and viruses.
NICE have given guidance with respect to the diagnosis and management of pneumonia (1):
- community-acquired pneumonia has an annual incidence of 5 to 10 per 1,000 adult population, and accounts for 5% to 12% of all lower respiratory tract infections managed by GPs in the community
- between 22% and 42% of people with community-acquired pneumonia will require hospital-based care
- hospital-acquired pneumonia occurs in around 0.5% to 2% of hospitalisations and is a common cause of morbidity and mortality
- the presence of hospital-acquired pneumonia increases hospital stays by an average of 7 to 9 days per person and accounts for a large number of antibiotics prescribed
- pneumonia accounts for 29,000 deaths per year in the UK, and 5% to 15% of people hospitalised with community-acquired pneumonia die within 30 days of admission, rising to 30% for those admitted to an intensive care unit
- more than half of pneumonia-related deaths occur in people older than 84 years
Start antibiotic treatment as soon as possible after establishing a diagnosis of community-acquired pneumonia, and within 4 hours of presentation to hospital (1):
For adults with community-acquired pneumonia, stop antibiotic treatment after 5 days
- unless microbiological results suggest a longer course is needed or
- the person is not clinically stable, for example, if they have had a fever in the past 48 hours or have more than 1 of the following signs of clinical instability:
- systolic blood pressure less than 90 mmHg
- heart rate more than 100 beats per minute
- respiratory rate more than 24 breaths per minute
- oxygen saturations of less than 90% on room air (or failure to meet long-term baseline oxygen requirements); note that oxygen saturation monitors may be inaccurate in people with pigmented skin
Offer a 3‑day course of antibiotics for babies and children aged 3 months (corrected gestational age) to 11 years with non-severe community-acquired pneumonia without complications or underlying disease (1):
- consider extending use of antibiotics beyond 3 days for babies and children aged 3 months (corrected gestational age) to 11 years if they are not clinically stable, for example, if they are in respiratory distress or their oxygen saturation levels have not improved as expected
- for all children and young people with community-acquired pneumonia, stop antibiotic treatment after 5 days unless microbiological results suggest a longer course is needed or the child or young person is not clinically stable
Key messages from the BTS guidelines on management of community acquired pneumonia include (2,3):
- clinical judgement, supported by the CRB65 score, should be used to decide whether to treat patients at home or in hospital
- when deciding on home treatment, the patient's social circumstances and wishes must be taken into account in all instances
- patients in the community should be reviewed after 48 hours, or earlier if clinically indicated
- patients with suspected CAP should be advised to rest, drink plenty of fluids and not to smoke
- pleuritic pain, in the context of CAP, should be managed with simple analgesia such as paracetamol
- pulse oximetry should be available to GPs and others responsible for assessing patients in the out-of-hours setting, for the assessment of severity and oxygen requirement in patients with CAP and other acute respiratory illnesses
- amoxicillin 500mg three times daily is the preferred antibiotic, with doxycycline or clarithromycin as alternatives, for example in those patients hypersensitive to penicillin
- microbiological investigations are not recommended routinely but may be appropriate in certain circumstances. For example, sputum examination should be considered for patients who do not respond to empirical antibiotic therapy
- in patients with suspected severe, life-threatening CAP referred to hospital, GPs should administer antibiotics in the community before transfer; benzylpenicillin 1.2g intravenously or amoxicillin 1g orally are preferred.
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