Managing Pneumonia in the Community

The clinical definition of community acquired pneumonia (CAP) that has been used in community studies has varied widely but has generally included a complex of symptoms and signs both from the respiratory tract and regarding the general health of the patients. Features such as fever (< 38 °C), pleural pain, dyspnoea, tachypnoea and signs on physical examination of the chest (particularly when new and localising) seem most useful when compared with the gold standard of radiological diagnosis of CAP.¹ The British Thoracic Society recommends abandoning the term 'atypical' pneumonias because there is no typical characteristic presentation of pneumonia.

Only a small range of pathogens causes CAP, with Streptococcus pneumoniae being the most frequent. Other common causes of community acquired pneumonia are Haemophilus influenzae and viruses, especially Influenza A and B. Other less common causes include Staphylococcus aureus, Gram negative enteric bacilli, Chlamydia pneumoniae, Moraxella catarrhalis, Mycoplasma pneumoniae, Chlamydophila psittaci, Coxiella burnetii and Legionella. There may be no identifiable pathogen and mixed infections are common. The frequency of pathogens can vary in specific patient groups, e.g. Mycoplasma and Legionella infections are less frequent in the elderly.

Incidence

• 12/1,000 population per year²
• Fifth leading cause of death in the UK
• Risk factors include:
  • Winter months
  • The very young and the very old
  • Chronic lung, heart, renal and liver disease
  • Diabetes mellitus
  • Immunosuppression.

• Symptoms: cough, purulent sputum which may be blood stained or rust coloured, breathlessness, fever, malaise.
• Diagnosis is unlikely if no focal chest signs and normal heart rate, respiratory rate and temperature.
• Elderly may present with mainly systemic complaints of malaise, fatigue, anorexia and myalgia. Young may present with non-specific symptoms or abdominal pain.
• Signs: bronchial breathing, crepitations, pleural rub, dullness with percussion.

• General investigations, including a chest x-ray, are not necessary for the majority of patients with suspected community acquired pneumonia who are managed in the community.
• Out of hours and emergency general practitioner assessment centres should consider using pulse oximeters to allow for simple assessment of oxygenation.
• Sputum samples should be sent for culture and sensitivity tests from patients with non-severe CAP who are able to expectorate purulent samples and have not received prior antibiotic therapy. Specimens should be transported rapidly to the laboratory. Sputum cultures should also be performed for patients with severe CAP, or those who fail to improve.
• Examination of sputum for Mycobacterium tuberculosis should be considered for patients with a persistent productive cough, especially if malaise, weight loss or night sweats, or risk factors for tuberculosis (e.g. ethnic origin, social deprivation, the elderly) are present.
• Serological investigations may be considered during outbreaks (e.g. Legionnaires' disease) or epidemic mycoplasma years, or when there is a particular clinical or epidemiological reason.

Adverse prognostic features

• Age 65 years and over.
• Presence of coexisting disease
• Core clinical adverse prognostic features
  • CRB-65 score - score 1 for each of the following):
    • Confusion: new mental confusion
    • Respiratory rate: raised >30/min
    • Blood pressure: low blood pressure (systolic blood pressure <90 mmHg and/or diastolic blood pressure <60 mmHg).
    • Age ≥65 years
  • CURB-65 score - same as CRB score with the addition of :
    • Urea: raised >7 mmol/l (when this is available - i.e. for patients being seen in hospital)
• Additional clinical adverse prognostic features
  • Hypoxaemia (SaO2 <92% or PaO2 <8 kPa) regardless of FiO2
  • Bilateral or multilobe involvement on the chest x-ray.

Referral to hospital

The need for hospital referral should be assessed using the recommended severity criteria (see CURB-65 score above) and clinical judgement.

• Patients who have a CURB-65 score of 0 or 1 are at low risk of death. They can be treated as having non-severe pneumonia and do not normally require admission to hospital for clinical reasons.
• Patients who have a CRB-65 score of 1 or 2 are at increased risk of death and hospital referral and assessment should be considered, particularly with Score 2.
• Patients who have a CURB-65 score of 3 or more are at high risk of death and should be managed as having severe pneumonia and be referred urgently to hospital.
• For all other patients the decision to treat at home or refer to hospital is a matter of clinical judgement. When deciding on home treatment, the patient's social circumstances and wishes must be taken into account in all instances.

• Patients with suspected CAP should be advised not to smoke, to rest, and to drink plenty of fluids.
• Pleuritic pain should be relieved using simple analgesia such as paracetamol.
• Nutritional support with supplements should be considered in prolonged illness.
• Review of patients in the community with CAP is recommended after 48 hours or earlier if clinically indicated. 'Core' and 'additional' adverse prognostic features should be assessed as part of the clinical review.
• Those who fail to improve after 48 hours of treatment should be considered for hospital admission or a chest x-ray.

Antibiotics

• Antibacterials are recommended in all suspected cases of pneumonia, starting as soon as possible.³ Choice should be based on culture results, local resistance patterns and prescribing policies.
• Uncomplicated community-acquired pneumonia⁴
  • Amoxicillin if previously healthy chest (or erythromycin if penicillin-allergic).
  • Add flucloxacillin if staphylococci suspected, e.g. in influenza or measles (or vancomycin if MRSA suspected).
  • Add erythromycin if 'atypical' pathogens suspected.
• Severe community-acquired pneumonia of unknown aetiology⁴
  • Cefuroxime (or cefotaxime) plus erythromycin.
  • Add flucloxacillin if staphylococci suspected (or vancomycin if MRSA suspected).
• Pneumonia possibly caused by atypical pathogens⁴
  • Erythromycin.
  • Severe Legionella infections may require addition of rifampicin.
  • Tetracycline is an alternative for chlamydial and mycoplasma infections.

Follow up

• Clinical review should be arranged for all patients at around 6 weeks.
• A chest x-ray should be arranged at that time for those patients who have persistent symptoms or physical signs or who are at higher risk of underlying malignancy (especially smokers and those over 50 years).
• In a patient who is improving clinically and for whom there are no concerning clinical features, it will usually not be necessary to perform further investigations just because radiological improvement lags behind clinical recovery.
• Further investigations, which may include bronchoscopy, should be considered in patients with persisting signs, symptoms, and radiological abnormalities about 6 weeks after completing treatment.

• Pleural effusion - usually sterile.
• Empyema: a reactive effusion can occur but is trivial. Empyema is potentially more serious and presents as the persistence of fever and leucocytosis after 4-5 days of appropriate antibiotic therapy.
• Lung abscess: can occur in disease due to S. pneumoniae and is classically seen in patients with staphylococcal or klebsiellar pneumonia.
• Pneumatocoele.
• Pneumothorax.
• Pyopneumothorax - eg. following rupture of a staphylococcal lung abscess in the pleural cavity.
• Deep vein thrombosis.
• Septicaemia, pericarditis, endocarditis, osteomyelitis, septic arthritis, cerebral abscess, meningitis (particularly in pneumococcal pneumonia).
• Post-infective bronchiectasis.
• Acute renal failure.

• Mortality from community-acquired pneumonia is about 1%.
• For patients in hospital, mortality is approximately 13-15% and it ranges from 22-54% in patients requiring intensive care.
• Early appropriate antibiotic therapy reduces mortality and morbidity.

• Influenza immunisation and pneumococcal immunisation
• Smoking cessation.