Top Tips: Community-Acquired Pneumonia

Dr Sinan Eccles Offers Top Tips for the Assessment and Management of Adults with Community-acquired Pneumonia in Primary Care

Each year, around 1 in 300 of the adult population in the UK will have an episode of community-acquired pneumonia (CAP),¹ with the incidence increasing with age. Only a small proportion of patients with symptoms of a lower respiratory tract infection (LRTI) presenting to primary care will have CAP,^2,3 and around one-third of them will require admission to hospital.³ It is important to identify which patients with an LRTI have pneumonia, and which of these need hospital assessment.

1. Differentiate Pneumonia from Acute Bronchitis

The key feature of pneumonia is the presence of consolidation: the filling of alveoli and adjoining ducts with inflammatory material. In primary care, where a chest X-ray to confirm the presence of consolidation is often not rapidly available, the clinical diagnosis of pneumonia relies on the examination findings of new focal chest signs in combination with symptoms of an LRTI and systemic features such as fever or rigors.⁴ Around 40% of patients with new focal chest signs treated with antibiotics in the community will have radiological evidence of pneumonia on chest X-ray.²

2. Reassure Patients that Antibiotics are Not Usually Indicated for LRTI

Getting the diagnosis right is important, as most patients with an LRTI in whom pneumonia is not clinically suspected do not benefit from antibiotics.^5,6 Antibiotics should be reserved for those who are systemically unwell, have symptoms or signs suggestive of serious illness and/or complications, or who are at a high risk of complications,⁶ including patients who:

• have significant pre-existing heart, lung, renal, liver, or neuromuscular co-morbidity
• are immunosuppressed
• are aged over 65 years with acute cough and two or more, or aged over 80 years with acute cough and one or more of the following criteria:
  • hospitalisation in the previous year
  • type 1 or 2 diabetes
  • history of congestive cardiac failure
  • current use of oral glucocorticoids.

Point-of-care C-reactive protein (CRP) testing can be helpful in patients with acute bronchitis in whom pneumonia is not clinically suspected. When it is not clear whether antibiotics should be prescribed for a patient after clinical assessment, the use of point-of-care CRP testing can significantly reduce the use of antibiotics without causing harm. An algorithm for suggested use of point of care CRP is shown in Figure 1.

3. Use CRB-65 to Help Decide Who Needs Hospital Assessment

In patients presenting to primary care with a clinical diagnosis of CAP, the CRB-65 score (Table 1) gives an indication of the risk of death.

Table 1: CRB-65 Score for Community-acquired Pneumonia⁸

The severity of pneumonia usually correlates with the risk of mortality, but clinical judgment must be exercised alongside the CRB-65 score when making decisions about when to refer patients for hospital assessment.⁷ Factors such as social circumstances, the wishes of the patient, and the stability of any co-morbid conditions should be taken into account. Patients with a score of 0 have a low risk of death (<1%) and are usually suitable for treatment in the community. Patients with a score of 1–2 have an intermediate risk of death (1–10% mortality) and those with a score of 3–4 have a high risk of death (>10% mortality). Hospital assessment should be considered for all patients with a score above 0, particularly those with a score of 2 or more.⁷

4. Give the Right Antibiotic at the Right Dose

National guidelines recommend amoxicillin 500 mg three times a day for 5 days as the first-line antibiotic for low-severity CAP, although local guidance may vary.^4,7 Doxycycline (200 mg urgently then 100 mg once a day, or 100 mg twice a day) or clarithromycin (500 mg twice a day) are suitable alternatives, for example in those with a penicillin allergy.^9,10 It is worth noting that there is a theoretical risk of doxycycline absorption being reduced by calcium intake, so patients taking calcium supplements should be advised to take these at a different time of day to doxycycline.¹¹

Dual antibiotic therapy is not usually indicated for patients treated in the community, and is reserved for patients with moderate- to high- severity CAP.⁷

5. Give Advice About Simple Measures

People with CAP should be advised to rest and to drink plenty of fluids. Smoking increases the risk of CAP and is likely to delay recovery.⁴ A diagnosis of CAP therefore affords a good opportunity to discuss smoking cessation. Paracetamol can help with fever or pleuritic pain.

6. Know When a Chest X-ray is Required

Most people with a clinical diagnosis of CAP suitable for treatment in the community do not require a chest X-ray. A chest X-ray is indicated if the diagnosis is in doubt and an X-ray will help with the differential diagnosis and acute management, if progress following treatment for a clinical diagnosis of CAP is not satisfactory, or if the patient is considered at risk of underlying lung pathology such as lung cancer.⁴

7. Send a Sputum Culture in Selected Cases

Most cases of CAP are caused by Streptococcus pneumoniae,^2,12 which is usually sensitive to first-line antibiotics in the UK. Therefore, a sputum culture is not necessary for most patients with low-severity CAP. It is helpful to send a sputum culture in patients with chronic lung disease such as chronic obstructive pulmonary disease (COPD) or bronchiectasis, because these patients are more likely to have had previous antibiotic courses and may have less common or more resistant pathogens requiring alternative antibiotics. Sputum culture should also be considered in patients who do not respond satisfactorily to first-line empirical antibiotics.⁴

If there is a suspicion of tuberculosis—for example, persistent productive cough, longer duration of symptoms, night sweats, and/or presence of risk factors such as social deprivation, ethnic origin, or older age—then sputum should be sent specifically for tuberculosis testing,⁴ which is not usually performed on routine sputum culture.

8. Identify Patients who Are Not Responding to Treatment

In most cases of low-severity CAP, symptoms should begin to improve within 3 days of starting treatment.⁷ Unsatisfactory progress at this point should prompt a consideration of alternative diagnoses such as heart failure, an assessment for complications of CAP such as development of a parapneumonic pleural effusion, and a consideration of whether a chest X-ray or hospital assessment is now required. Extending the course of antibiotics beyond 5 days is one possible management strategy in this situation,⁷ but it is important to consider these other factors in addition.

9. Be Alert to Repeated Courses of Antibiotics

If a patient has received several courses of antibiotics this should prompt a more detailed assessment. Consider whether these repeated courses are truly indicated, or if they represent the natural resolution of symptoms following CAP. If there is convincing evidence of ongoing illness, a search for an underlying problem should be considered. Most patients should undergo a chest X-ray and sputum culture at this point if they have not already done so,⁴ and additional investigations such as a peak flow diary or spirometry may be indicated if the history is suggestive of alternative pathology such as asthma or COPD. Persistent sputum production or persistent crackles on auscultation may require a CT scan or referral to secondary care to assess for bronchiectasis or pulmonary fibrosis.

10. Advise Patients that Symptoms Will Take Time to Fully Resolve

A short course of antibiotics is recommended for low-severity CAP as microbiological clearance of pathogens usually occurs early. However, it takes longer for symptoms, clinical signs, and the radiological changes on chest X-ray to resolve.

While fever and purulent sputum production usually improve quickly, other symptoms such as cough and lethargy take longer to resolve than the duration of the antibiotic course in most patients. Patients often expect a further course of antibiotics to expedite resolution of these symptoms. Explaining to patients the natural history and resolution of the symptoms of CAP at the time of diagnosis may help reduce unnecessary additional antibiotic courses.

The NICE guideline on pneumonia suggests that although the rate of improvement will vary based on the severity of pneumonia, most people can expect that by:⁷

• 1 week: fever should have resolved
• 4 weeks: chest pain and sputum production should have substantially reduced
• 6 weeks: cough and breathlessness should have substantially reduced
• 3 months: most symptoms should have resolved but fatigue may still be present
• 6 months: most people will feel back to normal.

Dr Sinan Eccles

Consultant physician in respiratory medicine

Royal Glamorgan Hospital, South Wales