1.1 What is lower respiratory tract infection?

Lower respiratory tract infection (LRTI) describes a range of symptoms and signs, varying in severity from non-pneumonic LRTI in the young healthy adult through to pneumonia or life-threatening exacerbation in a patient with severe disabling chronic obstructive pulmonary disease (COPD). The most common symptom is cough, which is new or changed in character. Other symptoms include sputum production, breathlessness, wheeze, chest pain, fever, sore throat and coryza. However, there is no unique set of symptoms that relate to LRTI.¹

LRTI can be difficult to distinguish from upper respiratory tract infection,² and not all lower respiratory tract symptoms are due to an infection that can be identified. Distinguishing pneumonia from non-pneumonic lower respiratory tract infection in the community is also difficult, particularly without diagnostic radiology. Evidence suggests that no combination of symptoms or clinical findings (i.e. pulse, respiratory rate, temperature, and chest examination) can reliably confirm the diagnosis of pneumonia.³

1.2 The need for a guideline

LRTI accounts for more general practitioner (GP) consultations per year than any other illness. The vast majority of cases are self-limiting and can be managed at home.^4,5,6 Data on the management of LRTI throughout Europe found that only 4.5% of patients seen in primary care were admitted to hospital, rising to 9% for the UK population.⁶

Although numerous studies demonstrate that antibiotic prescriptions are of no benefit in uncomplicated non-pneumonic LRTI, many such patients (66% of adults in one study⁷) do receive antibiotics. Practitioners may prescribe unnecessary antibiotics for clinical reasons that have no evidence base, such as colour of nasal discharge,⁸ or for non-clinical reasons such as the desire to reduce re-attendance, or belief that the patient expects an antibiotic.

There is no doubt that unnecessary antibiotic prescribing is harmful to the patient (side effects are a common cause of repeat visit to the GP) and causes selection of resistant bacteria, making subsequent infection more difficult to treat.^9,10,11 It is also harmful to the community as a whole, due to increased prescription costs and spread of resistant organisms within the community.⁹

This guideline focuses on the following key questions in the management of LRTI:

• When should antibiotics be prescribed?
• How can rates of reconsultation be reduced?
• When should patients be referred to secondary care?

1.3 Population covered by the guideline

This guideline covers adults (>16 years of age) presenting to primary healthcare services or Accident and Emergency departments with acute lower respiratory symptoms and/or signs which may be due to infection. This includes non-pneumonic LRTI, acute exacerbations of COPD, and pneumonia.

The guideline does not apply to patients with asthma (updated guidelines from the British Thoracic Society and SIGN will be published in 2002), known lung cancer (see the SIGN guideline,¹² under review 2002-3), cystic fibrosis, bronchiectasis, tuberculosis, human immunodeficiency virus infection or other forms of significant immunocompromise.

1.4 Professional groups to which the guideline applies

This guideline will be of interest to general practitioners, practice nurses, health visitors, community and hospital pharmacists, staff in Accident & Emergency departments, respiratory physicians and nurse specialists, infectious disease specialists, microbiologists and public health practitioners.