Brief Clinical Review: Non-Responding Pneumonia

A slowly resolving or non-resolving pneumonia (NRP) is a common clinical dilemma, affecting 10-20% of patients hospitalised with community-acquired pneumonia. Potential causes are many and include inadequate or inappropriate antibiotic therapy, antibiotic resistant pathogens, infectious complications, or incorrect diagnosis. Objective criteria have been described to define clinical stability and represent the best current definition of adequate treatment response. The time to clinical stability varies substantially between patients, being longer in older patients, patients with comorbidities, and patients with a higher severity of pneumonia. NRP is associated with increased mortality and requirement for intensive care unit admission, and so it is essential to identify these patients. Once non-response is recognised, patients should undergo a full re-evaluation, including microbiological testing, repeat chest X-ray and consideration of further imaging, and an increased spectrum of antibiotic therapy if drug resistant pathogens are suspected. A wide range of non-infectious disorders can masquerade as bacterial pneumonia, including pulmonary embolism, malignancy, interstitial lung diseases, alveolar haemorrhage, and vasculitis. There is no uniform recommended diagnostic or treatment approach for patients with NRP. The investigations and interventions required are determined on a case-by-case basis. The present article reviews the causes, investigation, and management of NRP, and presents an algorithm for identification and management of these patients.