Early outcomes in CAP: Clinical stability, clinical failure and nonresolving pneumonia

Clinical stability is the first step of clinical improvement in patients with pneumonia. Clinical stability has been proven to be useful in guiding the switch of antibiotic therapy from intravenous to oral formulations. Given its importance in patient management, several sets of criteria have been created to standardise its definition. However, a single set of criteria cannot fit everybody; therefore, a personalised approach based on the resolution of the patient's most prominent clinical features should be considered. Moreover, it is important to choose the set of criteria that best fits the standard of care at each site of practice. Clinical failure is considered a predictive factor of adverse clinical outcomes. The identification of the aetiology of clinical failure is important to determine the subsequent patient management. The term 'nonresolving pneumonia' is used to indicate a failure to improve without clinical deterioration. Few epidemiological data have been published on this condition. Therefore, future studies should specifically address this topic.