Lung Ultrasound In Ventilator Associated Pneumonia: Light Or More Shadow At Diagnosis

Abstract

Ventilator-associated pneumonia (VAP) is the most common health care-associated infection in intensive care units (ICU). Its appearance causes an increase in stay, mortality and economic costs. The traditional diagnostic criteria (clinical, radiological and microbiological) are a matter of growing controversy (the poor reliability of radiological criteria in ICU patients has been recognized). For a few years, lung ultrasound has occupied a vital place in the diagnostic arsenal of intensive medicine. Review articles and Meta-analyzes on lung ultrasound in the diagnosis of pneumonia have confirmed the usefulness of the method. The main ultrasonographic characteristics of VAP are the presence of pulmonary condensation and air bronchogram, with a sensitivity of 100% and a specificity of 80%. The image of condensation may correspond to other diagnoses such as pulmonary atelectasis caused by mechanical obstruction or compression, tumor consolidation and pulmonary embolism. On the other hand there are technical limitations (obese patients, patients with drainages and the location of the lesion) that compromise the diagnostic certainty. In conclusion, lung ultrasound is useful but has not yet provided all the light necessary for the successful diagnosis of VAP in ICUs.