CONTRIBUTION OF LUNG ULTRASOUND IN THE EARLY DIAGNOSIS OF VENTILATOR-ASSOCIATED PNEUMONIA: A PROSPECTIVE OBSERVATIONAL STUDY

Walid Sellami*, Inès Ben Mrad, Takwa Hkiri, Kamel Ben Salem, Iheb LABBENE and Mustapha Ferjani

ABSTRACT

Background: Ventilator-associated pneumonias(VAP) represent the most frequent nosocomial infection in the intensive care unit. Their diagnosis remains problematic and an early diagnosis could largely improve the prognostic outcomes. Several clinical, radiologic and biologic tools were developed to improve the speed and the diagnostic performance. Recently, lung ultrasound became a tool allowing to estimate the lung morphology at the bedside. The purpose of this study was to determine the sensibility, the specificity and the performance of diagnosis of lung ultrasound alone and associated to bronchoalveolar lavage. Methods: In a monocenter prospective study of 60 patients with suspected ventilator-associated pneumonia, conducted in the intensive care unit of the principal military hospital of instruction of Tunis over a period of 12 months, we investigated the diagnostic performance of lung ultrasound and the sensibility and specificity of the signs ultrasound of pneumonia which are: subpleural consolidation, lobar consolidation and arborescent/linear air bronchogram. We also evaluated the combination of lung ultrasound with direct examination of bronchoalveolar lavage. Results: The prevalence of VAP was 60%. The two groups (patients with and without VAP) were similar in terms of general characteristics. The only significant differences between the two groups occurred in purulent secretions: more common in patients with ventilator-associated pneumonia. Lobar/hemilobar consolidation had a specificity of 33% while subpleural consolidation and arborescent/linear air bronchogram had a specificity of 100% and a positive predictive value of 100%. The association between lung ultrasound and bronchoalveolar lavage had a specificity of 100% and a positive predictive value of 100%. Conclusion: The lung ultrasound is an available tool of practical bedhead among critical patients in intensive care unit. It is a valid alternative for the early and reliable diagnosis of VAP. She could also allow to follow their evolution under treatment.

Keywords: Lung, ultrasonography, resuscitation, ventilator-associated pneumonia, diagnosis.