Role of chest ultrasound in early diagnosis of ventilator-acquired pneumonia and its impact on the outcome

Background
The term ventilator-acquired pneumonia (VAP) refers to pneumonia that develops 48–72 h after endotracheal intubation. The accuracy of diagnosis is improved by combining clinical, laboratory, and radiographic criteria.


Purpose
This article offers an evidence for the role of chest ultrasound in early detection of VAP and its effect on the outcome in the respiratory ICU.


Patients and methods
A prospective study carried out on 100 consecutive patients, who were mechanically ventilated and developed VAP admitted to the respiratory ICUs of Ain Shams University Hospitals in the period from February 2019 to February 2020. All were subjected to chest radiograph and chest ultrasonography screening within 12 h of mechanical ventilation and followed up after obtaining informed written consent of one first-degree relative of the patients.


Results
For diagnosis of VAP requires a highly statistically significant increase in the detection of chest ultrasound findings (B lines, air bronchogram, and pleural effusion) serially in the first 72 h of patient hospitalization (P=0.001 for all). This was correlated with the outcome, there was a high statistically significant increase in air bronchogram and pleural effusion in mortality patients in the first 48 h by serial chest ultrasound (P=0.003, 0.002, respectively). After 72 h pleural effusion only was the finding that showed a highly statistically significant increase with mortality (P=0.001), with a sensitivity of 38.9% and specificity of 89%, and it was found to be the most important predictor of mortality by chest ultrasound after 72 h.


Conclusion
Chest ultrasound is a sensitive method for bedside detection of VAP. Sonographic findings of VAP was found to have a big impact on the outcome. The most important predictor of death in VAP assessment by chest ultrasound was pleural effusion in the first 72 h.