Ultrasound assessment of antibiotic-induced pulmonary reaeration in ventilator-associated pneumonia*

Objectives: To compare lung reaeration measured by bedside chest radiography, lung computed tomography, and lung ultrasound in patients with ventilator-associated pneumonia treated by antibiotics. Design: Computed tomography, chest radiography, and lung ultrasound were performed before (day 0) and 7 days following initiation of antibiotics. Setting: A 26-bed multidisciplinary intensive care unit in La Pitié-Salpêtrière hospital (University Paris–6). Patients: Thirty critically ill patients studied over the first 10 days of developing ventilator-associated pneumonia. Interventions: Antibiotic administration. Measurements and Main Results: Computed tomography reaeration was measured as the additional volume of gas present within both lungs following 7 days of antimicrobial therapy. Lung ultrasound of the entire chest wall was performed and four entities were defined: consolidation; multiple irregularly spaced B-lines; multiple abutting ultrasound lung "comets" issued from the pleural line or a small subpleural consolidation; normal aeration. For each of the 12 regions examined, ultrasound changes were measured between day 0 and 7 and a reaeration score was calculated. An ultrasound score >5 was associated with a computed tomography reaeration >400 mL and a successful antimicrobial therapy. An ultrasound score <–10 was associated with a loss of computed tomography aeration >400 mL and a failure of antibiotics. A highly significant correlation was found between computed tomography and ultrasound lung reaeration (Rho = 0.85, p < .0001). Chest radiography was inaccurate in predicting lung reaeration. Conclusions: Lung reaeration can be accurately estimated with bedside lung ultrasound in patients with ventilator-associated pneumonia treated by antibiotics. Lung ultrasound can also detect the failure of antibiotics to reaerate the lung.