B-Lines Quantify the Lung Water Content: A Lung Ultrasound Versus Lung Gravimetry Study in Acute Lung Injury

Seventeen Na-pentobarbital anesthetized, cannulated (central vein and carotid artery) minipigs were studied: five sham-operated animals served as controls and, in 12 animals, ALI was induced by injection of oleic acid (0.1 mL/kg) via the central venous catheter. B-lines were measured by echographic scanner in four predetermined chest scanning sites in each animal. At the end of each experiment, both lungs were dissected, weighed and dried to determine wet/dry weight ratio by gravimetry. After the injection of oleic acid, B-lines number increased over time. A significant correlation was found between the wet/dry ratio and B-lines number (r = 0.91, p < 0.001). These data suggest that in an experimental pig model of ALI/ARDS, B-lines assessed by lung ultrasound provide a simple, semiquantitative, noninvasive index of lung water accumulation, strongly correlated to invasive gravimetric assessment. (E-mail: gargani@ifc.cnr.it)