Lung flooding--a new method for complete lung sonography.

A sonographic examination of the lung has so far been impossible because of sound reflection. In conjunction with video-assisted thoracoscopic surgery, lung sonography would be helpful to make up for the lack of direct palpation. Animal experiments with pigs were performed to find out whether lung sonography becomes possible following bronchoalveolar flooding with a suitable liquid. The lung was filled with whole electrolyte solution through the left leg of a double-lumen endotracheal tube after resorption atelectasis (method 1) or compressive atelectasis (method 2). As an alternative, liquid perfluorocarbon was used (method 3). Under atelectasis, the lung thus flooded was investigated by ultrasound applied transpleurally and endobronchially. The first results proved that lung flooding is possible if certain prerequisites are fulfilled. Perfluorocarbon flooding led to total sound absorption which prevented sonography, whereas flooding with whole electrolyte solution made complete lung sonography possible, making visible the intrapulmonary vessels, bronchi and peribronchial lymphatic nodes. Measurements proved that the unilateral flooding caused no significant changes in the arterial and central venous pressure nor in transcutaneous oxygen saturation.