337.6: Ultrasound Scanning in Lung Procurement. Protocol For Decision-Making With the Purpose of Increasing Transplant Eligible Lungs

Abstract

Introduction: Despite having a similar population, Latin America performs 11x less lung transplant procedure than Europe. Improving brain death diagnosis and converting potential donors into real donors is key to improve these numbers. Ultrasonography (US) is common practice in Intensive Care Units. Available literature on its use in the management of brain death donors and lung procurement is extremely scarce. The selection and rejection of lungs for transplantation is usually done with chest X-rays, however US has shown better sensitivity and specificity for the diagnosis of pulmonary pathologies. Lung US allows to identify the reversible causes low PaO2/FiO2 ratio (PaFi), thus allowing to establish specific interventions which, if proved successful, could turn lungs into transplant-eligible lungs. Methods: Introducing a simple Protocol aiming at identifying and treating the main reversible causes of a low PaFi. Respiratory causes of a low PaFi ratio can be either parenchymal or pleural. Parenchymal causes: Pulmonary edema (either neurogenic or cardiogenic) determines the visualization of bilateral and symmetrical B lines. Fluid restriction prioritizing inotropic drugs to revert hypotension and usage of hypertonic solutions can reduce edema. Atelectasis, contusion and pneumonia can appear as patterns for unilateral B lines and/or consolidations. The presence of a static or dynamic air bronchogram can differentiate them. In atelectasis, fiberoptic bronchoscopy can revert the situation. In all other cases, a single lung transplant can be considered, which is a valid option in aged recipients when donors are scarce. Pneumothorax and pleural effusion are both pleural causes of a low PaFi. They can be easily diagnosed through an ultrasound scan, not there being a reason for rejection. Its resolution can turn these lungs into transplant eligible lungs. The pneumothorax —frequently anterior in ventilated patients in dorsal decubitus— may be overlooked in the chest x-ray. Diagnosis is made by the absence of pleural sliding and presence of a lung pint. Pleural effusion is anechoic, present quad sign and the sinusoid sign. The acquisition of skills to diagnose all these conditions does not require much reading and has a fast-learning curve (25 cases monitored). Results: This Protocol is currently used for donor decision-making and will be implemented prospectively by the lung transplant team to assess its ability to increase the number of lungs suitable for transplantation. Conclusions: US is a useful technique to identify reversible and treatable causes of a low PaFi, helping decision-making to increase the number of transplant eligible lungs.