Lung ultrasound in adult and paediatric cardiac surgery: is it time for routine use?

Respiratory complications are common causes of morbidity and the need of repeated X-ray examinations after cardiac surgery. Ultrasound of the chest, including the lung parenchyma, has been recently introduced as a new tool to detect many pulmonary abnormalities. Despite this, the use of lung ultrasound (LUS) in adult and congenital cardiac surgery remains limited. In particular, lung ultrasound has been mainly used in the evaluation of pleural effusion (PLE), but no consensus exists on methods to quantify the volume of the effusion. Usefulness of LUS for the assessment of diaphragmatic motion in children has also been highlighted, but no clear recommendation exists regarding its routine use. Accuracy of LUS in detecting pulmonary congestion after adult cardiac surgery has been demonstrated, whereas studies in children are still scarce, and data on pneumothorax and lung consolidations are limited in the paediatric population. There are methodological and practicality issues regarding diagnostic protocols (i.e. image views and their sequential order) and instrumentation (transducers and their setting) used in different studies. It also remains unclear which practitioner-the cardiologist, intensivist, pulmonologist or the radiologist, should perform the examination. Cost analysis pertaining to extensive clinical application of lung ultrasound in cardiac surgery has never been performed. Guidelines and recommendations are warranted for a systematic and extensive use of this technique in cardiac surgery at different ages, as it could serve as a useful, versatile tool that could potentially decrease time, radiation exposure and costs.