Ultrasound examination of the lungs in the intensive care unit

Abstract

Lung ultrasound is increasingly used in the critically ill adult. It allows prompt management based upon reproducible data and generates fewer computed tomography (CT) examinations, therefore decreasing irradiation, delays, cost, and discomfort to the patient. The aim of this article is to describe the value of ultrasound for lung imaging in the critically ill and state our experience in neonates. Review of studies published in the peer-reviewed international literature analyzing consecutive critically ill adults admitted to intensive care units, assessing pleural effusion, alveolar consolidation, interstitial syndrome, and pneumothorax, using a standardized ultrasound approach to the lung, with CT as the reference. The sensitivity and specificity of ultrasound are 92% and 93% for pleural effusion, 90% and 98% for alveolar consolidation, 93% and 93% for interstitial syndrome, 100% and 96% for complete pneumothorax, 79% and 100% for radio-occult pneumothorax. This article reviews data that validate the scientific value of lung ultrasound in adult medical intensive care units. We then present observations in the critically ill neonate. The discussion points to the methodologic issues raised in lung ultrasound in the neonate, i.e. mainly the limited access to a pertinent gold standard (CT). Some CT correlations are presented, confirming the value of lung ultrasound in the neonate. The standardized signs assessed in the adult are also found in the critically ill neonate, meaning a potential use in this field. Awaiting confirmatory CT studies, lung ultrasound can be taken into consideration as a possible bedside tool for completing bedside radiography.