Comparative Evaluation of Lung Contusion Assessment Using Ultrasound and Computed Tomography Scan in the First 24 Hours of Intensive Care Unit Admission

Abstract

Introduction: Lung contusion is a common condition often resulting from blunt trauma, and it is connected with substantial health complications and risk of death; therefore, timely diagnosis and treatment are essential. Ultrasonography is a valuable technique that significantly improves medical care, offering time efficiency and lifesaving benefits. This study aimed to evaluate lung contusion by comparing the use of ultrasound and computed tomography (CT) scan during the initial 24 hr of intensive care unit (ICU) hospitalization. Methods: Eighty patients with blunt chest trauma were enrolled in this study. Each patient underwent both chest CT scan and lung ultrasound examinations. Lung ultrasound was performed in 6 anatomical regions on each lung (anterior-superior, anteriorinferior, lateral-superior, lateral-inferior, posterior-superior, and posterior-inferior). Lung contusion was identified by observing localized pulmonary effusion along with disrupting the lung parenchyma. To evaluate the extent of lung damage, the ratio of partial pressure of oxygen in arterial blood to the fraction of inspired oxygen concentration (PaO2/FiO2 ratio) was utilized, while the extent of lung involvement was classified using the blunt pulmonary contusion score (BPC-18 score). Results: In this study, lung ultrasonography demonstrated a sensitivity of 93.6% for detecting lung contusions, with a specificity of 94.1%, positive predictive value (PPV) of 98.3%, negative predictive value (NPV) of 80%, and overall accuracy of 93.7%. Specifically, for the right lung, these measures were 90.9%, 96%, 98%, 82.7%, and 92.5%, respectively. For the left lung, the corresponding values were 88%, 96.6%, 97.7%, 82.8%, and 91.2%. The receiver operating characteristics (ROC) curve assessed the sensitivity and specificity of ultrasound in diagnosing lung contusions within the first 24 hr of ICU admission. The area under the curve (AUC) for this assessment was 0.939, indicating high diagnostic accuracy. Conclusion: While CT remains the standard for evaluating lung contusions, its accessibility may be limited due to various circumstances, especially during hemodynamic instability. In these situations, ultrasound is highly valuable in diagnosing lung contusions with exceptional sensitivity, specificity, and diagnostic accuracy. Chest ultrasound emerges as an essential, noninvasive, and safe diagnostic tool at the bedside in the ICU for detecting lung contusions.