Point-of-Care Lung Ultrasonography for Diagnosis of Pulmonary Contusions

In the Literature

Dicker SA, Lisciandro GR, Newell SM, Johnson JA. Diagnosis of pulmonary contusions with point-of-care lung ultrasonography and thoracic radiography compared to thoracic computed tomography in dogs with motor vehicle trauma: 29 cases (2017-2018). J Vet Emerg Crit Care (San Antonio). 2020;30(6):638-646.

The Research …

Pulmonary contusions are common in patients that have sustained vehicular trauma; however, these injuries may be initially underdiagnosed because they may not be associated with obvious abnormalities on physical examination. Moreover, conventional radiographic signs of pulmonary contusion often lag behind clinical signs. In humans, thoracic CT is the gold standard for diagnosing pulmonary contusions, although lung ultrasonography is also highly sensitive. In veterinary medicine, financial concerns and sedation requirements may limit the use of CT; less-expensive options should thus be explored. Lung ultrasonography is relatively inexpensive, minimally invasive, rapid, and available in many clinics.

In this study, regionally based lung ultrasonography, 3-view thoracic radiography, and thoracic CT were performed on 29 dogs following vehicular trauma. The lung-ultrasound protocol (veterinary bedside lung ultrasound examination [ie, Vet BLUE]¹) consisted of evaluation of the caudodorsal, perihilar, middle, and cranial lung regions on both sides of the thorax (8 regions total). These regions were evaluated for B-lines (ie, lung rockets) and C-lines (ie, shred sign)—artifacts that represent interstitial syndrome (ie, wet lung). The presence of these artifacts following blunt-force trauma are suggestive of pulmonary contusions.² 

Findings indicated that lung ultrasonography has a higher sensitivity than radiography for diagnosing pulmonary contusions when compared with thoracic CT, suggesting lung ultrasonography should be performed as part of trauma triage examination for rapid diagnosis of pulmonary contusions.

… The Takeaways

Key pearls to put into practice:

• Thoracic ultrasonography is useful during triage examination of a trauma patient for rapid diagnosis of pulmonary contusions, pneumothorax, and pleural effusion.

• Thoracic radiography is not sensitive enough to diagnose pulmonary contusions but may be useful in a later stage for identifying other trauma pathology (eg, fractures, diaphragmatic hernia).

• Pneumothorax may interfere with assessment for B- and C-lines on thoracic ultrasonography. In addition, B-lines should be interpreted with caution in patients with prior lung disease, as they may represent lung pathology other than pulmonary contusions.