Ultrasound in Trauma
Abdominal Trauma
In this context, detection of peritoneal effusion is such a basic step that it sums up the role of ultra- sound in pre-hospital use [2]. Fluid detected in the peritoneal cavity is usually blood, but urine, bile or digestive fluids can give effusions in trauma patients.
The rupture of a hollow organ gives pneu- moperitoneum.
The other findings should be dealt with sepa- rately. Analysis of the various parenchymas depends on the patient’s morphotype and diges- tive gas.A parenchymatous contusion (liver, spleen, or kidney) gives a heterogeneous, rather hypo- echoic than hyperechoic image (Fig. 24.1). Fracture of a parenchyma can yield a fine hyperechoic line (Fig. 24.2). A pancreas trauma gives the same patterns as acute pancreatitis. A subcapsular hematoma gives a hypoechoic image in a bicon- vex lens. The diagnosis of vascular pedicle rup- In the trauma context, ultrasound has a limited
place in patients who are lucky enough to arrive alive at a hospital where a CT whole-body exami- nation is readily available. CT in fact answers a majority of questions at the head, thorax and abdominal levels. However, the extreme handiness of a small, autonomous ultrasound device makes it possible to envisage a major role on site. In addi- tion, it is undoubtedly useful to invest time in ultrasound if in the future CT has limited access for reasons of irradiation. All abdominal and tho- racic and even cephalic disorders have ultrasound expression.
Thoracic Trauma
On site, ultrasound detects disorders requiring immediate management: hemothorax, pneumoth- orax, and selective intubation. A tamponade can be found easily as well as aortic rupture provided there is a favorable morphotype. Early signs of lung contusion are available. This is useful since early radiograph misdiagnoses these alveolar-inter- stitial disorders in 63% of cases [1]. Myocardial contusion can also give signs in two-dimensional ultrasound.
Diaphragmatic Rupture
A diagnosis of diaphragmatic rupture creates a challenge that CT and MRI are far from solving.
Ultrasound has no precise place here. Lacking experience, we cannot assess this area. The only comment to be made is that the diaphragm is almost always detectable using ultrasound in criti- cally ill patients (see Figs. 4.9, p 22, 15.5 and 15.7, pp 98 and 17.2 and 17.15, pp 117 and 126).
CHAPTER 24
Fig. 24.1. Liver contusion. Heterogeneous ragged image within the liver parenchyma in a patient with abdomi- nal trauma. V, inferior vena cava
ture, especially at the kidney, is usually better approached by Doppler and other imaging modal- ities (CT or angiography).
Cervicocephalic Trauma
The brain is not really accessible to ultrasound, but optic nerve analysis can give information on a pos- sible brain edema. Eyeball integrity can be checked using ultrasound. A solution of cervical vertebra continuity is also accessible to ultrasound from C1 to C7.
On-site checking for this accurate vertebra pile can provide vital information before CT on rachis stability. A traumatic dissection of the carotid artery can be detected using two-dimensional ultrasound alone, but we lack data to confirm this.
The hemosinus, cranial dish-pan fracture and many other points will undoubtedly be document- ed in the future.
Bone and Soft Tissue Trauma
Ultrasound can, if necessary, detect long-bone fractures (Fig. 24.3). Bones have a complex geome- try, but at certain levels such as femoral diaphysis, ultrasound can analyze the cortex with accuracy. A minimal solution of continuity can be detected by scanning. Ultrasound makes no pretense of replac- ing radiography, inasmuch as the probe can be harmful. However, in the sedated patient, this is no longer a problem, and the field of ultrasound is again broadened.
Indeed, a very wide-ranging domain needs to be created, with an investment in bone ultrasound that intensivists may not wish to undertake. On the other hand, it is not excluded that the coming decades will see the emergence of a new type of specialist who will be able to considerably simplify numerous situations where only radiography or CT supplied the answers, and in the radiology department.
Let us imagine a few situations: recognition of a cranial dish-pan fracture, a displacement of the cervical rachis (see Fig. 21.10, p 156), a long bone fracture (femur, tibia, fibula, humerus, radius, cubitus, fingers, etc.), even a rib fracture all give specific ultrasound signs. Multiple cases can be imagined from the most vital (odontoid) to the most functional (scaphoid). For each of these cases, radiography can provide solutions, but we are sure that ultrasound holds surprises in reserve.
With swelling of a limb, ultrasound can settle between hematoma, muscular contusion and venous thromboses.
Whole-Body Exploration: CT or Ultrasound?
Many authors highlight the role of CT in the initial assessment of the polytraumatized patient [3, 4].
CT provides a complete study of the deep organs, the skeleton (especially the cervical spine), a func- 166 Chapter 24 Ultrasound in Trauma
Fig. 24.2. Kidney fracture. The clear line (white arrow) indicates a virtual space at the level of the fracture. The black arrowheads delineate the hematoma of the renal space
Fig. 24.3. Displaced fracture of the femoral diaphysis.
The proximal and distal segments are 20 mm distant, without overriding (arrows). Real-time analysis clearly depicts this type of lesion
tional study by iodine injection that shows vascu- lar ruptures or parenchymal lesions at the liver, spleen, kidneys, etc. CT is more easily accepted (once the patient is on the table) since ultrasound can be harmful here.
However, CT is reserved for the most stable patients, i.e., the least severely traumatized. Un- stable patients are those who will definitely benefit from an immediate on-site ultrasound scanning (see Chap. 25). Let us recall that 20% of thoracic trauma cases do not arrive alive at the hospital
References
1. Schild HH, Strunk H, Weber W, Stoerkel S, Doll G, Hein K, Weitz M (1989) Pulmonary contusion: CT vs plain radiograms. J Computed Assist Tomogr 13:417–
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2. Rose JS, Levitt MA, Porter J et al (2001) Does the pre- sence of ultrasound really affect computed tomogra- phic scan use? A prospective randomized trial of ultrasound in trauma. J Trauma 51:545–550
3. Société de Réanimation de Langue Française (1989) Echographie abdominale en urgence, apports et limi- tes. In: Van Gansbeke D, Matos C, Askenasi R, Braude P, Tack D, Lalmand B, Avni EF (eds) Réanimation et médecine d’urgence. Expansion Scientifique Fran- çaise, Paris, pp 36–53
4. Société de Réanimation de Langue Française (2000) Stratégie des examens complémentaires dans les traumatismes du thorax. In: Léone M, Chaumoitre K, Ayem ML, Martin C (eds) Actualités en réanimation et urgences 2000. Elsevier, Paris, pp 329–346
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