Role of Ultrasound in Blunt Abdominal Trauma

Abstract

Summary and Conclusion U ltrasonography is considered the best modality in initial evaluation of blunt abdominal trauma patients as it is readily available, requires minimal preparation time, not invasive and may be performed with mobile equipment that allows greater flexibility in patient positioning. However, ultrasound examination is operator dependent. Lacerations of solid organs can be overlooked, injuries of the dome or lateral segments of the liver can be overlooked, especially in the presence of ileus or an uncooperative patient. Moreover, hepatic lacerations or hematomas may be difficult to detect, especially in the acute phase, when they are isoechoic to the normal liver. Pancreatic & gastrointestinal injures are difficult to be seen by ultrasonography, however presence of intaabdominal fluid (positive FAST) suggests intra-abdominal injury, CT should be performed. Ultrasonography is very useful in follow up of patients with minor intra-abdominal injury & decreases use of CT which has the disadvantages of being expensive, high dose radiation, contrast agent use. Repeated ultrasonography in patients of blunt abdominal trauma & close clinical observation increases the sensitivity of ultrasonography for intra-abdominal bleeding to nearly 100% & nearly no patient with intra-abdominal injury could be missed, as in some cases of intra-abdominal injury, there is minimal bleeding that it gives negative FAST on initial examination. In cases of positive FAST scan, the patient should not be operated on until the exact site of intra-abdominal injury is detected by ultrasonography or CECT unless the patient was hemodynamically unstable, as in some cases the intra-abdominal fluid could be ascites due to disease as liver failure, that repeated ultrasonography & close clinical observation of the patient help to avoid unnecessary laparotomy. In conclusion, ultrasonography is considered the initial imaging modality in evaluation of blunt abdominal trauma patients as it is noninvasive, readily available, low cost imaging and require minimal preparation time. However there`s limitation of ultasonographyas it doesn`t accurately detect the extent of the precise site of organ injury so patients with abdominal injury should be followed up with a CT scan to locate the origin of bleeding and evaluate the extent of injury. But CT scan also has some disadvantages as the scan requires long time, the patient need to be transferred from the emergency department to the CT suite, ionizing radiation is a factor to consider and intravenous contract media hazardous reactions especially to patients with high creatinine level, renal failure patients and pregnant women.