Many factors from delayed diagnosis to morbidity, mortality, malpractice anxiety, and hospital cost play a role in the management of patients with blunt trauma. CT is preferred for quick detection and grading of toracoabdominal, skeleton, and neurological injury in high-energy trauma [15]. However, it is difficult to distinguish between which patients CT is necessary and between which it is unnecessary. No pathological finding is observed in 74% of CTs performed in patients with blunt trauma [5]. In the study of Streck et al., it was reported that approximately 15% of patients with blunt trauma had intra-abdominal injuries and that non-operative treatment was generally sufficient [1]. In our study, 83.8% of abdominal CT performed with suspicion of intra-abdominal injury were normal. In our study, 2.5% intra-abdominal injury was detected. It was thought that the reason for the low rate of intra-abdominal injury in our study might be related to the fact that this study was performed in the general emergency service, not in the trauma center, unlike other studies.
In the study conducted by Streck et al., a clinical prediction rule containing five variables (abdominal pain, abnormal physical examination findings, abnormal CXR, AST > 200 IU/L, and amylase) was defined and it was emphasized that the application of this clinical prediction rule could help the emergency physician to make a CT scan decision in the evaluation of blunt trauma patients [8]. It has been reported that the intra-abdominal injury risk of the patients was determined in a short time and that CT was not required in the first evaluation in one third of the patients [8]. In another study, it was observed that the sensitivity of the five-variable clinical prediction rule in determining the risk of intra-abdominal injury was 97.5% and intra-abdominal injury was missed by 0.7% [10]. With the application of clinical prediction rule consisting of history and physical examination, 0.5% intra-abdominal injury was missed, CT scan decreased 23.2%, and hospital cost was reduced by 50% [6]. In the emergency department of our hospital, if the quaternary variable consisting of abdominal pain, abnormal physical examination finding, CXR, and AST > 200 IU/L is applied, the intra-abdominal injury may not be detected in only 0.17% of children with blunt trauma. The results of our study showed that the four-variable clinical prediction rule had a higher sensitivity and accuracy rate in identifying patients with a very low risk of intra-abdominal injury than patients with intra-abdominal organ injury. According to the four-variable clinical prediction rule, very low-risk patients do not require immediate CT. In very low-risk patients, we recommend 12–24 h of observation to avoid missing injuries. If we had applied the clinical prediction rule when evaluating patients, the number of CT scan would have been reduced by 50.5% and the hospital cost would have been reduced by 23.6%. The findings obtained in this study suggest that the application of the four-variable clinical prediction rule could reduce CT imaging and prevent unnecessary radiation exposure of the patients.
History and physical examination have an important role in the management of patients with blunt trauma [1, 7, 16, 17]. Holmes et al. reported that 0.1% of blunt trauma patients were abducted, CT scan was reported to decrease 23% by clinical decision rule including abdominal wall trauma symptom, Glasgow Coma Scale (GKS) score > 13, abdominal tenderness, thoracic wall trauma, abdominal pain, decreased respiratory noise, and vomiting [6]. Patients with abdominal pain, signs of peritoneal irritation, and abdominal wall trauma have a high risk of intra-abdominal injury [6, 9]. In our study, abdominal pain, abdominal guarding, and signs of trauma in the abdominal wall were associated with intra-abdominal organ injury, and it supported no need for urgent CT scans in patients without these findings.
Clinical prediction rules including laboratory tests such as pancreatic enzymes and hepatic transaminases have been used to detect intra-abdominal injury in patients with blunt trauma [9, 11, 16]. It was thought that increased AST increased the sensitivity of the clinical prediction rule [14], and an AST > 200 IU/L could be an indication for a CT scan [18]. In the study of Streck et al., it was stated that AST reflects potential liver damage or ischemia, which was high in 68.8% of patients with intra-abdominal injury [1]. In patients with blunt trauma, the elevation of AST or ALT alone does not diagnose liver injury. AST, ALT, examination, and hemodynamic status should be evaluated together [18]. In our study, 40% of patients with intra-abdominal injuries had AST > 200 IU/L. The results of our study suggest that patients with AST ≤ 200 U/L can be evaluated together with history and examination instead of emergency CT.
Routine CXR in patients with trauma is significant for parenchymal evaluation and detecting rib fractures that may occur in proportion to the severity of trauma [19]. It has been recommended that patients with rib fractures should be evaluated with further examination [20]. Patients with pathology on CXR have low GCS, and CT indication cannot be made only with low GCS [21]. Our study supports that although pneumothorax, lung contusion, and rib fracture, if other examination and laboratory findings are normal, immediate abdominal CT is not required, and close follow-up is required.
Limitations
The limitations of our study are as follows: a single-center, retrospective, general emergency service where pediatric and adult patients were evaluated together. There is a need for prospective and multi-center studies to be conducted in a pediatric trauma center.