SonoStudy: >12,000 kids – Identifying factors putting kids at low risk, not needing CT after trauma

There has been quite a bit of press lately on this –  Here and Here – And for good reason. With the ALARA principle, and being a pediatric population which has been studied so many times with regard to trauma and the need for CT, a recent study by Holmes et al published in Annals of Emergency Medicine did a multi-site study enrolling >12,000 kids and identified 7 factors that places children at very low risk for injury not requiring abdominal CT. A prior post discusses a study done by the same author and my thoughts of pediatric US in trauma. BTW – Dr. Holmes also discusses low risk factors for adult patients in a prior study too.

The prediction rule for pediatric patients consisted of (in descending order of importance):

No evidence of abdominal wall trauma or seat belt sign,

Glasgow Coma Scale score greater than 13,

No abdominal tenderness,

No evidence of thoracic wall trauma,

No complaints of abdominal pain,

No decreased breath sounds, and

No vomiting.

Now, I dont know about you, but to me it is quite obvious – we just now have a nicely powered study that we can use for all the doctors who want to CT despite all of the above being negative. The authors say that if any one of the above exist then a decision by the physician should be made as to what the next best management step would be – observation period with serial exams, ultrasound (holla!), CT – are all options depending on clinical judgement. Below is the abstract:

Study objective: We derive a prediction rule to identify children at very low risk for intra-abdominal injuries undergoing acute intervention and for whom computed tomography (CT) could be obviated.

Methods: We prospectively enrolled children with blunt torso trauma in 20 emergency departments. We used binary recursive partitioning to create a prediction rule to identify children at very low risk of intra-abdominal injuries undergoing acute intervention (therapeutic laparotomy, angiographic embolization, blood transfusion for abdominal hemorrhage, or intravenous fluid for ≥2 nights for pancreatic/gastrointestinal injuries). We considered only historical and physical examination variables with acceptable interrater reliability.

Results: We enrolled 12,044 children with a median age of 11.1 years (interquartile range 5.8, 15.1 years). Of the 761 (6.3%) children with intra-abdominal injuries, 203 (26.7%) received acute interventions. The prediction rule consisted of (in descending order of importance) no evidence of abdominal wall trauma or seat belt sign, Glasgow Coma Scale score greater than 13, no abdominal tenderness, no evidence of thoracic wall trauma, no complaints of abdominal pain, no decreased breath sounds, and no vomiting. The rule had a negative predictive value of 5,028 of 5,034 (99.9%; 95% confidence interval [CI] 99.7% to 100%), sensitivity of 197 of 203 (97%; 95% CI 94% to 99%), specificity of 5,028 of 11,841 (42.5%; 95% CI 41.6% to 43.4%), and negative likelihood ratio of 0.07 (95% CI 0.03 to 0.15).

Conclusion: A prediction rule consisting of 7 patient history and physical examination findings, and without laboratory or ultrasonographic information, identifies children with blunt torso trauma who are at very low risk for intra-abdominal injury undergoing acute intervention. These findings require external validation before implementation.