When can we avoid CT scans in children after Blunt Head Trauma? Michele Alzetta, MD - Chief Director Emerg dept Venice - Italy

Although an important and useful diagnostic tool, cerebral CT is associated with exposure to ionizing radiation, which is of greatest risk in the pediatric age range (with the risk of future neoplasia likely somewhere between 1 in 1000 to 1 in 5000, according to age). After blunt head trauma in children, when can we avoid CT? This very rigorous prospective study suggests a series of simple, validated clinical criteria. Patients younger than 18 years of age who came to one of 25 different hospitals in a U.S. pediatric research network because of head trauma in the preceding 24 hours were subdivided into two age ranges: younger than two, and two years or older. Almost 34000 patients were initially enrolled and data were collected and examined and clinical criteria predictive of absence of clinically-important traumatic brain injury were derived. Subsequently these criteria were validated by application to another approximately 8600 patients. Among children with none of the six predictors in the algorithm, the number of CT scans would be reduced in the validation group by 25% in children < 2 and by 20% in children two or more years old.
 
The study excluded patients with penetrating brain trauma, brain tumour or preexisting neurological pathology. It also excluded patients with totally insignificant trauma such as, for example, falls from ground height or trauma obtained while walking or running with no other sign or symptom of head trauma besides abrasions or lacerations, as these patients are at negligible risk for clinically-important TBI. Patients with coagulopathies or with GCS below 14 on arrival were enrolled but their data will be examined separately: a GCS < 14 is associated with traumatic brain injury in 20% of cases, and CT scan is therefore typically indicated.
 
The algorithm proposed achieved a negative predictive value greater than 99,9%.
 
 
  • Children less than two years old

 
Presence of: 1. GCS < 15 OR other signs of altered mental status (restlessness, somnolence, repetitivity, hyporeactivity) OR palpable skull fracture?
 

If yes, do CT scan. If no, go to step 2.

 
Absence of: 2. Occipital, parietal or temporal haematoma AND of loss of consciousness > 5 seconds AND of parent impression that the child is not behaving normally AND of important mechanism of trauma (ejection from vehicle, death of a passenger, rollover, collision of cyclist or pedestrian without helmet, fall from over 90 cm, high speed impact of object against skull) ?
 
If all these are absent, CT scan is not indicated. If one or more of the above four factors in #2 is present, CT scan should be considered but is not compulsory, depending on the clinical scenario. One must take into account physician experience, presence of multiple or of a single risk factor, clinical signs of deterioration, age below 3 months and preference of parents, to decide between CT and observation.
 
 
 
  • Children two years and older

 
Presence of: 1. GCS < 15 OR other signs of altered mental status (restlessness, somnolence, repetitivity, hyporeactivity) OR signs of basal skull fracture?
 

If yes, do CT scan. If no, go to step 2.

 
Absence of: 2. Loss of consciousness of any length of time AND episode of vomit whatever its characteristics AND of important mechanism of trauma (ejection from vehicle, death of a passenger, rollover, collision of cyclist or pedestrian without helmet, fall from over 150 cm, high speed impact of object against skull) AND severe headache ?
 

If all these are absent, CT scan is not indicated.

 
If one or more of the above four factors in #2 is present, CT scan should be considered but is not compulsory, depending on the clinical scenario. One must take into account physician experience, presence of multiple or of a single risk factor, clinical signs of deterioration and preference of parents,to decide between CT and observation.
 

Dr. Michele Alzetta We wish to thank Prof. Kuppermann for permission to publish and for revision of this brief review.

Prof Nathan Kuppermann et al. Identification of children at very low risk of clinically-important brain injuries after head trauma: a prospective cohort study The Lancet, Volume 374, Issue 9696, Pages 1160 - 1170, 3 October 2009