Hello Thanks for the query If trauma is associated with loss of consciousness that is uncertain or very brief( few seconds only), irritability( now resolved), behavioral changes if any, scalp hematoma( particularly nonfrontal), the risk of clinically important traumatic brain injury is approximately 1 percent for a child with at least one of these criteria. Multiple or worsening symptoms or signs likely put the child at greater risk than an isolated finding. If immediate CT is deferred for these patients, we suggest observation for four to six hours to ensure no progression of clinical findings that warrant CT. If there is vomiting even after several hours after trauma it is significant, consult your doctor if you notice any of symptoms mentioned above. I hope this answers your query well Wish you and your family good health With regard