A blow to the head can cause a collection of blood between the scalp and the skull, or between the skull and the brain. These two broad types of hematomas do not necessarily correlate with one another, and it’s relatively common to have one without the other. A hematoma in the scalp is not dangerous; hematomas between the brain and the skull are potentially dangerous and can be lethal. The brain can also have bleeding within the brain tissue itself, and these sorts of brain contusions can also occur without much external evidence of injury.
Some types of skull fractures are more likely to be associated with internal injury than others, and some of them have some external manifestations. A Battle sign is bruising behind the ear; raccoon eyes result from blood coloring the soft tissue around the eyes; hemotympanum (blood behind the eardrum) can be found with an otoscope. Clear stuff dripping out your nose that isn’t snot is not good either (it might be cerebrospinal fluid leaking through a cracked noggin).
In modern times we use CAT scans to look inside the head when the suspicion is high enough; this can be based on the mechanism of injury alone, the physical findings on exam, or the sensorium of the patient.
If a toddler does not appear completely normal (or perhaps if we can’t trust the guardian to follow them carefully and the mechanism of injury was potentially serious) we are likely to scan them. If they have a completely normal sensorium and only a minor scalp hematoma over a non worrisome part of the skull, it’s fine to use clinical judgment.
As to the cushioning effect of carpet: it does help. A sharp blow on concrete is different from carpeted wood stairs. But there’s no rule of thumb and the brain can be seriously injured just from being shaken around with various types of decelerations even in the absence of a blow sharp enough to fracture a skull. Skull fractures per se are no big deal as long as the bone isn’t depressed very far into the cranial cavity, and you can have serious injury without a skull fracture. The concern is always whether or not there is bleeding inside the skull or direct injury to the brain itself.
My hospital’s criteria for CT head in infants/toddlers is one or more of the following:
Loss of consiousness
Scalp laceration >5cm or haematoma over more than one suture line in the skull.
Fall from more than twice the height of the child
High impact head injury
Vomiting post head injury
Seizure post head injury
Drowsiness
Suspicious history or late presentation
Neurological deficit
If the baby is laughing at me, cooing and gurgling and letting me examine it, I’m not so worried. If baby doesn’t need a scan I let the parents go home and tell them to bring the kid back if they are concerned- on the basis that they’ll observe the child more closely than ER staff will.
Ya, it’s popular in medicine to get papers published by creating various algorithms or criteria for whether or not to do a particular study under what particular circumstances. (According to this paper http://www.bmj.com/cgi/content/full/333/7566/455 , 108 studies with guidelines for imaging kids as of 1999 ) You got yer Canadian criteria; yer New Orleans criteria…in the end what you need is good judgment shaped by by the papers, and not absolute criteria, since nothing is ever absolutely straightforward. One kids gets upset and urps from crying; another has protracted projectile vomiting. Both are vomiting, but both are not vomiting.
Wanna CT the urchin and meet the criteria? Just find something to make the history “suspicious.”
Me, I’m mostly about trying not to expose infants to massive amounts of radiation if at all possible
But yep, you can interpret the spit-up after that bottle as vomit and get a CT if you want.
The injury I mostly see is babies of about 12-18 months falling backwards out of high chairs. They either wriggle through the harness, or they so violently object to the food being offered that they fling themselves away from it and overturn the chair. The parents are usually in worse shape than the kids- they are almost universally white, shaky and look about ready to faint or vomit…the kids are generally fine with a happy grin and a small bruise.
I was also dropped on my head as a baby. According to my mother, the stroller she had bought for me was very poorly balanced and prone to tipping over backwards. One day, she turned away for a moment, the stroller flipped backwards, and WHACK went my head on the concrete.
