All posts by TheTraumaPro

CT Angiography Of The Head In TBI?

Trauma professionals rely heavily on diagnostic tests these days, particularly CT after blunt trauma. Apparently, the neurosurgeons at the Massachusetts General Hospital are asking for CT angiography of the brain on occasion in patients with TBI. Ostensibly, this is to rule out cases when a brain aneurysm causes a car crash or other blunt trauma.

WTF? Now, I know that we occasionally agonize over older victims of blunt trauma who come in pre-terminal or in arrest. Did they have an MI which caused the event, or did the trauma stop their heart? I had no idea that a ruptured/rupturing aneurysm was such a problem in blunt trauma.

So the surgeons at the MGH decided to critically look at this issue to see if the extra head scan was warranted. 

Here are the factoids:

  • 600 patients with blunt TBI over a one year study period were reviewed
  • 22% underwent CT angio in addition to the normal head CT
  • 66% had the CT angio immediately, 27% within 24 hours, and 7% beyond 24 hours after arrival
  • Specialists who requested the study were neurosurgeons (23), radiologists (15!), neurologists (7!!)
  • Reasons for getting the study: look for cause of subarachnoid hemorrhage (aneurysm) in 43, look for vascular injuries near a skull fracture in 14, rule out stroke in 4, and no particular reason in 71
  • Head CTA changed management in only 1 patient, prompting a formal angiogram which was negative
  • 33 patients (25%) had incidental findings on CTA, but none required any intervention in the hospital or on later followup

Bottom line: There is no value to adding CT angio of the head to the usual scan protocols. Having said that, if the patient was witnessed to lose consciousness prior to the event, and the CT shows subarachnoid hemorrhage in a more typical middle cerebral artery distribution, you might consider it to look for an aneurysm. That’s a lot of if’s. Just move the zebra off the CT scanner first. And as you can see from the last factoid above, if we scan it, we will find stuff. Fortunately, most of that stuff doesn’t need further workup or treatment.

Related posts:

Reference: Is CT angiography of the head useful in management of traumatic brain injury? J Am Col Surg 220(6):1027-1031, 2015.

Hypertension After Pediatric Renal Trauma

Renal injuries are not very common, and the number of pediatric kidney injuries is even smaller. One potential complication after this injury is hypertension. As usual, there are many theories as to why this occurs. There are undoubtedly areas of the injured kidney that are under-perfused. The most popular theory is that this results in release of renin, upregulating the renin-angiotensin system. 

But how much do we need to worry about this problem? Retrospective adult studies put the incidence at about 5%, and the onset generally occurs 2 to 8 weeks after injury. 

And what about children? Are they just small adults when it comes to this problem? Primary Children’s Hospital in Salt Lake City designed a retrospective study to try to answer this question. They examined 11 years of their own registry data on children, defined as <18 years old. They focused on high grade injuries (grade III-V), as these should have the highest incidence of complications.

Here are the factoids:

  • Hypertension was defined as elevated BP anytime after admission that required control with medication, but only after pain was controlled
  • 62 children sustained high grade injury, with an average age of 10
  • Most were grade III (21) and grade IV (40)
  • Four (6.5%) developed hypertension while hospitalized
  • Only two requiring ongoing medication months after discharge
  • None of the non-hypertensive children became hypertensive later

Bottom line: Obviously, these numbers are small. The fact that it took over 10 years

at a pediatric hospital to accumulate this data demonstrates the difficulty in getting good, actionable information. It looks like that the incidence is similar to adults (about 5%). It does seem that some patients recover and don’t need long-term medication. I recommend that everyone (adult and child) with a significant renal injury (grade 3+) be monitored for hypertension while in the hospital, and for 2-3 months after discharge by their primary practitioner.

Related posts:

Reference: The incidence of long-term hypertension in children after high-grade renal trauma. J Ped Surg, in press June 2015.

Sample TXA Policy

Many trauma centers insist on reinventing the wheel when it comes to policies and protocols. That’s why I like to share here. It’s so much easier to “borrow” from another center, tweak it until it works for yours, and save lots of time and effort.

Today, I’m sharing our adult “Adult Tranexamic Acid (TXA) in Trauma Patients” policy. The main points are:

  • Indications – adult trauma patient with enough blood loss to require transfusion or activation of the massive transfusion protocol
  • Timing Only give if the injury was known to occur within 3 hours, not within 3 hours of arrival in your center
  • Dosing – a simple loading dose of 1 gram in 50cc saline give slow push, followed by another gram infused over 8 hours
  • Exclusion criteria – Although many are listed, the trauma team will only be able to find out about a few: use of anticoagulants, previous dosing of prothrombin complex concentrate (PCC) or Factor VIIa, and possibly the presence of subarachnoid hemorrhage if a CT has been obtained. If the infusion has already started when one of these criteria is identified, stop the infusion.

Suggestion: To keep your trauma professionals from forgetting this adjunct to resuscitation, consider putting a sign on your massive transfusion protocol coolers that says “Do You Need TXA?” And keep it in the med dispenser near/in your resuscitation rooms so you can get it quickly!

Download the policy here (pdf)

Related posts:

More On The Value Of Motorcycle Helmets

Most trauma professionals recognize the value of motorcycle helmets. I’ve written many articles here on the topic (see below). There is high quality evidence that helmets decrease severity of injury in motorcycle crashes (fewer severe brain injuries, higher survival, etc). And we also know from other studies that riders are not protecting their brain at the expense of their spine and torso.

In the 1970s, 47 of US states had enacted universal helmet laws. It wasn’t long after that the federal government lost its authority to penalize noncompliance. So you know what happened. Special interest groups began to weaken and/or repeal these laws, one by one. Now, although some form of helmet law still exists in 47 states, they apply universally to riders in only 19. In the other 26, only young riders, inexperienced ones, or those with insufficient insurance must wear helmets. But how would law enforcement know that when they see the average motorcyclist whizzing by? Which means that the number of riders wearing them has decreased markedly.

The hard part of doing studies to look at the impact of helmets vs no helmets is placing a specific value on a life. A group at the Medical College of Wisconsin in Milwaukee designed a study to use a specific statistical method to attack this problem. They looked at the the value that one places on a marginal change in their likelihood of death. Another way to look at it is the cost of reducing the average number of deaths by one. This is the Value of Statistical Life analysis.

Here are the factoids:

  • Cost and population information was obtained from a number of federal databases
  • Injury information was obtained from the National Trauma Databank
  • 3951 motorcycle fatalities occurred during the one year study period
  • 77% died at the scene, 10% in the ED, and 13% as inpatients
  • 37% of riders did not wear helmets, but accounted for 69% of deaths
  • Helmet use increased survival in a crash by 50%
  • Costs for hospitalization and rehab (for survivors, obviously) were $5.5 billion for nonsurvivors vs $3.3 billion for survivors
  • The extra cost per fatality was about $800K
  • Therefore, (re)implementing universal helmet laws stands to save $2.2 billion per year

Bottom line: Enough numbers here to make your head spin. The $2.2 billion savings, along with a value of statistical life of $2.4 billion equals $4.6 billion in calculated gains. Obviously, the science appears more exact than it really is, but the numbers are large enough to confidently state that lots of money can be saved by simply wearing helmets. The hardest part of this is the human factor. Without legislation, people won’t wear helmets. And there are enough people that haven’t had to wear them, that they will lobby to keep it that way. Catch-22. The solution: prevention, although this will most likely be after the fact, when the patient is already injured and in the hospital. Do your part!

Reference: National mandatory motorcycle helmet laws may save 2.2 billion annually: an inpatient and value of statistical life analysis. J Trauma 78(6):1182-1186, 2015.