All posts by TheTraumaPro

Papers To Change Our Practice 2: Radiation Exposure

The second paper I’ll be discussing at the Penn Trauma reunion tomorrow deals with radiation exposure in trauma. Specifically, I’ll be talking about the amount of radiation the patient is exposed to during their initial evaluation. A lot of work is being published on this topic, but the paper I selected took a different and more accurate approach.

The trauma group at Sunnybrook in Toronto measured surface radiation exposure in a group of 172 major trauma patients. Dosimiters were placed on the neck, chest and groin, and were ideally kept there during the entire hospital stay. A software algorithm was used to calculate organ dose based on the surface measurements. This differs from the more commonly used method of counting studies and calculating dose based on published averages of radiation delivery.

The study was weakened by the number of patients that were excluded or who decided to remove their dosimeter at some point. But a number of interesting facts were revealed:

  • Patients received an average of 5 CT scans and 14 plain xrays during their stay
  • The average total effective dose was 23mSv, about 10 times the normal background exposure for an entire year
  • A surprisingly high dose was delivered to the thyroid, which is more sensitive to radiation exposure
  • A total of 190 extra cancer mortalities would be expected per 100,000 patients, given these exposure numbers
  • Radiation was underestimated using non-dosimeter techniques

Bottom line: We know radiation exposure occurs in our patients, and we know that it’s increasing. It won’t be that long until we start to see the after-effects of these imaging studies, especially in younger patients. What you can’t see does hurt your patients! We need to quickly strike a balance between avoiding missed injuries and irradiating the patient. Specific guidelines to direct ordering of radiographic studies must be developed, and our radiology colleagues need to continue to strive for techniques that adhere to the ALARA (as low as reasonably achievable) philosophy.

Related posts:

Reference: Radiation exposure from diagnostic imaging in severely injured trauma patients. J Trauma 62(1):151-156, 2007.

Papers To Change Our Practice 1: Tranexamic Acid

The first paper I’ll be presenting on Friday at the Penn Reunion deals with tranexamic acid (TXA). This drug works differently than the quick clotting agents out there. It’s an antifibrinolytic, so it actually prevents clot breakdown. It has been approved by the FDA for use in hemophiliacs undergoing dental work and for menorrhagia. Thrombotic complications have been described, so it cannot be used with prothrombin complex concentrate or recombinant activated factor VII.

The most recent and best known study on TXA is the CRASH-2 study. It was extremely well designed and included over 20,000 patients in hospitals spanning 40 countries. The study design has survived serious scrutiny. They found that TXA use in trauma patients reduced the relative risk of death by 9% (from 16% to 14.5%). The risk of death specifically from bleeding was reduced by 15%. And use of TXA in the most severely injured patients, those who would die of bleeding on the day of randomization, was reduced by 20%. CRASH-2 suggested that TXA was of most benefit when given within 3 hours of injury and in patients with a systolic pressure less than or equal to 75 torr. There were no adverse events or differences in thrombotic events, including deep venous thrombosis.

Bottom line: TXA has been shown to be effective, safe and inexpensive (about $200 for treatment using retail pricing). It is the only drug that has been shown to reduce all-cause mortality from bleeding in a high quality trial. And it only needs to be used in 67 major trauma patients before one life will be saved. It has already been adopted by some hospitals in both the US and the UK. Trauma centers should begin to think about incorporating this important drug into their initial treatment protocols now. HOWEVER: Since it is not FDA approved in the US, we may have to wait a little longer here to start using it in earnest. And think about the possibilities when EMS can start giving it in the field!

Reference: Effects of tranexamic acid on death, vascular occlusive events, and blood transfusion in trauma patients with significant haemorrhage (CRASH-2): a randomised, placebo-controlled trial. Lancet. 2010;376:23–32.

25th Reunion Of The Penn Trauma Program

I’m traveling to Philadelphia this week to celebrate the 25th anniversary of the trauma program at the University of Pennsylvania. I am one of the three founding surgeons and have been asked to speak at the academic forum portion of the program. I’ll be talking about three papers that should have changed our practice.

For the remainder of the week I’ll be writing about those three papers. They involve the use of an agent that helps control bleeding, radiation exposure in trauma imaging, and the use of technology developed outside the field of medicine to treat trauma patients.

Tune in as I work my way through those important studies. And on Friday, I’ll be tweeting any important or interesting info presented at the academic forum.

Could Be A Urethral Injury, But The Catheter’s Already In?

You’re seeing a trauma patient, probably a transfer from somewhere else. Either they told you there “may have been” some blood at the tip of the urethra, or maybe you see it smearing the outside of a urinary catheter that’s already in place! How do you proceed from here?

First, try not to get into that situation. Make sure that everyone on your team knows that gross blood at the meatus, male or female, means urethral injury until proven otherwise. If it’s not gross blood, it could be that the patient was incontinent and has hematuria from other causes. The fear with passing a catheter across a urethral injury is that it may convert a partial tear to a complete one. Reconstruction and complications from the latter are far more serious.

But the catheter is there. What to do?

First, leave the catheter in place. You must assume that the injury is present, and you need to rule it in or rule it out in order to decide what to do with the catheter. If the injury is not really there, then you can remove the catheter when indicated. If it really is present, then the urethral injury is being treated appropriately.

Next, do a urethrogram. I’ve previously described how to do it here, but the technique I describe is only appropriate for uncatheterized patients. The technique must be modified to use thin contrast and a method to inject alongside the catheter. To do this, fill a 20-30cc syringe with contrast (Ultravist or similar liquid) and put an 18 gauge IV catheter on the tip (no needles, please). Slide the IV catheter alongside the urinary catheter, clamp the meatus with your fingers, pull the penis to the side and inject under fluoroscopy. The contrast column will not be as vivid as with a regular urethrogram because it is outlining the urinary catheter, so there is less volume.

If the contrast travels the length of the urethra and enters the bladder without leaking out into soft tissue, there is no injury. If there is contrast leakage, stop injecting and plan to call a urologist.

Finally, be on the lookout for associated injuries. Urethral injuries are frequently found in patients with anterior pelvic fractures and perineal injuries.

Related post:

Link: blood at the urethral meatus (Atlas-Emerg-Medicine.org.ua from McGraw-Hill)

Thanks to JP for suggesting this topic!

The better is the enemy of the good

From the poem “The Prude Woman” by Voltaire, 1772.

This adage is particularly important in medicine. Every test and treatment we order has an upside (hopefully) that will reveal something or make our patient better. Unfortunately, we tend to ignore the inescapable downsides, which include cost and unanticipated consequences. These consequences are the discomfort, side effects, and dangers that come with any medical intervention. And in some cases, the results of an unneeded test may be in error or show some red herring that leads us on a wild goose chase of other interventions that compound the danger.

Bottom line: All trauma professionals need to think about everything they do to a patient, especially the risks they will inflict and the benefits that might accrue. Consider how it will influence your care. Will anything that is revealed change what you do? If not, you don’t need it. And your patient certainly doesn’t need the costs and hidden dangers that go along with it.