Some lessons learned about whether you’re really as smart as you think. This 20 minute presentation by me was the keynote at last year’s Trauma Education: The Next Generation conference in St. Paul.
This year’s conference still has spots available for the live presentation. You can stream it free via LiveStream. If you would like to receive continuing education credits, register for the live or streamed performance so we can get your credits to you. Click here to register.
Diagnostic imaging is a mainstay in diagnosing injuries in major trauma patients. But the big questions are, how much is enough and how much is too much? X-radiation is invisible but not inocuous. Trauma professionals tend to pay little attention to radiation that they can’t see in order to diagnose things they can’t otherwise see. And which may not even be there.
There are two major camps working in emergency departments: scan selectively and scan everything. It all boils down to a balance between irradiating enough to be satisfied that nothing has been missed, and irradiating too much and causing harm later.
A very enlightening study was published last year from the group at the University of New South Wales. They prospectively looked at their experience while moving from selective scanning to pan-scanning.They studied over 600 patients in each cohort, looking at radiation exposure, missed injuries, and patient injury and discharge disposition variables.
Here are the interesting findings:
Absolute risk of receiving a higher radiation dose increased from 12% to 20%. This translates to 1 extra person of every 13 evaluated receiving a higher dose.
The incidence of receiving >20 mSv radiation dose nearly doubled after pan-scanning. This is the threshold at which we believe that cancer risk changes from low (<1:1000) to moderate (>1:1000).
The risk of receiving >20 mSv was lower in less severely injured patients (sigh of relief)
There were 6 missed injuries with selective scanning and 4 with pan-scanning (not significant). All were relatively minor.
Bottom line: Granted, the study groups are relatively small, and the science behind radiation risk is not very exact. But this study is very provocative because it shows that radiation dose increases significantly when pan-scan is used, but there was no benefit in terms of decreased missed injury. If we look at the likelihood of being helped vs harmed, patients are 26 times more likely to be harmed in the long term as they are to be helped in the short term. The defensive medicine naysayers will always argue about “that one catastrophic case” that will be missed, but I’m concerned that we’re creating some problems for our patients in the distant future that we are not worrying enough about right now.
Autotransfusing blood that has been shed from the chest tube is an easy way to resuscitate trauma patients with significant hemorrhage from the chest. Plus, it’s usually not contaminated from bowel injury and it doesn’t need any fancy equipment to prepare it for infusion.
It looks like fresh whole blood in the collection system. But is it? A prospective study of 22 patients was carried out to answer this question. A blood sample from the collection system of trauma patients with more than 50 cc of blood loss in 4 hours was analyzed for hematology, electrolyte and coagulation profiles.
The authors found that:
The hemoglobin and hematocrit from the chest tube were lower than venous blood (Hgb by about 2 grams, Hct by 7.5%)
Platelet count was very low in chest tube blood
Potassium was higher (4.9 mmol/L), but not dangerously so
INR, PTT, TT, Factor V and fibrinogen were unmeasurable
Bottom line: Although shed blood from the chest looks like whole blood, it’s missing key coagulation factors and will not clot. Reinfusing it will boost oxygen carrying capacity, but it won’t help with clotting. You may use it as part of your massive transfusion protocol, but don’t forget to give plasma and platelets according to protocol. This also explains why you don’t need to add an anticoagulant to the autotransfusion unit prior to collecting or giving the shed blood!
The Trauma Professional's Blog provides information on injury-related topics to trauma professionals. It is written by Michael McGonigal MD, the Director of Trauma Services at Regions Hospital in St. Paul, MN. Regions is a Level I Adult Trauma Center, and has partnered with Gillette Children's Specialty Hospital to become the first Level I Pediatric Trauma Center in the Upper Midwest.