All posts by TheTraumaPro

Technology: Airbags For Motorcyclists?

A manufacturer of high-end protective gear for motorcycle and auto racing has developed a fully self-contained airbag system that can be worn. The airbag is easily zippered and connected into a compatible outer jacket, made only by Alpinestars (of course). The airbags expand in much the way that auto airbags do, and they offer protection to the back, shoulders, kidneys, chest, and upper abdomen. A set of colored LEDs on the left sleeve show the rider the status of the system at all times.

A built-in microprocessor samples a set of accelerometers 500 times per second. If any linear or rotational force occurs that is outside of allowed parameters, the airbags inflate well before any impact to the torso occurs. The system is powered by a rechargeable battery that allows for about 25 hours of riding time between charges.

Will this be adopted by the general riding public? Probably not in the near future. The airbag system costs over US $2000, and requires service every two years (US $225). And if it deployed? Another US $550 to repack it. But it’s just a matter of time before similar protective devices worn under a riding jacket make their way to the market at an affordable price.

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REBOA: All It’s Cracked Up To Be?

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is all the rage. Trauma professionals attending meetings and update courses can count on an update on this interesting technology. But what is it, exactly, and does it work?

REBOA has been around in one form or another for 60 years! In theory, there are five steps for using this technique. 

  1. Access a femoral artery using Seldinger technique
  2. Insert a balloon catheter and move it into position proximal  to the suspected aortic injury
  3. Inflate the balloon to decrease blood loss at the site of injury
  4. Once the injury has been addressed in the OR, slowly deflate the balloon
  5. Then remove it

It’s basically a way of cross-clamping the aorta within the abdomen noninvasively before the patient is opened in the OR. Here’s a diagram that shows what this looks like. Simple, right?

The authors of a recent paper performed an epidemiologic study analyzing data from the Japan Trauma Data Bank over an 8 year period. They performed some sophisticated analyses to try to reduce the usual issues that occur when perusing typical trauma data bank data.

Here are the factoids:

  • Over 45,000 patient records were reviewed, and 452 were included in the study. This is a very large number, as relatively few centers use this technique.
  • The REBOA patients were very badly injured, with a median ISS of 35 and an overall high mortality (76%)
  • The non-REBOA matched patients were less severely injured, with a median ISS of 13 and a 16% mortality
  • When matched for probability of survival using TRISS methodology, the REBOA patients had a significantly higher mortality

Bottom line: What does this mean? Basically, that there is an association with higher mortality given similar injury severity and physiologic compromise, in Japan. The study is another piece in the jigsaw puzzle, and not a good one. Sure, things may be done differently in other countries. And the use of REBOA as a “last ditch effort” certainly may result in higher mortality. But it may not be all it’s cracked up to be. Any use of this technique should be critically evaluated, preferably as part of a well designed study. It’s not for the unprepared or faint of heart.

Reference: Survival of severe blunt trauma patients treated with resuscitative endovascular balloon occlusion of the aorta compared with propensity score-adjusted untreated patients. J Trauma 78(4):721-728, 2015.

EAST Guidelines: Blunt Traumatic Aortic Injury

The Eastern Association for the Surgery of Trauma (EAST) has been helping trauma professionals through the publication of practice guidelines for more than 15 years. Members of EAST donate their time to review reams of literature, good and bad, to try to determine the answers to common or puzzling clinical questions.

Why follow a practice guideline? Quite simply, if properly developed, a guideline represents our best understanding of the “correct” answer to the question posed. And as many of you who follow this blog already know, things that “seem to make sense” frequently are totally wrong. Your own experience is poignant, but the pooled experience of the many others who contributed to research on the topic in question is much more significant.

So on the the practice guideline for blunt traumatic aortic injury (BTAI). This one answers three questions. I will list each, followed by the conclusions reached through the literature review.

1. In patients with suspected BTAI, which diagnostic modality should be chosen: CT angiography of the chest, or conventional catheter angiography?

  – Catheter angiography was the standard for decades. When the first EAST guideline on this topic was released 15 years ago, CT angiography was only a level III recommendation because experience with it was lacking. CT technology has advanced rapidly, with multiple detectors, helical scanning, and incredible computing power. Although the quality of the evidence is somewhat low, the panel strongly recommends the use of CT angiography due to its ready availability, speed, low invasiveness, and ability to detect and define other injuries.

2. Should endovascular or open repair be selected in order to minimize stroke, renal failure, paraplegia, and death?

  – Once again, the quality of available data is so so. However, it was possible to detect differences in outcome in comparative studies. The panel strongly recommends the use of endovascular repair in patients who do not have contraindications due to its lower blood loss, mortality, and paraplegia, and equivalent risk of stroke. Furthermore, it is performed more frequently now than open repair, and experience is thus greater at many institutions, further reducing complications.

3. Should the repair be performed immediately or delayed in order to minimize stroke, renal failure, paraplegia, and death?

  – Literature review revealed that the incidence of renal failure and paraplegia were lower with delayed repair, while renal failure was the same in patients with significant associated injuries. There was benefit to delaying repair until resuscitation was achieved and any other life threatening injuries were addressed. The panel recommends that delayed repair be carried out once these other conditions have been corrected. The procedure should not be delayed until the next morning for the convenience of the surgeons.

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Reference: Evaluation and management of blunt traumatic aortic injury: a practice guideline from the Eastern Association for the Surgery of Trauma. 78(1):136-146, 2015.

SCIP: Importance Of Prophylactic Antibiotics In Trauma Laparotomy

Quite a lot of research has been done on the efficacy of prophylactic antibiotics in the prevention of infectious complications after surgical procedures. Antibiotics are now routinely given prior to most elective surgical procedures. In the US, the Centers for Medicare and Medicaid Services has formalized this into part of the Surgical Care Improvement Project (SCIP), which mandates the use of an appropriate antibiotic within 1 hour preop and stopping it within 24 hours postop.

But what about emergent cases, like trauma laparotomy? Ensuring timely antibiotic administration is difficult due to the rapid events leading up to the operation. And sometimes it is not clear whether a hollow viscus injury has occurred until after start of operation, so the antibiotic choice may change in the middle of the case.

Two busy urban trauma centers with high penetrating injury rates looked at one year of experience in patients undergoing trauma laparotomy. They compared surgical site infections (SSI) in patients who received SCIP-compliant antibiotic administration vs those who did not.

Here are the factoids:

  • Patient mix was 30% blunt, 44% gunshot, 27% stab wounds
  • There were 151 SCIP-compliant patients and 155 noncompliant ones
  • Half of the noncompliant group did not receive the appropriate antibiotic (usually Cefazolin in hollow viscus injury), and half had antibiotics given for more than 24 hours
  • SCIP-compliant patients had significantly fewer wound infections and shorter length of stay. Mortality was the same.

Bottom line: I recommend adhering to SCIP prophylactic antibiotic guidelines for trauma laparotomy. There is no reason why this subset of patients should be treated any differently, and this study presents evidence that it is beneficial. Using the SCIP guidelines in emergent surgery reinforces the usual preop routine in hospitals that have already embraced them. In general, blunt trauma patients undergoing laparotomy should receive prophylaxis that covers skin organisms. Since penetrating trauma has a much higher chance of involving the intestinal tract, broader spectrum antibiotics should be selected. In either case, use the antibiotic that has been selected for this purpose by your hospital. And be sure they are stopped during the first 24 hours.

Reference: “SCIP"ping antibiotic prophylaxis guidelines in trauma: the consequences of noncompliance. J Trauma 73(2):452-456, 2012.

What Happens When A New Trauma Center Opens In Your Back Yard?

For trauma centers, it’s a zero sum game. The number of trauma patients in a given geographic location is fixed. (Actually, it goes up slowly over time as the population increases). So if a new center opens, those patients are redistributed. The new center gets more patients because they are now “designated.” And the existing centers get fewer because there are not as many patients left.

This is a phenomenon that is growing more widespread as more lower level trauma centers come online. Areas like Phoenix, Denver, and parts of Florida are particularly hard hit. Established Level I and II centers are complaining because their volumes are down, which can cause a hit to the financial bottom line.

Seems to make sense. But is it true? A time series analysis was carried out using Pennsylvania trauma system data to gauge the impact of opening new Level II and III centers on an existing Level I center. Ten years of data were gathered, looking at volume and mortality changes during the following sequence of designations:

  • A new Level II opens 70 months into the study period
  • A new Level III opens at 95 months, then closed 11 months later
  • A new Level II and Level III open at 107 months

Here are the factoids, from the perspective of the Level I center:

  • Volume at the Level I center grew slowly over the 70 months that no new trauma centers were operating
  • Volume dropped 10% when the first Level II opened, and 13% when the Level II and III opened simultaneously
  • There was no change when the temporarily accredited Level III opened
  • Overall, the Level I center treated 1,903 fewer patients than expected after the other centers opened, an overall decrease of 10% 
  • Average injury severity and revised trauma score remained the same at the Level I, but mortality decreased (!)

Bottom line: More trauma centers generally equals fewer patients for existing ones. Unfortunately, the decision to become a trauma center these days, especially levels II and III, tends to be based on business factors. The American College of Surgeons Committee on Trauma (ACSCOT) released a position statement early this year regarding the designation of multiple trauma centers in a geographic location. They basically have left it up to the individual states or trauma systems to optimize placement or limit numbers. They also emphasize that the numbers need to support best patient care, not necessarily best business strategy. Unfortunately, politics will not let this happen. I believe that the tightening of verification requirements for centers that are verified by the ACSCOT (as in the new Orange book criteria) will serve to shake out the centers that barely meet them. But only time will tell.