Tag Archives: AAST2016

Procedures

Efficacy Of Preperitoneal Packing For Pelvic Fractures

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A multi-center trial published in 2015 showed an astounding 32% mortality rate for patients with shock from pelvic fracture. And as I continue to preach, going any place but the OR is dangerous for the patient. Unfortunately, it’s generally not feasible to operatively fix the pelvis acutely, and external fixation has limited impact on ongoing hemorrhage.

If the patient can be stabilized to some degree, interventional radiology can be very helpful. Unfortunately, access after hours involves some degree of time delay. Ideally, the team arrives in 30 minutes or less. But the patient may not be ready, so time to procedure may increase significantly.

So preperitoneal packing of the pelvis (PPP) has now become popular. Years ago, we tried to pack the pelvis from the inside (peritoneal cavity), but it never worked very well. You can push sponges deep into the pelvis as firmly as you want, but the intestines will not keep them from expanding back out of the pelvis.

PPP entails making a lower midline incision, but not entering the peritoneal cavity. A hand is then slid along the anterior surface of the peritoneum around the inside of the iliac wing. Sponges can then be pushed around toward the sacrum, applying direct pressure over bleeding fracture sites and the overlying tissues.

preperitoneal-packing

Image courtesy of ACSSurgery.com

But does it work? Denver Health performed an 11 year retrospective review of their experience with 2293 patients with pelvic fractures. They looked at time to intervention, blood product usage, and mortality.

Here are the factoids:

  • A total of 128 patients underwent PPP
  • Most were younger (mean age 43) and badly injured (mean ISS 48)
  • Median time from door to OR was 44 minutes
  • Patients received an average of 8 units of RBCs intraop, and an additional 3 units in the ensuing 24 hours
  • Overall mortality was 21% (27 of 128), but 9 (7%) were due to severe head injury

Bottom line: Compared to other published studies, time to “definitive management” with PPP was very short. Blood usage also dropped quickly after the procedure. Mortality seems to be much better than expected at about 13%. These results suggest that if you have to wait for angio, or your patient is too unstable to go there, run to the OR first to do some PPP.

And don’t forget these other important management tips:

  • If you see any posterior pelvic fracture on the initial pelvic x-ray, call for blood
  • If the blood pressure softens at any point activate your massive transfusion protocol
  • Apply a binder, especially for open book type fractures
  • Always get a CT in stable patients to help your orthopedic surgeons plan, and to identify contrast blushes
  • If the patient has to go to OR first to stabilize them, consider angio afterwards. You’ll probably find something they can fix.
  • Think about using your hybrid OR!

Reference: Preperitoneal pelvic packing reduces mortality in patients with life-threatening hemorrhage due to unstable pelvic fractures. AAST 2016, Paper 32.

Education

Are Graduating General Surgery Residents Qualified To Take Trauma Call?

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Trauma training during general surgery residency has changed dramatically over the past two decades. Although we like to blame the 80-hour work week rule on everything, there are other factors that may be at play. Increasing use of nonoperative management, availability and increasing scope of interventional radiologists, and the increasing number of surgical subspecialists are certainly significant.

The surgical group at LAC+USC looked at changes in operative caseloads, type of surgery performed, and the impact that concurrent subspecialty training has had on trauma operative volumes. The authors reviewed 16 years of ACGME data on resident surgical procedures in various body regions by year of training. They specifically looked at the impact of implementation of the 80-hour work week.

Here are the factoids:

  • There was a trend only (p=0.07) toward decreased operative trauma cases
  • The number of trauma laparotomies increased, vascular procedures decreased, and neck explorations and thoracotomies remained stable
  • Trauma vascular procedures decreased for surgical residents, but increased for vascular fellows
  • Individual resident operative volumes in chest, abdomen, solid organ, and extremities decreased after implementation of the 80-hour work week
  • Based on this, the authors recommend residents who are interested in a career in trauma and acute care surgery have fellowship training (??)

AAST2016-Paper29

Bottom line: Well, it was a catchy title, at least. Or is it a promotion for trauma fellowships? I hope the authors have some really good statistics to help this paper out. You may not be able to read the table above well, but the differences between pre-80 hour and post-80 hour are not that impressive, and the SD or SEM (can’t tell what they are) are uncommonly narrow, which amplifies the p values. And other than the number of laparotomies going up, the other numbers looked fairly constant. I look forward to the presentation and critique of this paper at the meeting. Not sure it will escape unscathed.

Reference: Is your graduating general surgery resident qualified to take trauma call? A 15-year appraisal of the changes in general surgery education for trauma. AAST 2016, Paper 39.

Trauma Systems

How Many Trauma Centers Should There Be?

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Trauma centers seem to be popping up all over the US. Many metropolitan area have literally scores of centers at various levels. And yet there are swaths across this country where you won’t find a single Level I, and only a few Level IIs. In most states, there is little guidance from the designating authority regarding whether a new trauma center is feasible or even needed. The American College of Surgeons (ACS) has given little guidance over the years, except for a white paper in 2015 that essentially said that it is up to the designating authorities to determine this.

Last August, the ACS organized a consensus conference to try to develop an objective method for figuring out when enough is enough. There was unanimous support for developing a tool that would encourage designation to meet the needs of the trauma patient, not the financial needs of a hospital or hospital system. This Needs-Based Assessment of Trauma Systems (NBATS) tool looks at 6 factors, some of which take a little calculation to complete. A point score is arrived at that predicts the additional number of trauma centers that may be needed. Currently, this tool is in draft form and is in the process of being optimized.

Click here to download the draft document.

So far, this has been a theoretical exercise. But a group at Stanford decided to test the tool on the entire state of California. They used a variety of data sources to compile the needed numbers, and did some complicated spatial analyses of transport times to accurately calculate NBATS scores.

Here are the factoids:

  • 74 trauma centers were identified in the state – 15 Level I, 37 Level II, 14 Level III, and 8 Level IV
  • The state was broken down into 30 Local Emergency Medical Service Agency trauma service regions
  • Only 4 of the 30 regions had scores suggestion that they had enough trauma centers
  • The tool suggested that 9 regions needed 1 more trauma center, 13 would require 2 more, and 4 would require 3 more
  • The model also suggested that 3 regions already had more than needed

Bottom line: There is already literature showing that adding additional (too many?) trauma centers to a region can have a negative impact on patient volumes and resource availability at Level I and II centers. This tool may allow state trauma systems to more objectively determine exactly where more centers are justified, enabling them to rise above the usual political battles (maybe). Unfortunately, the tool does not take available surgical resources in the region (trauma surgeons, neurosurgeons,  orthopedic surgeons) into account, or provide guidance on which levels of new centers should be developed. But it’s a good start to help solve a sticky problem.

Reference: ACS needs based assessment of trauma systems (NBATS) tool: California example. AAST 2016, Paper #24.

Prehospital

Validation Of The Air Medical Prehospital Triage Score (AMPT)

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Unneeded use of helicopter emergency medical services (HEMS) air transport is a problem around the world. This scarce and valuable resource tends to be over-utilized, resulting in unnecessary costs to patients and the health care system in general. Unfortunately, good and objective criteria for HEMS transport have been hard to come by.

A group at the University of Pittsburgh published a study earlier this year, developing an objective scoring system based on a huge dataset from the National Trauma Databank. They used a portion of the data to develop a model, and the remainder to test it. They developed the AMPT, which identified patients that showed a survival benefit with helicopter transport:

AAST2016-Oral23

For this AAST abstract,  they sought to validate the scoring system using an entirely different database, the Pennsylvania Trauma Systems Foundation registry. They used 14 years of data, and reviewed nearly a quarter million records. Once again, the authors were looking at in-hospital survival.

Here are the factoids:

  • 20% of patients were transported by air
  • But only 11% were predicted to benefit by using AMPT
  • For patients with an AMPT score < 2, transport by air did not increase survival
  • For patients who had an AMPT score >2 and were actually transported by air, survival was improved by 31% (!)

Bottom line: It looks like the AMPT score is a good predictor of improved survival for patients transported by air. But wait, it’s not that cut and dried. These statistics are based on populations; they cannot predict exactly which individual patient will benefit. What about those patients who actually died? Perhaps if they had gotten to the hospital a little faster, they would have done better? This is certainly a nice new tool to use in the decision-making process, but it can’t be the only one. 

References:

  • The air medical prehospital triage score: external validation supports ability to identify injured patients that would benefit from helicopter transport. AAST 2016, Paper #23.
  • Development and validation of the air medical prehospital triage score for helicopter transport of trauma patients. Ann Surg 264(2):378-385, 2016.
Anatomy

The Cardiac Box: Meaningful For Gunshot Wounds?

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A common dogma in trauma training is: “Watch out for the box!” This area on the anterior chest is purported to indicate high risk of cardiac injury in patients with penetrating trauma.

Where is it, exactly? Technically, it’s the zone extending from nipple to nipple, and from sternal notch to xiphoid.

The cardiac box

But is the dogma true? A number of (old) papers mapped out the location and incidence of cardiac injury in stabs to the chest and upper abdomen. And there is a pretty good correlation. For stab wounds. But what about gunshots?

A team at Emory University ran a retrospective review of their trauma registry data over a three year period.

Here are the factoids:

  • They saw nearly 90 patients per year with penetrating chest wounds. Of these, 80% were gunshots (!) Many had more than one penetration.
  •  Of the 233 gunshots inside “the box”, 34% injured the heart
  • The remaining 44 gunshots outside “the box” hit the heart 32% of the time
  • The authors suggest shifting the definition of “the box” toward the left, so that it extends from anterior midline, wraps around the left chest, and ends in the posterior midline (see below)

new-cardiac-box

Bottom line: Here’s the problem. Knives are attached to a handle which tends to stay outside your patient. Thus, it can only go so deep. But a bullet will keep going until something stops it, or it runs out of gas. So it makes sense that the traditional boundaries of “the box” don’t apply. But extending it to include the left lateral chest and exclude everything on the right side? It may make statistical sense in this study, but common sense dictates that the trauma professional needs to think about the heart any time a gunshot goes anywhere near the chest or upper abdomen. Do not limit yourself to any “box!”

Reference: Redefining the cardiac box: evaluation of the relationship between thoracic gunshot wounds and cardiac injury. AAST 2016 Paper #12.