All posts by TheTraumaPro

The Ultimate 3D Bioprinter?

3D printing is becoming a big deal when it comes to replacement parts for people. Substantial advances have been made over the past 5 years, and a new printer under development from a company called Aether looks more advanced than most others in the field.

Most printers have a relatively limited number of biomaterials (”inks”) that they can print at one time, and many of the actual materials are proprietary. They tend to be very expensive, sometimes $200,000 or more.

Aether has developed what I would call a great “pilot” printer to demonstrate that this can be done better and more cheaply. The printer in the 8 minute video is printing two pieces of bone connected with a tendon. In this case, the printer uses 6 “inks” including graphene for bones and stem cells to seed them as well as the tendon. The printer can actually print a mix of organic and organic “inks” with up to 10 syringes (”cartridges”). And in this case, it actually embeds two transistors and wires in the product. Printing bionic parts? And the final cost of this printer is projected to be under $10,000.

A number of other companies are out there competing in this market. They are providing tissue samples and skin for drug testing and research. So expect technology to advance and prices to fall as these printers become more sophisticated and more clinically useful.

Website: http://www.aether1.com/

I have no financial interest in Aether.

Platelet Count After Spleen Injury

In most trauma textbooks, the most commonly injured solid organ is the spleen. There is a lot of work available that tells trauma professionals how to detect and manage spleen injuries. However, the treatment of the sequelae is less clear cut. We know that the platelet count generally rises after spleen injury, and especially if it is removed. We think we know that we should be on alert if the platelet count goes over 1 M per microliter (ul) to avoid thrombisis.

What happens during the usual hospital course? Is venous thrombosis actually a problem? A group at St. Michael’s Hospital in Toronto performed a 5 year retrospective review of their patients with splenic injury to try to answer these questions. Children and patients with known pre-existing coagulopathy or that were taking anticoagulants were excluded. All were managed with prophylactic low molecular heparin, although the specific product or protocol were not described.

Here are the factoids:

  • A total of 156 patients were enrolled over 5 years. – This is a relatively low number (31/year). In contrast, here in bustling metropolitan St. Paul we see 80-100 per year.
  • Nonoperative management was performed in 84% of cases, with angio-embolization added in another 8%. The other 8% were taken to OR, where most underwent splenectomy. – This is spot on with national data. However, looking at their injury grade breakdown, it seems like they take out a higher than usual number of low grade spleens.
  • Platelet count rose steadily after admission, peaking at day 16-17.
  • Splenectomy patients had a mean peak platelet count of 890K/ul.
  • Nonop management patients had a mean peak of 604K/ul.
  • Extreme thrombocytosis (counts > 1M/ul) occurred in 25 patients (16%). It occurred in 41% of splenectomy patients, but only 6% of nonop patients.
  • Although DVT and PE occurred in these patients (8%, which seems a bit high), there was no association with thrombocytosis, extreme thrombocytosis, or aspirin use. – This is most likely due to the small size of the study. 

Bottom line: This small study provides some interesting and important information regarding the platelet count trend after splenic injury. Although there was not enough power to look at the association with DVT, PE, and the value of aspirin treatment for extreme thrombocytosis, the platelet count trend info was very interesting. It looks like we should be checking a platelet count about 2-3 weeks after injury to make sure it’s not reaching extreme levels. This can be scheduled during their postop or post-discharge visit. A reminder should also be sent to the primary care physician to be on the lookout for extreme thrombocytosis for the first three weeks post-injury.

Reference: Thrombocytosis in splenic trauma: In-hospital course and association with venous thromboembolism. Injury, in press, 2016.

Why People Don’t Change Their Minds Despite The Data

Has this happened to you?

Your (emergency physician / neurosurgeon / orthopaedic surgeon) colleague wants to (get rib detail xrays / administer steroids / wait a few days before doing a femur ORIF). You question it based on your interpretation of the literature. You even provide a stack of papers to them to prove your point. Do they buy it? Even in the presence of randomized, double-blinded, placebo-controlled studies with thousands of patients (good luck finding those)?

The answer is generally NO! Why not? It’s science. It’s objective data. WTF?

Sociologists and psychologists have shown that there is a concept that they call the Backfire Effect. Essentially, once you come to believe something, you do your best to protect it from harm. You become more skeptical of facts that refute your beliefs, and less skeptical of the items that support them. Having one’s beliefs challenged, even with objective and authoritative data, causes us to hold them even more deeply. There are plenty of examples of this in everyday life. The absence of weapons of mass destruction in Iraq. The number of shooters in the JFK assassination. President Obama’s citizenship.

Bottom line: It’s human nature to try to pick apart a scientific article that challenges your biases, looking for every possible fault. It’s the Backfire Effect. Be aware of this built in flaw (protective mechanism?) in our psyche. And always ask yourself, “what if?” Look at the issue through the eyes of someone not familiar with the concepts. If someone challenges your beliefs, welcome it! Be skeptical of both them AND yourself. You might just learn something new!

Hard Time Discharging Your Trauma Patient?

Trauma services tend to have fairly rapid patient turnover. Many of the patients that are seen have injuries that are easily managed, leading to discharge within one to two days. On the flip side, some have such severe injuries that they may be in the hospital for weeks or even months. But regardless of injury, there are always a few who we just can’t seem to discharge at all. Why does this happen?

The trauma program at the Massachusetts General Hospital looked at 5 years worth of admission data on adult patients. They looked at the usual hospital demographics, billing information, hospital financial information, and discharge disposition. The ultimate goal was to identify patients who had an excessively prolonged hospitalization (defined as 2 standard deviations above the average length of stay for the associated Diagnosis Related Group) and why.

Here are the factoids:

  • 155 of 3237 admitted patients (5%) had an extended stay. The total number of admits seems weird, since this would average out to only 650 admissions per year to this busy hospital.
  • The usual injury severity demographics were similar.
  • Extended stay patients tended to be older, sustained blunt trauma, were Medicare or no-pay patients, and were discharged to facilities other than home.
  • Length of stay was 3 times longer than the usual patients
  • Hospital cost was 3 times higher, and the hospital lost a lot of money on them.
  • In-hospital mortality was lower for these patients (?!).
  • The biggest factors delaying discharge were transfer to a rehab or other post-acute care facility, and self-pay or Medicare pay status.

Bottom line: Extended stay in the hospital when not medically indicated is a bad thing, and it’s a system problem. The chance of complications is always present, including deep venous thrombosis, exposure to resistant organisms, UTI, pneumonia, and medication error, just to name a few. And it’s generally bad for the hospital’s financial health, as well. If you are experiencing this at your center, carefully analyze the reasons why it typically occurs. Then work proactively to address them.

  • Identify potential problem discharge patients on their first day in the hospital
  • Develop special arrangements with post-discharge facilities.
  • Hire skilled (and aggressive) social workers
  • Don’t give up!

Related post:

Reference: Excessively long hospital stays after trauma are not related to the severity of illness. JAMA Surg 148(10):956-961, 2013.

The  July Trauma MedEd Newsletter Is Available!

This month’s newsletter addresses the trauma practice guidelines and protocols. Here are the topics covered:

  • Why create protocols / guidelines?
  • What’s the difference, and why is one preferable to the other?
  • Developing your own
  • Sample guidelines for: chest tube management, solid organ injury, TBI on warfarin, and management of SAH / IPH / skull fracture without neurosurgery!

Subscribers received this issue last week. Subscribe now and be sure to get the next issue early.  So sign up for early delivery now by clicking here!

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