All posts by TheTraumaPro

Central Line Insertion Causes Hypercoagulability?

Again, I’m not a fan of animal studies. But this one, presented at EAST 2012, involves both pigs and humans and is so intriguing I just have to share it. The authors have a track record of studying coagulation issues with thromboelastography (TEG) in both animals and people. They previously showed that hypercoagulability detectable by TEG occurs after insertion of pulmonary artery catheters in swine and critically ill humans.

In this follow-on study, they looked at TEG profiles in 16 healthy swine and 8 critically ill humans after insertion of a central venous catheter (CVC). They found that CVC insertion induced the same type of hypercoagulable state. TEG clotting time and initial clot formation time decreased, and fibrin cross-linking accelerated. The changes were somewhat less in humans, but were still significant in both groups. All coag tests (PT, PTT, INR) and measured coag factors (von Willebrand, AT III) were unchanged.

Interestingly, in the animal group the hypercoagulable state persisted for at least 3 hours after CVC removal. And the hypercoagulability could be prevented with enoxaparin, but not heparin.

Bottom line: The idea that hypercoagulability could be induced by central arterial or venous catheter placement is intriguing, although this work has not been replicated by others yet. What if hypercoagulability occurs with any invasion of the vascular system? We may eventually discover that the increased incidence of DVT we have been fighting in the hospital setting is in part due to our ubiquitous use of IVs and routine blood draws.

Reference: Insertion of central venous catheters induces a hypercoagulable state. Presented at the 25th Annual Scientific Assembly of EAST, Orlando FL, 2012.

By Request: Tranexamic Acid In Trauma

I have received several requests to write about tranexamic acid (TXA) and trauma patients. There continues to be a lot of interest in this agent, especially in the military, and there are some good, recent trauma papers to review. Additional papers are being published on its use for control of bleeding, mostly in non-trauma journals.

Tranexamic acid works differently than the quick clotting agents out there. It is anantifibrinolytic, 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%. 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 and mortality from bleeding in a high quality trial. It has already been adopted by some hospitals in both the US and the UK. 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. Trauma centers should begin incorporating this important drug into their initial treatment protocols now.

Final thought: Unless new studies uncover major flaws with this drug, it will eventually be started by EMS in the field in select cases.

Reference: Tranexamic acid for trauma patients: a critical review of the literature. J Trauma 71(1):S9-S14, 2011.

A Better Way To Repair Nerve Injuries?

I’m usually not too keen on animal studies. Many times, the translation from animal to human just doesn’t work out. However, a study published last week on nerve injury caught my interest.

Nerves don’t heal well. The problem is that the neurons at the injured nerve endings tend to die back. Small vesicles form that seal the damaged ends, such that repairs that occur after sealing do not reliably re-establish continuity.

A group of researchers at the University of Texas at Austin and Vanderbilt experimented with manipulating the micro-environment at the injured ends of the nerve to control vesicle formation and action. 

The researchers have practiced a new technique on about 200 rats, severing a number of peripheral nerves, including the sciatic. After injury, a calcium-free hypotonic salt solution containing methylene blue (an antioxidant) was injected into the area. This shuts down the mechanism for vesicle formation, preventing the body from prematurely closing the cut ends of the neurons.

Next, the cut nerve ends were approximated using microsuture technique without any sharp debridement. Polyethylene glycol was then injected into the repaired area. This serves to dehydrate the outer membranes of the neurons and to induce them to flow back together. Finally, an isotonic calcium rich solution was applied to the repair to induce vesicle formation and fusion to close any remaining holes in the plasmalemma.

The video above shows the remarkable results. Most rats began moving the injured extremity immediately upon awakening from anesthesia. Nearly all had regained 60-70% of function within 2-4 weeks of injury.

Bottom line: If this pans out (in the somewhat distant future), expect to see possible interventions beginning in the field immediately after injury, starting with injections of the hypotonic calcium-free solution. Surgeons will take it from there. This is an animal study to keep an eye on!

Video: Rats walking after sciatic nerve injury (courtesy NewScientist.com)

Reference: Rapid, effective, and long-lasting behavioral recovery produced by microsutures, methylene blue, and polyethylene glycol after completely cutting rat sciatic nerves. J Neuroscience Res, published online 3 Feb 2012.

Trauma PI: Chasing Rumors

Trauma performance improvement (PI) is part art and part science. I tend to segregate the process into 3 segments: inputs, processing, and outputs. There are lots of possible inputs, including violation of specific audit filters (too long to OR, open fracture delay, etc.),  referrals from M&M discussions, incident reports and video reviews of trauma resuscitations, to name a few.

There is one PI input that has the potential to be a problem, though: word of mouth. You know, someone tells the trauma program manager that things just didn’t go well during that last trauma resuscitation. This is a perfectly legitimate way to identify PI issues. However, “word of mouth” can be categorized by source into “identified” and “anonymous." 

Word of mouth sources that are identified are not a problem. Anonymous ones are. All too often, these unsigned notes or suggestion box drops or phone messages are initiated by someone with an axe to grind. Most of the time, there is no basis for the incident that has been reported. The PI program can spend lots of time and energy trying to track down these perceived "problems”, and nothing ever comes of it.

There are two major problems with unsourced word of mouth “tips”:

  • There is no way to get additional information about the event from the source
  • It is not possible to thank the source for the information and let them know what was done to correct the issue

Bottom line: Performance improvement “tips” from anonymous sources are usually unfounded and a waste of time to investigate. Let it be known that your PI program is happy to receive written or verbal notices of potential problems that need to be pursued. However, every request must have a name and contact number and/or email included or it will be discarded.

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CMS Meaningful Use And The Trauma Flow Sheet

Apologies to all my international readers. This US specific post may make your head spin.

Over the past two years, I’ve discussed the problems associated with trying to force the trauma flow sheet into an electronic form (see links below). It just doesn’t work yet. In 2009, the US government Centers for Medicare & Medicare Services (CMS) designed a set of financial incentives to move healthcare providers and hospitals toward using an electronic health record (EHR). This incentive program is called “meaningful use." Could this force trauma centers to use it for their trauma flow sheet?

The answer is a resounding NO. Meaningful Use seeks to reduce errors, improve the availability of patient information for providers, help develop best practices, and automate processes such as filling prescriptions. Hospitals have until the end of 2012 to complete Stage 1, in which they establish a baseline for EHR use. Stages 2 and 3 will follow in 2013 and 2015, where EHR usage will be further integrated by expanding the usage requirements. The exact guidelines for Stages 2 and 3 have not been determined yet.

So what is actually required in Stage 1? A list of 24 objectives (for hospitals) as been developed. A slightly different list has been developed for healthcare providers. The hospital list consists of 14 core objectives which must be met, and another list of 10 objectives, and the hospital can pick any 5 to meet.

Here is a summary of the core list. All must be implemented:

  • Use computerized order entry
  • Perform drug allergy and interaction checks
  • Maintain an active problem list
  • Maintain an active drug list
  • Maintain an active drug allergy list
  • Record certain demographic info
  • Record certain vital signs
  • Record smoking for patients age > 13
  • Report required clinical quality measures to CMS
  • Implement one clinical decision support rule
  • Provide an electronic copy of the patient’s health information if requested
  • Provide an electronic copy of any discharge instructions
  • Be able to exchange key health information between providers
  • Protect all of this EHR information

Here’s the non-core list. Any five of 10 must be implemented:

  • Implement drug formulary checks
  • Record advance directives
  • Incorporate lab tests
  • Be able to generate lists of patients
  • Identify patient education resources
  • Perform medication reconciliation
  • Help transition the patient to another setting of care
  • Submit data to immunization registries
  • Be able to report data to state registries
  • Be able to submit surveillance data to public health systems

Bottom line: Did you see any mention of the trauma flow sheet here? NO. There is no language requiring specific portions of the record to be in electronic form. And since technology still has not advanced to the point where meaningful data input or report output can be generated by an EHR version of the trauma flow sheet, it should not be used for this purpose. A paper trauma flow sheet that has been scanned into the EHR is still the gold standard.

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