All posts by TheTraumaPro

Zebra Alert: Blunt Injury To The Thoracic Duct

Today I’m going to review a very uncommon clinical problem in trauma: injury to the thoracic duct. To review, the lymphatic system coalesces into channels along the spine. These vessels travel upwards to drain into the venous system as the left and right lymphatic ducts. The exact drainage points vary, but are near the junctions of the internal jugular and subclavian veins bilaterally. Technically the larger of the two, the left lymphatic duct, is termed the thoracic duct. However, injuries can occur on either side.

Injuries to the lymphatic ducts are very rare due to their small size and their protection by surrounding structures and tissues. For this reason, the literature on this topic consists almost exclusively of case reports. Injury can occur from direct penetration by gunshots or stabs, or may be associated with high energy blunt trauma. It has also been reported to occur in cases of multiple posterior rib fractures and vertebral fractures.

In the rare event that these ducts are damaged, they pose a major management problem because lymph does not clot. These vessels are not self-sealing like most others in the body. They will only close through healing (scarring) or by ligation. The typical disruption occurs near the junction of the duct with the venous system, so lymph (chyle) typically accumulates in the thorax on the affected side. This results in a hydrothorax until the patient begins eating, when it turns chylous and makes the diagnosis easy. Here a various shades of chyle that you might see in the chest tube drainage.

If in doubt, triglyceride levels can be measured, and a value greater than 110 mg/dL is considered positive.

Initial management is usually dietary, via reduction in fat intake to render the drainage clear. This may be accomplished by a low fat diet or by TPN. I don’t really buy the effectiveness of this, since the fat content is not what causes the leak to persist. It merely makes it unusual to look at. I suspect that the 1-2 week period that most recommend for dietary treatment just provides an opportunity for normal healing/scarring to occur. Octreotide should be given as well because it may decrease overall lymphatic output. Lower output accelerates closure because the amount of scarring needed to close the smaller hole is less.

Interventional radiologists have attempted embolization and needle maceration of the ducts, but the few of these described have been unsuccessful. This is not recommended.

If closure is not achieved in two weeks, then consideration should be given to surgical ligation of the leaking duct. This structure is small and thin-walled, and not the easiest to see. Fats should be administered via NG (olive oil and cream have been described) at the start of the operation to stimulate chyle production. This allows easier identification of the leak site intraoperatively. Suture ligation, clipping, or both can be used to stop the leak.

References:

  1. A case of a traumatic chyle leak following an acute thoracic spine injury: successful resolution with strict dietary manipulation. World J Emerg Surg 6:10, 2011.
  2. Blunt rupture of the thoracic duct after severe thoracic trauma. J Trauma Open 3:e000183. doi:10.1136/tsaco-2018-000183m 2018.
  3. Bilateral Chylhotorax after Falling from Height. Case Reports in Surg  article 618708, 2014.

Little-Known Whole Blood Transfusion Program: Part 2

In my last post, I described a long-standing whole blood transfusion program that was implemented by Royal Caribbean Cruise Lines (RCCL)about 10 years ago. Today, I’ll dig into the specifics of their protocol and review their results.

Here is an image of the protocol. You can click it to download a full-size pdf copy.

Here are the key points in the protocol:

  • It is only implemented if it will take more than 4 hours to get the patient ashore for more advanced care
  • If the patient is hemodynamically stable, permissive hypotension to MAP 75 is encouraged and TXA infusion / Vitamin K administration are considered when appropriate. The patient disembarks at the next port of call with advanced hospital capabilities.
  • If hemodynamically unstable, two large bore IVs are maintained, TXA and Vitamin K are given when appropriate, and whole blood collection and administration are initiated. Helicopter / coast guard transport is deemed acceptable to closest advanced hospital.

And here are the guidelines for donor selection:

  • The donor hierarchy is:
    • sexual partner of the patient
    • male passenger with blood donor card
    • male passenger without blood donor card
    • female passenger with blood donor card (beware of TRALI)
    • medical staff members
    • crew
  • Only one unit is taken from each donor, and they must not be anemic

Here are the factoids describing RCCL’s seven year experience with the program:

  • 73 patients received transfusions, including 67 passengers and 6 crew
  • Mean hemoglobin on presentation was 6
  • A total of 1-6 units were given
  • Six patients ultimately died; no details were given
  • There were no ABO seroconversions, and only two adverse reactions occurred, both allergic
  • The majority of the medical staff felt that this was a valuable program

Bottom line: This is the first whole blood transfusion program I have seen outside of hospitals and the military. Royal Caribbean has incorporated lessons learned from both in developing their protocol. It includes all the principles of balanced resuscitation, including limiting crystalloids, permissive hyportension, and 1:1:1 transfusion ratios. There are many other opportunities to implement similar protocols in areas where medical capabilities are austere, and this protocol should be used as a model to develop them.

A Little-Known Whole Blood Transfusion Program

I’m just getting back from a speaking engagement at the 30th Annual (!) Parkview Trauma Symposium in Fort Wayne, Indiana. I love traveling around the country and speaking, because I have the opportunity to hear other fascinating speakers and pick up new tidbits for personal use and to share. This was one of my favorite symposia and the speakers were fantastic.

My colleague, Scott Thomas, is the Trauma Medical Director at Memorial Hospital of South Bend in Illinois and gave an excellent talk on goal directed, whole blood transfusion. The use of whole blood is growing in the US, as I’ve written about previously. However, I was totally unaware of the systematic use of this product in a unique industry: cruising.

Royal Caribbean Cruise Lines (RCCL) implemented a whole blood transfusion program in 2008 on a subset of its more than 40 cruise ships. The guests on cruise ships tend to be an older population, similar to what many trauma centers in the US encounter. Similarly, many have medical comorbidities that require them to take anticoagulants or antiplatelet agents, and they may develop bleeding conditions while on board.

A good deal of cruise time is spent at sea and away from ports that have major medical facilities. Helicopter transport from the ship is not readily available due to distance from shore, so patients who experience serious illness must be cared for in the onboard medical facilities until within striking range of a faster coast guard ship. It is not practical to store blood on board, so bleeding patients presented a real problem in the past.

In response to this, RCCL implemented a program that was very forward thinking for its time. It emphasized:

  • Transfusion based on hemodynamics, not a hemoglobin reading
  • Anticoagulant reversal, if possible
  • Use of TXA
  • Limited use of crystalloid
  • Permissive hypotension
  • Use of fresh, whole blood

Wow! And this was 10 years ago. In my next post, I’ll start working through the protocols and logistics that RCCL uses for this program in the (relatively) austere medical / trauma environment aboard a cruise ship.

Related post:

Last Chance To Participate In The Trauma PI Coordinator Survey!

Thanks to all who have already participated in the Trauma PI Coordinator Survey! I’m beginning to wind it down, and will be closing it this Sunday night. If you have not taken part, please take a moment to read the following and fill it out!

Trauma performance improvement (PI) is a very complicated business, and more trauma centers fail their verification visits due to PI problems than for any other reason. The amount of information reviewed in the trauma PI program and the volume of documentation required can be quite onerous, but is necessary to assure the highest quality trauma care.

Many centers are now hiring trauma PI coordinators (TPIC) to free up other personnel from this time consuming task. Do you have a trauma PI coordinator, or do you wish you did? Please take two minutes to fill out a quick survey. I am trying to determine how many centers do and how many do not have a PI coordinator. I’d also like to correlate the center demographics with PI coordinator presence or absence.

For that reason, you must have one key piece of information before you fill out the survey. I need the total number of trauma registry admits for your center. You can find this out from your trauma program manager (TPM) or the lead registrar. Or better yet, have your TPM fill out the survey!

The survey will close this Sunday night, and then I will publish the results here in the next few weeks. I’ll show TPIC FTEs vs center level and type, trauma volume, and other fun tidbits that might help those have-nots out there get one of their own!

You can access the survey by clicking here

Thanks for participating!

Use Of Whole Blood For Massive Transfusion

We’ve been using fractionated blood components in medicine, and trauma specifically, for over 50 years. So why doesn’t component therapy work so well for trauma? Refer to the following diagram. Although when mixed together the final unit of reconstituted blood looks like whole blood, it’s not. Everything about it is inferior.

Then why can’t we just switch back to whole blood? That’s what our trauma patients are losing, right? Unfortunately, it’s a little more complicated than that. The military has been able to use fresh warm whole blood donated by soldiers which has been stored for just a few hours. That is just not practical for civilian use. We need bankable blood for use when the need arises.

This ultimately means that we need to preserve the blood, and this requires a combination of preservatives to prevent clotting and keep the cellular components fresh, and refrigeration to avoid bacterial growth. This is not as simple as it sounds. Adding such a preservative to whole blood dilutes it by about 12%. And there are concerns that cooling it may have effects on platelet function. Recent data suggests that platelet function in cooled whole blood is preserved, but platelet longevity is decreased.

There are other issues with the use of whole blood as well. It contains a full complement of white blood cells, and this may be related to reports of venous thrombosis, respiratory distress, and even graft vs host disease. Unfortunately, removing the white cells (leukoreduction) also tends to remove the platelets, and there is little literature detailing the safety of this practice.

Another problem is the plasma component in whole blood. Universal donor (type O) whole blood may contain significant amounts of anti-A and anti-B antibodies. For these reasons, most blood banks limit the number of whole blood units transfused to a handful. A recent paper from OHSU in Portland details a massive transfusion in which 38 units were given to one patient. There was no transfusion reaction, but platelet counts dipped precipitously. All centers currently using whole blood utilize only low-titer anti-A and anti-B units.

So does whole blood work as expected in the civilian arena? The data is still incomplete, but the total transfusion volume appears to be decreased in patients without severe brain injury. With the increased interest and use of whole blood, it is imperative that more safety and efficacy studies are forthcoming.

Here are some tips on getting started with your own whole blood program:

  • Develop a relationship with a supplier of whole blood. Hammer out the details of the exact product (product age, leukoreduction, titer levels, returnability if not used).
  • Obtain approval from your hospital’s Transfusion Committee!
  • Work with your blood bank to develop processes to ensure proper availability and accountability. What is the maximum number of units that can be used in a patient? When should units be returned to the general pool to ensure they are not wasted?
  • Decide where whole blood will be available. Obviously, the blood bank will house the majority of the product. But should you have it in an ED refrigerator? On air or ground EMS units? These situations demand several extra layers of oversight and add greatly to complexity.
  • Educate, educate, educate! Make sure everyone involved, in all departments, are familiar with your new MTP!

References:

  1. Whole blood for resuscitation in adult civilian trauma in 2017: a narrative review. Anesth Analg 127(1):157-162, 2018.
  2. Massive transfusion of low-titer cold-stored O-positive whole blood in a civilian trauma setting. Transfusion, Epub Dec 27, 2018.