Tag Archives: transfusion

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.

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.

Why Do We Use Fractionated Blood Components?

Tomorrow, I’ll be writing about the use of the newest and greatest blood product: whole blood. Wait, isn’t that what we started out a hundred years ago? How is it that we are even debating the use of blood component therapy vs whole blood? Most living trauma professionals only remember a time when blood components have been infused based on which specific ones were needed.

Prior to about 1900, blood transfusion was a very iffy thing. Transfusions from animals did not go well at all. And even from human to human, it seemed to work well at times but failed massively at others. In 1900, Landsteiner published a paper outlining the role of blood groups (types) which explained the reasons for these successes and failures. With the advent of blood storage solutions that prevented clotting, whole blood transfusion became the standard treatment for hemorrhage in World War I.

When the US entered World War II, it switched to freeze-dried plasma because of the ease of transport. However, it quickly became clear that plasma-only resuscitation resulted in much poorer outcomes. This led to the return to whole blood resuscitation. At the end of WWII, 2000 units of whole blood were being transfused per day.

In 1965, fractionation of whole blood into individual components was introduced. This allowed for guided therapy for specific conditions unrelated to trauma. It became very popular, even though there were essentially no studies of efficacy or hemostatic potential for patients suffering hemorrhage. The use of whole blood quickly faded away in both civilian and military hospitals.

The use of fresh whole blood returned for logistical reasons in the conflicts in Iraq and Afghanistan. A number of military studies were carried out that suggested improved outcomes when using whole blood in place of blood that has been reconstituted from components. That leads us to where we are today, rediscovering the advantages of whole blood.

And that’s what I’ll review tomorrow!

Massive Transfusion And Tranexamic Acid (TXA)

Tranexamic acid has been in use for decades, just not for trauma. The CRASH-2 trial was a massive multi-country study showed that there was a slight mortality reduction from 16% to 14.5% in trauma patients who had or were at risk for “significant hemorrhage.” Moreover, there was no difference in vascular occlusive events, blood product transfusions, or need for surgery. Sounds great, right?

The MATTERs trial was initiated by the US military and tried to address some of the perceived shortcomings of CRASH-2 and found an absolute mortality reduction of 6.7%. But it also showed DVT rates that were 12x higher and PE rates 9x higher when this drug was given.

Since those two studies, a significant number of critiques have been published, as well as some additional research. Unfortunately, this has only served to cloud the picture. TXA is very inexpensive and readily available, so there has been a significant move to adopt both in the trauma center, as well as during prehospital care prior to arrival.

The trauma group at Denver Heath published a study of 232 patients with a 20% mortality rate from their injuries. They identified three subsets of patients based on their fibrinolytic response upon presentation to the hospital: physiologic fibrinolysis (49% of patients), hyperfibrinolysis (28%), and fibrinolytic shutdown (23%).

They found that mortality significantly increased in those receiving TXA who were physiologic or hyperfibrinolytic, but unchanged in those in shutdown. They cautioned that giving this drug before the patient’s fibrinolytic status was known could contribute to mortality.

Bottom line: So confusing! And many centers already include TXA in their massive transfusion protocol. Most have not seen unexpected mortality after giving the drug, so the jury is not in yet. Each trauma center should weigh the currently known pros and cons, and decide whether they are “believers” or not. Carefully review all mortalities and thrombotic complications after administration to see if there was any relation to the use of TXA.

References:

  1. Massive transfusion protocols and the use of tranexamic acid. Current Opinion Hematol 25(6):482-485, 2018.
  2. Tranexamic Acid is Associated with Increased Mortality in Patients with Physiologic Fibrinolysis. J Surg Res 220:438-443, 2017.
  3. CRASH-2 Study of Tranexamic Acid to Treat Bleeding in Trauma Patients: A Controversy Fueled by Science and Social Media. J Blood Transfus Article 874920, 2015.

ABC: A Quick & Dirty Way to Predict Massive Transfusion

It’s nice to have blood available early when major trauma patients need it. Unfortunately, it’s not very practical to have several units of O neg pulled for every trauma activation, let alone activate a full-blown massive transfusion protocol (MTP). Is there any way to predict which trauma patient might be in need of enough blood to trigger your MTP?

The Mayo Clinic presented a paper at the EAST Annual Meeting several years ago that looked at several prediction systems and how they fared in predicting the need for massive transfusion. Two of the three systems (TASH – Trauma Associated Severe Hemorrhage, McLaughlin score) are too complicated for practical use. The Assessment of Blood Consumption tool is simple, and it turns out to be quite predictive.

Here’s how it works. Assess 1 point for each of the following:

  • Heart rate > 120
  • Systolic blood pressure < 90
  • FAST positive
  • Penetrating mechanism

A score >=2 is predictive of massive transfusion. In this small series, the sensitivity of ABC was 89% and the specificity was 85%. The overtriage rate was only 13%.

The investigators were satisfied enough with this tool that it is now being used to activate the massive transfusion protocol at the Mayo Clinic. Although the abstract is no longer available online, it appears to be remarkably similar to a paper published in 2009 from Vanderbilt that looks at the exact same scoring systems. Perhaps this is why it never saw print? But the results were the same with a sensitivity of 75% and a specificity of 86%.

Here’s a summary of the number of parameters vs the likelihood the MTP would be activated:

ABC Score         % requiring massive transfusion
0                                1%
1                               10%
2                               41%
3                               48%
4                             100%

Bottom line: ABC is a simple, easy to use and accurate system for activating your massive transfusion protocol, with a low under- and over-triage rate. It doesn’t need any laboratory tests or fancy equations to calculate it. If two or more of the parameters are positive, be prepared to activate your MTP, or at least call for blood!

In my next post, I’ll look at the impact of using ABC based on prehospital information.

Related post:

References: 

  • Comparison of massive blood transfusion predictive models: ABC, easy as 1,2,3. Presented at the EAST 24th Annual Scientific Assembly, January 26, 2011, Session I Paper 4. (No longer available online)
  • Early prediction of massive transfusion in trauma: simple as ABC (assessment of blood consumption)?J Trauma 66(2):346-52, 2009.