Tag Archives: hemorrhage

What Is: Life Threatening Bleeding In The Anticoagulated Patient – Part 2

In my last post, I showed you some of the current definitions of “life-threatening” bleeding used in patients who are anticoagulated, as well as some for lesser degrees of bleeding. Confusing, right? How are we to ever know what is truly life-threatening so we can justify intervention/reversal with potent and/or expensive drugs and blood products?

It’s time for a more universal definition. The most important thing to recognize up front is that it is absolutely impossible to provide a comprehensive set of definitions that take every possible scenario into account. The list would be confusingly long. We really only need a few rules that are a bit more generalized. But then, how do we keep providers from just doing what they want, and coming up with some subjective or anecdotal justification? Bear with me for a day or two.

Today, I’ll lay out my two “universal definitions” of significant bleeding in an anticoagulated patient. Note that I didn’t say “life-threatening” bleeding. There is also such a thing as “limb-threatening” or “tissue-threatening” bleeding, and yet other ways to be harmed from uncontrolled bleeding due to anticoagulants.

If you look through all the various criteria that I included in the last post, you can see that they generally fall into two categories: physiologic and anatomic. The key is to reach a balance of being specific enough without being overly so. This still allows for some degree of clinician judgment. But as you will see in my next post, there also has to be some type of scrutiny and review of that judgment.

So here is what I propose. Bleeding is considered significant and/or life-threatening if either of these are true:

  1. (Physiologic) Bleeding that causes hemodynamic compromise (hemorrhagic shock) or changes in vital signs indicating progression toward it (increasing pulse rate, decreasing blood pressure).

  2. (Anatomic) Bleeding into a body region or tissues that has a high likelihood of causing death, disability, or the need for operative intervention.

In my next post, I’ll show you how to operationalize these definitions into a workable process for making decisions about reversing anticoagulation.

 

What Is: Life Threatening Bleeding In The Anticoagulated Patient – Part 1

We are moving into a world where more and more people are taking anticoagulants. And as the number of possible anticoagulant drugs increases, the prospect of reversing them becomes more complicated. Just as the price of those medications continues to climb, so does the price of the agents used to reverse them.

The decision to reverse an anticoagulant, the speed of reversal, and choice of reversal agent all depend on an assessment of the severity of bleeding. Some reversal drugs such as prothrombin complex concentrate (PCC) act almost immediately but are expensive. Others take time, but are cheaper such as plasma and vitamin K.

Unfortunately, trying to come to a consensus on what constitutes life-threatening bleeding is very difficult. Over the years, numerous studies have been done, with almost as many definitions of bleeding. As you know, I am generally against reinventing the wheel. Borrowing someone else’s excellent work saves a lot of time and anguish.

But when it comes to defining dangerous bleeding, we are faced with so many definitions, it just begs for a “unifying theory.” I’ll show you some of the more commonly used definitions below. At the very bottom, I’ve included a link to a very comprehensive list of definitions that have been used.

First, there’s TIMI (Thrombolysis in Myocardial Infarction trial) and GUSTO (Global Use of Strategies to Open Occluded Arteries trial). (Please remember how much I dislike cute acronyms.)

The following consolidated definition was published in the Journal of Thrombosis and Haemostsis way back in 2005:

If you want to look at a more comprehensive list of a lot of definitions, download the document from the link below.

So how do we make sense of all this? As trauma professionals and clinicians on the front line of anticoagulant reversal, we need a simple definition. I’ve recently looked over as many definitions as I could lay my hands on. 

In my next post, I’ll propose a simplified set of definitions. And I’ll be very interested in your input and comments. They will ultimately end up as a definition that we will use at my own trauma center. And maybe yours.

Related post:

Reference:

  • Definition of major bleeding in clinical investigations of antihemostatic medicinal products in non-surgical patients. Journal of Thrombosis and Haemostasis, 3: 692–694, 2005.

How To Remember Those “Classes of Hemorrhage”

The Advanced Trauma Life Support course lists “classes of hemorrhage”, and various other sources list a similar classification for shock. I’ve not been able to pinpoint where these concepts came from, exactly. But I am sure of one thing: you will be tested on it at some point in your lifetime.

Here’s the table used by the ATLS course:

classes_of_shock

The question you will always be asked is:

What class of hemorrhage (or what % of blood volume loss) is the first to demonstrate systolic hypotension?

This is important because prehospital providers and those in the ED typically rely on systolic blood pressure to figure out if their patient is in trouble.

The answer is Class III, or 30-40%. But how do you remember the damn percentages?

multiscore-maxi1

It’s easy! The numbers are all tennis scores. Here’s how to remember them:

Class I up to 15% Love – 15
Class II 15-30% 15 – 30
Class III 30-40 30 – 40
Class IV >40% Game (almost) over!

Bottom line: Never miss that question again!

Can Prehospital Providers Accurately Estimate Blood Loss? Part 2

I’ve previously written about the difficulties estimating how much blood is on the ground at the trauma scene. In general, EMS providers underestimated blood loss 87% of the time. The experience level of the medic was of no help, and the accuracy actually got worse with larger amounts of blood lost!

A group in Hong Kong developed a color coded chart (nomogram) to assist with estimation of blood loss at the scene. It translated the area of blood on a non-absorbent surface to the volume lost. A convenience study was designed to judge the accuracy that  could be achieved using the nomogram. Sixty one providers were selected, and estimated the size of four pools of blood, both before and after a 2 minute training session on the nomogram.

Here’s what it looks like:

Note the areas across the bottom. In addition to colored square areas, the orange block is a quick estimate of the size of a piece of paper (A4 size since they’re in Hong Kong!)

Here are the factoids:

  • The 61 subjects had an average of 3 years of experience
  • Four scenarios were presented to each: 180ml, 470ml, 940ml, and 1550ml. These did not correspond exactly to any of the color blocks.
  • Before nomogram use, underestimation of blood loss increased as the pool of blood was larger, similar to the previous study
  • There was a significant increase in accuracy for all 4 scenarios using the nomogram, and underestimation was significantly better for all but the 940ml group
  • Median percentage of error was 43% before nomogram training, vs only 23% after. This was highly significant.

Bottom line: This is a really cool idea, and can make estimation of field blood loss more accurate. All the medic needs to do is know the length of their shoe and the width of their hand in cm. They can then estimate the length and width of the pool of blood and refer to the chart . Extrapolation between colors is very simple, just look at the line. The only drawback I can see occurs when the blood is on an irregular or more absorbent surface (grass, inside of a car). 

Related posts:

Reference:  Improvement of blood loss volume estimation by paramedics using a pictorial nomogram: a developmental study. Injury article in press Oct 2017.

How To Remember Those “Classes of Hemorrhage”

The Advanced Trauma Life Support course lists “classes of hemorrhage”, and various other sources list a similar classification for shock. I’ve not been able to pinpoint where these concepts came from, exactly. But I am sure of one thing: you will be tested on it at some point in your lifetime.

Here’s the table used by the ATLS course:

classes_of_shock

The question you will always be asked is:

What class of hemorrhage (or what % of blood volume loss) is the first to demonstrate systolic hypotension?

This is important because prehospital providers and those in the ED typically rely on systolic blood pressure to figure out if their patient is in trouble.

The answer is Class III, or 30-40%. But how do you remember the damn percentages?

multiscore-maxi1

It’s easy! The numbers are all tennis scores. Here’s how to remember them:

Class I up to 15% Love – 15
Class II 15-30% 15 – 30
Class III 30-40 30 – 40
Class IV >40% Game (almost) over!

Bottom line: Never miss that question again!