Tag Archives: resuscitation

Best Of AAST 2021: Are We Getting Better At Balanced Resuscitation?

The way we resuscitate major trauma patients has been changing over the past decade. Even the 10th edition of the ATLS course has recognized that so-called balanced resuscitation is important. This concept limits the use of crystalloid and relies more heavily on blood component administration in ratios that more closely approximate whole blood.  Balanced resuscitation typically translates as the use of less than two liters of crystalloid, and blood product transfusion ratios of 1:1 to 2:1 (PRBC to plasma).

We have also recognized the critical importance of rapid control of major hemorrhage, which is best accomplished in an operating room.  The group at the University of Arizona massaged the TQIP database to see if these changes are having a significant impact on our patients.

They looked at five years worth of data, specifically reviewing information on adult patients with both transfusion and laparotomy occurring within four hours of arrival. The authors performed regression analyses to identify trends over the study period.

Here are the factoids:

  • Nearly 10,000 patients met study criteria with a mean age of 44 and ISS 34
  • Patients were in shock, with mean SBP 78 and median number of transfusions of 9 PRBC and 6 plasma
  • Time to laparotomy decreased from 1.87 hours to 1.37 hours over the five year period
  • 24-hour mortality decreased from 23% to 19% during the study
  • Blood product ratio decreased from 1.93:1 to 1.73:1
  • The authors state that the blood product ratio was independently associated with 24 hour mortality (odds ratio of 1.09) and in-hospital mortality (1.10) (??)

The authors conclude that resuscitation is becoming more balanced and time to surgery shorter, with a significant improvement in mortality.

Bottom line: Well, this is an interested study of associations. It uses a large database, which of course limits some of the information available. There are obvious trends toward faster time to OR (by 30 minutes) and a 4% improvement in survival. But the transfusion ratio really looks to be about the same. 

Let’s do the math, assuming that an average of 10 units of PRBC were given. A ratio of 1.93 would mean that 5.2 units of plasma were give (1425 cc, assuming 275 cc per unit). The ratio of 1.73 noted in 2017 would then be 5.8 units, or 1590 cc. This is an increase in FFP transfusion of 165 cc.

The authors stated that the improvement in transfusion ratios was statistically associated with the improvement in survival. I think this is one of those situations where there is a big difference between statistical significance and clinical significance. Do you really think that giving just 165 additional ccs of plasma could have that much overall effect on survival?

My suspicion is that there is a true association between the more rapid time to OR (and presumably surgical control) and survival. It’s just that the numbers were not clean enough to meet statistical rigor.

This is an interesting abstract, and shows that we are slowly getting better at controlling bleeding. But I think the most important takeaway is that we are not as good at balanced resuscitation as we think we are. We seem to be hovering at the 2:1 ratio, and only very slowly moving toward 1:1.

Questions for the authors / presenter:

  • Were you able to see a correlation between time to OR and survival?
  • Please comment on the association between transfusion ratios and survival, especially given the very small change over time.
  • Please clarify the in-hospital mortality and 24-hour mortality variables. In-hospital mortality suddenly pops up at the end of the results, but was never mentioned before.

Reference: AFTER 9,000 LAPAROTOMIES FOR BLUNT TRAUMA, RESUSCITATION IS BECOMING MORE BALANCED AND TIME TO INTERVENTION SHORTER: HOW LOW CAN WE GO? AAST 2021, Oral abstract #3.

EAST Guidelines: TEG And ROTEM In Coagulopathic Trauma Patients

In my last post, I explained why TEG is not so easy to use. Today, I’ll share the new Eastern Association for the Surgery of Trauma (EAST) practice management guidelines for using TEG and its twin, ROTEM for bleeding patients.

TEG first appeared in the trauma literature in 2008. A paper by John Holcomb showed that it was superior to the standard lab tests (PT, aPTT, and activated clotting time) in monitoring hemorrhagic shock in pigs. Since then, research has exploded with TEG papers. There have been about 50 published annually for the last four years.

In this month’s Journal of Trauma, EAST published their most recent practice management guideline, dedicating it to TEG. They identified over 6,000 potential papers and ultimately settled on 38 articles. They used them to attempt to answer three questions regarding use of these devices during resuscitation.

Question 1

In adult trauma patients with ongoing hemorrhage, should TEG/ROTEM be used vs non-TEG/ROTEM monitoring to guide transfusion strategy in order to reduce mortality, blood product transfusions and the need for additional hemostatic interventions such as angioembolization, endoscopy, or operation?

Answer: Only seven studies were found regarding this question. All but one showed no difference in 24 hour and hospital mortality. They also showed an inconsistent effect on blood product usage with some showing no difference and some shower less transfused product.

Nonetheless, EAST “conditionally recommended” the use of TEG/ROTEM. This is based  solely on the presumption that it can reduce the risk of blood transfusions by using a test that is harmless.

Question 2

In adult surgery patients with ongoing hemorrhage, should TEG/ROTEM be used vs non-TEG/ROTEM monitoring to guide transfusion strategy in order to reduce mortality, blood product transfusions and the need for additional hemostatic interventions such as angioembolization, endoscopy, or operation? Note the shift here to non-trauma patients.

Twenty one studies were found addressing this question. Most papers showed no difference in reoperation rate. There were also no consistent differences in transfusion of various blood products. And the vast majority showed no difference in mortality.

But once again, EAST conditionally recommended the use of this test in these patients, mainly because it is believed to be harmless.

Question 3

In adult critically ill patients with ongoing hemorrhage, should TEG/ROTEM be used vs non-TEG/ROTEM monitoring to guide transfusion strategy in order to reduce mortality, blood product transfusions and the need for additional hemostatic interventions such as angioembolization, endoscopy, or operation?

There were only 10 studies relating to this question, and they included patients with a variety of surgical and medical problems. TEG/ROTEM was no better than non-TEG parameters in predicting the need to transfuse, but did somewhat better than clinical judgement. Once again, there was no consistent effect on the number of transfusions given, although some studies showed that use of non-TEG/ROTEM studies resulted in fewer units of red cells, platelets, and cryoprecipitate given.

Interestingly, although there was little difference in the number of units transfused, fewer patients required transfusion using TEG/ROTEM. There was no difference in mortality or interventions to stop bleeding.

Yet again, EAST conditionally recommended use of TEG/ROTEM in these patients despite the very low level of evidence. Again, this is mainly because of the lack of perceived harm in using it, and the possibility that it might reduce exposure to blood products.

Bottom line: Hmm. I remain skeptical. What EAST is saying is that, hey it’s harmless and there’s a chance that it might reduce a patient’s exposure to blood products, so why not? I have a vial of bat wings and eye of newt that might do the same thing. As long as it’s harmless, right?

Well, it may be clinically harmless, but it costs money and time. First, you have to buy the machine. Luckily, they are much cheaper than a CT scanner. But then the manufacturer kills you with the disposables. Like a cheap inkjet printer, you have to keep buying $40 ink cartridges every few weeks to keep it working. Except TEG cartridges cost more than $40.

And don’t overlook the time spent training people in how to interpret the curves. And developing a system to obtain the specimen and pay people to run the equipment. It all adds up, and yet the papers can’t show us any dramatic clinical results.

I’ll probably irritate the TEG/ROTEM true believers, but it still seems like a device searching for a great clinical problem to solve. IMHO we need much more high-quality research to help us figure out how this tool can help us with our trauma / surgical / critical care patients.

Reference: Thromboelastography and rotational thromboelastometry in bleeding patients with coagulopathy: Practice management guideline from the Eastern Association for the Surgery of Trauma. J Trauma 89(6):999-1017, 2020.

Prehospital Lactate: Ready For Prime Time?

A few months ago, I started to notice a new piece of information coming across on my trauma activation pages: point of care lactate level. I had heard nothing about this prior to these pages, and was curious to know whether this was a new policy/practice, or some study that was in progress. So, of course, I had to do a little bit of reading to find out what was up with that. I’ll share that with you today.

Serum lactate has been used since forever in the inpatient setting, especially in the ICU. It is used as a surrogate for tissue hypoxia and/or metabolic acidosis. A number of studies have found that hypoperfusion is frequently underappreciated, since we tend to use crude vital signs (BP and pulse) which may look normal in early hypovolemia. Serum lactate guided therapy has been shown to improve survival in some studies, and can indicate that resuscitation is proceeding appropriately. Patients who do not show early improvement in their lactate levels are more likely to be refractory to resuscitation, and have higher mortality.

So it would make sense that if prehospital trauma professionals could identify occult tissue hypoperfusion in the field, appropriate resuscitation could start earlier. And nowadays, one can find a point of care device to measure just about anything. Thus, the extra tidbit of information on my trauma pages.

But remember, just because something makes sense doesn’t mean that it actually works. Thus, a group at the University of Birmingham (in the UK) did a systematic review of the literature through 2015, looking specifically at lactate levels obtained in the prehospital setting.

Here are the factoids:

  • Of the 2,415 articles screened, only 7 were suitable for analysis
  • These studies were judged to be of “low” or “very low” quality
  • The methods by which the lactate level were obtained (venous vs capillary), timing, and documentation were highly variable
  • The authors concluded that there is not yet enough data to support point of care lactate in the field

Bottom line: Point of care lactate drawn in the field would seem to be a good idea. Unfortunately, there aren’t any studies yet that are good enough to make this a standard practice. As with any new technique, if there’s no data then you MUST participate in a well designed study so it can be shown, yea or nay, that the practice is a good one. So join up!

Reference: Prehospital point-of-care lactate following trauma: a systematic review. J Trauma 81(4):748-755, 2016.

EAST 2016: Measuring Volume Status Using Jugular Ultrasound

We’re getting pretty handy using ultrasound at
the bedside to tell us some interesting things. It started with FAST exams in
the ED. Then we added a few views and came up with the Extended FAST, which was
helpful in showing potential chest pathology.

Ultrasound made its way into other areas of the
hospital, and is now used routinely to place IV lines, arterial lines, and
central venous catheters. I’ve previously written about using ultrasound to
evaluate volume status by imaging the IVC in the abdomen. And now, the group at
Shock Trauma in Baltimore is trying to reach even further.

They are now using IVC variations and cardiac
stroke volume variations to assist in volume assessment in critically ill
patients. These studies have a learning curve, especially the stroke volume
calculations. They performed a study that evaluated another possible window
into the patient’s volume status, the positional internal jugular change.

The diameter of the IJ was evaluated while the patient
was flat, and again when the head was elevated to 90 degrees. A fluid bolus was
given, and the positional change in diameter was measured again. The results
were then correlated with changes in measured stroke volume of at least 10%.

Here are the factoids:

  • This prospective, observational study involved 159 patients over 1.5
    years
  • Positional IJ diameter change was much better than IVC diameter changes
    (receiver operating characteristic areas of 0.93 vs 0.67)
  • The authors tried to use the stroke volume variation during passive leg
    raise (odd, but doesn’t involve sitting the patient up), and concluded they
    could not accurately assess it. This arm of the study was abandoned.

Bottom
line: Leave it to the folks at Shock Trauma to come up with more weird yet interesting
stuff. This is very preliminary data, and their analysis is ongoing. Any
application of this study will be somewhat limited, since many patients are not
allowed to sit up due to their injuries or baseline hemodynamic status. We will
see where this technique
ends up: in our armamentarium, or in the trash heap.

Go for the
jugular: assessing volume responsiveness in critically ill surgical patients.
EAST 2016 Oral abstract #32.

What If You Don’t Have TEG For Trauma?

The new hot items in trauma care are thromboelastography (TEG) and ROTEM (thromboelastometry), a new spin on TEG from the TEM Corporation. These tools allow for in-depth assessment of factors that influence clotting. We know that rapidly recognizing and treating coagulopathy in major trauma patients can reduce mortality. So many trauma centers are clamoring to buy this technology, citing improved patient care as the reason.

But new technology is always expensive, and isn’t always all it’s cracked up to be. TEG and ROTEM require an expensive machine and a never-ending supply of disposable cartridges for use. Some hospitals are reluctant to provide the funds unless there is a compelling clinical need.

Surgeons at the University of Cincinnati compared the use of TEG with good, old-fashioned point-of-care (POC) INR testing in a series of major trauma patients seen at their Level I center.

Here are the factoids:

  • This was a retrospective review of 628 major trauma patients who received both TEG and POC INR testing using an iSTAT device over a 1.5 year period
  • Median ISS was 13, and there were many sick patients (20% in shock, 21% received blood, 11% died)
  • INR correlated with all TEG values, with better correlation in patients in shock
  • Both INR and TEG correlated well with treatment with blood, plasma, and cryoprecipitate
  • Processing time was 2 minutes for POC INR vs about 30 minutes for TEG
  • Charges for POC INR were $22,000 vs $397,000 for TEG(!!)

Bottom line: Point of care INR testing and TEG both correlate well with the need for blood products in major trauma patients. But POC INR is much cheaper and faster. Granted, the TEG gurus will say that you can tailor the products administered to meet the exact needs of the patient. But in all my travels, I have never visited a center that has fully and effectively incorporated TEG or ROTEM into their massive transfusion protocol. Before you make the financial leap to buy these new toys, make sure that you have a very good clinical reason to do so.

Related posts:

Reference: All the bang without the bucks: defining essential point-of-care testing for traumatic coagulopathy. J Trauma 79(1):117-124, 2015.