Tag Archives: resuscitation

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.

EAST 2015: 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. Presented at EAST 2015, Paper 30.

Does Hemostatic Resuscitation Really Work?

Hemostatic resuscitation (HR) is the new buzzword (buzz phrase?) these days. The new ATLS course touts it as a big change, and quite a few publications are being written about it. But, like many new things (think Factor VII), will it stand the test of time?

It has long been recognized that hemorrhage from trauma is bad. Mortality rates are high, and traditional management with crystalloids and then blood products leads to persistent coagulopathy, troublesome bleeding, tissue injury, and finally death. HR was devised to address the early coagulopathy. It concentrates on early coag correction with plasma and platelets, permissive hypotension, and rapid definitive correction of hemorrhage.

The end result of HR has been measured, and both organ perfusion and coagulopathy can be corrected with it. Unfortunately, these measurements are typically taken once hemorrhage control has been achieved. Is looking at (or beyond) the endpoint really the best way to gauge its effectiveness? 

A robust multicenter study scrutinized looked at coagulopathy correction and organ perfusion during active hemostatic resuscitation. They used ROTEM to gauge the former, and lactate levels for the latter. Values were measured on arrival and after administration of every 4 units of blood. Only patients who received at least 4 units were included (106 subjects).

Here are the factoids:

  • Average admission lactate was 6.2 meq/L, so these patients were sick
  • Patients with a lactate > 5 did not clear it until after hemorrhage was controlled and no further blood was needed
  • 43% of patients were coagulopathic by ROTEM on arrival. 
  • Coagulopathy increased for every 4 units of blood given, despite a plasma infusion ratio of close to 1:1 throughout their resuscitation

Bottom line: This was a well-done study on a relatively large number of patients, although a number of weaknesses and potential improvements are pointed out in the discussion. There’s a lot of data in the paper, and I urge you to read it in depth. But it seems to show that hemostatic resuscitation is not necessarily doing what we want it to do during the acute phase of hemorrhage. Both bleeding AND transfusions must be stopped before it appears to work. And even then, there is a delay before ROTEM and lactate parameters return to normal. For now, rapid control of hemorrhage is of utmost importance. We still need to figure out how tools like ROTEM or TEG and various serum markers will help us while we accomplish it.

Reference: Hemostatic resuscitation is neither hemostatic nor resuscitative in trauma hemorrhage. J Trauma 76(3):561-568, 2014.