Guidelines for External Hemorrhage Control

Hot off the press from Prehospital Emergency Care is the newly released Guidelines for External Hemorrhage Control provided by the ACS Committee on Trauma. This is a pretty nice summation of the available evidence and, as such, it is recommended that you grab yourself a copy and read through the full-text yourself. Having said that, here is a summary of what was stated within this paper...

The authors of this paper ("reps from the military's Tactical Casualty Combat Committee, PHTLS, civilian state EMS directors, trauma surgeons, emergency physicians, a pediatric surgeon, an EMS researcher, a GRADE methodologist, and a paramedic" - from USA & Canada) systematically reviewed the literature regarding the use of tourniquets and hemostatic agents for the management of life-threatening extremity and junctional hemorrhage. After sifting through the evidence, the authors then applied GRADE methodology to formulate and answer relevant clinical questions regarding these products as well as to summarize the quality of the evidence.

Here's what they came up with:

Tourniquets

1. We recommend the use of tourniquets in the prehospital setting for the control of significant extremity hemorrhage if direct pressure is ineffective or impractical. [Strength: Strong; Quality: Moderate]
2. We suggest using commercially produced windlass, pneumatic, or ratcheting devices that have been demonstrated to occlude arterial flow. [Strength: Weak; Quality: Low]
3. We suggest against the use of narrow, elastic, or bungee-type devices. [Strength: Weak; Quality: Low]
4. We suggest that improvised tourniquets be applied only if no commercial device is available. [Strength: Weak; Quality: Low]
5. We suggest against releasing a tourniquet that has been properly applied in the prehospital setting until the patient has reached definitive care. [Strength: Weak; Quality: Low]

Junctional Hemorrhage Devices

"We believe this is an important area for further study, but did not find sufficient evidence to make a recommendation at this time."

Topical Hemostatic Agents

1. We suggest the use of topical hemostatic agents, in combination with direct pressure, for the control of significant hemorrhage in the prehospital setting in anatomic areas where tourniquets cannot be applied and where sustained direct pressure alone is ineffective or impractical. [Strength: Weak; Quality: Low]
2. We suggest that topical hemostatic agents be delivered in a gauze format that supports wound packing. [Strength: Weak; Quality: Low]
3. Only products determined effective and safe in a standardized laboratory injury model should be used. [Strength: Weak; Quality: Low]

Additional Recommendations

• We advise that tourniquets and topical hemostatic agents be used under clinical practice guidelines and following product specific training.
• We advise that hemostatic agent training for prehospital personnel include proper wound packing and pressure application techniques.
• We advise that tourniquets and topical hemostatic agents use be expanded to include all prehospital personnel, including emergency medical responders.

Bibliography:

Bulger et al."An Evidence-Based Prehospital Guideline for External Hemorrhage Control: American College of Surgeons Committee on Trauma" Prehospital Emergency Care 2014, 18(2):163–73.

TXA Fully Reverses Fibrinolysis in Swine Model of Simulated Hyperfibrinolysis & Acidosis.

The Paper: Debarros et al. "Tranexamic acid corrects fibrinolysis in the presence of acidemia in a swine model of severe ischemic reperfusion." J Trauma Acute Care Surg 2014; 76(3): 625-33.

Study Design: Prospective controlled in vivo swine model.

PICO:

• Population: 10 healthy yorkshire swine under general anesthesia with controlled hemorrhage, simulated hyperfibrinolysis, and acidosis (discussed in more detail below).
• Intervention: 1000mg IV TXA (n=5).
• Control: No TXA (n=5).
• Outcome: Resolution of fibrinolysis as measured by ROTEM Maximum Lysis (ML) directly after TXA administration.

What they did:
The pigs were intubated and placed on invasive monitors (PA + arterial) under general anesthesia. Blood samples were then drawn at baseline and repeated at 30 minutes, 1 hour, and 4 hours post-resuscitation. To achieve simulated hemorrhage ischemic-reperfusion injury, all pigs were bled 35% of their total circulating volume (26ml/kg) through their inferior vena cava via a midline laparotomy. Immediately after, the aorta was cross-clamped and pigs were left for 50 minutes to create a "severe truncal ischemia". Resuscitation phase began after a 5 minute controlled release of the aortic clamp. 30 minutes into the resuscitation, all pigs were given 100mg tPA. At 35 minutes, the intervention group was given 1000mg TXA. Crystalloid was given to all animals who's MAP < 40 and PCWP < 150% baseline. Epinephrine was given if MAP < 40 mmHg and PCWP > 150% of baseline.

Results:

• All pigs survived.
• At the time of TXA administration, average pH was 7.2.
• In intervention group, Maximum Lysis returned to baseline 10 minutes after administration of TXA (92% vs 9%, p<0.001).

% Maximum Lysis (Times)	TXA	No TXA
Baseline	9.2%	8.6%
30 Minutes (just after tPA)	99.4%	100%
45 Minutes (just after TXA)	9%	91.6%
4 Hours	2.8%	1.8%

Limitations:

• Swine model does not directly represent human model of coagulation. Authors acknowledge that swine coagulation profile is much more robust and, because of this, both groups returned to baseline at the end of resuscitation at 4 hours.
• Serum lactate was significantly higher in the TXA group (3.5mmol/L vs 7.0mmol/L) → authors state this may be due to a higher epinephrine requirement in intervention group (unable to know for sure as it was not powered to answer that question).
• Simulated model of "trauma-induced coagulopathy" is not consistent with actual traumatic coagulopathy.

What can we take home from this study?

• While this certainly is not practice changing by any means, it does seem to show effectiveness of TXA in an acidic environment. 

Reblog (Trauma Pro Blog): EAST 2014: Device Alert! Instant Hgb Monitor

Dr. McGonigal, of The Trauma Professional's Blog, posted briefly this morning on the results of a hugely interesting abstract from EAST 2014. Check it out here.

http://regionstraumapro.com/post/72871485249