SHOCK & TRAUMA’S LETHAL TRIAD

Shock is defined as “a pathophysiologic state in which the circulatory system is unable to perfuse tissues and meet oxygen demand adequately.” (Revell, 2003) Shock should never be described by a blood pressure.   A blood pressure is a poor indicator of the patients overall perfusion. 

Everyday, clinicians are faced with trauma’s lethal triad, which is comprised of hypothermia, acidosis and coagulopathy. (Rotondo M, 1997) When the clinician fails to address each aspect of the triad the results quite often result in fatal consequences.  The good news is that small interventions that address each arm of the lethal triad are both cost efficient and rather simple.

HYPOTHERMIA

We are all well aware of the alphabetic mnemonic is widely published in a number of trauma text books and manuals (For those of you who are not: A: Airway, B: Breathing, C: Circulation, D: Disability, E: Expose), unfortunately the “E” has turned out to be a double edged sword.  Prehospital providers have become samurai with their trauma shears and literally within mere minutes can have the victim of a trauma completely exposed to the elements and strapped to a hard plastic board.  The prehospital provider then expedites the patient the closest trauma center where the staff expose the patient again (assuming that the patient was that 1 in a billon who was covered with a Mylar blanket) and begin to infuse copious amounts of room temperature intervenous fluids.  At which point the patient is taken to CT (notoriously cold, even to the staff, and yes that is why the CT techs are always wearing sweaters), followed shortly there after by a trip to the operating room.  During this typical scenario, did anyone notice that the issue of hypothermia might have started to become problematic?

So why focus on something so simple?  Can a lowered body temperature really make that big of a difference?   YES!  Think of hypothermia as having its own triad.

Anticoagulation:

The clotting cascade, an item of vital importance when dealing with penetrating trauma is adversely affected by temperature, as the temperature of the trauma patient decreases the bodies ability to halt bleeding decreases proportionately, the body quickly looses is ability to clot. (Ferrara, 1990) (Watts, 1998)  Rohrer found that “enzymatic reactions of the coagulation cascade are strongly inhibited by hypothermia”. (Rohrer MJ, 1992)

In short, the clotting cascade has been shown to be adversely affected by temperature.  So to stop your patient from bleeding out keep them warm!

ATP Consumption:

            Adenosine triphosphate (ATP) is the human bodies fuel, without it the engine simply does not run.  When you look at the patient that has suffered a traumatic injury, there very quickly becomes an imbalance between supply and demand.  As catecholamines surge through he patient’s body, fuel (ATP) is used.  This causes a high demand, with no supply.  To further complicate the issue, like in the scenario detailed above the patient’s core body temperature begins to fall.  The patient then begins to shiver and shake generating his or her own source of heat.  This in turn increases the ATP expenditure, thereby stressing the already hypoperfused and hypoxic patient.

Patient Comfort:

            This is the portion of the article that generates the most laughter.  Patient comfort, how can we even consider patient comfort?  A patient presents to the trauma room after suffering multiple stab wounds.  Why must the clinician turn their attention from the fact that the patient is continuously bleeding from multiple stab wounds?   Well, firstly removing attention from active bleeding site is not the goal.  The goal here is to intervene on the lethal trauma triad before it spirals out of control. Addressing comfort is a simple intervention that both the nurse and physician can do, and this simple intervention can have monumental results.

           

It is well understood that being involved in a trauma can have far reaching physiologic as well as psychological effects.  The health care team can intercede before the patient is even admitted to the trauma room by altering the ambient temperature of the room.  Then once the patient arrives immediately following the primary survey warming blankets, and preferably a head covering should be provided for the patient. As discussed previously by maintaining normothermia the health care provider intercedes and decelerates the downward spiral of the clotting cascade.  This also prevents the patient from trembling, which utilizes already scarce and valuable ATP.  Lastly, the patient is in a particularly vulnerable state, to provide comfort, warmth, and a sense of safety and security serves to make a difficult experience a little psychologically more tolerable.

References

Watts, D. e. (1998). Hypothermic coagulopathy in trauma:effect of varying levels of hypothermia on enzyme speed, platlet function, and fibrinolytic activity. Journal of Trauma , 44 (5), 846-854.

Ferrara, A. e. (1990). Hypothermia and acidosis worsen coagulopathy in the patient requiring massive transfussion. Americian Journal of Surgery , 160 (5), 515-518.

Gubler K., G. L. (1994). The impact of hypothermia on dilutional coagulopathy. Journal of Trauma (36), 847-851.

Kashuk JL, M. E. (1982). Major abdominal vascular trauma: A unifid approach. Journal of Trauma (22), 672-679.

Revell, M. ,. (2003). Endpoints for fluid Resuscitation in hemorrhagic shock. The Journal of Trauma , 54, S63-S67.

Rohrer MJ, N. A. (1992). Effect of hypothermia on the coagulation cascade. Critical Care Medicine , 20 (10), 1402-1405.

Rotondo M, Z. M. (1997). The damage control sequence and underlying logic. Surg Clin North America (77), 761-777.