Understanding Shock VIII: Prehospital Course of Care

Now that we have a pretty good idea of how shock works, what does it all mean for our treatment in the field?

Much like cardiac arrest and some of the other “big sick” emergencies, there are really a couple essential interventions we need to execute, maybe a couple others that aren’t a bad idea, and beyond that, our main job is to ensure that we don’t kill our patient by wasting time doing anything else.

 

Step 1: Control the bleeding

As we emphasized ad nauseam, the number one goal with the bleeding patient is to stop the bleeding. No need to beat this to death, but just remember: if you can control the bleeding, yet don’t get much of anything else done, you’re doing absolutely fine.

 

Step 2: Transport to surgery

In most significant cases of hemorrhage, definitively controlling the bleeding will require surgical intervention. We don’t do surgery, but we do set the stage, which is why it’s essential for us to know what we’re doing. Get thee to a trauma center, and quickly!

Can other hospitals perform surgical intervention? Sometimes. Maybe. A world-class trauma surgeon might happen to be in the building for a conference. Maybe the operating room is between scheduled procedures and happens to be clean and available. But the point to a trauma center is that it’s guaranteed to have certain resources available, and that’s the kind of place we want to bring these patients. 9 times out of 10, if we transport them elsewhere, they’ll simply end up being transferred back out to the trauma center anyway, making the whole exercise essentially one very long transport. Can a small community hospital help stabilize the patient before surgery? Sure — but as we know, everything else is a distant second priority to bleeding control. Even transfusing blood may need to be done sparingly until the leak has been corked.

What about ALS? Do these patients need paramedics? Now, if they acutely decompensate and need airway management or other interventions you can’t provide (or have other issues like pneumothorax), then ALS-level care would be valuable. But outside of that, and even granting that to a certain extent, a medic unit is not going to stitch up the bleeding, and meeting them will certainly delay transport to surgery at least by a few minutes. True, they’ll be able to initiate IV access that can be used for blood later, but in most cases this takes mere seconds at the ED (where there’s plenty of room, good lighting, and ample personnel) — and prehospital IVs will sometimes be replaced anyway.

 

Step 3: Promote oxygen delivery

Okay, you shock technician, now what?

Can we talk about coagulopathy of trauma — aka the “deadly triad”?

Bleeding control is the priority, right? And bleeding control requires clotting. But there’s a set of conditions guaranteed to obstruct clotting, and three of them are almost always present during hemorrhagic shock.

One is hemodilution. When we top off our bleeding patients with non-blood fluids, as we’re so fond of doing, it dilutes both oxygen-carrying capacity (since we’re not adding red blood cells) and clotting speed (since we’re not adding platelets or clotting factors). So this one’s our fault, and can be readily avoided by simply resisting the urge to replace blood with salty water.

One is acidosis. If you’ve been paying attention, you know that acidosis tends to develop in shock due to anaerobic cellular activity, and can be further encouraged by overzealous fluid administration. Is this the end of the world? (After all, a little acidosis might even improve oxygen delivery by shifting the oxyhemoglobin dissociation curve.) Well, the trouble is that acidosis also leads to coagulopathy. According to some in vitro studies, in fact, even mild acidosis can precipitously decrease platelet aggregation, and in significant acidosis platelets won’t activate at all. Zero.

The last is hypothermia. Not only do cold patients have poor oxygen delivery and other problems, they clot poorly; low temperatures cause coagulopathy too.

Now, we can’t do much about the initial trauma. We can discourage acidosis by limiting fluid use, and ensuring that ventilations remain adequate. What about hypothermia? Do our trauma patients get cold? What would you expect when you take someone who’s bleeding, strip them naked on a cold sidewalk, pump cold saline into their veins, and chuck them into an ambulance carefully heated to your comfort?

Keep your trauma patients warm. This is not about human kindness or TLC, this is a serious and important intervention for shock. Hypothermia is great for cardiac arrest, it may be beneficial in some other scenarios, but it is not good for bleeding people.

How about supplemental oxygen? Well, I suppose so. In the patient with adequate respirations, it is doubtful that “topping off” their PaO2 will affect them appreciably; but as they begin to decompensate, they’ll need all the help they can get.

Positioning? Remember how big a deal they made about the Trendelenburg position in school — how it pulls blood from the lower extremities into the core? And ever noticed how it’s not exactly our number one emphasis in the field? Trendelenburg has little real evidence supporting it, and the bulk of what does exist suggests its effect is fairly minimal — it moves only a little blood, the effect is transient, and the body’s compensation can actually cause a paradoxical reduction in core perfusion. Mostly these studies were done in healthy people, so it’s possible that our shocky patients do get a little benefit — and one supposes that if things are dire enough to need every last cc of blood, you can give it a shot. But typically it won’t do you too many favors. (I certainly wouldn’t advise propping the patient bolt upright, though!)

 

Step 4: Supportive care

Supportive care means battling secondary problems as they arise.  It doesn’t mean waffling over nonsense while your patient bleeds out.

If the patient’s airway is compromised, or you have legitimate reason to think that it may become compromised, then it should be managed. If they’re breathing inadequately, they’ll need assistance. Beyond that, any other care should only occur after you’ve stuck a cork in the bleeding and started rolling toward the guys with knives. Cardiac fiddling, pain management, splinting or minor bandaging — these should take place en route or simultaneous to other care, if at all. Shock kills people; is a nice sling-and-swath going to save them?

Spinal immobilization? It’s been pretty definitively shown to hurt rather than help in penetrating trauma. What about combined blunt and penetrating? There’s no evidence that it helps and some evidence that it’s harmful. We have no reason to think that tying people to boards does anything good, but we do know that wasting time here does everything bad. So if your local protocols demand immobilizing these patients, I won’t tell you otherwise — but please, at least, try and hurry.

That’s it, folks. Let’s wrap it all up next time by talking about recognizing the beast.

Key points:

  1. Stop the bleeding to the greatest extent possible in the field.
  2. Immediately and without delay transport to a facility capable of emergency surgery.
  3. Provide other supportive care as necessary, without delaying #1 and #2.
  4. Maximize oxygen delivery with supplemental O2, keeping the patient warm, and consider the Trendelenburg position.
  5. Minimize delays created by any and all non-essential care.

 

Go to Part IX or back to Part VII

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