Treatment Options – GSW – Reflections
Last week, I presented a scenario in which your ambulance responded to the scene of a shooting. You were presented with a 25 year old male, in obvious distress, with multiple wounds to his chest and abdomen. Your patient has a patent airway and has labored breathing with clear, equal lung sounds. He has no radial pulse but does have a bounding carotid pulse. The patient has no history, medications or allergies. The blood pressure on scene is “70 systolic” according to your partner. So how did you treat the patient?
TO C-SPINE OR NOT TO C-SPINE?
Obviously this is a critical patient. Based on the new CDC Field Triage Guidelines (discussed here), the patient meets criteria for transport to the highest level of trauma care in your system based on his blood pressure and the presence of multiple penetrating injuries to the torso. Now how to extricate this patient? Traditionally, patients with penetrating trauma have been placed in spinal precautions “just in case”. Now, however, that thought process is changing. The last time I took PHTLS, the recommendation was made to avoid spinal precautions in patients with penetrating injury to the torso as long as there were no distal neurological deficits. Additionally, studies  have surfaced indicating that placing such patients in spinal precautions may delay and complicate treatment. This this retrospective study, 357 patient records were analyzed from the hospital and over 75,000 were analyzed from the National Trauma Data Bank. Spinal immobilization was considered beneficial if a patient had a spinal fracture which required surgery but did not have a spinal cord injury (which would present in the field with neurological deficits). The idea being that a fracture which was significant enough to require surgery, but did not yet cause deficits could be worsened during the prehospital time. From the hospital, no patients presented with spinal fracture but without symptoms of spinal cord injury. From the National Trauma Data Bank, 26 patients presented in the group which could benefit from spinal immobilization. For those of your keeping track, that’s 0.03% of patients. Worded another way, 99.97% of penetrating trauma patients, in a data set consisting of 75,000, did not “benefit” from spinal precautions. Now weigh the amount of time it takes to c-spine that patient. Maybe not the best idea for our patient?
TWO LARGE BORE IVs WIDE OPEN?
It used to be that every trauma patient was given two “large bore” IV’s and then flooded with fluids. The theory being that providing IV fluid would boost the blood pressure and maintain the oxygenation of the tissues despite significant hemorrhage. The obvious issue with this theory is that saline does not carry oxygen and increasing the circulating volume of a patient with significant hemorrhage only “waters down” the blood, decreasing the oxygen carrying capacity and reducing the ability of the blood to clot. The name of the game now is permissive hypotension.
Breaking the word down, permissive hypotension basically means “allowing low blood pressure”. So how low is low enough? Well let’s look back at the reason why we would give a fluid bolus in the first place. What are we concerned with in patients with uncontrolled hemorrhage? Ultimately, the worry relates to losing the ability to perfuse the brain. If we fall below that threshold, the patient begins to suffer hypoxia of the brain tissues. If we are too far above that threshold, the pressure exerted on already-formed clots can cause those clots to fail, increasing bleeding. One study I read  recommended a systolic blood of 60 mmHg as an end point, but it makes more sense, in the field, to rely on the presence of a carotid pulse. This can help to take a lot of the guess work out of fluid resuscitation. Basically, if the patient has a carotid pulse, the brain is being perfused.
It is important to note that while evidence exists for utilizing permissive hypotension for penetrating trauma, the extrapolation of that practice to blunt-injury or traumatic brain injury patients is not currently supported by evidence .
What about the basics? Since the patient has a penetrating injury to the chest, it would be appropriate to cover those sites with occlusive dressings. Additionally, while the patient does have good lung sounds now, the potential exists to develop a pneumothorax or possibly a tension pneumothorax. Since the patient is hypotensive with absent radial pulses, pulse oximetry is unlikely to be a reliable indication of oxygenation. In this case, end-tidal capnography and central skin signs, along with repeat lung sounds is likely a better choice to ensure that the patient stays oxygenated.
Speaking of oxygenation, what flow rate should this patient receive oxygen at? Most responders would put this patient on high flow oxygen because it can’t hurt right? Wrong. As discussed a while back on EMS Garage, there is some evidence to show that more isn’t better when it comes to oxygen. By introducing oxygen (by definition an oxidizer) we run the risk of increasing the number of free radicals circulating through the body potentially increasing tissue damage. We do, however, want to maintain adequate oxygenation to this patient’s brain. So since we are already ensuring that the patient has a carotid pulse and is therefore perfusing his brain, I’ll take the cop-out answer here and say that we should provide oxygen at a flow rate which is adequate to maintain level of mentation. Basically, if we know that the patient is getting blood to his brain, we should give him enough oxygen that his mentation stays the same.
While there is some evidence  to show that length of prehospital time does not affect patient outcome in trauma patients, you’d be hard pressed in most systems not to transport this patient with lights and sirens. Additionally, in all of the systems I’ve worked, this patient would be considered a “full” or “level 1″ trauma upon arriving at the trauma center. So light it up.
So if you said that you would reduce scene time, omit spinal precautions, apply occlusive dressings, provide adequate oxygenation and monitor respirations, start two IV’s but only provide enough fluid to maintain carotid pulses and transport “code 3″, you ran the call the way I would and the way the evidence says you should. Disagree? Let me know!
 – Brown, JB; et. al. “Prehospital spinal immobilization does not appear to be beneficial and may complicate care following gunshot injury to the torso”. J Trauma 2009 Oct;67(4);774-8.
 – Geeraedts, LMG; et. al. “Exsanguination in trauma: A review of diagnostics and treatment options”. Injury 2009;40;11-20.
 – Stahel, PF; et. al. “Current trends in resuscitation strategy for the multiply injured patient”. Injury 2009;40S4;S27-S35.
 – Newgard, CD; et. al. “Emergency Medical Services Intervals and Survival in Trauma: Assessment of the “Golden Hour” in a North American Prospective Cohort”. Annals of Emergency Medicine 2010 March;55(3);235-46.
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