Emergency Medicine Forum

Keeping up with Emergency Medicine information

Emergency Medicine Forum header image 1

Case #169 “I’m not stopping; I’ve just been shot!” by Charlene Irvin Babcock, MD, FACEP

March 12th, 2014 · Medical Emergencies

Triage notifies you that a male is driving to the hospital after being shot.  The police called it in as they saw him speeding down side streets and running stop signs.  The cop pulled up next to the car with his police lights and sirens on. The car would not pull over.  The guy yelled out the window that he had just been shot and he’s driving to the hospital.  The cop pulled ahead and ran lights and sirens all the way to get him there quickly.

A stretcher is waiting at the ambulance bay, and the man jumps out of the car and hops onto the stretcher. He is quickly wheeled into the resuscitation suite.

Quick history reveals he was by his open trunk, heard some gunshots, felt 2 stinging him (one in buttocks and one in the side).  He looked down as blood began soaking his shirt, and he jumped into the car to get to the hospital.

You’ve asked for the usual six things that sick people get: IV, oxygen, monitor, a set of vital signs, undress the patient and draw some blood. Primary survey revealed airway and breathing intact (he was speaking full sentences), but he did describe feeling short of breath.  Capillary refill is slow, and you can barely feel a femoral pulse.  A GSW is noted in the right flank, and pressure is applied to the bleeding site. He has a rigid abdomen.  He is moving all extremities normally, and mentation is normal.  Vital signs:  Systolic Blood pressure 85, pulse 140, RR28.

1. What IV fluids do you order?  How much?

While many still do not practice, and all experts do not agree regarding the evidence of permissive hypotension, I do believe the many studies supporting this practice.  (See response to question #2 for details).  The real issue is how hypotensive to let the patient get before you initiate fluids.  In this case, the patient is talking, coherent with a normal consciousness.  So, 2 large bore IV access were obtained, and hep- locked.  As he was talking, mentation was normal, and had a penetrating injury to his abdomen; we focused on getting him to the OR and not on just bringing his blood pressure up with fluids.

2. What is permissive hypotension, and what blood pressure goal is ideal?

For a great discussion of the history of permissive hypotension, see this link: http://www.jems.com/article/patient-care/permissive-hypotension-trauma-resuscitat.

Basically, permissive hypotension refers to the practice of allowing a patient to be hypotensive by not pouring in large volumes of crystalloids (Normal Saline or Ringers Lactate). (1) This goes against the long standing mantra of automatic 2 large bore IV’s and 2 liters of crystalloids for all trauma patients.  When the patient has a penetrating torso injury (firearm or knife related), then there is a significant probability that there is an uncontrolled hemorrhage (inside the torso arterial injury of some sort that cannot be controlled by external pressure).  In this case, hypotension creates the natural situation that allows for some degree of hemostasis (low pressure in the vessel from low blood pressure, slower leak of blood, more time for clotting to occur).  When we automatically pour in large volumes of crystalloid, we 1) dilute the clotting factors and oxygen carrying capacity (diluting hemoglobin) and 2) raise the blood pressure making it much more likely we will ‘pop the clot’ thereby increasing blood loss.

So in permissive hypotension, you allow the patient to remain hypotensive (at some level) until control of hemorrhage has occurred (ie in the operating room).  The evidence for this is very strong.  In fact, one of the biggest questions is not whether we should do this, but what blood pressure is ideal.  In other words, do you allow the patient to have a blood pressure of 40 systolic?

To answer that, there was a great study published in 2011 in the Journal of Trauma. (2)  In this study, 90 patients were randomized to 2 groups:  low mean arterial pressure (50mm Hg) and high mean arterial pressure (65mm Hg).  (Consider what these MAP’s translate into:  a blood pressure of 70/40 gives you a MAP of 50, and 95/50 gives you a MAP of 65).  IN this study they authors found:  “Hypotensive resuscitation is a safe strategy for use in the trauma population and results in a significant reduction in blood product transfusions and overall IV fluid administration. Specifically, resuscitating patients with the intent of maintaining a target minimum MAP of 50 mm Hg, rather than 65 mm Hg, significantly decreases postoperative coagulopathy and lowers the risk of early postoperative death and coagulopathy.”

When I practice this in the ED setting, I find that there is an additional unmeasured benefit to permissive hypotension.  The hypotension promotes a rapid transport to the OR.  We are programed to like a minimum of 90 systolic, so when it drops below that, we tend to have a heightened sense of urgency.

3. How do you calculate Mean Arterial Pressure?

Mean arterial pressure:   MAP = ( (2xDiastolic) + Systolic) / 3

Diastole counts for twice as much as systole because 2/3’s of the cardiac cycle is spent in diastole.

4. What is the average cost to society for every patient suffering a firearm related injury that survives?  What about if they die?

The Pacific Institute for Research and Evaluation did an extensive evaluation of the societal cost of firearm injury in the US, based on 2010 costs. (3) This evaluation was more comprehensive than previous studies as it included costs of police, criminal justice, emergency transport etc.   They found that the societal costs for each hospital admitted firearm injury was 426,200/victim.  For those discharged from the ED, the cost was cheaper (116,372). And for those fatally injured from firearms, the cost was over 4 million per victim (4,699,759).  This is related to the lost wages by the victim mortally injured, and the cost of incarceration of the perpetrator.  This is an astronomical number! And, it suggests there is likely a cost savings to programs to prevent firearm related injuries in locations with large numbers of firearm related injuries occur.

http://www.childrenssafetynetwork.org/cost-gun-violence.

Outcome:
Patient was expedited to the OR quickly, and had a colon injury.   He had a partial colectomy, with a diverting colostomy.  He suffered blood clots post op, but was eventually discharged.  He survived.  I spoke with him a few months later (incidental ED visit)…the perpetrator was never arrested,but he was looking forward to getting his colostomy revised.

CME NOW AVAILABLE: Now you can earn one FREE credit hour in Category I towards the requirements for Michigan licensure and of the Physician’s Recognition award of the AMA by completeing the following EM Forum CME test.

References:
1.  Beeson J, Starnes t.  Permissive Hypoension in Trauma Resuscitation.  JEMS 2013 April.  Accessed at:   http://www.jems.com/article/patient-care/permissive-hypotension-trauma-resuscitat
2.  Morrison CA1, Carrick MM, Norman MA, Scott BG, Welsh FJ, Tsai P, Liscum KR, Wall MJ Jr, Mattox KL. Hypotensive resuscitation strategy reduces transfusion requirements and severe postoperative coagulopathy in trauma patients with hemorrhagic shock: preliminary results of a randomized controlled trial.  J Trauma. 2011 Mar;70(3):652-63. doi: 10.1097/TA.0b013e31820e77ea.
3.  The cost of firearm violence.  Childrens safety network.  Accessed at:   http://www.childrenssafetynetwork.org/cost-gun-violence

→ No CommentsTags: