Staten Island Corner

Let the trauma patient be hypotensive?

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CCT 4 AM. Trauma Note – GSW to abdomen. On arrival, wound to RUQ, another to L flank. HR 130s, BP 70s/40s. The CCT junior throws in two 14 gauge peripheral IVs, and attaches the trauma lines.  Two liters NS go in in minutes. BP comes up to 100s/60s.  FAST is positive, CXR/pelvic  x-ray are negative and the patient is taken to the OR for ex-lap. Sounds like a well-run trauma code.

 But what if I told you those 2 L may have done harm?

           A NEJM [1] paper from 1994 compared “immediate” vs delayed fluid resuscitation in patients with penetrating trauma to the torso and SBP<90.  The findings were…impressive. The immediate group started IVF on EMS arrival and was continued in the ER if the SBP < 100.  This group averaged 2.5L IVF prior to OR.  The delayed group “did not receive” any IVF until they reached the OR (they averaged 300ml of IVF prior to the OR). Out of 598 patients, mortality was 70% in the immediate group vs 62% in the delayed (P=0.04) groups with an NNT for a life-saved of 12.5 with similar characteristics between the two groups.  The delayed resuscitation group also had shorter hospital stays, lower PT, aPTT, and a trend (p=0.08) for decreased complications such as ARDS, sepsis, ARF, coagulopathy, wound infection, and pneumonia. 

   This begs the question, are we harming our trauma patients with fluid?

            The leading theory is that the fluids cause higher BP, which can dislodge clots and lead to more bleeding by increasing pressure behind a wound.  The fluids may also dilute platelets and clotting factors, hindering much needed clot formation.

 But is this potentially practice changing article reproducible?

 

Dutton  2002 trauma, from Shock trauma [2]

            110 patients with undifferentiated hemorrhagic shock (excluding TBI patients) were randomized to goal SBP 100 vs goal SBP 70.   Here there was no difference in mortality, with 4 deaths in each group. Problems – the study may not have been powered to detect a difference, the SBP >100 group had higher ISS scores (p=0.10), and the average BP for each group was 114 vs 100.  Yes, that’s right, the group with the goal SBP of 70 had an average SBP of 100.  I question how applicable this is to actual permissive hypotension, where some animal studies have claimed the ideal MAP is 50. 

 

Turner  2003  [3]

            Undifferentiated trauma patients (1,309 total) were randomized to IV fluids started in the field by EMS versus on ED arrival. There was no change in mortality or complication rates. Curiously, only 30% of patients in the receiving fluids group actually received fluids in the pre-hospital setting.  And 20% of the no fluids group received fluids in the pre-hospital setting.  And the patient population was selected by trauma without selecting for hypotension. More concerning is the estimated 12-13 minute delay in transport due to EMS placing an IV in the field. 

 

Morrison 2011 [4]

This study is currently in progress with only an abstract published on their first 90 patients.  In this prospective rct, patients with hemorrhagic shock requiring immediate surgery are divided into goal MAP of 50 vs 65. So far, the MAP of 50 group had significantly lower post-op mortality without a significant change in mortality at 30 days.  They were less likely to develop immediate post-op coagulopathy and less likely to die from post op bleeding.   

 

Cochrane 2003 [5]

            What lit search would be complete without good old Cochrane.  They declared: “We found no evidence for or against the use of early or larger volume IVF administration in uncontrolled hemorrhage…large, well concealed, RCTs are urgently needed to establish the optimal fluid resuscitation strategy.”

 

Animal studies [6]

            Without enough human data, let’s look at animal studies for a possible answer.  There have been voluminous animal trials ranging from cut aortas to sliced spleens to blast injuries in pigs. According to a systemic review of the animal trials, animal studies have shown fluid resuscitation decreases mortality in severe hemorrhage but increases mortality in those with less severe hemorrhage. They recommend human trials. I’m honestly not sure how applicable these trials are to what we see in the ED. 

 

            Of course, no lit search is complete without a paper from Dr. Sinert.  An animal study by Dr. Baron [7], him, and Dr. Scalea showed that a MAP of 50 due to hemorrhagic shock in pigs for 60 minutes versus 35 minutes led to higher lactates and base deficits.  The question remains, how applicable is this to mortality/complications in our trauma patients.

 

So what do you think?  When will give our trauma patients IV fluid?  How much?  Does it matter if they have blunt or penetrating trauma?

 

References

1.  Bickell et al. Immediate Versus Delayed Fluid Resuscitation for Hypotensive Patients with Penetrating Torso Injuries. NEJM; Oct 1994: vol 331, number 17, 1105-1109

2.  Dutton RP, Mackenzie CF, Scalea TM. Hypotensive resuscitation during active hemorrhage: impact on in-hospital mortality. J Trauma. 2002 Jun;52(6):1141-6

3. Turner J, Nicholl J, Webber L, Cox H, Dixon S, Yates D. A randomised controlled trial of pre-hospital intravenous fluid replacement therapy in serious trauma. Health Technology Assessment 2000;4(31):1–47.

4. Morrison et al. Hypotensive Resuscitation Strategy Reduces Transfusion Requirements and Severe Postoperative Coagulopathy in Trauma Patients With Hemorrhagic Shock: Preliminary Results of a Randomized Controlled Trial. Journal of Trauma-Injury Infection & Critical Care: March 2011 – Volume 70 – Issue 3 – pp 652-663

5. Kwan I. Timing and volume of fluid administration for patients with bleeding. Cochrane Database Syst Rev. 2003;(3):CD002245.

6. Mapstone et al. Fluid resuscitation strategies: a systematic review of the animal trials. J Trauma. 2003 Sept; 55(3): 571-89

7. Baron BJ, Sinert RH, Sinha AK, Buckley MC, Shaftan GW, Scalea TM. Effects of traditional versus delayed resuscitation on serum lactate and base deficit. Resuscitation. 1999 Dec;43(1):39-46.

The views expressed on this blog are the author's own and do not reflect the views of their employer. Please read our full disclaimer here. Any references to clinical cases refer to patients treated at a virtual hospital, Janus General Hospital.
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andygrock

  • Resident Editor In Chief of blog.clinicalmonster.com.
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