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Resuscitation from Shock: Blood, Substitutes, Colloids, or Crystaloids?. Onier Villarreal, MD, FACEP Associate Medical Director Brandon Regional Hospital. Disclosures. No conflicts of interest pertinent to this talk. Rationale.
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Resuscitation from Shock: Blood, Substitutes, Colloids, or Crystaloids? Onier Villarreal, MD, FACEP Associate Medical Director Brandon Regional Hospital
Disclosures • No conflicts of interest pertinent to this talk
Rationale • Much debate has ensued in the past several years about the best approach for resuscitation of the trauma patient. • Recent (and not so recent…) literature points to the fact that the algorithms of aggressive fluid resuscitation may not be optimal for management of the patient in shock. • Coagulopathy and inflammation have been recognized as major factors influencing the management of shock.
Objectives • Discuss algorithms for the fluid and intravascular volume management of a trauma patient in shock. • Review different trauma scenarios and possible approaches to resuscitation in each. • Understand the pros and cons of using different resuscitation options during trauma-related shock.
Bleeding • Blood loss (volume) = area x rate x time • Area is determined by the extent of initial injury or the need for surgical exposure. • Rate of blood loss is a function of the tissues involved and the blood pressure • Time of bleeding is a function of the rate of blood loss with subsequent fall in blood pressure, the rate of blood coagulation, and the effect of interventions
The human coagulation system is slow and weak • Clotting takes time (2-10 minutes in the best of circumstances) • Clots are physically weak • There is limited clotting material to work with (even in the whole body) • 10 grams of fibrinogen total • 15 mL of platelets total in normal individuals
Human blood clotting is weak because it has to be! • Ten times more people die from clotting than from bleeding (heart attacks, strokes, pulmonary emboli, etc). • Moderate bleeding is an uncommon event, but clotting is a continuous threat. • The body evolved to deal with bruising and minor to moderate bleeding.
Massive injury leads to the rapid consumption of coagulation factors • You have only small amounts of coagulation factors in your body. Normal endothelium prevents their activation. • Damaged endothelium allows continuous cycles of factor activation and inactivation (consumption).
Hemorrhagic shock • Shock is defined as a state of decreased oxygen delivery to the tissues as a consequence of acute blood loss. • Blood pressure is a poor marker for shock. • Monitor end-points of resuscitation for adequacy of management.
Resuscitation parameters • Central mixed venous oxygenation is the first laboratory value to be altered in an acutely bleeding patient. • Increased oxygen extraction. • Lactate is a marker for end-organ perfusion. • If not cleared in the first 48 hours after the trauma, mortality approaches 100%.
Bleeding • The severity of the patient’s shock condition should dictate management • SvO2, lactate • Control the rate of bleeding • Involve the surgeons early • Bleeding is dependent on BP • Permissive hypotension • Hemostatic resuscitation
Early Advice about IV Fluids “Injection of a fluid that will increase blood pressure has dangers in itself … If the pressure is raised before the surgeon is ready to check any bleeding that might take place, blood that is sorely needed may be lost.” Cannon, JAMA 70:618-621, 1919
Case 1 • 24 y/o female involved in motor vehicle collision, unrestrained driver. • GCS 15 • Evidence of open left femur fracture, no active bleeding noticed. • No other injuries suspected • HR 110, BP 80/50, RR 22 • How much fluid should we give? Which type? Blood products?
Case 1 • Factors to consider in this case are as follows: • Patient’s age and sex • Mechanism of injury: Suspicion of controlled bleeding due to open left femoral fracture • Patient’s mental status: intact • Vital signs, MAP = 60
Case 1 • In this case, given that the only suspected source of bleeding is a left open femoral fracture, the approach may be as follows: • Control of bleeding site (may require surgery). • Crystalloid infusion of 1 to 2 liters IV to a systolic blood pressure of around 90 mmHg. • Assess patient for other injuries. • Continue trauma management.
Hemorrhagic hypotension • When the bleeding site is controlled, and no ongoing hemorrhage is suspected, crystalloids are the resuscitation fluid of choice if the patient shows no sign of end-organ failure. • No evidence of major differences in outcomes using normal saline versus lactated ringer’s solution. • If there is no further deterioration, no role for the use of colloids or blood products.
Case 2 • 32 y/o male, otherwise healthy, involved in motor vehicle collision, restrained backseat passenger. • GCS 15 • Complains of severe abdominal pain, distended abdomen is present • No other injuries suspected • HR 140, BP 70/40, RR 25
Case 2 • Factors to consider in this case are as follows: • Patient’s age and sex • Mechanism of injury: Suspicion of uncontrolled bleeding due to abdominal injury. • Patient’s mental status: intact • Vital signs, MAP = 50 • Should we resuscitate this patient? Up to what extent?
Permissive hypotension • In the case of suspected uncontrolled bleeding, permissive hypotension is an acceptable strategy. • The theory behind this is that we do not want to further dilute the available blood, therefore diminishing clot factors and oxygen carrying capacity. • We do not want to avoid normalizing the blood pressure because of possibility of worsening the hemorrhage.
Permissive hypotension • Studies done in Houston in the 1980’s [1] and Baltimore in the 1990’s [2] showed increased morbidity and/or mortality with aggressive fluid resuscitation prior to surgical repair in patients with uncontrolled hemorrhage and without concomitant brain injury. This finding has been replicated in subsequent studies. • Emphasis should be on rapid transport to the hospital and emergent surgical control of bleeding.[3]
Permissive hypotension • Some fluid resuscitation, however, is better than no fluid based on animal models.[4] Target a systolic blood pressure of 80 – 90 mmHg and strive to achieve prompt surgical control of the hemorrhage. • Crystalloids should be the initial fluid of choice for these patients.[5] Albumin and hetastarch (colloids) have not been shown to be superior to crystalloids, and in some cases, can be harmful.[6,7]
Permissive hypotension • This approach is also termed permissive hypovolemic resuscitation. • Therefore, be careful if you need to intubate these patients! • Positive pressure ventilation can decrease venous return in the hypovolemic patient, and this in turn can exacerbate your shock state! • Anticipate you may need more fluids. • Consider vasopressors (norepinephrine).
Case 2 – Mr. Belly • After 2 liters of IV normal saline… • GCS 11/15 • Patient lethargic, moaning. • HR 150, BP 60/30, RR 28 • Blood lactic acid = 6 mmol/L • Abdomen exam unchanged • The surgeon is busy in the operating room. What is the best fluid management plan?
Hemostatic Resuscitation • This approach incorporates the use of blood and blood-products (mainly plasma) in an attempt to decrease the amount of bleeding, increase intravascular volume and maintain organ perfusion in the setting of acute blood loss. • Most accepted protocols utilize a 1:1 or 2:1 ratio of red blood cell transfusions to plasma transfusions.[8] • Do not attempt to normalize blood pressure!
Hemostatic Resuscitation • The patient still needs definitive (surgical) control of bleeding. • Hemostatic resuscitation principles can also be used as part of a massive-transfusion protocol and to continue treating coagulopathy and bleeding after surgical repair. • Use the least amount of blood and plasma required for coagulation factor repletion and improvement of oxygen delivery to the tissues.[9]
Case 3 – Mr. Brain • A 62 y/o male falls from the roof of his house. Family saw him “shaking” and he is now unresponsive. • GCS 5/15 • Patient has a distended abdomen and subcutaneous emphysema in his chest. • HR 140, BP 70/40, RR 25
Case 3 – Mr. Brain You start management per ATLS guidelines. What should be your approach to fluid resuscitation?
Polytrauma patient • Polytrauma patients can be a challenge to manage, specially in the setting of traumatic brain injury (TBI). • A single episode of hypotension (defined as MAP less than 90 mmHg) has been shown to double mortality in TBI patients in some studies.[10,11] • Attempt to keep you systolic blood pressure above 90 mmHg at all times and follow neurological exams closely for changes. Consider ICP monitoring if available.
Hypertonic Saline • In order to address the issue of brain perfusion and avoidance of hemodilution in TBI patients, some studies looked at using hypertonic saline as a resuscitation fluid. • Unfortunately, no studies showed a survival benefit at 6 months. Some studies were stopped due to lack of benefit. [10,11] • The current recommendation is to use crystalloids and blood products in the resuscitation phase of TBI.
Hypertonic Saline • Consider hypertonic saline solutions if the patient develops an acute brain herniation syndrome as a bridge to definitive therapy (craniotomy). • Colloids are harmful in TBI![5,9] • Implement same concepts as in hemostatic resuscitation, but is it ok to be more aggressive. • This is another instance to consider vasopressors. Avoid hypotension in TBI at all costs!
A word on blood substitutes… • Recently there has been much interest in oxygen-carrying solutions to substitute blood in resuscitation. • These fluids ideally would be able to carry oxygen to the tissues without having the adverse effects of blood transfusions. • So far trials have been marred by no real survival benefits and a concern for side effects (added bleeding, cardiovascular events).
General concepts • Remember to titrate fluid or blood replacement to a quantifiable parameter of resuscitation. • Lactate, ScVO2 • Blood pressure is not an adequate marker of perfusion! • Based on current evidence, judicious use of crystalloids and blood products using a hemostatic resuscitation approach should be the mainstay of your treatment plan.
References • Bickell WH, Wall MJ Jr, Pepe PE, et al. Immediate versus delayed fluid resuscitation for hypotensive patients with penetrating torso injuries. N EnglJ Med 1994; 331:1105–1109. • Dutton RP, Mackenzie CF, Scalea T. Hypotensive resuscitation during active hemorrhage: impact on in-hospital mortality. J Trauma 2002; (52):1141–1146. • Pepe PE, Dutton RP, Fowler RL. Preoperative resuscitation of the trauma patient. Current Opinion in Anesthesiology 2008, 21:216–221 • Capone AC, Safar P, Stezoski W et al. Improved outcome with fluid restriction in treatment of uncontrolled hemorrhagic shock. J Am CollSurg 180: 49-56, 1995 • Evidence-based Colloid Use in the Critically Ill: American Thoracic Society Consensus Statement. Am J RespirCrit Care Med Vol 170. pp 1247–1259, 2004 • The SAFE Study Investigators. A Comparison of Albumin and Saline for Fluid Resuscitation in the Intensive Care Unit. N Engl J Med 2004; 350:2247-2256 • Lissauer ME, Chi A, Kramer ME, Scalea TM, Johnson SB. Association of 6% hetastarch resuscitation with adverse outcomes in critically ill trauma patients. Am J Surg. 2011 Jul;202(1):53-8. • Davenport R, Curry N, Manson J, De’Ath H, Coates A, Rourke C, et al. Hemostatic effects of fresh frozen plasma may be maximal at red cell ratios of 1:2. J Trauma 2011;70:90-5. • Harris T, Thomas R, Brohi K. Early fluid resuscitation in severe trauma. BMJ 2012;345:e5752
References • Cooper JD, Myles PS, McDermott FT, Murray LJ, Laidlaw J, Cooper G, et al. Pre-hospital hypertonic saline resuscitation of patients with hypotension and severe traumatic brain injury: a randomized controlled trial. JAMA 2004;291:1350-7. • BulgerEM, May S. Out-of-hospital hypertonic resuscitation following severe traumatic brain injury: a randomized controlled trial. JAMA 2010;304:1455-64.