Fluid Resuscitation in Shock

Evie Marcolini, MD Assistant ProfessorEmergency Medicine and Critical CareYale University School of MedicineNew Haven, Connecticut USA

Case #1

• 68 year old female, brought by family• Not feeling well x 4 days

– Heart rate: 140– Blood pressure: 80/60– Respiratory rate: 30– Temperature: 40C/104F

• Productive cough x 3 days, decreased oral intake

• History of smoking, emphysema, hypertension and diabetes

Case #2

• 26 year old male, unhelmeted driver of a motorcycle that struck a tree

• Found unresponsive– Heart rate: 140– Blood pressure: 80/60– Respiratory rate: 30– Temperature: 35.5C/96F

• Patient is pale, cool, sweaty, no evidence of external bleeding, chest trauma or limb trauma

• Abdomen distended, rigid

• How should we treat these two patients with respect to fluid resuscitation?

• What is the latest evidence supporting guidelines for fluid resuscitation?

• How do these two patients differ with respect to their fluid requirements?

Objectives

• Review the types of Shock

• Review the evidence for fluid resuscitation: how much to give?

• Describe the fluid options for resuscitation

• Outline the goals of fluid therapy

• Special considerations

Types of Shock

• Hypovolemic – Hemorrhage– Body fluid loss (gastrointestinal)

• Distributive – Sepsis– Anaphylaxis

• Cardiogenic– Myocardial infarction– Cardiac valve dysfunction

• Obstructive– Tension pneumothorax– Cardiac tamponade

Types of Shock

• Hypovolemic –Hemorrhage

• Distributive –Sepsis

Overall Shock Treatment

• Depends on type of shock• Fluid is a common denominator

– Attenuate inflammatory response– Decrease organ injury– Improve survival

• Fluid bolus resuscitation is controversial– Penetrating trauma– Sepsis

Fluid ResuscitationWhat are the questions?

• How much fluid is enough?

• Which type of fluid is best?

High volume fluid controversy

• US military recommendations:

– Hypotensive resuscitation should be used until hemorrhage control is obtained

– 1:1:1 resuscitation should be used until hemorrhage is controlled

– No data exists to show that colloids are superior to other fluids for resuscitation

McSwain NE et al; J Trauma 2011 Aug;71(2):520

• 600 hypotensive patients with penetrating torso injuries

• Delayed resuscitation resulted in improved survival, fewer complications and shorter hospital length of stay

Bickell WH et al. NEJM 1994; 331:1105-9

Early aggressive fluids• May prevent hemostatic

clot formation• May dilute clotting factors• May contribute to

acidosis, hypothermia and coagulopathy

• Damage control (DCR) resuscitation avoids these risks

Duchesne JC et al. Am Surg 2011 Feb;77(2):201-6

• What about non-traumatic septic shock patients?

Gold Standard…

• “Resuscitation goals included targeted CVP 8-12”

• 5000 ml vs 3500 ml fluid given in the first 6 hours of therapy

• “Mortality decreased from 46% to 30%”

Rivers E et al, NEJM 2001;345:1368-77

• “Resuscitation goals for severe sepsis and septic shock include the following:– Central venous pressure: 8–12 mm Hg – Mean arterial pressure >65 mm Hg – Urine output >0.5 mL/kg/hr– Central venous (superior vena cava) or mixed venous

oxygen saturation >70%

• There is no evidence-based support for one type of fluid over another

Dellinger RP et al, Crit Care Med 2004;32:858-873

New Standard…

• 800 patients with septic shock receiving 5 micrograms of norepinephrine per minute

• “A more positive fluid balance at 12 hours and over 4 days is associated with increased mortality”

• CVP was correlated with fluid balance at 12 hours, but there was no significant correlation on days 1-4

Boyd JH et al, Crit Care Med 2011;39:259-265

New Standard…

• 1200 septic patients admitted to European ICUs in a 2 week period

• “A positive fluid balance was among the strongest prognostic factors for death”

Vincent JL et al. Crit Care Med 2006; 34:344-353

What can we conclude about how much fluid to give?

• Trauma– Judicious use of fluids until surgical

hemostasis seems to be beneficial

• Non-trauma– Early goal directed therapy with endpoint of

CVP 8-12 has been the gold standard– Evidence is mounting for benefit of less

aggressive fluid therapy

What about types of fluid?

• Fluid options– Human blood products– Crystalloids– Colloids

• Prospective liberal vs conservative transfusion study

• No improved outcome for transfusion to Hb levels of 10g/dl as opposed to 7 g/dl

Hebert PC et al. NEJM 1999;34:409-17

• 4900 patients, prospective multi-center observational cohort study

• The number of RBC units transfused is an independent predictor of worse clinical outcome

Corwin HL et al. Crit Care Med 2004; 32:39-52

Recommendations for trauma resuscitation

• Prehospital – 1:1 resuscitation should be used a much as

possible (blood:plasma)

• In-hospital– 1:1:1 resuscitation should be the goal until

hemorrhage is controlled (blood:plasma:platelets)

– Management of initial coagulopathy of severe blood loss is best achieved by early plasma infusion

McSwain NE et al; J Trauma 2011 Aug;71(2):520

Crystalloids

• Normal saline• Lactated Ringer’s• Hypertonic saline• Plasmalyte

Solution Na Cl K Ca Mg Lactate Acetate Gluconate

0.9% NaCl 154 154 0 0 0 0 0 0

Lactated Ringer’s 130 109 4 3 0 28 0 0

3% NaCl 513 513 0 0 0 0 0 0

Plasmalyte 140 98 5 0 3 0 27 23

Amounts in meq/liter

Crystalloid composition

0.9% Saline

Advantages– Most commonly used,

familiar

– Higher osmolarity than Ringer’s Lactate; better for brain injury patients

– May be advantageous in patients with metabolic acidosis

– Inexpensive

Disadvantages• Expansion of interstitial

volume

• Dilutional hyperchloremic acidosis, leading to systemic vasodilation, pulmonary edema and coagulopathy

• Larger volume needed, causing abdominal compartment syndrome, pulmonary edema

Lactated Ringer’s

Advantages– Sydney Ringer added

potassium and calcium to NS to enhance contractility of frog hearts

– Alexis Hartman added sodium lactate to correct but not overcorrect metabolic acidosis

Disadvantages• Pro-inflammatory, activates

neutrophils

• Cannot be infused with RBC’s due to calcium which binds citrated blood anticoagulant

• Contains potassium, risk of hyperkalemia in renal failure patients

Hypertonic Saline

Advantages– 3%, 5%, 7.5%, 23%– Raises blood pressure by

volume expansion– Improves microcirculation– Immunomodulation

potential– Improves myocardial

contractility– Reduces interstitial and

endothelial edema

Disadvantages• Hypernatremia • Lacking evidence of

improved outcome for patients with trauma or sepsis

Plasmalyte

Advantages

• Physiologic, balanced• Osmolality/pH similar to

plasma• Acetate metabolizes to

bicarbonate, produces less CO2 than lactate

• Volume and electrolyte deficit correction

• Contains metabolizable bases that replace bicarbonate

• No calcium - can be combined with blood and medications

Disadvantages

• Magnesium may counteract vasoconstriction

• Possible bradycardia, hypotension, worsening microcirculation

• No evidence for superiority over other crystalloids

• More expensive (debatable)

Crystalloids

• There is no proven benefit of one crystalloid over another

• Each patient scenario may benefit from different characteristics of each solution

• Knowledge of the advantages and disadvantages of each solution translates to patient benefit

Colloids

• Electrolyte solution with large molecular weight molecules

• Theory: increased oncotic pressure keeps fluid within vascular space

• Regional differences • UK, China, Australia heaviest users

Why consider Colloids?

Advantages • More effective volume

expansion• Less weight (military use)• Recommended for

– Low protein states– Malnourishment– Intolerance of large

volumes– Ortho/reconstructive

(prevention of thrombus)

Disadvantages • Not proven to reduce

mortality• More expensive

• Prospective, 7000 patients randomized to albumin versus saline for fluid resuscitation

• Showed that albumin or normal saline results in similar mortality

The SAFE study investigators. NEJM 2004;350:2247-56

Colloid myth-busting• More effective plasma expansion

– Theory, not borne out in literature– Over time, both are equally effective– Adequate resuscitation achieved with 1-2 fold of

total crystalloid compared to colloid– Colloids do not stay intravascular longer, and

may leak into the interstitium

• Synthetics equally safe, less expensive than albumin– Not enough evidence; may contribute to renal

failure, coagulopathy and tissue storage– Albumin may be safer in cirrhosis/SBP, harmful in

TBI

Colloids

• Naturally-occurring– Albumin – Dextran– Blood

• Synthetic – Hydroxyethyl starch (HES)– Gelatins

Albumin5% / 25%

Dextran40 / 70

Hetastarch Gelufosine

Molecular weight 70 / 70 40 / 70 450,000 30,000

Sodium level 130-160 154 154 154

Osmolality 300-1500 308 310 n/a

Volume expansion 500-1700 500-1000 500-700 500

Duration <24 h <6-24 h <36 h <4 h

Allergic reaction (%) 0.011 0.007-.069 0.085 0.066

Colloid composition

Albumin

• Predominant plasma protein• First derived from plasma in World War II• From pooled human serum albumin• Available in 5% or 25% concentration• Recommended for severe hypoalbuminemia

and cirrhosis

Albumin

Advantages– Does not cause

inflammation– Small volume– Primary antioxidant effects– Effects of 25% long-lasting

(up to 12 hours)– Given with loop diuretic to

mobilize fluid in volume overload

– More expensive, less available

Disadvantages– Transfusion reactions– Reduced ionized calcium

levels – depressed myocardial function

– Decreased GFR in burn patients

– Expensive (up to 30x more than crystalloid)

Dextran

Advantages– Glucose polymer– Lowers blood viscosity

via disaggregation– Prevents deep venous

thrombosis– Reduced Factor VIII

activity/fibrin clot formation

– 40,000D or 70,000D molecular weight

Disadvantages• Can be associated with

kidney injury with pre-existing renal dysfunction or hypovolemia

• Can cause anaphylactic reaction (rare)

Hydroxyethyl Starch“Hespan”

– Derived from amylopectin– 6% isotonic solution– Low, medium and high molecular weight– Hydrolyzed by amylase, cleared by kidney

Hydroxyethyl Starch“Hespan”

Advantages– Low volume, easy to

transport– Rare anaphylaxis– Preserves splanchnic

perfusion– Used in US military in

limited volume to reduce risk of coagulopathy

Disadvantages– Can cause renal

failure in septic shock patients

– May cause coagulopathy and hyperchloremic acidosis

– Theoretical maximum daily dose = 1.5 liters

– May accumulate in plasma and tissues

Hextend

Advantages• Hextend = 6% Hetastarch

in lactated electrolyte buffer

• Approved by US Food and Drug Administration for hypovolemia in elective surgery

• No good data on safety in volume resuscitation

Disadvantages • Limited to 1.5 liters• Needs more data to show

outcome improvement

Gelatin

Advantages– Derived from bovine

bone material– Smaller molecular

weight than other colloids

– Rapidly excreted by kidneys

Disadvantages

• Relatively short intravascular half-life

• Risk of anaphylaxis

Colloid conclusions?

• HES has best risk/benefit profile– Not enough data– Synthetics cause more anaphylaxis than

albumin

• Newer HES is safer– Inconclusive literature– Used extensively in Scandanavian and Swiss

ICU’s– Canadian survey shows that marketing may

influence practice

Goals of Fluid Therapy

• Replace losses• Protect the kidneys• Maintain osmolarity• Maintain acid-base and electrolyte balance

Special Cases

• Traumatic brain injury– Not candidate for permission hypotension– Hypotension and hypoxia are two strong

markers of poor outcome

• Burns– Large fluid requirements up front to restore

intravascular volume and maintain end-organ perfusion

What can we conclude about how much fluid to give?

• Trauma– Judicious use of fluids until surgical

hemostasis seems to be beneficial

• Non-trauma– Early goal directed therapy with endpoint of

CVP 8-12 has been the gold standard– Evidence is mounting for benefit of less

aggressive fluid therapy

What type of fluid is best?

• It really depends on the patient and your situation– Is your patient a trauma or a medical patient?– Is there a high risk of bleeding?– Is cost an issue?– Does your patient have allergies?

Case #1

• 68 year old female, brought by family• Not feeling well x 4 days

– Heart rate: 140– Blood pressure: 80/60– Respiratory rate: 30– Temperature: 40C/104F

• Productive cough x 3 days, decreased oral intake

• History of smoking, emphysema, hypertension and diabetes

Case #1• This patient needs fluid for :

– Loss replacement, renal protection, osmolarity and acid-base performance

• There is no great evidence to support the cost of colloid therapy versus crystalloid

• Blood transfusion risk outweighs benefit unless hematocrit is below 7

• A more positive fluid balance at 12 hours and over 4 days is associated with increased mortality, and CVP is unreliable after 12 hours

• If colloid is used, coagulopathy should be monitored

Case #2

• 26 year old male, unhelmeted driver of a motorcycle that struck a tree

• Found unresponsive– Heart rate: 140– Blood pressure: 80/60– Respiratory rate: 30– Temperature: 35.5C/96F

• Patient is pale, cool, sweaty, no evidence of external bleeding, chest trauma or limb trauma

• Abdomen distended, rigid

Case #2

• This patient needs fluid for – Loss replacement, renal protection,

osmolarity and acid-base performance

• Hypotensive resuscitation should likely be limited to Systolic blood pressure <100

• Colloids may stay in the system longer, but outcome benefit is not yet proven

Conclusions

• Trauma– Judicious use of fluids until surgical

hemostasis seems to be beneficial– Early aggressive fluid therapy may be harmful

• Non-trauma– Early goal directed therapy with endpoint of

CVP 8-12 has been the gold standard– Evidence is mounting for benefit of less

aggressive fluid therapy

Conclusions

– Blood products should be given judiciously, and in a 1:1:1 fashion as appropriate until hemorrhage is controlled

– Overaggressive fluid therapy may exacerbate the lethal triad of coagulopathy, hypothermia and acidosis

– There is no proven benefit of one crystalloid over another

– Colloids do not show an outcome improvement over crystalloids

– Each patient scenario should be considered individually

Thank you!

Evie Marcolini Assistant Professor

Emergency Medicine and Critical Care