Table of contents
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Resuscitation Targets
- Targets:
- Used to be urine output and BP
- Now: (Reach in 24 hours)
- Oxygen Uptake (VO2) > 100 mL/min/m^2
- Defined by: VO2 = Q x Hb x 1.34 x (SaO2 - SvO2) x 10
- Lactate < 2.0
- Arterial Base Deficit > -2 mmol
- Oxygen Uptake (VO2) > 100 mL/min/m^2
- Can predict fluid deficit:
- Class I = 5 mL/kg
- Class II = 15 mL/kg (postural tachycardia)
- Class III = 25 mL/kg
- Class IV = 35 mL/kg
Different Fluids
-
Volume
Infused
Type of Fluid Plasma Volume
Expansion (mL)
1.000 mL D5W 100 1,000 mL Lactated Ringer's 250 1,000 mL 0.9% Saline 275 250 mL 7.5% Hypertonic Saline 1,000 1000 mL 5% Albumin 700 100 mL 25% Albumin 450 500 mL Pentastarch 500 Plasma
And Paul Marino's "The Little ICU Book"
(From "Little ICU book" and Stapczynski JS et al (Emerg Med Prep 1994)
- Isotonic Saline
- Higher sodium, chloride, osmolality.
- Drawbacks:
- Hyperchloremic metabolic acidosis --> can create confusion esp in DKA management.
- Lactated Ringer's
- Ringer's introduced in 1880 as calcium containing solution (promotes cardiac contraction in frogs).
- Lactate added as a buffer in 1930's
- Physiologic concentration of free calcium (but as consequence sodium must be lower to balance charge)
- Lactate used to drop chloride concentration to 109 mEq/L (close to plasma 103)
- Recommended for surgery, DKA, trauma, burns
- Drawbacks:
- Calcium can bind drugs (amphotericin, ampicillin, thiopental) - do not mix solutions.
- Calcium can bind citrated anticoagulant in blood products, causes clot formation in donor blood.
- Contraindicated as a diluent for blood products.
- Normal pH Fluid: Normosol / Isolyte / PlasmaLyte
- Contain acetate and gluconate buffers (pH 7.4)
- Also potassium (5 mEq/L) and Mg (3 mEq/L), and phosphate (1 mEq/L)
- Not popular, but recommended as substitute for isotonic saline for washing salvaged RBC's.
- Contain acetate and gluconate buffers (pH 7.4)
- Dextrose Solutions
- Dextrose was initially a nutrient in IV fluids (1L of 5% D5W gives 170 kcal/L)
- 3L daily = 500 kcal = enough to meet daily requirements without breaking down proteins.
- Drawbacks:
- Expands intracellular fluid (not desired effect), only small portion intravascular.
- Metabolized by hypoxic tissues to lactate (more acidosis?)
- Can cause poor glycemic control (worse outcomes).
- Colloid Fluids
- Large molecules that do not move out of vascular compartment.
- Create "Colloid Osmotic Pressure" (COP)--> retains water in vascular compartment.
- Most colloids have COP similar to plasma (stay in plasma), some have higher COP (draw fluid intro vascular space).
- [i.e. 5% albumin COP = plasma COP]
- Colloids MUCH (3 times) more effective than crystalloids in increasing plasma volume.
-
Fluid Mol. Wt. Manufacturer Duration Colloid
Osm. Press.
Plasma Volume
to Infused Volume
Unit Size Cost (AWP)
2005 Redbook
Crystalloids Isotonic Saline Hospira - 0.275 1,000 mL $1.46 Ringer's Lactate Hospira - 0.250 1,000 mL $1.48 Colloids 5% Albumin 69 kDa Bayer 12h 20 mmHg 0.7 - 1.3 250 mL $30.63 25% Albumin 69 kDa Bayer 12h 70 mmHg 4.0 - 5.0 50 mL $30.63 6% Hetastarch 450 kDa Abbott 24h 30 mmHg 1.0 - 1.3 500 mL $27.63 10% Dextran-40
(6% Dextran-70)
26 kDa Hospira Dex-40: 6h
Dex-70: 12h
40 mmHg 1.0 - 1.5 500 mL $14.96 Taken from "The ICU Book" by Marino 2008. - Albumin
- Heat-treated preparations of human albumin - available as 5% (50g/L) and 25% (250 g/L) in isotonic saline.
- Solution of 5% comes in aliquots of 250 mL (~70% plasma retention), but lost after 12 hours.
- 25% albumin 3x COP of plasma, draws fluid into interstitial space (increment 4-5x infused volume). Given in 50 mL aliquots where hypovolemia associated with edema (i.e. hypoalbulinemia).
- 25% albumin = no appropriate for replacing volume losses.
- Old Research: Increased mortality attributed to albumin infusion
- New Research: Cannot reproduce increase in mortality, but reduced morbidity (comp w/ crystalloid)
- Hydroxyethyl Starch
- Synthetic starch polymer available as 6% solution in isotonic saline.
- 3 preparations (based on molecular weight [MW])
- High MW, Medium MW, Low MW
- Only High MW available in US.
- Drawbacks:
- Increased bleeding with High MW (decreased Factor VIII, and vWF, impaired platelets) [esp if >1.5L is infused in 24hrs]
- Elevates amylase levels (2-3x ULN) for 1 week, making it look like pancreatitis.
- (amylase cleaves hetastarch before renal clearance)
- Accumulates in liver and kidney
- Studies:
- Increased death, AKI, dialysis with 10% HES solution (200kDa) --> caused lower kDa HES to be used.
- Scandinavian trial 6% HES vs. Ringer's Lactate in severe sepsis --> increases mortality.
- CHEST Trial: 7000 adults in ICU 6% HES vs. saline --> no mortality difference, but more dialysis in HES group
- Still used in military, and OR's for rapid volume expansion (but max 33-50 mL/kg)
- Dextrans
- Glucose polymers papared as 10% dextran-40 or 6% dextran-70 (different molecular weights)
- (Both diluted with normal saline)
- Dextran-70 preferred due to longer duration (12h vs. 6h)
- Rarely used due to drawbacks
- Drawbacks:
- Bleeding tendency (Decr. platelet aggregation, Factor VIII, vWF, enhanced fibrinolysis) [not an issue if low-doses used < 20mL/kg/day]
- Coat surface of RBCs, interfere with crossmatching blood. (must wash RBC's prior to Xmatching)
- Also increase ESR (interact with sediment of RBCs)
- Acute renal failure (suspected, not proven)
- Glucose polymers papared as 10% dextran-40 or 6% dextran-70 (different molecular weights)
- Albumin
Colloid vs. Crystalloid
- Colloid Pros
- Much more effective in plasma volume expansion
- 1/3 to 1/4 of volume required to expand the same amount of intravascular volume as crystalloid
- Much more effective in plasma volume expansion
- Colloid Cons
- Expensive
- No documented survival benefit (cannot justify expense)... many studies show equal efficacy
- Crystalloid Pros
- Can cause similar intravascular volume expansion, and much cheaper (must infuse more volume)
- Crostalloid Cons
- Not effective in intravascular volume expansion (goes interstitial)
- Generally:
- Select fluid type for each scenario
- i.e. dehydration --> loss of extracellular fluid --> use crystalloids
- i.e. hemorrhage --> loss of intravascular fluid --> use colloids
Hypertonic Resuscitation
- Using 7.5% NaCl
- Infusing hypertonic saline causes double plasma volume expansion (moves water out of cells)
- Note: No firm indications for hypertonic resuscitation at the present time (2008)
- Potential uses:
- Military (can carry smaller volumes of fluids for larger resuscitation)
- Closed head injury trauma patients (limit cerebral edema)
- Hemorrhage from vascular injury (limit loss from injured vessel)
- Subarachnoid hemorrhage (6% hetastarch in hypertonic saline effective in reducing ICP)
Important Trials
- SAFE Study
- No difference in mortality between Albumin and Normal Saline
- Subgroup: increase in death at 2 years in pts with TBI (traumatic brain injury)
- Albumin = higher ICP
- Finfer 2011:
- Albumin = mortality benefit at 28 days in pts with severe sepsis
- Subgroup: no difference in pts with or without hypoalbuminemia.
- FEAST Study (Fluid Expansion as Supportive Therapy)
- African 3141 children presenting with febrile illness randomized to:
- Fluid Bolus (20-40mL/kg) vs. Maintenance (albumin or crystalloid)
- Result: Bolus = worse outcomes
- Result: No difference albumin vs. crystalloid
- African 3141 children presenting with febrile illness randomized to:
- Scandinavian trial 6% HES vs. Ringer's Lactate in severe sepsis --> increases mortality.
- CHEST Trial: 7000 adults in ICU 6% HES vs. saline --> no mortality difference, but more dialysis in HES group
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