Fluid Management Flashcards

1
Q

anion gap

A

difference between cations and anions

Na+-(Cl-+HCO3-)

Normal = <12

>12 indicates pt has metabolic acidosis

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2
Q

Respiratory acidosis results in…

A
  • reduced myocardial contractility
  • increased PVR
  • decreased SVR
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3
Q

Respiratory alkalosis results in…

A
  • hypokalemia
  • hypocalcemia
  • dysrhythmias
  • bronchoconstriction
  • cerebrovasoconstricion
  • hypotension
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4
Q

Metabolic acisosis results in…

A
  • reduced myocardial contractility
  • increased PVR
  • decreased SVR
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5
Q

Metabolic alkalosis results in…

A
  • hypokalemia
  • hypocalcemia
  • arrhythmias
  • compensatory hypoventilation/hypercarbia
  • reduced tissue oxygenation
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6
Q

treatment of metabolic alkalosis

A
  • expansion of intravascular volume
  • administer K
  • administer carbonic anhydrase inhibitor
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7
Q

Base excess or deficit

A
  • Used to measure deviation from normal bicarbonate level to help determine adequacy of intravascular volume
  • 0 = normal bicarbonate level
  • -2 to <0 = metabolic acidosis (base deficit)
  • >0 to +2 = metabolic alkalosis (base excess)
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8
Q
A
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9
Q

Plasma solute concentrations

A
  • Na: 140
  • K: 4.3
  • Mg: 2
  • Cl: 105
  • HCO3-: 24
  • phosphate: 2
  • Protein: 1
  • Total Osm: 291
  • pH: 7.4
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10
Q

ECF solute concentrations

A
  • Na: 140
  • K: 4.3
  • Mg: 2
  • Cl: 105
  • HCO3-: 24
  • phosphate: 2
  • protein: 0
  • Total Osm: 290
  • pH: 7.4
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11
Q

ICF solute concentrations

A
  • Na: 12
  • K: 120
  • Mg: 40
  • Cl: 5
  • HCO3-: 12
  • Phosphate: 100
  • protein: high
  • Total osm: 290
  • pH: 7.2
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12
Q

sources of intra-op fluid requirements

A
  • maintenance
    • healthy adults require 2.5L/day over 24 hours
  • fluid deficit
  • Blood loss
  • evaporative loss
  • 3rd space loss
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13
Q

calculating maintenance fluids

A
  • 4-2-1 rule
  • 4 ml/kg/hr for first 10 kg
  • 2 ml/kg/hr for second 10 kg
  • 1 ml/kg/hr for each additional kg
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14
Q

Fluid deficit

A
  • the maintenace requirement multiplied by the number of hours pt was NPO
    • if receiving maintenace IVF, no NPO deficit
  • if baseline hypovolemia exists, consider the overall deficit greater than just NPO deficit
    • replace fluid to restore MAP, HR and filling pressures BEFORE induction
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15
Q

Fluid deficit replacement strategy

A
  • 1/2 of deficit replaced during first hour of surgery
  • 1/4 of deficit replaced during second hour of surgery
  • 1/4 of deficit replaced during third hour of surgery
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16
Q

Blood loss estimations

A
  • soaked gauze 4x4 = 10 ml
  • soaked laparotomy pads = 100-150 ml
  • suction containers
  • floor and drapes
  • consider if gauze and pads are being used wet or dry by surgeon
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17
Q

floor spill approximations

A
  • 1 inch diameter = 5ml
  • 2 inch diameter = 20 ml
  • 3 inch diameter = 45 ml
  • 4 inch diameter = 80 ml
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18
Q

Estimated blood volume

A
  • neonates
    • premie = 95 ml/kg
    • term = 85 ml/kg
  • infant = 80ml/kg
  • child = 70 ml/kg
  • adult
    • men = 75 ml/kg
    • women = 65 ml/kg
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19
Q

allowable blood loss

A

ABL = (EBV x (starting HCT - allowable HCT))/ starting HCT

*helps anesthetist plan when to transfuse patient

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20
Q

Evaporative loss

A
  • evaporative loss is directly related to amount of surface area of surgical wound and duration of exposure
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21
Q

3rd space loss

A

due to fluid shifts and intravascular volume deficit caused by redistribution of fluids

Ex. trauma, infection, burns, ascites

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22
Q

Replacing evaporative and 3rd space losses

A
  • short, superficial procedure = 0-2ml/kg/hr
  • moderate, uncomp untra-abd, orthopedic = 3-5 ml/kg/hr
  • Severe, long, invasive = 6-9 ml/kg/hr
  • Emergency, mult injuries = 10-15 ml/kg/hr
23
Q

Blood loss replacement

A
  • 3:1 crystalloid for blood
  • 1:1 blood/colloid for blood
24
Q

ERAS

A
  • enhanced Recovery after surgery
    • fluid philosophy of avoidance of sodium and water overload
    • carboloading pre-op
    • maintain normothermia
    • avoid opioids
    • **questioning science behind replacement of 3rd space losses
25
Q

Goal directed fluid therapy

A
  • using advanced monitoring to make estimations of functional circulating volume
  • is the patient going to respond to fluid?
    • stroke volume variation
    • pulse pressure variation
    • systolic pressure variation
26
Q

Frank Starling curve

A
27
Q

hypotonic solutions

A
  • Osm 253
  • replaces water loss
  • called “maintenance fluids”
    • not used in OR
  • Example: D5W
  • water moves into ISF and cells
28
Q

isotonic solutions

A
  • osm 300
  • replaces water and electrolyte loss
  • called replacement fluids
    • used in OR
  • ex: LR, NS
29
Q

hypertonic solutions

A
  • D5 1/2 NS osm (432), 3% NS osm (1026)
  • for hyponatremia or shock
  • draws fluid into intravascular space
30
Q

LR facts

A
  • NS with electrolytes (K+, Ca++) and buffer (lactate)
  • isotonic (275)
    • provides 100 ml free water per liter of solution
    • tends to lower Na+
  • lactate gets converted to bicarb
  • solution most similar to ECF
  • avoid in ESRD b/c it contains K+
  • do not mis with PRBC as the Ca++ binds to citrate in blood
31
Q

LR electrolytes

A
  • Na+ 130 mEq/L
  • K+ 4 mEq/L
  • Ca++ 3 mEq/L
  • Cl- 110 mEq/L
  • lactate 28 mEq/L
  • glucose 0g/L
  • pH 6.5
32
Q

Normal saline facts

A
  • 0.9% NaCl in water
  • isotonic: osm 308
  • in large volume produces high Cl- content which leads to dilutional hyperchloremic acidosis
  • preferred solution for diluting PRBCs
33
Q

0.9% NS electrolytes

A
  • Na+ 154 mEq/L
  • K+ 0 mEq/L
  • Ca++ 0 mEq/L
  • Cl- 154 mEq/L
  • lactate 0 mEq/L
  • glucose 0 g/L
  • pH 6.0
34
Q

Normosol-R electrolytes

A
  • Na+ 140 mEq/L
  • K+ 5 mEq/L
  • Ca++ 0 mEq/L
  • Cl- 98 mEq/L
  • glucose 0 g/L
  • Mg++ 3 mEq/L
  • Acetate 27 mEq/L (buffer)
  • gluconate 23 mEq/L
  • pH 7.4
35
Q

D5W

A
  • hypotonic solution: osm 260
  • rarely used perioperatively
    • causes free water intoxication and hyponatremia
  • provides 170-200 calories/1000 ml for energy
    • can cause hyperglycemia
    • except in DM pt receiving insulin or neonate
36
Q

3% NaCL

A
  • Na/Cl 513 mEq
  • used rarely for low volume resuscitation
  • mostly used to treat hyponatremia
  • risk of hyperchloremia, hypernatremia, and cellular dehydration
37
Q

Colloid solutions

A
  • onsmotically active
    • stay intravascular 3-16 hours while crystalloid stays about 15 minutes
  • high molecular weight
  • volume administered is equivalent to fluid/blood lost from intravascular volume
38
Q

albumin

A
  • obtained from fractionated human plasma
    • possible to have reaction
  • does not contain coagulation factors or blood group antibodies
  • available as 5% or 25%
    • size of molecule, which determines different oncotic pressures
  • 5% solution common in OR
    • 5% solutions causes oncotic pressure of 20
39
Q

Dextran

A
  • Synthetic colloid
  • water soluble glucose polymers that get enzymatically degraded to glucose
    • might have to give extra insulin
  • Dextran 70- used for volume expansion
    • draws fluid in from ISF
  • Dextran 40- used for prevention of thrombosis
    • decreases viscoscity of blood
40
Q

Dextran side effects

A
  • anaphylactoid reaction
  • platelet inhibition
  • noncardiac pulmonary edema
  • inerference with crossmatching
41
Q

Hetastarch

(Hespan 6%)

A
  • synthetic colloid
  • as effective as albumin for volume expansion
  • nonantigenic- does not create immune response
  • cheaper than albumin
  • stored in reticuloendothelial system for several hours and renally excreted
  • max dose: <20 ml/kg/day because it pulls SO much fluid from cells
  • oncotic pressure 30
42
Q

indications for blood transfusions

A
  • expand intravascular volume
  • *increase oxygen carrying capacity
  • hemoglobin and hematocrit
    • rarely if HGB > 10
    • definitely if HGB <6
    • if between, depends on pts risk for complications and inadequate oxygenation
    • use of “trigger” not recommended
43
Q

risks of blood product administration

A
  1. Hepatitis B or C
  2. HIV
  3. Bacterial sepsis
  4. allergic reactions/febrile reactions
  5. lung injury
  6. hemolytic reactions
  7. noncardiogenic pulmonary edema
  8. acute hypotensive transfusion reaction
44
Q

PRBCs facts

A
  • Type and Rh factor is sufficient for most people to be compatible
  • 1 unit PRBC increases HGB 1 gm/dl
  • HCT of one unit is 70%
    • decreases as the PRBCs age
45
Q

PRBCs reconstituted with:

A
  • 0.9% NS
  • 5% dextrose in 0.4% NS
  • 5% dextrose in 0.9% NS
  • Normosol-R
46
Q

PRBC citrate toxicity

A
  • citrate binds to Ca++, causes hypocalcemia
  • monitor ionized calcium
47
Q

complications of autologous blood

A
  1. anemia
  2. pre-op myocardial ischemia from the anemia
  3. administration of the wrong unit
  4. need for more frequent blood transfusion
  5. febrile and allergic reaction
48
Q

Platelet facts

A
  • one unit comes from centrifuging single unit of whole blood
  • volume 200-400 ml
  • one unit increases platelet count 7,000-10,000 one hour after transfusion
  • incidense of platelet related sepsis is 1 in 12,000
    • bacterial contamination risk 1:2,000
49
Q

Platelet uses

A
  1. thrombocytopenia
  2. dysfunctional platelets
  3. active bleeding
  4. platelet count <50,000
50
Q

FFP facts

A
  • contains clotting factors and plasma proteins
  • volume 200-250 ml
  • must be ABO compatible
  • each unit increases each clotting factor level by 2-3%
51
Q

FFP uses

A
  1. urgent reversal of warfarin
  2. know coagulation factor deficiencies
  3. correction of microvascular bleeding when PT or PTT is increased
  4. correction of microvascular bleeding in a pt transfused with more than one blood unit when PT and PTT cannot be obtained in timely fashion
52
Q

cryoprecipitate facts

A
  • the last thing to consider transfusing
  • derived from precipitate remaining after FFP is thawed
  • ABO compatible
  • administer rapidly through filter 200 ml/hr, complete within 6 hours
53
Q

cryoprecipitate contents

A
  1. factor VII
  2. fibrinogen
  3. vWF
  4. XIII
54
Q

Cryoprecipitate uses

A
  1. von Willebrand’s disease
  2. fibrinogen deficiencies