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Flashcards in fluid and blood product management Deck (105)
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1
Q

what is the major component of the body?

A

water (50-70% of body weight)

2
Q

what is water percentage influenced by?

A
  • gender
  • age (decreases with age; water babies vs. dry elderly)
  • tissues (fat holds less water than lean tissue; thin person has more water than obese person)
3
Q

describe intracellular fluid volume

A
  • 2/3 of total body water (28 L in a 70 kg male; 40% total body weight)
  • fluid inside all cells, aqueous medium
  • most of the potassium is here
4
Q

describe extracellular fluid volume (ECF)

A
  • 1/3 of total body water (14 L in 70 kg male; 20% total body weight)
  • fluid outside cells in cardiovascular system, organs, and interstitial spaces
  • most of sodium is here
  • two compartments: plasma volume (PV) and interstitial fluid volume
  • compartment that is replaced with fluid management
5
Q

describe plasma volume (PV)

A
  • 1/4 of ECF (3.5 L)
  • intravascular fluid, but outside the erythrocytes
  • 8-9% of total body water
6
Q

describe interstitial fluid (ISF)

A
  • 3/4 of ECF (10.5 L)
  • extravascular, interstitial fluid, extracellular
  • separated from the plasma volume by the walls of the blood vessels
  • very little in the form of free fluid (increased clinically is edema)
  • lymph, cavity fluid (peritoneal, pericardial, pleural), transcellular fluids (salivary, hepatic, biliary, pancreatic, dermal, mucosal, etc.)
7
Q

what happens continuously between the different fluid compartments?

A

there is a continuous exchange of water between the different fluid compartments

8
Q

what forces influence the movement of fluid between the compartments?

A
  • hydrostatic pressure

- osmotic pressure

9
Q

what is hydrostatic pressure?

A

the pressure within the capillaries from the weight of the blood and the pressure from the cardiac pumping mechanics

10
Q

what results from hydrostatic pressure?

A
  • small amounts of intravascular plasma volume moving into the interstitial fluid compartment
  • typically, this water returns to the venous capillaries from the interstitial fluid compartment maybe through the lymph
11
Q

what is osmotic pressure?

A

the hydrostatic pressure that must be applied to the solution of greater concentration to prevent water movement across the membrane
*forces wanting to keep fluid in; “pulls” on fluid

12
Q

how does osmotic pressure work?

A

when two compartments are separated by a semipermeable membrane with aqueous solutions of unequal concentrations, the water will move from the more dilute to the more concentrated solution in an effort to equalize the concentrations

13
Q

which end of the capillary has a net loss (fluid moving out)?

A

arterial end

*more loss on arterial end than gain on venous end

14
Q

which end of the capillary has a net gain (fluid coming back in)?

A

venous end

15
Q

what does the solutions that exist in the compartments contain that accounts for osmotic forces?

A

electrolytes

  • Na+: plasma, interstitial (extracellular)
  • K+: intracellular
    proteins: albumin
16
Q

what is the purpose of fluid management?

A

maintain tissue perfusion

17
Q

what is tonicity?

A

compares osmolality of solutions; the effect of a solution on the cell volume

18
Q

describe isotonic

A
  • osmolality of solution is the same (isoosmotic) as that of body fluids
  • nothing happens to the cell
  • NS, LR, plasmalyte
  • plasmalyte is very similar to normal plasma
  • NS is isotonic but is different and too much can create acidosis
19
Q

describe hypertonic

A
  • osmolality of solution is higher than body fluids causing water to move out of cells
  • shrinks cells
  • 5% NS, 10% Mannitol
  • neuro use; helps shrink cerebral edema or shrinks cerebral tissue to allow surgeon easier access to site and closure of cranium
20
Q

describe hypotonic

A
  • have a lower osmolality than body fluids causing absorption of water by cells
  • cell swells (bursts)
  • rarely ever want this to happen
  • 1/2 NS, D5W (starts off isotonic but the metabolism of glucose causes to become hypotonic and absorb water
  • avoid in neuro patients (increases swelling)
  • avoid with any ischemia (glucose products increase damage)
21
Q

what contributes to volume deficit?

A
  • prolonged NPO time
  • bowel prep
  • blood loss
  • excessive blood drawn
22
Q

what clinical signs may be seen with volume deficit?

A
  • blood pressure: orthostatic hypotension; > 20 mmHg indicates a deficit of 6-8% (w/o vasodilation); decreased BP with inspiratory gas flow (PPV decreases VR)
  • heart rate: increases with hypotension; r/o medication related
  • mucous membrane moisture: dry
  • skin turgor: poor
  • urine output: decreased
23
Q

what is considered mild dehydration?

A

-less than 5% wt loss
-dry mouth, malaise, decrease UOP
-normotensive, normal cap refill
May be d/t vomiting or diarrhea

24
Q

what is considered moderate dehydration?

A

5-10% reduction in body weight

  • lethargy, loss of appetite, thick mucous membranes, oliguria, eyes sunken, depression of anterior fontanelle (in infants up to 6 months)
  • normotensive, HR increased, capillary refill slowed to 3 seconds
25
Q

what is considered severe dehydration?

A

> 10% decrease in body weight

  • hypotension less than 60 mmHg, tachycardia, mottled cool skin, cap refill greater than 3 sec., anuria
  • if suspected, give 10-20 ml/kg bolus (caution with CHF)
26
Q

what contributes to volume excess?

A
  • excessive fluid administration
  • fluid absorption
  • cirrhosis of the liver
  • renal failure
27
Q

what procedures put the pt. at risk for fluid excess?

A

transurethral resection of the prostate (TURP) and hysteroscopy

  • both open up sinuses which absorb irrigation fluid
  • best option is a regional with these procedures since Na+ changes are easily indicated with CNS changes which can not be assessed with GA
  • know pre op Na+ levels
28
Q

what clinical signs would indicate volume excess?

A
  • edema: scleral, conjunctiva, pulmonary edema if severe
  • diuresis: > 100 ml/hr
  • initially HTN, progresses to hypotension if cardiac failure
  • *if in CHF, treatment should be completed before selective anesthesia; unless surgery is a matter of death, delay and consult cardiology
29
Q

how does volume deficit influence sodium concentration?

A
  • increased concentration
  • electrolyte free water is lost, serum sodium and serum osmolality increase
  • d/t inadequate water intake, fever, loss of fluid from burns
30
Q

how does volume excess influence sodium concentration?

A
  • decreased concentration

- when water is present in body fluids in excess, the serum sodium and serum osmolality decrease

31
Q

when is hyponatremia seen with hypovolemia?

A

when electrolyte rich fluids are lost and replaced with water

  • vomitus, diarrhea, fistula drainage
  • treatment: replacement fluids with electrolytes (LR)
32
Q

when is hyponatremia seen with normovolemia?

A

when kidneys fail to conserve sodium

33
Q

when is hyponatremia seen with hypervolemia?

A

absorption of fluids from TURP, if D5W used to replace volume deficit

34
Q

what are crystalloids?

A
  • initial fluids
  • intravascular half life 20-30 minutes
  • LR, NS, plasmalyte
  • choice based on fluids being replaced
  • isotonic
35
Q

describe LR

A
  • more physiologic than NS in large volumes
  • contains sodium (103), chloride (109) potassium (4), calcium (3), and lactate (28)
  • if give massive blood transfusion, not good to run with LR since Ca+ eventually binds with the citrate in the blood
36
Q

describe NS

A
  • large volumes produce dilutional hyperchloremic acidosis (bicarb decreases as chloride concentration increases)
  • preferred for transfusing PRBCs
  • best option for renal failure since no potassium
  • no electrolytes but isotonic osmolality
37
Q

describe plasmalyte

A
  • more similar to plasma
  • doesn’t contain Ca+ so can give with blood
  • if giving a lot of volume, doesn’t alter pH like LR or NS
38
Q

what are colloids?

A
  • fluids with a higher molecular weight than crystalloids
  • contain large osmotically active substances (proteins, glucose, etc.) giving greater osmolality (10% Dextran > 25% albumin > 6% Dextran > 6% Hetastarch > FFP = 5% albumin)
  • intravascular half life 3-6 hours
  • risk for anaphylaxis
  • may develop coagulopathy
39
Q

what are indications for colloid use?

A
  • severe hypovolemia (corrects more rapidly than crystalloids)
  • may preload with a colloid if extreme blood loss is expected
  • no O2 carrying capacity so must replace RBCs
40
Q

describe albumin

A
  • natural
  • from pooled donor plasma (increased risk of contracting infection)
  • heated to 60 degrees C to reduce viral infections, hepatitis v. blood products
  • high molecular weight proteins
  • 25% in small volume (50cc) = hypertonic
  • 5% with volume expanded with NS to 250-500 cc = isotonic
41
Q

describe Dextran

A
  • synthetic
  • dextrose starches: Macrodex, Rheomacrodex
  • improves micro-circulation by decreasing blood viscosity and platelet effects
  • can have significant effect on coagulation
  • if more than 1.5 gms/kg given, bleeding times need to be checked
  • potential for anaphylactic reaction
  • Dextran 1 acts as hapten, binds with antibodies to prevent reaction (give prior to running fluid)
  • must use a pump
42
Q

describe Hespan (hetastarch)

A
  • synthetic: plant starch
  • dilutional effect of coagulation
  • inhibits platelets/clot formation (impairing von Willebrand factor and factor VIIIc)
  • 20 ml/kg (500-1000 ml) is the max to infuse to avoid coagulopathy
  • no antigenic effect; rare anaphylaxis
43
Q

describe Voluven

A
  • hydroxyethyl starch (tetrastarch)
  • allows 50 ml/kg per day
  • more rapidly metabolized, higher clearance (20-30x higher), minimal tissue storage
  • equivalent to hetastarch d/t higher number at a lower molecular weight; no decrease in osmotically active particle
44
Q

what is the recommended ratio when replacing fluids with a crystalloid?

A

3:1
replace with 3x fluid loss
ex: lost 200 ml, replace 600 ml

45
Q

what is the recommended ratio when replacing fluids with a colloid?

A

1: 1
ex: lost 200ml, replace 200 ml

46
Q

what are the advantages of crystalloid use?

A
  • inexpensive
  • promotes urinary flow
  • restores 3rd space loss
  • used for extracellular fluid replacement
  • used for initial fluid resuscitation
47
Q

what are disadvantages of crystalloid use?

A
  • dilutes plasma proteins
  • causes reduction of capillary osmotic pressure
  • causes peripheral edema
  • has a transient effect
  • has potential for pulmonary edema
48
Q

what are advantages of colloid use?

A
  • causes sustained increase in plasma volume
  • requires smaller volumes for resuscitation
  • causes less peripheral edema
  • tends to remain intravascular
  • more rapid resuscitation
  • useful in conditions of altered vascular permeability
49
Q

what are disadvantages of colloid use?

A
  • expensive
  • can cause coagulopathy (dextran > hetastarch > hextend)
  • can cause anaphylactic reaction (dextran)
  • decreases Ca++ (albumin)
  • can cause renal failure (dextran)
  • can cause osmotic diuresis
  • can cause impaired immune response (albumin)
50
Q

what are 4 requirements of fluid management?

A
  • maintenance fluid infusion
  • correction of pre existing volume deficit
  • replacement of ongoing fluid losses
  • adjustment of amount and composition of fluids
  • normothermic, normal metabolic rate replace 1.5 ml/kg/hr
51
Q

describe maintenance fluids

A
  • greater fluids required for decreasing size (smaller or younger require more)
  • there is a deficit association between metabolic rate and water requirements
  • smaller size has greater metabolic rate requiring more fluid
  • 1 ml of water is required for every kcal expended
  • 4-2-1 rule
52
Q

explain the 4-2-1 rule

A

-for the first 10 kg of weight start rate of 4 ml/kg/h
-for the next 10 kg (10-20 kg) add 2 ml/kg/hr
-for each kg above 20 kg add 1 ml/kg/hr
ex: 25 kg child maintenance fluid requirements
first 10 kg = 4 ml/kg/hr; next 10 kg (from 10-20kg) add 2 ml/kg/her; for remaining 5 kg add 1 ml/kg/hr (40 + 20 + 5 = 65 ml/hr)

53
Q

using the 4-2-1 rule for maintenance fluid requirements, what is the rate required for a 70 kg pt.?

A

first 10 kg = 40 ml/hr
next 10 kg = 20 ml/hr
remaining 50 kg = 50 ml/hr
total rate = 110 ml/hr

54
Q

describe replacement of fluid deficits

A
  • pre op deficits
  • calculate maintenance fluid rate
  • multiply by the number of hours NPO
  • *administer 1/2 over the first hour, then 1/4 each over the next two hours
  • also assess for volume deficits
    ex: 7 hrs NPO, 70 kg pt.: maintenance rate of 110 ml/hr multiplied by 7 hrs = 770 ml
55
Q

describe replacement of ongoing fluid loss

A
  • intra op blood loss
  • with initial blood loss, ISF and extravascular fluid are transferred to the intravascular space, which maintains PV
  • if replacing blood loss with crystalloid, they must be given 3x blood loss (replenishes intravascular and ISF)
  • if colloids used to replace blood loss, usually given 1:1 since they remain intravascular
  • when risk of anemia is > than risk of transfusion, give PRBCs 1:1
  • even if RBCs don’t need to be replaced, always replace volume (decreased N/V, shorter post op stay)
56
Q

describe third spacing

A
  • the distributional change of isotonic solution from a functional fluid compartment to a nonfunctional space
  • caused by surgical trauma, muscle injuries, burns, peritonitis, or ascites (all cause tissue damage)
  • starts with incision during surgery
  • difficult to assess the degree of surgical trauma so look at procedure and use most restrictive fluid replacement plan if only minimal third spacing
57
Q

describe evaporative losses

A
  • air turnover in operative suite
  • respiratory evaporation
  • skin, wound, airway loss
  • skin and airway: 0.5-1 ml/kg/hr loss
58
Q

give examples of procedures and estimated third spacing and evaporation along with recommended fluid replacement

A
  • minimal (herniorrhaphy, lap chole): 0-2 ml/kg
  • moderate (open cholecystectomy, not involving bowel): 2-4 ml/kg
  • severe (bowel resection): 4-8 ml/kg
59
Q

when should you give a blood transfusion?

A
  • Hct 25 if pathophysiology can tolerate
  • Hct 29 if elderly
  • individual pt. decision depending on if pathology requires maximization of O2 carrying capacity
60
Q

what are estimated blood volumes for adults?

A

-men: 75 ml/kg
-women: 65 ml/kg
(avg 70 ml/kg)

61
Q

how is allowable blood loss calculated?

A

ABL=
estimated blood volume (EBV) x (Hct start - Hct allowed) all divided by Hct start
(if use Hgb or 8 g/dl or 10 g/dl in elderly or cardiac/pulmonary disease)

62
Q

how is estimated red cell mass (ERCM) calculated?

A

-EBV x Hct

63
Q

how is acceptable red cell loss (ARCL) calculated?

A

ERCM - ERCM at target Hct

*ERCM at target Hct = EBV x target Hct, so ERCM(25) = EBV x 25

64
Q

how is acceptable blood loss (ABL) calculated?

A

ARCL x 3

65
Q

what are the antigens on the erythrocytes’ membranes that determines blood type?

A

A, B, Rh (D)

*no antigen is O Type

66
Q

what antigens are in the plasma?

A
  • anti-A and anti-B form in the plasma naturally to which ever antigens that are not present
    ex: Type A has A antigens and antibodies against B antigens
  • D antibodies only form when exposed to the antigen (- mom w/ + baby)
67
Q

describe blood Type A

A
  • A antigen on RBC
  • anti-B antibodies in serum
  • compatible with A, O
68
Q

describe blood Type B

A
  • B antigen on RBC
  • anti-A antibodies in serum
  • compatible w/ B, O
69
Q

describe blood Type AB

A
  • A and B antigens on RBC
  • no antibodies
  • compatible w/ AB, A, B, and O
70
Q

describe blood Type O

A
  • no antigens on RBC
  • anti-A and anti-B antibodies in serum
  • compatible w/ O only
71
Q

describe Rh positive blood

A
  • D antigen on RBC (in addition to A or B if present)
  • no antibodies against D antigen present in serum
  • compatible with Rh + and Rh -
72
Q

describe Rh negative blood

A
  • no D antigen on RBC
  • anti-D if sensitized present in serum
  • compatible with Rh - only
73
Q

what happens during the typing procedure?

A

donor blood is exposed to serum of known antibodies and observed for antigen antibody reaction
*confirmation of the result is by mixing the donor serum with erythrocytes of a known antigen

74
Q

what happens with ABO incompatibility?

A

hemolysis of RBCs (can lead to renal failure)

75
Q

which antigen is the most common?

A

D antigen, appearing on 85% of patient’s RBCs (Rh +)

76
Q

describe crossmatching

A

-45-60 minutes
-unit specific
-double checks ABO and Rh type (5 min)
3 tests
-Major: donor’s RBCs (cell’s antigens from the bag) with recipient’s plasma (serum with antibodies)
-Minor: recipient’s RBCs with donor’s plasma (not much plasma in donor PRBCs)
-check for IgE antiboides (Kell, Kidd)
**crossmatch does an in vitro check of what is to occur in vivo

77
Q

describe type and screening

A
  • check ABO and Rh type of recipient
  • 30 min
  • not unit specific, just screened for antibodies in general
  • indicated if blood loss is a possibility, but no likely
  • stored blood is available to more than one pt.
78
Q

how quick can type specific blood and O negative blood be available?

A
  • type specific: 5 minutes

- O negative: immediately

79
Q

what are the chances of reaction between crossmatching, type and screening, type specific, and O negative?

A
  • crossmatch: 1: 100,000
  • type and screen: 1: 10,000
  • type specific: 1: 1,000
  • O negative: 1: 500
80
Q

describe transfusion of O negative blood

A

-no antigens on RBCs
-Rh negative has no D antigen
-Universal donor
-small amount of plasma in PRBCs of O neg (2 units) can contain sufficient amounts of anti-A and anti-B antibodies to result in hemolysis
**once O negative is given, have to stick with O negative
(better to start with crossmatch, then type and screen, then type specific and save O negative as last resort)

81
Q

describe blood storage

A
  • CPD (citrate-phosphate-dextrose) or CPD-A (adenine) preservative added
  • stored at 1 to 6 degrees Celsius
  • last 21 days for CPD
  • lasts 35 days for CPD-A
  • over time blood changes
  • K+ is 3.9 at day one; 21 at day 21
  • pH at day 1 is 7.1; 6.9 at day 21
  • PCO2 is 48 at day 1; 140 at day 7
  • viable platelets is 10% at day 1; 0 at day 7
  • factor V, VII 70% day 1; 20% day 7
  • *fresh blood is better
82
Q

describe packed red blood cells

A
  • volume 250-300 ml
  • Hct 70-80%
  • indication: anemia associated with acute blood loss; to increase oxygen carrying capacity of blood
  • reconstitute with crystalloid (NS, Plasmalyte) 50-100 ml (decreases viscosity and can give faster; don’t use too much or will dilute Hgb)
  • less plasma than whole blood (only used with blood loss > 1500)
83
Q

how does PRBCs increase Hct?

A

for every 1 ml of PRBCs transfused per kg of body weight, Hct should rise about 1%

84
Q

how much should each unit of PRBCs raise Hct?

A

based on average blood volume of 5000 ml, each PRBC unit should raise the Hct by 3-4%

85
Q

with pediatrics, how does transfusion raise Hct and Hgb?

A

10ml/kg will increase Hct by 10% or Hgb by 3%

86
Q

describe platelets

A
  • indications: tx of thrombocytopenia w/o giving unnecessary blood
  • one unit increases plt. count 10,000 to 20,000 mm3 one hour after
  • half-life approx. 24 hrs.
  • risks: sensitization to HLA antigens on cell membranes; transmission of viral disease d/t multi donors (may give Tylenol before)
87
Q

when should platelets be giving during a spleenectomy?

A
  • spleen is chewing up platelets
  • start when artery to spleen is clamped so new platelets wont be used up
  • surgery will start with a low platelet count
88
Q

describe fresh frozen plasma

A
  • plasma protein form a unit of whole blood that is frozen within 6 hours of collection (must be thawed so plan ahead)
  • contains coagulation factors except platelets (may need to give both)
  • indication: treatment of coagulation factors (may be diluted out); if no response from heparin
  • single unit (250 ml) should raise levels by 7-8%
  • risks: transmission of viral diseases and allergic reactions
89
Q

describe cryoprecipitate

A
  • primary source of von Willebrand factor; also contains factor VIII, fibrinogen, and fibronectin
  • indications: treating hemophilia; DIC w/ fibrinolysis
  • risks: transmission of viral diseases and allergic reactions
90
Q

describe a febrile transfusion reaction

A
  • most common
  • temperature rarely increases above 38 degrees C
  • treat by slowing transfusion and giving antipyretics and maybe Benadryl
91
Q

describe an allergic transfusion reaction

A
  • fever, pruritus, and urticarial
  • treat by admin. antihistamines
  • in severe cases, discontinue blood
  • look for hgb in the urine to r/o hemolytic reaction
  • usually r/t to plasma products
92
Q

describe hemolytic transfusion reaction

A
  • d/t ABO incompatibility
  • primarily occurs when a human error leads to admin. of ABO incompatible blood
  • even if everything checks out, if see signs, treat! (error usually in lab)
93
Q

what are signs of hemolytic reaction?

A
  • first sign under GA is hypotension
  • free hgb in the urine also a sign (acute renal failure is caused by precipitation of contents of hemolyzed RBCs in the distal renal tubules)
  • flush with fluid to prevent tubules clogging
  • DIC is initiated by material released from hemolyzed RBCs (again, flush with fluids)
  • volume of RBCs transfused determines severity of reaction so STOP
94
Q

what is the treatment for hemolytic transfusion reaction?

A
  • DC transfusion
  • infuse crystalloid (NS)
  • administer mannitol or Lasix or dopamine
  • administer sodium bicarb to alkalinize the urine and increase the solubility of products in the renal tubules
  • confirm hemolysis (send to lab)
  • re crossmatch
  • return unused portion of donor unit to blood bank
  • treat coagulopathy with platelet and coagulation factors (FFP and platelets)
  • *alert surgeon and anesthesiologist
95
Q

what are the chances of infectious disease with transfusions?

A
  • HIV: 1: 1,400,000
  • hepatitis C: 1: 1.9 million
  • 1: 10,000 transfused pts. will develop chronic hepatitis leading to liver failure or hepatocellular cancer (out of the chance of catching hepatitis C)
  • everyone is immune suppressed with transfusion
96
Q

describe microaggregates

A
  • formed in storage by platelets and leukocytes and increases with time in storage
  • associated with pulmonary dysfunction
  • fewer in PRBCs than whole blood
  • administer blood through 40 micron filters
  • standard blood filter is 170 micron filter
97
Q

what are the risks with large volume transfusions?

A
  • hypothermia: cardiac irritability (v fib) shivering, increased VO2 (*must warm blood)
  • hyperkalemia: K+ content increase with time storage; transfusion of one unit every 5 min. causes increase; if see peak T wave consider CaCl
  • acid-base changes: pH of stored blood becomes more acidic the longer it is stored; preservative has pH 5-6.5
  • citrate metabolism to bicarb may contribute to metabolic alkalosis
  • citrate binds calcium resulting in hypocalcemia (rare)
  • supplement Ca++ if transfusion rate > 50 ml/min, hypothermia or liver disease interferes with metabolism of citrate, or neonate
98
Q

describe dilutional thrombocytopenia risk with transfusions

A
  • platelets abent from stored blood after 24 hrs

- platelet level below 100,000 associated w/ increased bleeding

99
Q

describe dilution of factors V and VIII with transfusions

A
  • only 5-20% of normal level are necessary for normal clotting
  • rare that this is a problem
  • if needed, give FFP (usu. if need to try anything)
100
Q

describe DIC with transfusions

A
  • activation of the coagulation system with consumption of platelets and coagulants
  • remove the cause and administer platelets and FFP
101
Q

what are alternatives to blood transfusions?

A
  • autologous transfusions
  • cell saver
  • normovolemic hemodilution
  • donor-directed transfusions
102
Q

describe autologous blood transfusions

A
  • pt. donates own blood
  • collection started 4-5 weeks prior to surgery
  • donation allowed if Hct is 34%
  • may be given iron supplements
  • minimum of 72 hrs b/w donations to allow plasma volume to normalize
  • not complication free: clerical errors, allergic reactions to ethylene oxide
103
Q

describe cell saver

A
  • blood salvage and reinfusion
  • used during cardiac, vascular, and orthopedic cases
  • suction with heparin solution to collect
  • when sufficient amount is collected, RBCs are concentrated and washed to remove debris and anticoagulant and reinfused
  • hematocrit usually 50-60%
  • best if blood loss exceeds 1000-1500 ml (peds may not be an option)
  • contraindications: septic wound, malignant tumor
  • for anticipated significant blood loss
104
Q

describe normovolemic hemodilution

A
  • blood is removed from the patient just prior to surgery and replaced with crystalloid or colloid to achieve a Hct of 21-25% (must be a healthy pt.)
  • stored in a CPD bag until the end of surgery (6 hrs.) or end of blood loss (better), if possible to keep hemodynamically stable until stopped (individual based)
  • then reinfused
  • principle is that the number of RBCs lost in a dilute blood loss is reduced; yet CO is maintained by the normovolemic state
105
Q

describe donor directed transfusions

A
  • blood donated from ABO compatible friends and family members
  • requires 3-7 days to process
  • studies have shown that bank blood is safer or there is no difference (higher potential to transmit viral disease)