Blood Therapy Flashcards
Purpose of Parenteral Fluid Therapy
maintenance fluids
replacement of fluids lost as a result of surgery and anesthesia
correction of electrolyte disturbances
Lactated Ringers avg ph
6.5
Lactated Ringers osmolarity
273mOsm/L
Lactated Ringers Electrolyte composition
130 mM Na 109 mM CL 29 mM lactate 4mM K 2.7 mM Ca2+
Normal Saline pH
5
Normal saline osmolarity
308mOsm/L
Normal saline composition
154mM Na and Cl
Advantages of Crystalloids
inexpensive promotes urinary flow restores third space loss used for ECF replacement used for initial resusitation
Disadvantages of Cystalloids
dilutes plasma proteins reduce capillary osmotic pressure peripheral edema transient potential for pulmonary edema osmotic diuresis impaired immune response
Advantages of Colloid
sustained increase in plasma volume
requires smaller volume for resusitation
less peripheral edema
more rapid resuscitation
Disadvantages of Colloid
can cause coagulopathy (dextan >hetastartch >hextend)
anaphylatic reaction (dextan)
decreases Ca2+ (albumin)
can cause renal failure (dextran)
Main categories of IV fluids
crystalloids and colloids
Crystalloids
normal saline
lactated ringers
Colloids
albumin
plasmanate
dextran
hetastarch
Normal saline
hyperchloremic
metabolic acidosis
Lactated ringers
metabolic alkalosis
potassium accumulation in patients with renal failure
Colloids
solutions containing osmotically active substance of high molecular weight that do not easily cross the capillary membrane and space and expand circulating volume
Albumin
manufactured from pooled donor plasma
indications for albumin
treatment of shock d/t loss of plasma, acute burns, fluid resusicatation, hypo-albumineamia, following paracentesis, liver transplantation
Adverse reactions for albumin
pruritus, fever, rash, N&V, tachycardia
Albumin is supplied
5% and 25% solutions
Duration of Albumin
16-24 hours
Plasmanate
protein containing colloid
Indications of plasmanate
hypovolemic shock (esp burn shock) hypoproteinia (low protein states)
Adverse reactions of plasmanate
reactions, chills, fever, urticaria, N&V
Duration of Plasmanate
24-36 hours
Supplied of Plasmanate
5% solution in 250ml and 500ml
Dextran
artifical colloid: polysaccharides molecules
Indications of Dextran
improve micro-circulatory flow in microsurgeries, extracorporeal circulation during cardiopulmonary bypass
Adverse Reactions of Dextran
anaphylaxis, coagulation abnormalites, interference with cross match blood, precipitation of acute renal failure
Dextran Supplied
dextran 70
6% solution with average Mw 70,000;
Dextran 40
10% solution with avg Mw 40,000
Hetastarch
synthetic
made from plant starch
Indications of Hetastarch
hypovolemia
Max dose of hetastarch
20ml/kg
Adverse Reactions of Hetastarch
hypersensitivity, coagulopathy, hemodilution, circulatory overload, metabolic acidosis
Hetastarch is Supplied
Hespan 6% solution in NS
Duration of Hetastarch
24-36hour
Hextend
6% hetastarch in a buffered solution
lactate buffer
balanced electrolytes
physiologic glucose
Hextend Study
found that hextend could be given in volumes exceeding 20ml/kg without coagulopathy
Voluven
smaller molecule than other HES solution
less plasma accumulation
safer in patients with renal impairment
comparable effects on volume expansion & hemodynamics as other HES solutions
associated with fewer effects on coagulation
acceptable alternative to albumin
Blood component therapy
may be neccessary to increase oxygen carrying capacity increase intravascular volume, and restore hemostasis
Transfusion triggers
perioperative blood loss clinical condition of the patient patient specific blood volume calculation of allowable blood loss access to patient blood type patient preferences
Benefits of Blood Component Therapy
increased oxygen carrying capacity
improved coagulation
Risks of Blood Component Therapy
infection
incompatibility
Estimating Blood Loss (subjective)
measuring net suction volume and counting or weighing sponges
usually underestimated
Estimating Blood Loss (objective)
sodium fluorescein dye
Estimating Blood Loss
POC testing of Hgb or Hct
does not measure amount of blood loss
Clinical Symptoms of Patient
tachycardia
decreased mixed venous oxygen saturation
measurement of systemic oxygen delivery (DO2)
Measuring DO2
DO2= CO xCaO2
CO=
HR xSV
HR x SV
preload
inotropy
afterload
CaO2
1.34 x Hgb x SpO2 + 0.003 xPaO2
Blood volume of full term infant
80-90ml/kg
blood volume of infant
80ml/kg
Blood Volume of Adults
65-70ml/kg
BV of Obese Adult
50ml/kg
Maximum allowable blood loss
EBV x (starting hematocrit - target hematocrit)/ starting hematocrit
Establishing Blood Compatibility
Type and Screen
Antibody testing
Type and Cross
Type and Screen
ABO test Rh Test (aka type D)
Rh Positive test
Rh D Antigen
Rh negative test
no Rh D antigen
Type and Cross
ultimate test of blood compatibility
Type A Blood Group Compatibility
A O
A antigen
Anti-B antibodies
Type B Blood Group Compatibility
B O
B antigen
Anti-A antibodies
Type AB Blood Group Compatibility
AB A B O
Type O Blood group Compatibility
O
Anti- A antibodies
Anti-B antibodies
RH +
RH+ and RH -
RH -
RH-
anti-D if sensitized
Universal Recipient
AB+
Universal Donor
O-
RBC
hemorrhage & improve oxygen delivery to tissues
Indications for RBC
symptomatic in high risk patients
acute blood loss of > 30% BV
hemodynamically unstable patients
FFP
reversal of anticoagulant effects
Platelets
prevent hemorrhage in patients with thrombocytopenia or platelet function defects
Cryoprecipate
hypofribinogenemia (setting of massive hemorrhage or consumptive coagulopathy)
Changes in Banked Blood
depletion of 2,3 diphosphoglycerate (DPG)
Depletion of ATP
oxidative damage
increased adhesion to human vascular endothelium
acidosis
altered morphology of red blood cells (change shape, decreased flexibility)
accumulation of microaggregates
Hyperkalemia
absence of viable platelets
absence of factors V and V111
hemolysis
accumulation of pro-inflammatory metabolic and breakdown of products
Transfusion Trigger
no single transfusion threshold should be based on the specific clinical situation
Hgb < 5g/dl significant mortality
Hgb >10g/dl
usually unneccessary
Hgb 6-10g/dl
based on clinical factors
Hgb <6g/dl
usually neccessary
Most common Surgical Procedures Requiring Transfusion
orthopedic (especially hip and knee replacement) colorectal cardiac major vascular liver transplant trauma
Patient blood management
strategy to reduce unneccessary transfusions and maximize patient outcomes
- optimize patient’s own red blood cell mass
- minimize blood loss
- optimize patient’s physiologic tolerance of anemia
Preoperative Strategies
screen for and treat anemia
treat ion deficiency and administer erythropoiesis- stimulating agents as indicated
identify and manage any bleeding risks such as medications or chronic diseas
assess patient reserve adn optimize patient’s specific tolerable blood loss
formulate management plan with evidence- based transfusion strategy
pre-operative autologous blood donation in select situation
may require preop visit up to 30 days to elective surgery to accomodate therapy
Intra-operative Strategies
perform elective surgery when hematologically optimized
use meticulous blood-sparing surgical techniques
continually measure and assess hemoglobin and hematocrit
plan and optimize fluid management of non-blood products
optimize cardiac output, oxygen delivery, and ventilation
use blood salvage and autologous transfusion when possible
Postoperative strategies
treat anemia with erythropoiesis-stimulating agents and iron deficiency as indicated
vigilant monitoring and management of postoperative bleeding
avoid and/or treat infections promptly
carefully manage anticoagulant medications
Class 1 hemorrhage
<15% reduction in BV
<750ml of BL
>10 Hgb
transfusion not necessary if no pre-existing anemia
Class 2 Hemorrhage
15-30% reduction of volume
750-1500ml
8-10 Hgb
not necessary unless pre-existing anemia or cardiopulmonary disease
Class 3 hemorrhage
30-40% BV
1500-2000ml BL
6-8Hgb
probably neccessary
Class 4 hemorrhage
> 40% BV
2000ml
<6 hgb
neccessary
Massive RBC Transfusion
replacement of estimated blood volume within 24 hours
>10 units of RBCs over 24 hours
50% of BV within 3 hours or less
Massive Transfusion Concerns
dilutional coagulopathy or diluational thrombocytopenia
banked blood anticoagulated with sodium citrate, which binds calcium and inhibits coagulation
rapid infusion can decrease ionized calcium (aka calcium intoxication)
Fresh Frozen Plasma
contains all coagulation factors
Indications for FFP
deficiency of coagulation factors with abnormal coagulation test in the presence of active bleeding
planned surgery or invasive procedure in the presence of abnormal coagulation tests
reversal of warfarin in the presence of active bleeding
warfarin-related intracranial hemorrhage
planned procedure when vitamin K is inadequate to reverse the warfarin factor deficiency with no alternative therapy
trauma patients requiring massive transfusion
Indications for Platelet
prevent bleeding or stop ongoing bleeding in patients with low platelet or functional platelet disorders
Normal platelet count
150,000-450,000 cells/ul
Tranfuse platelets for
less then 50,000 cells/ul but not more than 100,000 cell/ul
50-100k microvascular bleeding or at risk for continued bleeding
Platelet transfusion threshold in bleeding patients
< 50,000 in severe bleeding including disseminated intravascular coagulation
< 30,000 when bleeding not life threatening or considered not severe
<100,000 for bleeding in multiple trauma patients or patients with intracranial bleed
Prophylactic Transfusion Threshold
before neurosurgery or ocular surgery <100
before major surgery <50,000
in dic <50,000
before central line placement <20,000
before epidural anesthesia <80,000
vaginal delivery platelet transfusion is considered at <30 and when traumatic delivery then <50,000
Cryoprecipitate
contains factor VIII (von willebrand factor) & fibrinogen
Indications of Cryoprecipitate
patients with von willebrand disease or patients with probable or documentated deficit in fibrinogen (<80-100)
administer as rapidly as possible (rate atlease 200 an hour)
Blood Transfusion Complications
most common and serious- incompatibility
results in an immune reaction with risk of an acute hemolytic reaction
1/2 of all deaths are caused by procedural or administrative error
clinical picture complicated by GA, which can obscure the symptoms associated with hemolytic reaction
transfusion-associated graft vs host disease
results when donor lymphocytes incorporate themselves into the tissues of the recipient, leading the recipient immune system to attack the embedded recipient tissues
rash, leukopenia, thrombocytopenia
sepsis, death and usually occur as a result
Transfusion related acute lung injury
acute lung injury occuring within 6 hours of transfusion in individuals previously free of ALI
believed to occur as frequently as 1:432 units of platelets or as infrequently as 1:7900 units of FFP
likely underreported because may be confused wiht other forms of ALI
Transfusion Related immunodulation
presence of leukocytes in allogenic blood
homologous transfusions which invariably contain some leukocytes have been implicated in immunosuppression of recipients leading to unexpectedly early recurrence of cancer adn higher then expected rates of postoperative infection
Nonhemolytic transfusion reactions
occurence 1-5% of all transfusions
fever
chills
urticaria
Leukoreduction
use of filters to reduce the level of WBC
proven to be effective in reducing the incidence of nonhemolytic transfusion reactions and is likely to be effective in the reduction of TRIM
leukocytes exert a variety of immunodulatory effects on the recipient in a magnitude that is proportional to the length of time the donor unit is stored
Alternatives to Blood Transfusion
donor directed blood transfusion
autologous blood transfusion
Donor directed blood transfusion
homologous blood transfusion from a donor selected by the recipient and believed by some to decrease the risk of transmission of disease
Cell Salvage
aspiration of blood shed into the surgical field, which is washed to removed debris and then reinfused
Cell salvage is used in
cardiac orthopedic radical prostatectomy nephrectomy AAA aneurysm
Contraindications of Cell salvage
surgery involving wounds contaminated by bacteria, sepsis, bowel contents, amnotic fluid or malignant cells
Preoperative Blood Donation
collection and storage of recipient’s own blood for re-infusion at a later date
half of autologously donated blood is discarded contributing to waste
Pre-Op blood donation risks:
preop anemia (resultant myocardial ischemia)
bacterial contamination
clerical erro
Acute Normovolemic Hemodilution
transfusion alternative involving the removal of whole blood from a patient immediately before or after the initation of anesthesia and surgery and replacing volume with crystalloid or colloid solution
blood lost during surgery will have a low hematocrit
reinfusion of the whole blood (with a normal hematocrit as well as clotting factors) is initated when intraoperative loss of blood has stopped, or earlier if the patient’s condition warrants it
1 Unit of PRBCs will increase
1 hgb g/dl and Hct 2-3% in adults
10ml/kg transfusion of PRBCs will
increase Hgb by 3g/dl and hct by 10%
Platelets are 1 unit
200-400cc
One unit of platelets increases
platelet count by 7l-10k 1 hour post transfusion
Do platelets need to be ABO compatible?
no
How much does one unit of FFP increase clotting level factors by?
2-3%
When is FFP contraindicated?
augmentation of plasma volume or albumin concentration
