Practice Guidelines for Perioperative Blood Transfusion and Adjuvant Therapies

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Practice Guidelines for Perioperative Blood
Transfusion and Adjuvant Therapies
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• Anesthesiology 2006105198-208

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Purpose of the Guidelines

• Improve the perioperative management of blood
  transfusion and adjuvant therapies
• Reduce the risk of adverse outcomes associated
  with transfusions, bleeding, or anemia.
• Update on the relative risks that cause morbidity
  and mortality associated with blood transfusion
  and adjuvant therapies.

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Focus

• Perioperative management of patients undergoing
  surgery or other invasive procedures in which
  significant blood loss occurs or is expected.
• (1) patients undergoing cardiopulmonary bypass or
  cardiac surgery, urgent or emergent procedures,
  obstetric procedures, organ transplantation, and
  major noncardiac surgery (2) patients with
  preexisting blood disorders or acquired
  deficiency secondary to massive bleeding (3)
  critically ill patients and (4) patients who
  elect not to undergo transfusion.
• Excluded neonates, infants, children weighing
  less than 35 kg, and nonsurgical patients.

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Availability and Strength of Evidence(1)

• Support sufficient randomized controlled trials
  indicates a statistically significant
  relationship( plt0.01)
• Suggest case report and observational studies,
  relationship between intervention and outcome
• Equivocal not found significant differences
  among groups or conditions
• Silent No identified studies address
  relationship between intervention and outcome
• Insufficient too few studies investigate
• Inadequate available studies cannot be used to
  assess the relationship

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Availability and Strength of Evidence(2)

• Strongly Agree Median score of 5 (at least 50
  of the responses are 5)
• Agree Median score of 4 (at least 50 of the
  responses are 4 or 4 and 5)
• Equivocal Median score of 3 (at least 50 of the
  responses are 3, or no other response category or
  combination of similar categories contain at
  least 50 of the responses)
• Disagree Median score of 2 (at least 50 of the
  responses are 2 or 1 and 2)
• Strongly Disagree Median score of 1 (at least
  50 of the responses are 1)

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Preoperative Evaluation

• Previous medical records, physical examination,
  identify risk factors for (1) organ ischemia
  (e.g., cardiorespiratory disease), which may
  influence the ultimate transfusion trigger for
  red blood cells (e.g., hemoglobin level), and (2)
  coagulopathy (e.g., use of warfarin, clopidogrel,
  aspirin), which may influence transfusion of
  nonred blood cell components.
• Checking congenital or acquired blood disorders,
  vitamins or herbal supplements that may affect
  coagulation, or previous exposure to drugs (e.g.,
  aprotinin) that may, upon repeat exposure, cause
  an allergic reaction.

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Preoperative Evaluation

• Patients should be informed of the potential
  risks versus benefits of blood transfusion, and
  their preferences elicited.
• Laboratory results including, but not limited to,
  hemoglobin, hematocrit, and coagulation profiles
  should be reviewed if they are appropriate and
  available.
• Additional laboratory tests should be ordered
  based on a patient's condition (e.g., clinical
  coagulopathy) or institutional policy.

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Preoperative Preparation(1)

• Well enough in advance to correct or plan for the
  management of risk factors associated with
  transfusions.
• Elective surgery discontinuing anticoagulation
  therapy for a sufficient time in advance of
  surgery. If sufficient time has not elapsed,
  surgery should be delayed.
• Clopidogrel last for approximately a week,
  warfarin last for several days depending on
  patient response and the administration of
  reversal agents (e.g., vitamin K, prothrombin
  complex concentrate, recombinant activated factor
  VII, or fresh frozen plasma).
• The risk of thrombosis versus the risk of
  increased bleeding should be considered when
  altering anticoagulation status.
• Assure that blood and blood components are
  available for patients when significant blood
  loss or transfusion is expected.

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Preoperative Preparation(2)

• Antifibrinolytic therapy should not be routinely
  administered. However, such therapy may be used
  for reducing the volume of allogeneic blood
  transfused for patients at high risk of excessive
  bleeding (e.g., repeat cardiac surgery). The
  risks and benefits of instituting
  antifibrinolytic therapy should be assessed on a
  case-by-case basis.

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Preoperative Preparation(3)

• Erythropoietin should be administered when
  possible to reduce the need for allogeneic blood
  in certain selected patient populations (e.g.,
  renal insufficiency, anemia of chronic disease,
  refusal of transfusion).
• Erythropoietin administration is expensive and
  requires time (in weeks) to induce a significant
  increase in hemoglobin concentration.
• Vitamin K or another warfarin antagonist should
  be used for reversal of warfarin to potentially
  avoid transfusion of FFP.
• Where autologous blood is required or preferred,
  the patient may be offered the opportunity to
  donate blood before admission. However, the Task
  Force cautions that preoperative anemia may be
  induced in addition to an increase in total
  intraoperative autologous or allogeneic
  transfusions, as well as costs.

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Intraoperative and Postoperative Management of
Blood Loss and Transfusions

• Red Blood Cell Transfusion
• Management of Coagulopathy
• Monitoring and Treatment of Adverse Effects of
  Transfusions

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Red Blood Cell Transfusion
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Monitoring for Blood Loss

• Visual assessment of the surgical field should be
  periodically conducted to assess excessive
  microvascular bleeding (i.e., coagulopathy).
• Standard methods for quantitative measurement of
  blood loss (e.g., suction and sponge) should be
  used.

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Monitoring for Inadequate Perfusion and
Oxygenation of Vital Organs

• Conventional monitoring systems (blood pressure,
  heart rate, oxygen saturation, urine output,
  electrocardiography).
• Special monitoring systems (echocardiography,
  mixed venous oxygen saturation, blood gasses).

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Monitoring for Transfusion Indications

• Measure hemoglobin or hematocrit when substantial
  blood loss or any indication of organ ischemia
  occurs. Red blood cells should usually be
  administered when the hemoglobin concentration is
  low (e.g., less than 6 g/dL in a young, healthy
  patient), especially when the anemia is acute.
• Red blood cells are usually unnecessary when the
  hemoglobin concentration is more than 10 g/dL.
  These conclusions may be altered in the presence
  of anticipated blood loss.
• Intermediate hemoglobin concentrations (i.e., 6
  to 10 g/dL) justify or require red blood cell
  transfusion should be based on any ongoing
  indication of organ ischemia, potential or actual
  ongoing bleeding (rate and magnitude), the
  patient's intravascular volume status, and the
  patient's risk factors for complications of
  inadequate oxygenation( low cardiopulmonary
  reserve and high oxygen consumption).

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Transfusion of Red Blood Cells

• Maintain adequate intravascular volume and blood
  pressure with crystalloids or colloids until the
  criteria for red blood cell transfusion are met.
• Adequate quantities of red blood cells should be
  transfused to maintain organ perfusion.
• When appropriate, intraoperative or postoperative
  blood recovery and other means to decrease blood
  loss (e.g., deliberate hypotension) may be
  beneficial.
• Acute normovolemic hemodilution, although rarely
  used, may also be considered.

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Management of Coagulopathy
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Visual Assessment of The Surgical Field and
Laboratory Monitoring for Coagulopathy

• Visual assessment of the surgical field should be
  jointly conducted by the anesthesiologist and
  surgeon to determine whether excessive
  microvascular bleeding (i.e., coagulopathy) is
  occurring. Visual assessment for excessive blood
  loss should also include checking suction
  canisters, surgical sponges, and surgical drains.
  
• Laboratory monitoring for coagulopathy platelet
  count, prothrombin time (PT) or international
  normalized ration (INR), and activated partial
  thromboplastin time (aPTT). Other tests may
  include fibrinogen level, assessment of platelet
  function, thromboelastogram, d-dimers, and
  thrombin time.

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Transfusion of Platelets(1)

• Platelet count should be obtained before
  transfusion of platelets in a bleeding patient,
  and a test of platelet function should be done in
  patients with suspected or drug-induced platelet
  dysfunction (e.g., clopidogrel).
• In surgical or obstetric patients with normal
  platelet function, platelet transfusion is rarely
  indicated if the platelet count is known to be
  greater than 100 x 103/µl
• Usually indicated when the count is below 50 x
  103/µL in the presence of excessive bleeding.
  Vaginal deliveries or operative procedures
  ordinarily associated with limited blood loss may
  be performed in patients with platelet counts
  less than 50 x 103/µL.
• Platelet transfusion may be indicated despite an
  apparently adequate platelet count if there is
  known or suspected platelet dysfunction (e.g.,
  the presence of potent antiplatelet agents,
  cardiopulmonary bypass) and microvascular bleeding

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Transfusion of Platelets(2)

• The determination of whether patients with
  platelet counts between 50 and 100 x 103/µL
  require therapy, including prophylactic therapy,
  should be based on the potential for platelet
  dysfunction, anticipated or ongoing bleeding, and
  the risk of bleeding into a confined space (e.g.,
  brain or eye) . When the platelet count cannot be
  done in a timely fashion in the presence of
  excessive microvascular bleeding (i.e.,
  coagulopathy), platelets may be given when
  thrombocytopenia is suspected.
• Thrombocytopenia due to increased platelet
  destruction (e.g., heparin-induced
  thrombocytopenia, idiopathic thrombocytopenic
  purpura, thrombotic thrombocytopenic purpura),
  prophylactic platelet transfusion is ineffective
  and rarely indicated.
• The proper dose of platelets should be based on
  recommendations of the local institutional
  transfusion committee.

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Transfusion of Fresh Frozen Plasma

• Coagulation tests (i.e., PT or INR and aPTT)
  should be obtained before the administration of
  FFP in a bleeding patient. Transfusion of FFP is
  not indicated if PT, INR, and aPTT are normal.
• Indication (1) correction of excessive
  microvascular bleeding (i.e., coagulopathy) in
  the presence of a PT greater than 1.5 times
  normal or INR greater than 2.0, or an aPTT
  greater than 2 times normal (2) correction of
  excessive microvascular bleeding secondary to
  coagulation factor deficiency in patients
  transfused with more than one blood volume
  (approximately 70 mL/kg) and when PT or INR and
  aPTT cannot be obtained in a timely fashion (3)
  urgent reversal of warfarin therapy (4)
  correction of known coagulation factor
  deficiencies for which specific concentrates are
  unavailable or (5) heparin resistance
  (antithrombin III deficiency) in a patient
  requiring heparin.
• Not indicated solely for augmentation of plasma
  volume or albumin concentration.
• Dose achieve a minimum of 30 of plasma factor
  concentration (usually achieved with
  administration of 1015 mL/kg FFP),
• Urgent reversal of warfarin
  anticoagulation, 58 ml/kg FFP
• Four to five platelet concentrates, 1 unit
  single-donor apheresis platelets, or 1 unit fresh
  whole blood provide a quantity of coagulation
  factors similar to that contained in 1 unit FFP.

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Transfusion of Cryoprecipitate

• Fibrinogen concentration should be obtained
  before the administration of cryoprecipitate in a
  bleeding patient. Transfusion of cryoprecipitate
  is rarely indicated if fibrinogen concentration
  is gt150 mg/dL.
• Indication (1) when the fibrinogen concentration
  is less than 80100 mg/dL in the presence of
  excessive microvascular bleeding, (2) to correct
  excessive microvascular bleeding in massively
  transfused patients when fibrinogen
  concentrations cannot be measured in a timely
  fashion, and (3) for patients with congenital
  fibrinogen deficiencies( after consultation with
  the patient's hematologist).
• Fibrinogen concentration between 100 and 150
  mg/dL the potential for anticipated or ongoing
  bleeding and the risk of bleeding into a confined
  space (e.g., brain or eye).
• Bleeding patients with von Willebrand
  disease should be treated with specific
  concentrates if available. If concentrates are
  not available, cryoprecipitate is indicated.
• 1 unit of cryoprecipitate contains 150250 mg
  fibrinogen. 1 unit of FFP contains 24 mg
  fibrinogen/ mL. 1 unit of FFP delivers the
  equivalent amount of fibrinogen as 2 units
  cryoprecipitate

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• Drugs to treat excessive bleeding Desmopressin
  or topical hemostatics such as fibrin glue or
  thrombin gel should be considered when excessive
  bleeding occurs.
• Recombinant activated factor VII When
  traditional well-tested options for treating
  excessive microvascular bleeding (i.e.,
  coagulopathy) have been exhausted, recombinant
  activated factor VII should be considered.

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Monitoring and Treatment of Adverse Effects of
Transfusions

• Check for signs and symptoms of bacterial
  contamination, transfusion-related acute lung
  injury (TRALI), and hemolytic transfusion
  reactions, including urticaria, hypotension,
  tachycardia, increased peak airway pressure,
  hyperthermia, decreased urine output,
  hemoglobinuria, and microvascular bleeding.
• Before instituting therapy for transfusion
  reactions, stop the blood transfusion and order
  appropriate diagnostic testing.

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Bacterial Contamination

• Most frequently platelets
• Leading cause of death from blood transfusions.
  The increased risk of bacterial overgrowth is
  related to a storage temperature of above 20-24
  C. Many blood banks are now culturing their
  platelet concentrates.
• Fever within 6 h after receiving platelets,
  sepsis from contaminated platelets may be a
  possibility.

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Transfusion-related Acute Lung Injury (TRALI )

• Noncardiogenic pulmonary edema, resulting from
  immune reactivity of certain leukocyte antibodies
  a few hours after transfusion.
• Top three most common causes of transfusion
  related deaths
• Appear 1-2 h after transfusion and maximum force
  within 6 h. Hypoxia, fever, dyspnea, and even
  fluid in the endotracheal tube may occur.
• No specific therapy
• Stopping transfusion
• Critical care supportive measures
• Most patients recover in 96 h

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Infectious Diseases

• Transfusion-induced hepatitis and autoimmune
  deficiency syndrome are now rare after use of
  nucleic acid technology. The human
  immunodeficiency virus, hepatitis C virus, and
  West Nile virus can now be detected by this
  technology.
• Malaria, Chagas disease, severe acute respiratory
  syndrome, and variant Creutzfeldt-Jakob disease
  cannot be detected.

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Transfusion Reaction

• General anesthesia may mask the symptoms of both
  hemolytic and nonhemolytic transfusion reactions.
• Signs of hemolytic reactions include hypotension,
  tachycardia, hemoglobinuria, and microvascular
  bleeding, but these may be erroneously attributed
  to other causes in the anesthetized patient.
• Most common signs of a nonhemolytic transfusion
  reaction in awake patients include fever, chills,
  or urticaria. However, these signs may not be
  detectable during anesthesia.

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