transfusions & surgery christopher j. gresens, m.d. vp & medical director, clinical services...
TRANSCRIPT
Transfusions & SurgeryTransfusions & Surgery Christopher J. Gresens, M.D.
VP & Medical Director, Clinical ServicesBloodSource
Surgical Transfusion Medicine
Objectives – At the conclusion of this presentation, participants will be able to …
1. Summarize the best means for optimizing the transfusion of – and reducing the need to transfuse – surgical patients;
2. Describe special transfusion considerations for patients in emergent need of blood.
Surgical Transfusion Medicine – Outline 1/2
• Preoperative Approaches– Correcting Anemias Prior to Surgery– Preventing Unnecessary and Iatrogenic Blood
Loss– Preoperative Autologous Blood Collections
• Intraoperative Approaches– Intraoperative Blood Salvage– Acute Normovolemic Dilution
• Postoperative Approaches
Surgical Transfusion Medicine – Outline 2/2
• Transfusions in Emergency Situations– Introduction– What is Shock (Especially, Hemorrhagic
Shock)? And … – … What Are Its Consequences?– The Nuts and Bolts of Emergency
Transfusions– Challenges Associated with Massive
Transfusions
Surgical Transfusion Medicine
Preoperative Approaches
1. Correcting Anemias Prior to Surgery
2. Preventing Unnecessary and Iatrogenic Blood Loss
3. Preoperative Autologous Blood Collections
Correcting Anemias• The surgeon must decide if the level of
anemia and the risk of surgical blood loss from the planned procedure require specific action
• Elective surgeries should generally be delayed until treatable preoperative anemias can be corrected
• Oral/intravenous iron + erythropoietin (if practicable) may be warranted in some cases
• In other cases, different approaches may be required – e.g., to correct a different, underlying cause of anemia
Preventing Unnecessary Blood Loss
• Restrict diagnostic phlebotomies via the ordering of fewer tests and the practice of lower volume blood draws
• Manage anticoagulation carefully, e.g., discontinue or modify the use of anti-clotting agents such as:– Aspirin– Other anti-platelet agents (e.g., clopidogrel)– Anticoagulants (e.g., heparin and warfarin)
Preoperative Autologous Collection
• “Self-donated” blood• “Target” usually is RBCs• Relaxed donor eligibility criteria• Minimum hematocrit = 33%• No absolute minimum age• No absolute weight limits• Increased donation frequency
Preoperative Autologous Blood – Contraindications
• Significant cardiac abnormalities (e.g., aortic stenosis, severe coronary artery disease or congestive heart failure)
• Very recent myocardial infarct or cerebrovascular accident
• Potential bacteremia
• Hematocrit < 33%
• < 72 hours from time of surgery
Preoperative Autologous Blood – Risks
• Development of anemia due to donation process (see Kanter et al.)
• Small risk of septic & several other transfusion reactions
• Remote risk of wrong blood unit being transfused
• Blood will not be immediately available in an emergency
Preoperative Autologous Blood – Other Issues
Preop Auto Blood Donations Before Elective Hyster-ectomy. M.H. Kanter et al. JAMA. 1996; 276: 798-801.
• Design: Retrospective; compared 140 elective hyster- ectomy patients who gave auto blood with 123 who didn’t.
• Results: 25 of 140 autologous donors were transfused (3 with allogeneic RBCs); 1 of the other 123 was transfused (p < 0.001).
• Conclusion: “For hysterectomy patients, donation of autologous blood causes anemia and is associated with a more liberal transfusion policy. Elimination of preoperative autologous donation for these patients should not result in frequent exposure to allogeneic blood”
Preoperative Autologous Blood – Other Issues
• Venous access• Iron
supplementation• Special handling• Fees• Unused autologous
units are destroyed
Preoperative Autologous Blood – More Issues
• Crossover to allogeneic supply – Virtually never done
• Transfusion criteria for autologous blood are sometimes debated – Should they be same as, or different from, those for allogeneic blood?
• Local hospitals have varying policies regarding the use of confirmed HBV- and HIV-infected units
• Cost-effectiveness – In many situations, the use of preoperatively collected autologous blood may never by cost-effective (per traditionally utilized criteria)
Autologous Blood Transfusions in Total
Joint Replacement Surgery:
The Marshall Hospital/BloodSource
Experience
C. Gresens et al. Transfusion 2002; 42 (Suppl): 18S-19S.
Marshall Hospital/BloodSource Total Joint Replacement (TJR)
Surgery Blood Use StudyBackground
Many orthopedic surgeons advise their total joint replacement surgery patients to consider making preoperative autologous blood donations (PABDs) to reduce the need for perioperative allogeneic transfusions.
We examined the use of blood transfusions by such patients to understand better the impact of PABDs on perioperative transfusion requirements.
Marshall Hospital/BloodSource TJR Surgery Blood Use StudyMethods: Retrospective review of primary, one-joint TJR surgery patient charts (at Marshall Hospital) and autologous donor charts (at BloodSource).– Blood volume was estimated as: Patient mass (kg)
x 0.069 L/kg (male) or 0.065 L/kg (female).
– Autologous blood was transfused as pRBCs.
– Perioperative blood salvage was not used.
– Criteria for transfusion of autologous and allogeneic blood were identical.
Marshall Hospital/BloodSource TJR Surgery Blood Use StudyResults• Date Range: July 2000-March, 2001
• N = 43 (19 male; 24 female)
• Surgical Procedures: Primary, unilateral joint replacement surgeries:
– Knee--29 (67%); Hip--14 (33%)
• Ages of Patients: Mean = 67.1 (45-86 years)
Marshall Hospital/BloodSource TJR Surgery Blood Use Study
• Twenty-four patients (57%) made PABDs:– 17 (71%) were knee surgery patients– 7 (29%) were hip surgery patients
• PABD Profile– Mean # of PABDs/patient = 1.9 (1-2) units– In total, 45 PABDs were made by these 24
patients.
Marshall Hospital/BloodSource TJR Surgery Blood Use Study
– Summary of hematocrit data for the “non-autologous donor/patients,” immediately prior to surgery (n = 19)
• Average Hematocrit = 42.2% (35.6-to-49.6%)
Summary of Hematocrit Data for the “Autologous Donor/Patients” (n = 24)
Hct Prior to
1st Donation Hct Prior to 2nd Donation
Hct Immediately Prior to Surgery
Average 41.5% 38.0% 36.5% Median 42% 37% 35.5% Range 34-46% 33-45% 30.1-45.2%
Marshall Hospital/BloodSource TJR Surgery Blood Use Study
• Mean Estimated Blood Volumes– Autologous Donor/Patients: 5.8 L– Non-Autologous Donor/Patients: 5.5 L (p > 0.05)
Estimated Perioperative Blood Loss
For Autologous Donor/Patients
For Non-Auto Donor/Patients
a. Average = 315 mL b. Median = 250 mL c. Range = 0-to-1000
mL
a. Average = 263 mL b. Median = 250 mL c. Range = 100-400
mL
Marshall Hospital/BloodSource TJR Surgery Blood Use Study
• Nine of the 24 autologous donor/patients (39%) required perioperative autologous RBC transfusions– Mean = 1.9; Median = 2; Range = 1-2 units;– Five (56%) were knee and 4 (44%) were hip;– 17 total auto units transfused.
• Only one of the 19 non-autologous donor/patients (5%) required a single allogeneic RBC transfusion (p < 0.05).
Marshall Hospital/BloodSource TJR Surgery Blood Use Study
Conclusions:• PABDs prior to TJR surgery were associated
with:– A moderate reduction in patient hematocrits;– A large increase in perioperative transfusions;– 62% of PABDs not transfused.
• PABDs no longer are routinely recommended for primary, one-joint TJR surgery patients at Marshall Hospital.
Preoperative Autologous Blood – Other Issues
The Cost Effectiveness of Preoperative Autologous Blood Donations. J Etchason, L Petz, et al. NEJM. 1995; 332: 719-724.
• Design: Decision-analysis model for cost effectiveness assessment (based upon 1992, UCLA data); looked at total hip replacement, coronary artery bypass grafting, abdominal hysterectomy, & transurethral prostate resection patients.
• Results: “The cost-effectiveness values ranged from $235,000 to over $23 million per quality-adjusted year of life saved.”
• Conclusion: “The increased protection afforded by donating autologous blood … may not justify the increased cost.”
Surgical Transfusion Medicine
Intraoperative Approaches
1) Intraoperative Blood Salvage
2) Acute Normovolemic Dilution
Intraoperative Blood Salvage
• Collection and re-infusion of blood lost during surgery
• Alternative to pre-operative autologous blood collection
• Can be especially useful for massively bleeding patients
• Semi-automated systems are available for this purpose
Intraop Blood Salvage – Considerations
• Washed vs. unwashed?
• Guaranteed blood compatibility
• May be acceptable to Jehovah’s Witnesses (particularly if the collection/reinfusion circuit is circular)
Intraoperative Blood – Contraindications
• Infection/contamination of surgical field
• Cancer involving surgical field
Perioperative Blood Salvage – Risks
• Coagulopathy
• Hemolysis
• Air embolism (Linden et al.)
Perioperative Blood Salvage – Risks
Fatal Air Embolism Due to Perioperative Blood Recovery. J.V. Linden et al. Anesth Analg. 1997; 84: 422-426.
• Design: Retrospective review of 127,586 periop blood salvage procedures (PBSPs) and 8,955,619 conventional transfusions (CTs); 1990-1995.
• Results: 4 fatal air embolism cases occurred in association with PBSPs (1 in 30,000-38,000); none with CTs.
• Conclusion: Even when considering all the other risks associated with CTs, the risk for a fatal complication during PBSP is far higher than that for CTs.
Acute Normovolemic Hemodilution (ANH)
• ANH involves collecting blood from a patient in the OR at the start of surgery, for re-infusion later in the surgery or during the immediate postoperative period.
• > 4 units may be removed (with simultaneous 3:1 crystalloid or 1:1 albumin replacement).
• In properly selected and monitored patients, a target Hct of 20-25% may be acceptable.
Acute Normovolemic Hemodilution – Considerations
• Lowers blood viscosity
• Reduces RBC loss during surgery
• No testing required
• Ideal candidate has good preop hematocrit & will lose > 1 L intraoperatively
• Exclusion criteria include anemia, renal failure, signifi-cant coronary artery disease, and others
Acute Normovolemic Hemodilution – Risks
• Critical organ ischemia
• Dilutes circulating coagulation factors
Surgical Transfusion Medicine
Postoperative Approaches
Post-operative Blood Salvage
• Cardiac & orthopedic surgical patients
• Blood collected from drainage devices
• Defibrinogenated• Unwashed• Can only be stored for
up to 6 hours at room temperature
Post-operative Blood Salvage
Red Cell Loss Following Orthopedic Surgery: The Case Against Postoperative Blood Salvage. J. Umlas et al. Transfusion. 1994; 34: 402-406.
• Design: The volume of salvaged RBCs was measured for the first 6 hours postoperatively & compared to total RBC loss and volume of allogeneic RBCs transfused.
• Results: Mean postoperative RBC losses in 31 THR & 20 TKR patients were 55 + 29 and 121 + 50 mL, respectively.
• Conclusion: “The relatively small red cell loss in the postoperative period in most arthroplasty patients does not appear to justify the routine use of this technique.”
Surgical Transfusion Medicine
Transfusions in Emergency Situations
1) Introduction
2) What is Shock (Especially, Hemorrhagic Shock)? And …
3) … What Are Its Consequences?
4) The Nuts and Bolts of Emergency Transfusions
5) Challenges Associated with Massive Transfusions
Emergency Transfusions – Introduction
• A variety of indications exists for the use of blood transfusions in emergency medicine
• This discussion will focus primarily on those transfusion indications pertaining to hemorrhage; however, other reasons for emergency transfusions exist, including all of the ones for which patients generally require transfusions, such as . . .
Emergency Transfusions – Introduction
… Selected Examples of Non-Hemorrhagic Indications for Emergency Transfusions:• Complications of sickle cell disease or thalassemia;• Worsening chronic anemia or thrombocytopenia in
a patient with leukemia, myelodysplasia, etc.;• Severe hemolysis secondary to warm autoimmune
hemolytic anemia;• . . .
Emergency Transfusions – Introduction
• Most trauma patients are treated without transfusions being performed.
• A five-year study at Vanderbilt University revealed that only 27% of patients admitted for trauma at their institution required blood
(Wudel JH et al: Massive Transfusion: “Outcome in Blunt Trauma Patients.” J Trauma 31: 1, 1991).
Emergency Transfusions – Introduction
• Another study, looking at 8,000 trauma patients at Cooper Hospital (Camden, NJ), over a similar time period, showed that only 8% needed transfusions (Ross S & Jeter E. In: Clin. Pract. of Transf. Med., 3rd ed. (eds. Petz LD, et al.), 1995.).
• Still, a significant minority of trauma patients require transfusions – sometimes MASSIVE TRANSFUSIONS (usually defined as the transfusion of one blood volume of RBCs within 24 hours).
Shock
• The primary indication for the administration of IV fluids and blood in trauma/emergency surgery patients is hemorrhagic shock.
• Definition of shock: Pathophysiologic inadequacies in both:– The delivery of substrate and O2 and …
– … The removal of metabolic end-products from peripheral tissues.
Types of Shock
• Hemorrhagic: Caused by severe blood loss;• Metabolic: Associated with profound fluid loss due
to injury or illness (e.g., burns or dehydration);• Septic: Caused by the toxins from severe (usually
bacterial) infections;• Neurogenic: Usually caused by head/spinal injuries;• Psychogenic: Also known as fainting;• Anaphylactic: Due to severe allergic reactions;• Cardiogenic: Caused by damage/injury to heart.
Most Common Causes of Hemorrhagic Shock
• Penetrating trauma
• Blunt trauma
• GI bleeding
• Ob/Gyn bleeding.
Graphics from MDChoice.com
Shock – Its Coagulopathic Consequences
• Often in shock, a coagulopathy results due to the activation and/or consumption of coagulation factors.
• Certain crush injuries (especially cerebral) can lead to DIC (disseminated intravascular coagulation).
High velocity gunshot wound (MDChoice.com)
Trauma to legs caused by train (MDChoice.com)
Shock – Its Coagulopathic Consequences
DIC is coagulation activation occurring to an abnormal degree, with so much thrombin generated that it overwhelms the natural thrombin inhibitors. From Merck Manual Online (2003)
Shock – Its Coagulopathic Consequences
Ultimately, DIC results in:
• Activation (and, often, depletion) of other coagulation factors
• Fibrinolytic bleeding (the major clinical sign of DIC) and hemolysis (microangiopathic hemolytic anemia)
• Thromboses (sometimes more subtle, resulting in CNS deficits, acute renal failure, and/or other organ ischemia)
Fibrinolysis predisposes the patient to bleeding, both directly (via destruction of fibrin clot) and indirectly (via compromised platelet function).
Shock – Its Coagulopathic Consequences
Fibrinolysis naturally allows for the control and remodeling of clots, and normally is a healthy process. When it occurs in concert with DIC, however, it can contribute heavily to bleeding (MDChoice.com).
Normal Blood Clot Formation
Shock – Some of Its Other Consequences
• Acidosis may result from inadequate O2 delivery and waste product removal.
• The loss of thermal regulation and a decrease in heat production (which may be worsened both by the environment and the use of cold intravascular fluids) may cause in vivo dysfunction of platelet and clotting factor function.
• Prolonged shock ultimately can lead to multisystem organ failure and (eventually) death.
Management of Emergency Transfusions
Important factors affecting the management of emergency (especially massive) transfusions include:• Experience of trauma care providers;• Availability and quality of ICUs and ORs;• Turnaround time for STAT
hematology/coagulation testing;• Reliability (largely related to staffing experience
and levels) of transfusion service.
Decision to Transfuse Emergently
The decision to transfuse (urgently or otherwise) requires a detailed clinical analysis, looking at:• The patient’s clinical condition;• His/her initial hemoglobin level, platelet count, PT
(INR), PTT, and fibrinogen level;• His/her response to fluid resuscitation;• Coexisting cardiac, respiratory, and vascular
conditions;• Measurements of tissue oxygenation.
Emergency Transfusions – Why/When?
• Primary Purposes: To: 1) Restore O2 delivery and tissue perfusion2) Reverse the effects of shock (by maintaining
intravascular volume and blood pressure); and …3) Reduce bleeding (by maintaining coagulation
function).• Initially:
– Observe response to rapid crystalloid/colloid infusion (if transfusion is not immediately indicated);
– Evaluate for ongoing, external bleeding;– Look for injury patterns consistent with large blood
loss.
Emergency Transfusions – Why/When?
• Monitor clinical signs (e.g., heart rate, blood pressure, central venous pressure);
• Monitor laboratory values (e.g., hematocrit, platelet count, PT/PTT, fibrinogen);
• The decision to transfuse typically is made by emergency room physicians or anesthesiologists and surgeons;
• Clinical experience and judgment reign supreme (and may take precedence over lab values).
Selection of Blood – Whole Blood Vs. Components• Since the 1960’s, most blood in U.S. has been
separated into components, allowing for:1) Meeting specific needs of patients;
2) Minimizing risk of volume overload; and
3) Benefiting several patients from a single blood donation.
• Some physicians prefer whole blood for massive transfusion cases; however, stored whole blood completely loses platelet function after 48 hours and shows progressive loss of factor VIII (rapidly) and factor V (more slowly).
Emergency Pre-Transfusion Testing
• Urgently required blood transfusions should not be withheld solely because compatibility testing is incomplete.
• Nevertheless, all parties involved in such a transfusion should remember that they face certain increased risks when transfusing blood that has not gone through the “usual” compatibility testing process.
Group O Vs. Type-Specific RBCs – How Long Can You Wait?
From LD Petz et al.’s Clinical Practice of Transfusion Medicine, 3rd ed. 1995.
Time You Can Wait Type of RBC Available Comments
< 5 minutes O-negative, un-crossmatched 0.2–0.6% of population has RBC antibody(ies) (though serious hemolysis is rare)
15 minutes after clots get to blood bank
Type-specific, un-crossmatched
Risk same as for O-negative
45 minutes after clots get to blood bank
Type-specific, crossmatched (unless an RBC antibody is present)
No RBC antibody found; blood compatible by crossmatch
90-minutes-to several-hours Type-specific, crossmatched, antigen-selected unit
If blood needed before testing complete, do not withhold
Using Rh-Positive Blood for Rh-Negative Patients
• Only ~ 15% of donor population is Rh(D)-negative.• If supplies of Rh(D)-negative RBCs are limited,
Rh(D)-positive RBCs often should be used for male and postmenopausal female patients (once presence of anti-D has been excluded).
• Decision when to switch from Rh(D)-negative to Rh(D)-positive RBCs should be made on a case-by-case basis.
• Rh is far less important for platelets, and not at all important for FFP or cryoprecipitate.
Types of RBC Units
• Generally, transfuse RBCs stored in additive solutions (e.g., AS-1, AS-3, AS-5)– More dilute (Hct 50-60%), so flows faster– Larger volume (approx. 350 mL)
• Rarely, use CPDA-1 RBCs– More concentrated/lower volume (approx. 250 mL)– Generally used for larger volume (> 20 mL/kg)
neonatal transfusions or fetal transfusions
Transfusing Your Patient When Compatible Blood Is Hard to Find
I. Patient Has Multiple Alloantibodies (not all of which can be immediately honored)• Group I (ABO, Rh, Kell, Duffy, Kidd, Ss)--Clinically
Significant Antibodies: Antigen-negative RBCs should be transfused, except in extreme emergencies.
• Group II (Cha/Rga, Xga, Bg, “HTLA,” Csa, Kna, McCa, JMH)--Benign Antibodies: Antigen-positive RBCs may be transfused (even if Ab is 37° reactive)
From LD Petz., et al’s Clinical Practice of Transfusion Medicine, 3rd ed. 1995.
Transfusing Your Patient When Compatible Blood Is Hard to FindI. Patient Has Multiple Alloantibodies (not all of which
can be immediately honored) – Continued• Group III (Lea/Leb, M, N, P1, Lua/Lub, A1)--Usually
Benign, Though Possibly Clinically Significant (if Ab is 37° reactive): Crossmatch-negative RBCs may be used, without need to phenotype blood.
• Group IV (Yta, Vel, Ge, Gya, Hy, Sda, Yka)--Sometimes Clinically Significant: Efforts should be made to obtain antigen-negative RBCs or use autologous RBCs.
From LD Petz., et al’s Clinical Practice of Transfusion Medicine, 3rd ed. 1995.
Transfusing Your Patient When Compatible Blood Is Hard to Find
II. In the Massive Transfusion Setting – Consider:• Using some antigen-negative, compatible units up
front; then . . .• Once the patient’s serum has been diluted
sufficiently such that the antibody screen no longer is reactive (usually after > 1 blood volume has been replaced), switch to incompatible units;
• Finally, top patient off, at the end, with the remaining antigen-negative units (6-8 units, for an adult-sized patient, if possible).
Transfusing Your Patient When Compatible Blood Is Hard to Find
III. For Autoimmune Hemolytic Anemia Patients– Often, all units will be crossmatch-incompatible.– Numerous special methods for compatibility testing
exist, but sometimes you have no choice other than to transfuse immediately (consider the “modified in vivo crossmatch”).
– “Blood should never be denied a patient with a justifiable need, even though the compatibility test may be strongly positive. Probably the most common mistake is reluctance to transfuse even those patients with severe anemia.” (Larry Petz, MD, 2002)
Transfusing Your Patient When Compatible Blood Is Hard to Find
IV. Insufficient ABO-Compatible RBCs (Gulp!)– Use intraoperative salvage device, if available– Push volume repletion (with crystalloid/colloid) hard!– As early as possible, switch plasma infusions to
something compatible with the ABO type of the incompatible RBCs (best choice: AB plasma)
– Identify “most-nearly-compatible” (ABO-incompatible) units (e.g., group A2 RBCs for a group O patient)
– Hyperhydrate patient, alkalinize urine, etc.
Emergency Blood Orders
• Written standard operating procedures (SOPs) for providing emergency transfusions should exist
• The physician who requests an uncrossmatched RBC unit must (eventually) document the rationale; however, the hospital blood bank should not allow this “paper requirement” to delay release of the blood to the patient’s bedside.
• Hospital blood banks must have SOPs for managing blood supplies in times of shortages
Massive Transfusions – Dilutional Coagulopathy
Important Note: The “dilutional coagulopathy” is not related to transfusions, but, rather, to blood loss. In fact, if a patient is appropriately transfused with FFP, platelets, and/or cryoprecipitate, such a coagulopathy need not develop.
Relationship between the volume of plasma (or blood) lost and the patient’s original plasma (or blood) remaining [from AABB Technical Manual, 13th ed., 2001]
Massive Transfusions – Dilutional Coagulopathy
• Approximately 37% of original plasma constituents remain after rapid exchange of a single blood volume (after 2 or 3 blood volumes are exchanged, remaining elements drop to about 15% and 5%, respectively).
• Coagulation activity usually is adequate after 1 blood volume replacement; platelet counts rarely drop below 100,000/uL until > 1.5 blood volume replacement.
Massive Transfusions – Dilutional Coagulopathy
In fact, Hiippala et al., in a controlled clinical evaluation looking at 60 massively bleeding patients, demonstrated that:• The critical (50,000/uL) platelet level was not
reached until an average loss of 2.30 BVs, & . . .• Critical levels of prothrombin (20%), factor V (25%),
and factor VII (20%) were not reached until 2.01, 2.29, and 2.36 BVs, respectively, were lost.
Hiippala ST et al. Anesth Analg. 1995; 81: 360-5.
Massive Transfusions – DIC• Disseminated intravascular coagulation (DIC) is
reported in 5-30% of massively transfused trauma patients.
• DIC can be caused by blunt trauma/tissue injury resulting in tissue and cell fragments entering blood stream, causing immediate activation of clotting system.
• DIC also is seen in: – Severely burned patients (triggered by hemolysis and tissue
necrosis).
– Head trauma patients (due to release of thromplastins from brain).
Massive Transfusions – DIC
• Microvascular thrombosis plays a major role in the multisystem organ failure associated with DIC.
• This problem generally is accompanied by simultaneous activation of fibrinolytic pathways; thus, both microthrombi and hemorrhage may be seen.
Massive Transfusions –Providing Components with
Hemostatic Factors• Determine patient’s coagulation status, whenever possible,
with appropriate lab tests.• Clinical Guidelines: (1) Extent/location of injury; (2) Duration
of shock; (3) Response to initial fluid resuscitation; and (4) Risk of complications (e.g., intracranial bleeding).
• Lab-Based Guidelines for Specific Components – Give:
1) Platelets if platelet count is < 80-100,000/uL
2) FFP immediately (in a 1:1 ratio of FFP to RBCs); and …
3) Cryoprecipitate if fibrinogen approaches < 100 mg/dL.
Massive Transfusions –Complications
• Immune Hemolysis: Due either to ABO/other red cell antigens or nonimmune causes;
• Citrate Toxicity: Ca2+ salts occasionally are indicated;
• Hyperkalemia: More problematic in tiny patients;• Reduced Red Cell [2,3-DPG]: ??? How much of
a problem is this in adult patients? May be offset by increased cardiac output, vasodilation, and local acidosis).
Massive Transfusions – Complications
• Reduced Red Cell [ATP]: May cause reduced deformability (role of this phenomenon unclear);
• Hypothermia: Degree is proportional to the number of units transfused;
• The Various Other Adverse Sequelae of Transfusions.
Rapid Infusion Devices and Blood Warmers
Rapid-infusion devices can be used to hold banked RBCs, washed salvage RBCs, FFP, crystalloid, and colloid.
From LD Petz, et al’s Clinical Practice of Transfusion Medicine, 3rd ed., 1995.
Rapid Infusion Devices and Blood Warmers
Roller pumps transport the blood through high-flow-rate microag-gregate filters, and then through a high-capacity blood warmer, allowing blood to be delivered as fast as 5 L/hour.
From LD Petz, et al’s Clinical Practice of Transfusion Medicine, 3rd ed., 1995.
Rapid Infusion Devices and Blood Warmers
Platelets and cryoprecipitate are generally delivered downstream (i.e., not put into the reservoir)
From LD Petz, et al’s Clinical Practice of Transfusion Medicine, 3rd ed., 1995.
Rapid Infusion Devices and Blood Warmers
Level 1 Technologies’ Hotline™ Blood Warmer
Warms up to 5 L/hour in 35-40° C range
Disclaimer: This is just one device among several in its class, and is not meant to serve as an advertisement for Level 1)
Pros and Cons for Autologous versus Allogeneic Blood
BenefitsAllogeneic AutologousAvailable 24/7 Your own blood
Fully tested Fully tested (sometimes we even identify heretofore unknown infections)
Completely compatible (if correct unit is used)
Pros and Cons for Autologous versus Allogeneic Blood
RisksAllogeneic Autologous
Infection Infection (? Less risk)
Immune reactions Remote risk of incompatibility or allergic or anaphylactic reaction (if wrong unit or a
synthetic allergen is introduced)
Circulatory overload, Same
citrate toxicity, etc.
Mild anemia
Not often available for emergency
Pros and Cons for Autologous versus Allogeneic Blood
One more “risk” of autologous blood:
Cost
Surgical Transfusion Medicine – Summary 1/2
• Preoperative Approaches– Correcting Anemias Prior to Surgery– Preventing Unnecessary and Iatrogenic Blood
Loss– Preoperative Autologous Blood Collections
• Intraoperative Approaches– Intraoperative Blood Salvage– Acute Normovolemic Dilution
• Postoperative Approaches
Surgical Transfusion Medicine – Summary 2/2
• Transfusions in Emergency Situations– Introduction– What is Shock (Especially, Hemorrhagic Shock)?
And … – … What Are Its Consequences?– The Nuts and Bolts of Emergency Transfusions– Challenges Associated with Massive
Transfusions
Thank You …To all of our friends/colleagues in the audience…