Enhanced oxygen carrying capacity Improved homeostasis with blood component therapy Volume support of Cardiac output
Whole blood Packed Red Blood Cell Leukoreduced Red Blood Cell Fresh Frozen Plasma Cryoprecipitate Platelet concentrate Prothrombin Complex Single Donor Plasma
Contain same amount of Haemoglobin as whole blood, but much of plasma has been removed. Haematocrit 70%,whereas whole blood 40% Reconstituted with 5% Dextrose,0.4% saline,5% Dextrose in 0.9% saline,0.9% saline and Normosol-R with a ph of 7.4.
Citrate phosphate Dextrose Adenine (CPDA-1) anticoagulant preservative in which Blood stored at 1 degree celsius-6 degree celsius Addition of Adenine to CPD solution allows RBC to synthesize ATP and extend storage time from 21 days to 45 days. Shelf life can be further extended to 42 days AS- 1(Adsol),AS-3(Nutricel) or AS-5(Optisol)
The Practice Guidelines for Blood Component Therapy developed by the American society of Anaesthesiologists (ASA) state that “red blood cell transfusion is rarely indicated when the hemoglobin concentration is greater than 10 g/dl and is almost always indicated when it is less than 6 g/dl”
Increased Cardiac output Redistribution of Cardiac output Increased Oxygen extraction Changes in Oxygen-Hemoglobin affinity
VALUE WHOLE BLOOD PACKED RED BLOOD CELL Volume(ml) Erythrocyte mass (ml) 200 Hematocrit(%) Albumin(g) Globulin(g) Total Protein(g) Plasma sodium(meq) Plasma Potassium (meq) 15 4 Plasma Acid (meq) Donor-to-recepient ratio 1 unit per patient 1 unit per 4-6 patients
Limited ability to increase Cardiac Output Coronary artery disease Myocardial dysfunction β-Adenergic Bloackade Inability to redistribute cardiac output Low SVR states Occlusive vascular disease Left shift of Oxygen-Haemoglobin curve
Abnormal Haemoglobins Presence of recently transfused Hb (decreased 2,3- DPG) Hb S (sickle cell disease) Acute Anemia (limited 2,3-DPG compensation) Ongoing or imminent blood loss Traumatic/surgical bleeding Placenta previa or accreta,abruption,uterine atony Clinical coagulopathy
Prepared by differential centrifugation of whole blood or by plateletpheresis techniques. Stored at room temperature;satisfactorily kept for 7 days. Platelet concentrate transfusion,third leading cause of transfusion-related deaths (following sepsis). One unit of platelet concentrate will increase platelet count of a 70-kg recepient by ,000/µL;One apheresis unit →30,000-60,000/µL
American Society of Anesthesiologists (ASA) Task force recommendations: Prophylatic platelet transfusion is ineffective and rarely indicated when thrombocytopenia is due to increased platelet destruction (eg.idiopathic thrombocytic purpura) Prophylatic platelet transfusion rarely indicated in surgical patients with thrombocytopenia due to decreased platelet production when platelet count >1,00,000 and usually indicated when platelet count > 50,000
Surgical and obstretic patients with microvascular bleeding usually require platelet transfusion if platelet count >1,00,000 and usually indicated platelet count <50,000;Therapy to be based upon patients bleeding risk. Vaginal deliveries or operative procedures ordinarily associated with insignifcant blood loss maybe undertaken in patients with platelet count <50,000. Platelet transfusion maybe indicated despite an apparently adequate platelet count if there is known platelet dysfunction and microvascular bleeding.
Contains all plasma proteins particularly factors ν and νιιι ASA task force recommended the administration of FFP with the following guidelines: For urgent reversal of Warfarin therapy;dosage 5- 8ml/kg For correction of known coagualation factor deficiencies for which specific correlates are unavailaible
For correction of microvascular bleeding secondary to coagulation factor deficiency in patients transfused with more than 1 blood volume and when prothrombin and partial thromboplastin time cannot be obtained in a timely fashion. Calculated to achieve a minimum of 30% plasma factor;dosage ml/kg. Contraindicated for augmentation of plasma volume or albumin concentration.
Replacement of isolated factor deficiencies Reversal of Warfarin effect Antithrombin ιιι deficiency Treatment of immunodeficiencies Treatment of thrombotic thrombocytopenic purpura Massive blood transfusion(when factors ν and νιιι < 25% normal) Requirements of above points if PT atleast 1.5 times longer than normal
Precipitate that remains when FFP thawed slowly at 4 degree celsius Primarily contains factor νιιι and fibrinogen;also has Von Willebrand factor and fibronectin All other plasma proteins in trace Used in Haemophillia A and fibrinogen deficiency treatment.
ABO compatibility not must. Administered within 6 hours after thawing. One unit increases fibrinogen levels by 5-7 mg/dL
Development of various infections Transfusion associated reactions(Hemolytic transfusion reaction) Transfusion related lung injury Left shift of oxygen dissociation curve Coagulopathy noticed with massive transfusions
Dilutional Thrombocytopenia Low levels of factor ν and νιιι Disseminated Intravascular Coagulation like syndrome Citrate Intoxication and Hyperkalemia Hypothermia Acidosis Transfusion associated Graft versus Host Disease Adverse ocular reaction Transfusion related immunomodulation
Type Occurrence in Red Blood Cell Units Transfused Infectious Human immunodeficiency virus 1 in 1.4–2.4×10 6 Hepatitis B 1 in 58,000–149,000 Hepatitis C 1 in 872,000–1.7× 10 6 Bacterial infection 1 in 2,000 Immunologic reactions Febrile nonhemolytic transfusion reactions 1 in 100 Anaphylactic transfusion reactions 1 in 20,000–50,000 ABO mismatch Hemolysis 1 in 60,000 Death 1 in 600,000 Leukocyte-related target organ injury 1 in 20 to 1 in 50 Transfusion-related acute lung injury 1 in 2000 Post-transfusion purpura Rare Transfusion services error 1 in 14,000
Signs and symptoms: Chills Fever Chest and flank pain Nausea Hemoglobinuria Bleeding diasthesis(noticed during surgery) Hypotension
STOP THE TRANSFUSION Maintain urine output at a minimum of ml/hr(generous fluid administration,mannitol,furosemide) Alkalinize the urine Assay urine and plasma hemoglobin concentrations Determine platelet count,partial thromboplastin time and serum fibrinogen levels Return unused blood to blood bank for repeat cross match Send patients blood and urine sample to blood bank for examination Prevent hypotension to ensure adequate renal blood flow
BLOOD CONSERVATION STRATEGIES
Increasing interest in in Blood conservation since last 15 years Significant risks of allogenic blood transfusion. Shortage of allogenic blood Patient choice Improvement in availaibilty of transfusion alternatives.
Advanced age Low preoperative red blood cell volume (preoperative anemia or small body size) Preoperative antiplatelet or antithrombotic drug Reoperative or complex procedures Emergency operations Noncardiac patient comorbidities
Pharmacologic agents: Hemostatic Drugs with Antifibrinolytic Properties Erythropoetin DDAVP Recombinant factor 7 A Devices to Aid Blood conservation: Cell Saver Ventilator-assisted Blood Conservation PEEP Oxygenator types Perfusion Blood Pumps Heparin Bonded Circuits Leukocyte Filtration
Pharmocokinetics: Inactive via oral route Rapid distribution into extravascular space Following redistribution plasma half life aprox.150 mins Less than 10% excreted as unchanged drug Slowly degraded as lysosomal enzymes Terminal elimination phase half life-10 hr
Mechanism of action: Inhibhits serine proteases that attenuates: Inflammatory responses Fibrinolysis Thrombin generation Inhibhits pro-inflammatory cytokine release and maintains glycoprotein homeostasis
Blood/Surface activation Intrinsic PathwayPlasminKallikrein Complement activation ClottingFibrinolysisKinins Cytokines/ Adhesion Molecules Systemic Inflammatory response Non Specific Serine Antiprotease:AprotininHeparin
1-2 million KIU followed by a continous infusion of 100, ,000 KIU/hr
Epsilon Amino Caproic Acid Tranexemic acid MOA: They inhibit plasminogen by binding to the lysine binding sites on the plasminogen molecule. Spare platelet function by inhibiting the deleterious effects of plasmin. Tranexamic acid is similar in action to Epsilon- aminocaproic acid but it is approximately 10 times more potent.
Dose: Intravenous loading dose of 10 mg/kg for tranexamic acid followed by 1 mg/kg/hr mg/kg of ε-aminocaproic acid followed by infusions of 25 mg/kg/hr
Endogenous glycoprotein-stimulates red cell production in response to hypoxia and anemia. Recombinant EPO: Reduce preoperative anaemia in patients undergoing autologous blood donation Safe and effective Drawbacks ◦ Expensive ◦ Hypertension ◦ Lag period: 4-6 days-less effective post operatively ◦ Beta blockers and cardiopulmonary bypass inhibit effect Dose U/kg s/c or I/v 3 times a week
Releases Endogenous factor VIII precursors Von Willebrand factor Tissue type plasminogen activator. Not helpful prophylactically to reduce bleeding after cardiac procedures. Helpful in patients with demonstrable and specific platelet dysfunction known to respond to this agent (eg, uremic or CPB-induced platelet dysfunction, type I von Willebrand’s disease). Dose 0.3 μg/kg iv, sc or intranasal
Vitamin K-dependent glycoprotein Currently FDA approved only for the treatment of severe bleeding episodes in hemophiliacs with factor inhibitors or patients with FVII deficiency Binds to tissue factor→ Activation of factor X (FXa) on the platelet surface (a phospholipid surface); FXa + Activated factor V→ prothrombinase complex → Thrombin formation.
Plasma concentrations ~50 nM→ partial Thrombin Generation Plasma concentrations ~ 100 to 150 nM → Full activation of Thrombin (Thrombin burst) Recommended dose for bleeding in hemophiliac patients is 90 µg/kg i.v. ◦ Doses for the treatment of uncontrolled hemorrhage varied from 15 to 180 µg/kg i.v Recommended as rescue therapy for severe intractable bleeding without an identifiable surgical source that is unresponsive to routine approaches after cardiac procedures using CPB.
Advantages Disadvantages ↓ risk of infection ↓ risk of transfusion reaction Safer in patients with rare blood groups & multiple antibodies No immunosuppression ? Acceptable to Jehovah’s Witnesses ↓ demand for allogenic blood products ↑ cost- setup cost inc. staff training Unused blood wasted ↑ risk of bacterial contamination
Positive End Expiratory Pressure Increased end-expiratory airway pressure (PEEP) exerts mechanical pressure on the myocardium and may limit microvascular bleeding after heart surgery. Use of prophylactic PEEP postoperatively is not effective.
Membrane oxygenator systems during cardiopulmonary bypass are preferred for reduction in blood utilization and improved safety. Advantages Fewer cerebral emboli Better biocompatibility Reduced blood utilization
Heparin coating of the oxygenator or of the entire bypass circuit Limits platelet activation Reduces complement activation Alters cellular adhesion to the bypass tubing Diminishes the inflammatory pulmonary injury seen after CPB Need of Low dose Heparin & consequently reduced protamine dose
Removal of one to two units of blood immediately before surgery To maintain circulating blood volume, the volume is replaced with crystalloid / colloid. Contraindications: ◦ Evolving acute myocardial infarction ◦ Unstable angina ◦ Cardiogenic shock ◦ Preoperative anemia ◦ Sepsis ◦ known bacteremia. Relative contraindications ◦ Low EF (< 30%)
Principle Lowering the red blood cell concentration (hematocrit) during surgery decreases the reduction in red cell mass lost for any given volume of blood lost. In cardiac surgery The blood removed before the institution of CPB is “protected” from the potential deleterious effects of platelet activation and consumption, hemolysis, complement activation, and the production of a variety of inflammatory cytokines associated with extracorporeal circulation
Autologous blood donation of as much as 2 units a few days to a few weeks preoperatively. Not routinely employed in cardiac surgery, because of possible increase in the incidence of myocardial infarction or hemodynamic instability. Useful in carefully selected (mostly elective) patients particularly when coupled with appropriately dosed erythropoietin therapy and/or iron therapy.
Evidence of infection and risk of bacteremia Scheduled surgery to correct Aortic Stenosis Unstable angina Active Seizure disorder Myocardial Infarction or CVA within 6 months of donation Patients with significant Cardiac or Pulmonary disease High grade left main coronary artery disease Cyanotic heart disease Uncontrolled hypertension
Advantages: Prevents transfusion transmitted disease Prevents red cell alloimmunization Supplements the blood supply Provides compatible-blood for patients Prevents some adverse transfusion reactions Provides reassurance to patients concerned about blood risks Disadvantages: Does not effect risk of bacterial contamination Does not effect risk of ABO incompatibility error Is more costly than allogenic blood Results in wastage of blood not transfused Increased incdence of adverse reactions Subjects patients to perioperative anemia and increased likelihood of transfusion
Recovery of blood from surgical drains followed by reinfusion after passing through a microaggrergrate filter (40 µm filter). Transfusion to be done within 6 hrs of collection. Volume not to exceed 1400 ml Low hematocrit value Practised in cardiac surgeries and following knee arthroplasty.
Fibrin Glue: Blood derivative Derived from a source of fibrinogen and factor Xlll (fibrinogen stabilizing factor) Applied directly to the site of bleed