minimizing intra-op transfusion requirements
DESCRIPTION
MINIMIZING INTRA-OP TRANSFUSION REQUIREMENTS. DR. NYAMARI FACILITATOR: DR. BHOYYO KIBET. RATIONALE. To minimize hazards associated with blood transfusion Hazards include infection, immunologic reactions, hypothermia, volume overload, dilutional coagulopathy, - PowerPoint PPT PresentationTRANSCRIPT
MINIMIZING INTRA-OP TRANSFUSION REQUIREMENTSDR. NYAMARIFACILITATOR: DR. BHOYYO KIBET
RATIONALE• To minimize hazards associated with blood transfusion• Hazards include infection, immunologic reactions,
hypothermia, volume overload, dilutional coagulopathy, • Conservation and optimal use of blood resources due to
perennial blood shortage• To improve outcomes in patients objecting blood transfusion
for religious/personal reasons
TRANSFUSION THRESHOLD• ABLEBV• EBV Premature neonates 95mL/kgFull term neonate 85mL/kgInfants 80mL/kgAdult men 75mL/kg Adult women 65mL/kg
STRATEGIES• Patient optimization• Minimization of blood losses• Alternatives to allogeneic blood
PATIENT OPTIMIZATION• Correction of anemia, thrombocytopenia• Optimize hemostatic function; stopping anti-coagulant therapy
early, NSAIDs, correction of coagulopathies• Minimizing diagnostic phlebotomy• Pre-operative Autologous Donation(PAD)
PAD• This involves a patient scheduled for elective surgery donating
blood prior to surgery• Hb ≥ 11g/dl or HCT ≥33% (AABB standards)• Donation done weekly at 10.5ml/kg• Efficacy is dependent on the patient’s intrinsic increase in
erythropoiesis• Endogenous erythropoietin response is sub optimal resulting
in only 11% expansion of RBC volume• Recombinant erythropoietin and daily iron supplements aid.
PAD
ADVANTAGES• Limits transfusion transmitted diseases• Prevents red cell alloimmunization• Provides compatible blood• Provides patient reassurance
PAD
DISADVANTAGES• Doesn’t reduce risk of contamination• May result in wastage of blood not transfused(5%)• Risk of perioperative anemia• More expensive
PAD
CONTRAINDICATIONS• Evidence of infection• Scheduled surgery for aortic stenosis• Unstable angina, MI, CVA, Cyanotic heart dx• Uncontrolled hypertension
MINIMIZING BLOOD LOSS• Acute Normovolemic Hemodilution(ANH)• Intra-operative cell salvage• Surgical technique• Anesthetic technique• Pharmacologic manipulation
ANH• Removal of whole blood from a patient while restoring the
circulating volume with acellular fluid shortly before significant blood loss
• End point is a Hct of 27%-33%• Blood collected in standard blood bags, stored at room
temperature• Re-infused during surgery after major blood loss
ceases( within 8hrs)• Re-infusion is done in reverse order.
ANH• The chief benefit is the reduction of RBC losses.• Concomitant decrease in arterial oxygen capacity• Compensatory increase in Cardiac output and reduction in
peripheral resistance.
ANH
CRITERIA• Likelihood of transfusion exceeds 10%• Absence of cardiac, hepatic or renal dx• Absence of hypertension• Absence of infection
ANH v/s PADANH PAD
LESS COSTLY EXPENSIVE
DECREASED BLOOD WASTAGE SIGNIFICANT BLOOD WASTAGE
MINIMAL CONTAMINATION HIGHER RISK OF CONTAMINATION
MINIMAL CLERICAL ERRORS HIGHER RISK OF CLERICAL ERRORS
INTRA-OP BLOOD SALVAGE• Involves the collection of blood from the surgical field into a
cell salvage device.• The cell salvage device:
a. Filters the collected blood(40nm filters) i.e. bone fragments, tissue debris
b. Anti-coagulates the bloodc. Separates RBCs from other cellular and liquid elementsd. Washes salvaged RBCs extensively with saline• The RBCs are then re-infused suspended in saline
CELL SALVAGE MACHINE
INTRA-OP BLOOD SALVAGE
INDICATIONS• Aortic reconstruction• Spinal instrumentation• Joint arthroplasty• Liver transplantation• Resection of A-V malformations• Trauma patients
INTRA-OP BLOOD SALVAGE
CONTRAINDICATIONS• Infection• Malignant cells• Urine and bowel contents in operating field• Amniotic fluid• Procoagulant material used in surgical field
INTRA-OP BLOOD SALVAGE
COMPLICATIONS• Massive air embolism• Dilutional coagulopathy• Nephrotoxicty by free Hb ( limit suction pressures to
150mmHg)
ANAESTHETIC TECHNIQUE• Maintainance of normothermia• Use of regional anesthesia when possible e.g. TJR surgery• Patient positioning• Avoiding high intra-thoracic pressures• Controlling blood pressure• Permissive hypotension• Controlling and maintaining a normal pCO2
SURGICAL TECHNIQUE• Meticulous surgical hemostasis• Use of diathermy, laser scapel• Use of tourniquet where applicable• Minimally invasive procedures if possible
PHARMACOLOGIC AGENTS• Serine protease inhibitors e.g. Aprotinin that are direct
plasmin inhibitors• Lysine analogues e.g. Tranexamic acid that inhibit conversion
of plasminogen to plasmin• Desmopressin that stimulates the release of vWF promoting
primary haemostasis• Recombinant activated factor VIIa• Fibrin glue
ALTERNATIVES TO BLOOD• Substances used to mimic and fulfill functions of biological
blood especially oxygen ‘carrying’• Hemoglobin based oxygen carriers• Perfluorocarbon based oxygen carriers
CONCLUSION• Adhere to protocols on transfusion of blood and its products• Where protocols are non-existent, develop the protocols• Pre-operative assessment and work-up of patients
REFERENCES• Miller’s anesthesia, 7th edition Autologous Transfusion,
Recombinant Factor VIIa, and Bloodless Medicine Lawrence T. Goodnough,Terri G. Monk
• Clinical Anesthesia, 6th Edition Hemostasis and Transfusion Medicine Barash, Paul G.; Cullen, Bruce F.; Stoelting, Robert K.; Cahalan, Michael K.; Stock, M. Christine