1) Blood conservation strategies are important in cardiac surgery to reduce bleeding and transfusions which can increase mortality and morbidity. 2) Preoperative interventions include managing antiplatelet drugs and anticoagulants, correcting anemia, and using drugs to increase red cell mass. 3) Intraoperative techniques involve autologous blood donation, maintaining normothermia, pharmacological agents like tranexamic acid, and restrictive transfusion triggers. 4) Close monitoring of bleeding and vital signs is also important intraoperatively to guide transfusions which should be a last resort.

1. B L O O D C O N S E R V AT I O N S T R AT E G Y
I N C A R D I A C S U R G E R Y - A N
A N E S T H E S I O L O G I S T
I N T E R V E N T I O N S
P R E S E N T E R – D r. V I N O T H N ATA R A J A N
M O D E R AT E R – D r. R A M E S H K E S H AV

2. INTRODUCTION
• Cardiac surgery – dual threat
1) perioperative bleeding problems and
2) attendant complications of blood and blood products transfusion.
• Bleeding due to
1) patient factors
2) inadequate surgical hemostasis
3) coagulation abnormality as a result of CPB.
• Although lifesaving, blood transfusion may be associated with
1) increased perioperative mortality and morbidity
2) prolonged hospital stay and
3) decrease the long term quality of life.

3. RISK FACTORS
Patient related variables
• Advanced age or age > 70 yrs
• Female gender
• Preoperative anemia
• Small body size

4. RISK FACTORS
Preoperative antithrombotic therapy
• High intensity (abciximab, clopidogrel, direct thrombin
inhibitors, low-molecular-weight heparin, long-acting
direct thrombin inhibitors, thrombolytic therapy)
• Low intensity (aspirin, Dipyridamole, Eptifibatide,
tirofiban)

5. RISK FACTORS
Preoperative coagulopathy
• Hereditary coagulopathy or platelet defect (von Willebrand’s
disease, Hermansky-Pudlak,BernardSoulier, Scott, Werlhof,
Glanzmann’s,hemophilia A or B, clotting factor deficiencies,
etc)
• Acquired coagulopathy or platelet abnormality (nonspecific
platelet defect measured by bleeding time, chronic lymphocytic
leukemia, cirrhosis, anticoagulant, drug-related polycythmia
vera,myelodysplastic syndrome, ITP, beta thalassemia, etc)

6. RISK FACTORS
• Cardiogenic shock, congestive heart failure, or poor left
ventricular function
• Renal insufficiency
• Insulin-dependent adult-onset diabetes mellitus
• Peripheral vascular disease
• Preoperative sepsis
• Liver failure or hypoalbuminemia

7. PREOPERATIVE INTERVENTIONS
• Management of dual antiplatelet drugs and anticoagulants.
• Correction of preoperative anemia
• Preoperative use of drugs increasing red cell mass/volume.
• Autologous preoperative blood donation and r-EPO
• Use of blood derivatives for blood conservation

8. DUAL ANTIPLATELET DRUGS
• platelet P2Y12 receptors irreversible inhibitors – discontinue as short as 3
days
• Point of care testing to identify clopidogrel nonresponders – surgery as early
as possible
• Addition of clopidogrel to aspirin in early postoperative period – associated
with bleeding – not recommended (except in ACS and pateient with recent
drug eluting stent placement)
• It is reasonable to discontinue low-intensity antiplatelet drugs (eg, aspirin) only
in purely elective patients without acute coronary syndromes before operation
with the expectation that blood transfusion will be reduced

9. ANTICOAGULANTS
• The current guideline recommends the withdrawal of oral
anticoagulants (warfarin) 72hr before surgery to lower the INR to < 1.5
and maintain anticoagulation with unfractionated heparin. APTT is
maintained twice the control values.
• For urgent warfarin reversal, administration of prothrombin complex
concentrate (PCC) is preferred but plasma transfusion is reasonable
• Plasma is not indicated for warfarin reversal in the absence of bleeding
• LMW HEPARIN discontinuation < 12 hrs before – associated with
more bleeding
- ACC AHA 2014

10. CORECTION OF PREOPERATIVE ANEMIA
• If anemic – consider peripheral smear study and ferritin measurement to rule out the type of
anemia
Ferritin < 30 mcg/l
Iron deficiency anemia and
commence iron therapy
Ferritin > 100 mcg/l
Check B12/folate levels, do liver
and thyroid function tests
Ferritin 30-100 mcg/l
Possible Iron deficiency anemia
and commence iron therapy

11. INCREASE RED CELL MASS
• Erythropoietin plus Iron given several days before cardiac surgery
• Dose 100-300 IU/kg/day SC every week for 4 weeks and 48 hrs before
surgery – more promisable results.
• Short term regimen is also available. (atleast started 4 days prior to
surgery)
• Contraindicated in patient having S.Creatinine > 1.5 mg/dl and patient
with unstable symptom. Very useful in canditates for jerovah’s witness

12. AUTOLOGOUS PREOP BLOOD
DONATION WITH R-EPO
• Preoperative autologous donation with recombinant erythropoietin use –
another method
• But at the risk of thrombotic events in cardiac surgery setup.
• Intraoperative autologous blood donation >>> preoperative
• No large scale studies available in cardiac patients.

13. USE OF BLOOD DERIVATIVES
• Plasma transfusion
1) in patients with serious bleeding in the context of single or
multiple coagulation factor defiencies.
2) for urgent warfarin reversal
3) as a part of massive blood transfusion (3:1)
4) prophylactically in patient with abnormal coagulation tests
undergoing cardiac surgery – debatable
• Platelet transfusion
1) platelet count < 50x109 cells/l or evidence of platelet
dysfunction. Risk of TRALI is more with platelet transfusion.

14. USE OF BLOOD DERIVATIVES
• Cryoprecipitate (fibrinogen, VW factor, Factor VIII and Factor XIII)
1) fibrinogen level below 1.0g/l – prophylactically
2) clinically significant bleeding in the context of coagulation factor
deficiencies
• Factor IX concentrates in haemophilia B patients and for Jehovah’s
witness

15. INTRAOPERATIVE INTERVENTIONS
• Intraoperative autologous blood donation with acute normovolemic
dilution technique (IABD-ANH)
• Maintainence of normothermia
• Pharmacological methods
• Transfusion triggers in cardiac surgery
• Intraoperative monitoring

16. IABD WITH ANH
• Performed before sternotomy
• Autologous blood collected from central line catheter and crystalloids are
replaced for withdrawn blood (1:1) slowly drained into anti-coagulated blood
bags intra-operatively.
• Finally, the fresh whole blood is returned at wound closure, providing red
cells, fresh clotting factors and platelets when they are most needed.
• Usually 30% of blood volume to maintain HCT in range of 20 – 30.
• Debois nomogram to calculate IAD volume ( suggested by Avgerinos et al)

17. Debois nomogram X axis – HCT: Y axis – weight in kg
Based on formula

18. IABD WITH ANH
Benefits
• Prevention from haemolysis due to
bypass
• decrease in blood loss via lap pads,
discard suction and field drapes
• Provision for fresh autologous
RBCs, platelets, and coagulation
factors after bypass
Contraindications
• Evolving myocardial infarction,
• Unstable angina,
• Cardiogenic shock,
• Pre-operative anaemia,
• Sepsis or known bacteraemia and
• Low ejection fraction (<30%)

19. MAINTAINENCE OF NORMOTHERMIA
Hypothermia = Platelet function and the coagulation cascade dysfunction.
<1°C in temp = ↑Blood loss by 16% and ↑ transfusion approximately by 22%.
1) Temperature monitoring
2) Employing warming
devices (warm fluids,body
warmers etc)

20. PHARMACOLOGICAL METHODS
• Antifibrinolytics agents >> aprotinin (potential risk of renal damage/mortality)
BART trial
• Antifibrinolytics – inhibitors of plasminogen, useful in oozing patient.
• Tranexamic acid >> EACA (10 times more potent)
• Dose of tranexamic acid 2.5mg/kg to 100mg/kg; (multiple RCTs)
maintainence 0.5mg/kg/hr to 4mg/kg/hr
• 50 mg/kg dose >>> 100 mg/kg dose (less seizures complication)

21. PHARMACOLOGICAL METHODS
• Desmopressin – reasonable to attenuate bleeding in uremic or CPB
induced platelet dysfunction and type 1 von-willebrand disease.
• Prophylactic use not recommended.
• Dipyrimadole is unnecessary to prevent graft occlusion in CABG, not
recommended for the control of postoperative bleeding.

22. TRANSFUSION TRIGGERS
- AABB GUIDELINES 2016

23. TRANSFUSION TRIGGERS
A restrictive threshold of Hb 7.5 mg/dl vs liberal 9.5 mg/dl

24. TRANSFUSION TRIGGERS - CPB
Hb levels Risk for
decreased
cerebral oxygen
delivery
Pateint
related
factors
Clinical
setting
Lab or
Clinical
data
Transfusio
n
< 6 g/dl No Nil Nil Nil YES
< 7 g/dl Yes Nil Nil Nil YES
> 6 g/dl No Yes Nil Nil Yes
> 6 g/dl No Nil Yes Nil Yes
> 6 g/dl No Nil Nil Yes Yes

25. TRANSFUSION TRIGGERS - CPB
1) Risk for decreased cerebral oxygen delivery = H/o CVA, diabetes and
carotid stenosis
2) Patient related factors = elder age, severe disease, poor cardiac
function and end organ ischemia
3) Clinical setting = massive (>30% ) or active blood loss
4) Lab or clinical data = SmvO2 < 50%, ScvO2 < 60%,ECG (newly
occurring ST elevation/depression/new onset arrhythmias,
echocardiography (newly occurring altered myocardial contractility)
-STS/SCA GUIDELINE 2011 UPDATE

26. TRANFUSION TRIGGER – OTHERS
• Prefer leukoreduced donor blood always.
• Standard storage blood >> fresh blood (less than 10 days) –
Transfusion associated microchimerism (TA-MC) :Dutch study
• Non red cell component – clinical evidence of bleeding – guided by
specific point of care tests that assess hemostatic function in a timely
and accurate manner (THROMBOELASTOGRAM)

27. TRANSFUSION TRIGGERS - OTHERS
• Transfusion of plasma = as part of a massive transfusion
algorithm in bleeding patients requiring substantial amounts of red-blood
cells (3:1).
• Platelet transfusion for patients having bypass who exhibit perioperative
bleeding with thrombocytopenia and/or evidence of platelet dysfunction.
• For clot stabilization - use of factor XIII or Cryoprecipitate after cardiac
procedures requiring cardiopulmonary bypass when other routine blood
conservation measures prove unsatisfactory in bleeding patients
-NICE guidelines 2015

28. PEDIATRIC CARDIAC SURGERIES
• Poses challenges due to a) their small blood volume
b) larger prime volume
c) presence of cyanosis
d) hypothermia
e) immature coagulation system
• Limit frequent flushing of invasive lines and restrict sampling volumes
• Use of “double stopcock techniques”
• Liberal transfusion strategy – not associated with MODS in many pediatric
population based studies

29. DOUBLE STOPCOCK TECHNIQUE
One for flushing :One for sampling
• A goal hematocrit of 30–35% should be achieved by blood conservation rather
than transfusion, wherever possible

30. INTRAOPERATIVE MONITORING
• Perfusion of vital organs monitoring – ASA standard monitors with urine
output.
• Visual assessment of surgical field
• Hb/Hct monitoring – serial ABG measurements
• Central venous/pulmonary artery catheters based parameters – ScvO2,
SmvO2
• Transoesophageal Echocardiography
• Pulse contour analysis /Flotrac devices (SVV, PVV, cardiac output)
• Activated clotting time (heparin and heparin reversal)
• Thromboelastography (baseline, when clinically abnormal bleeding and after
therapeutic interventions)

31. INTRAOPERATIVE MONITORING
 Continous Non-invasive Hb measurement devices and founds to be useful
in OFF PUMP CABG.
 Needs a large multicentric trials for its use and reliability in cardiac
surgeries requiring CPB.

32. CARRY HOME MESSAGE
• Identification of at risk patients
• Formulation of institutional collaborative
(Anesthesiologists/Surgeons/Perfusionists) transfusion threshold
algorithm and applying it
• Follow maximum blood conservation methods at each possible steps.
• Do more CONSERVATION rather than UTILIZATION.