Blood Transfusion and Heart Surgery at Alder Hey. Philip Arnold, Consultant Paediatric Cardiac Anaesthetist, Alder Hey Children s Hospital, Liverpool

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1 Blood Transfusion and Heart Surgery at Alder Hey Philip Arnold, Consultant Paediatric Cardiac Anaesthetist, Alder Hey Children s Hospital, Liverpool

2 Blood and Hearts Transfusion has always been a feature of heart surgery Blood used for: Preventing haemodilution during bypass Treatment of bleeding But also: Physiological manipulation

3 Reducing use of Blood WHY? Cost Limited resource Because giving blood to babies is best avoided (probably)

4 Mortality and Heart Surgery UK 30d mortality %, % ASD 10.10% 2.10% 0.00% (0) VSD 5.20% 1.40% 0.09% (1) Fallot 6.30% 3.50% 0.70% (6) CAVSD 13.90% 2.50% 1.19% (6) Fontan 18% 1.60% 0.76% (4) Switch 11.90% 3.40% 1.18% (5) Norwood % * 12.5% (47)*

5 Using less blood Smaller bypass circuits Defining transfusion thresholds On bypass After bypass Increasing haematocrit pre-operatively Increasing haematocrit at end of bypass Ultrafiltration Cell salvage

6 Using less blood Reduce blood loss Surgeons Drugs (antifibrinolytics) More directed management of coagulopathy Better management of coagulopathy Use of paediatric packs Cell salvage Avoid unnecessary haemodilution

7 Pump Prime 3 Kg neonate b.v. of 270mls, HcT of 35% (Hb of 11.7g/dl) Bypass circuit volume of 350mls plus 50mls for cardioplegia Clear prime Hct on bypass of 14% (Hb of 4.7g/dl)

8 Minimize circuit size Prime Volumes: Erasmus Micro-plegia Vacuum assisted drainage Arterial line filters Berlin 2008: 110mls

9 Transfusion Thresholds Pre-operatively, post-operatively, during bypass Cyanotic vs not cyanotic Ill vs not so ill Neonates vs older infants, children Clinical judgment Lots of doctors

10 Transfusion Thresholds Some evidence that lower haematocrits (>7 g/dl) are not associated with worse outcome in some critically ill children (TRIPICU study) Some evidence that lower haematocrits (>9g/dl) can be tolerated in some cyanotic children post operatively (Cholette et al 2011) Low haematocrits during bypass have been associated with worse neurological outcome (HcT <24%) (Jonas et al)

11 Causes of increased bleeding Complex surgery Coagulopathy Bypass Surgery Bleeding Patients

12 Management of Coagulopathy Begins with clinical assessment of bleeding May be room for more restrictive approach Implementation of algorithms based on monitoring (ie TEG) more difficult than in adult practice. Most (all) infants are coagulopathic

13 Method Interrogation of cardiac surgical database and of meditech transfusion records Data combined into single spread sheet All transfusions 2 days prior to 7 days after heart surgery involving bypass Episode truncated if second surgery in this time Episodes were ECMO required included if possible but use of blood related to ECMO excluded

14 Method Primary outcome is Donor Exposure for each episode. Donor identified from unique identifier for unit. Surgical Complexity (RACHS) score calculated from procedure description (Dr RJ)

15 Results 3008 episodes in 2680 patients transfusions from donors

16 Donor Exposures 100% 90% 80% Proportion Patients 70% 60% 50% 40% 30% > % 10% 0% Year

17 Results During this period there has been a substantial reduction in the exposure of patients Far fewer patients receiving greater than 2 exposures (50% vs. 87%) Those receiving no blood products increased from 1.6% to 9.2% (comparing with ). Greatest fall occurred 2004, at time of introduction of routine cell salvage

18 Mean DE by product

19 Results Red cell use fell more than other products Largest fall in 2004, at time of introduction of routine cell salvage

20 Non-red cell products Overall 40% of donor exposures are from nonred cells Proportion increasing: in % Platelets 17% of exposures, cryoprecipitate increases from 4.5% to 19.7%

21 Results Platelets FFP Cryo %* 36.9%* 10.3% % 22.4% 31.2%* Recent increase in use of cryoprecipitate, only partly offset by reduced use of FFP Small reduction in use of platelets P<0.001

22 Neonates During this period the proportion of neonatal patients has increased. Neonates (n=480) were more likely to be transfused greater than 2 exposures (92% vs. 58%, p<0.001) More likely to receive more than 10 donor exposures (8% vs. 4%, p<0.001)

23 Donor exposure neonates

24 Surgical Complexity Transfusion was related to surgical complexity During procedures with RACHS scores of 4-6 (n=575) patients were more likely to be transfused greater than 2 exposures (92% vs. 57%, p<0.001) More likely to receive more than 10 exposures (7.2% vs. 3.2%, p<0.001).

25 Large Transfusion 9.0% 8.0% 7.0% 6.0% 5.0% 4.0% 3.0% 2.0% 1.0% 0.0%

26 Large Transfusion 53% of donor exposure to those receiving >5 units (21% of patients) 17% of donor exposures to those receiving >10 units (4.2 % of patients) Little real change over time period Recent increase may be driven by increased use of cryoprecipitate

27 Cost Cost per patient Year Estimated cost of blood products over time period 2m (corrected to 2013 prices) Approximately 150 less per patient

28 Does it matter? Strong association with mortality Number of exposures Mortality 0 1.3% % % May be several explanations: Sick patients bleed more Patients having complex surgery bleed more Neonates bleed more Bleeding vs. transfusion vs. surgery Requires more examination % > %

29 Conclusion We are using less blood This is probably a good thing Incidence of very large transfusion is largely unchanged This is disappointing

30 Conclusion Reducing blood usage in heart surgery is challenging Best bets: Further reductions in bypass circuits Improved management of coagulopathy Use of blood transfusion as local quality indicator