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SICK NEONATE. Dr. M.Thomas. CUHT. Sick Neonates are one of the most heavily transfused group of patients in modern medicine. Survival has increased. ELBW - 50% receive first transfusion by 2 weeks and 80% get atleast 1 transfusion before discharge. N.Bishara et 2008.
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SICK NEONATE. Dr. M.Thomas. CUHT.
Sick Neonates are one of the most heavily transfused group of patients in modern medicine. • Survival has increased. • ELBW - 50% receive first transfusion by 2 weeks and 80% get atleast 1 transfusion before discharge. N.Bishara et 2008. • Should I transfuse this baby today, or would I better wait ? • Packed red cells are the most common blood product administered to sick neonates.
History. • 1492 – Pope Innocent VIII. • 1615 – Andreas Libavius, techniques. • 1628 – William Harvey. • 1818 – James Blundell. • 1900 – Karl Landsteiner. • 1910s – anticoagulants added & refrigerating. • 1950s – separation of blood products. • 1960s – plastic collection bags.
Why do we transfuse ? • To ensure adequate tissue oxygenation. • To treat clinically significant anaemia. • Tissue oxygenation – type and con: Hb, 2,3DPG, and cardiopulmonary function. • How can we assess TO ? • Peripheral fractional O2 extraction- NIRS. • Capillary whole blood lactate.
It is not that simple, ….. when to transfuse pretem babies ? • Anaemia experienced by the small pretem depends on a lot of factors. • Benefits of blood transfusion – can be life-saving when given to replace blood lost acutely. • But given to anaemic preterm to ( ? ) replace that lost by natural attrition and phlebotomy IS NOT THAT CLEAR. • Anaemia of prematurity.
Anaemia of Prematurity. • In the third trimester, foetal RBC production transitions from liver to the marrow. • EPO a glycoprotein hormone is the driving force. • EPO production also switches from liver to the kidney near term. • After birth term infants show a physiologic drop in haematocrit accompanied by a fall in EPO levels. • This leads to the ‘physiologic nadir’ at around 3 months. • Oxygen delivery to tissues is well preserved and signs of anaemia are rarely seen in the term infants.
Anaemia of Prematurity. • Preterm experience a lower nadir resulting in a normocytic, normochromic anaemia. • Nadir is inversely related to gestational age. • Most preterms tolerate AOP well. • The smallest and sickest develop signs & symptoms like tachycardia, tachypnoea, apnoea, poor weight gain, O2 requirement, decreased activity, pallor etc: • The above symptoms lead to increased hospital stay and infectious complications. • Natural history of AOP is exacerbated by iatrogenic factors like low haematocrit at birth, phlebotomy and endogenous factors as rapid growth, shortened RBC lifespan and expansion of blood volume.
AOP – Management. • Red blood cell tranfusion. • Erythropoietin (EPO). • Nutrition. • Limiting blood loss by phlebotomy. • Newer trends or practices ???
AOP – RBC Transfusion. • For many years was the ONLY effective treatment. • Protocols for transfusion were largely unstandardized. • Although given to improve tissue oxygenation………… • Hebert et al,1999 in an RCT compared the outcomes in critically ill adult patients managed with liberal (Hb >10 g/dl) to a restrictive (Hb >7 g/Dl), found ICU and hospital mortality rates were lower in the restrictive group. • This study kick-started a rethink of transfusion strategies in the ICU.
RBC Transfusion. • As the ICU world was getting used to the idea that smaller might be better in terms of Hb concentrations, along came the bombshell in the form of SOAP study. • Evaluated 3147 pt; across 198 ICUs across Europe, reported that red cell transfusions were NOT associated with increased mortality in multivariate analysis or propensity case matching. • What about neonatal studies ?
RBC Transfusion. • Infection risk - lowest now with donor screening, testing for infection, leucoreduction and irradiation. • Donor exposure has been minimized by single donor techniques like pedipacs. • A lot of transfusion studies became largely irrelevant.
RBC Transfusion. • Iowa – single centre, randomised, 100 pt:, mean birth wt: 0.95kg, mean age 28wk, transfusion thresholds – Hb or haematocrit, compared a ristrictive to liberal thresholds, restrictive Hb – 7.3g/dl, primary outcome whether using restrictive criteria would reduce the number of transfusions in the 500 – 1300g babies. • PINT – multicentre , randomised, 451 pt:, birth wt: 0.77kg, capillary Hb, restrictive to liberal, looked at impact of tranfusion on incidence of a composite outcome of death, ROP, BPD, abnorm: brainUSS in babies <1kg.
RBC Transfusion. • Iowa – restrictive group got less topup, but no: of donor exposure was not reduced. • PINT – topup less in restrictive, but total no: not different as transfusion was given outside study protocol, no: of donor exposure alone not decreased, but total donor exposure including platelet, plasma etc: decreased. • Total no: of pt: who got no transfusion at all decreased, Iowa – restrictive 10 v 12 liberal and in PINT- rest: 11 v 5% liberal.
RBC Transfusion. • Iowa – adverse outcomes were more common in restrictive group , major cranial USS findings, and composite outcomes of severe brain injury / death was more in restrictive, 16% v 2%. • PINT – no effect of transfusion practices on brain injury / death, 31% in both group. • Apnoeas more in Iowa restrictive, but no different in PINT. • Conclusions………
Erythropoetin. • Dose related effect. • Few trials done, few awaited. • Does reduce transfusion volume and number. • Best works in the stable, growing prem. • Early versus late administration regimes. • So why are we not routinely using it ? • Adverse effects. • Most important findings from earlier r-EPO trials was that implementing standard transfusion critera alone safely reduced the no: of transfusions.
Newer trends. • Delayed cord clamping. • Aladangady et al: Infants blood volume in a controlled trial of placental transfusion at preterm delivery, Pediatrics 2006; 117:93-8. • Strauss RG et al: A RCT comparing immediate versus delayed cord clamping in preterm infants, Transfusion 2008; 48:658-65. • Rabe H et al: A systematic review and meta-analysis of a brief delay in clamping the cord of preterm infants, Neonatology 2008, 93:138-44. • Milking the umbilical cord at birth. • Hosono s et al: Cord milking reduces need for RBC transfusions and improve neonatal adaptations in infants born <29 weeks, a RCT, Arch Dis Child Fetal Neo Ed 2008, 93: F14-19.
Decrease Phlebotomy. • Microsampling techniques. • Batching of blood labs. • Cord blood sampling for immediate postnatal labs. • Removing central lines as soon as possible. • Ordering tests judiciously. • Point of care (POC) devices. • In-line umbilical catheter analyzer.
Conclusions. • When should we transfuse preterm neonates ? • PROBABLY AT BIRTH. • Think of strategies to minimize procedures which worsens Anaemia of Prematurity. • Have agreed written, transfusion guidelines….. IT HELPS. • Have we enough strategies to completely aviod transfusions yet ? NO.
FUTURE. • Are there better indicators of transfusion than Hb: or haematocrit ? • More accurate but still practical transfusion triggers have so far eluded researchers.
Transfusion criteria: then & now. • In the 1990s. • When 5 – 10% blood vol; lost in 48 hr, in <1500g to keep Hb: > 13g% in the first week, to treat symptoms of anaemia in convalescent infants (3-8wk). • Current restrictive guidelines for VLBW infants. • Moderate to significant vent: to keep Hb: >11g% or Hct: >35%. • Infants with mini: vent: to keep Hb: >10g% or Hct: >30. • Infant with supplemental O2 alone to keep Hb: >8g% or Hct: >25, if they are tachycardic, tachypnoeic, increased O2 need, poor wt: gain, multiple A & Bs, before surgery etc: • Asymptomatic infants to keep Hb: > 7g% or Hct: >20.