Neonatal red blood cell transfusions

Abstract

Red blood cell and blood product transfusions in the fetus, neonate and premature infant are often administered with poorly defined indications and unintentional adverse consequences. Products may be altered in an effort to limit potential adverse events or be specially selected to meet the unique needs of a specific diagnosis. One area of particular concern to neonatologists is selecting blood for small volume (5-20 ml/kg) transfusions in prematures.For infants, red blood cells (RBC's) collected in anticoagulantadditive solutions and administered in small aliquots over the shelf life of the product to decrease donor exposure has supplanted the use of fresh RBC's where each transfusion resulted in a donor exposure. The safety of this practice has been documented and procedures established to aid a transfusion service in making these products available. Less well established are the indications for transfusion in this population; haemoglobin or haematocrit alone are likely insufficient unless clinical findings like oxygen desaturation, apnea and bradycardia are part of the criteria used to define transfusion need. The comorbidities that increase oxygen demands in these infants, like bronchopulmonary dysplasia and increased oxygen consumption to accommodate growth, must be part of the decision to transfuse. Non-invasive methods or assays that will reflect the unique pathophysiology of oxygen delivery and peripheral oxygen offloading are needed. Red blood cells for small volume transfusionMost newborns of 24 -27 weeks' gestation will require transfusions of RBC's [1]. Restrictive guidelines have been developed which have decreased donor exposure and transfusion number, but several factors continue to contribute to the need to transfuse. These include iatrogenic anaemia, oxidative haemolysis often from sepsis, and rapid growth with concomitant protein and iron deficiency. The selection of the transfusion product continues to be controversial. Specific issues include (1) age of the blood and hence the quantity of intraerythrocyte, 2,3DPG and oxygen offloading capacity;(2) potassium content which increases over storage time;(3) solute load from the anticoagulant solutions which might result in osmotic diuresis with subsequent alteration of cerebral microcirculation with resultant periventricular haemorrhage; (4) transfusion-associated viral diseases and graft-vs.-hostdisease resulting from passive transfer of viral-infected monocytes and engraftable lymphocytes, respectively.Several clinical articles and one review have addressed the transfusion of RBC's packaged in small volumes in different anticoagulant-solutions to reduce donor exposure [2][3][4][5][6][7][8]. The solutions have in common the use of mannitol, glucose, sodium chloride, phosphate and other additives (Table 1). To ensure that the haematocrit is more comparable to a standard packed RBC's, and to decrease the volume of blood in very low birth weight infants where volume overload is common, they can be concentrated by either centrifugation [9] or inverted...

Red Blood Cell Transfusion in Preterm Infants: Current Evidence and Controversies

“…It has been proposed that anaemia causes reduced mesenteric blood flow leading to intestinal hypoxia and subsequent mucosal injury [8, 36-39]. There is evidence to suggest that this transient hypoxia followed by re-oxygenation (e.g., after RBCT to treat anaemia) is a component of the pathogenesis of diseases involving a change in blood flow to the bowel, including NEC, through reperfusion injury [11, 18, 22-24, 40]. The association between Hb, tissue perfusion, and oxygen delivery is not clear [39]; the critical Hb level at which the risk from anaemia outweighs the risk of NEC from RBCT has not been identified [64, 71].…”

“…The RBCT guidelines used in the Neonatal Unit (NNU) are subjective and generalized [17, 18]. Anaemia impacts the clinical status when the oxygen-carrying capacity drops below an adequate threshold to meet the demands of oxygen consumption.…”

Neonatal RBC Transfusions – Comparison of Two Patterns

“…Several theoretical and practical studies have demonstrated that using RBC stored up to 42 days is safe. It has been proven that possible changes in biochemical or toxic factors are of no clinical significance provided that transfusion volumes are small [5][6][7]. Thus, this rationale does not apply to large-volume transfusions, such as exchange transfusion or transfusion in extensive surgery.…”

“…Despite the knowledge gained from research and practice in prescribing RBC transfusion, there are still controversies and a lack of unique indications in neonatal transfusion therapy [1,7,15]. In our ward, RBC transfusion guidelines allow for some physician discretion on site.…”

“…The traditional use of fresh blood (<7 days of storage) has been replaced in many neonatal centers by repeated use of dedicated units of stored red blood cells (RBC; <42 days of storage) for each infant. One of the costs of diminished DER is a worsened metabolic profile of RBC after extended storage [5][6][7]. The aim of this study was to compare the red blood cell (RBC) transfusions in a neonatal ward over the last 5 years with the hypothetical use of blood satellite packs.…”