Effect of blood transfusions on the outcome of very low body weight preterm infants under two different transfusion criteria

Red blood cell transfusion is not associated with necrotizing enterocolitis: a review of consecutive transfusions in a tertiary neonatal intensive care unit

OBJECTIVE

To explore the association between red blood cell transfusion and necrotizing enterocolitis (NEC) in a neonatal intensive care unit with liberal transfusion practices.

STUDY DESIGN

A retrospective cohort study was conducted for all infants weighing <1500 g who received at least 1 packed red blood cell transfusion between January 2008 and June 2013 in a tertiary neonatal intensive care unit. The primary outcome was NEC, defined as Bell stage II or greater. The temporal association of NEC and transfusion was assessed using multivariate Poisson regression.

RESULTS

The study sample included 414 very low birth weight infants who received 2889 consecutive red blood cell transfusions. Twenty-four infants (5.8%) developed NEC. Four cases of NEC occurred within 48 hours of a previous transfusion event. Using multivariate Poisson regression, we did not find evidence of a temporal association between NEC and transfusion (P = .32).

CONCLUSION

There was no association between NEC and red blood cell transfusion. Our results differ from previous studies and suggest that the association between NEC and transfusion may be contextual.

Transfusion practices in a neonatal intensive care unit in a city in Brazil

Objective

Newborn infants are the most heavily transfused population inside intensive care units. The hemoglobin level used to indicate the need of transfusions is not well established. The aim of this study was to evaluate transfusional practices in newborns in the neonatal intensive care units of one specific city.

Methods

Red blood cell transfusion practices of all transfused newborns in all five of the neonatal intensive care units of the city were analyzed. Data are reported as descriptive statistics, including numbers and percentages and means and standard deviation. Univariate analysis, followed by stepwise logistic regression was performed in respect to transfusional data and outcomes.

Results

A total of 949 patients were admitted to the intensive care units during the 12-month study period with 20.9% receiving at least one transfusion, most (62.4%) of whom received more than one transfusion. The mean number of transfusions per infant was 2.7 ± 2.16; in the liberal transfusion group the mean number was 1.59 ± 1.63 and in the restrictive group it was 1.08 ± 1.51. The mean hemoglobin and hematocrit levels were 9.0 g/dL (±1.4 g/dL) and 27.4% (±4.3%), respectively. The most common indications for blood transfusions were sepsis and prematurity.

Conclusion

This study shows that the characteristics and the transfusion practices for newborns admitted in the neonatal intensive care units of Juiz de Fora are similar to recent pubications. There was no significant reduction in the number of transfusions per child in the restrictive group compared to the liberal group. Restrictive transfusions are an independent risk factor for peri-intraventricular hemorrhages and death.

Red blood cell transfusion in newborn infants

Red blood cell transfusion is an important and frequent component of neonatal intensive care. The present position statement addresses the methods and indications for red blood cell transfusion of the newborn, based on a review of the current literature. The most frequent indications for blood transfusion in the newborn are the acute treatment of perinatal hemorrhagic shock and the recurrent correction of anemia of prematurity. Perinatal hemorrhagic shock requires immediate treatment with large quantities of red blood cells; the effects of massive transfusion on other blood components must be considered. Some guidelines are now available from clinical trials investigating transfusion in anemia of prematurity; however, considerable uncertainty remains. There is weak evidence that cognitive impairment may be more severe at follow-up in extremely low birth weight infants transfused at lower hemoglobin thresholds; therefore, these thresholds should be maintained by transfusion therapy. Although the risks of transfusion have declined considerably in recent years, they can be minimized further by carefully restricting neonatal blood sampling.

Feeding practices and other risk factors for developing transfusion-associated necrotizing enterocolitis

AIMS

The objective of this study is to determine the incidence of and risk factors for necrotizing enterocolitis (NEC) and transfusion-associated NEC (TANEC) in very-low-birth-weight (VLBW) infants pre/post implementation of a peri-transfusion feeding protocol.

STUDY DESIGN

A retrospective cohort study was conducted including all inborn VLBW infants admitted to the Duke intensive care nursery from 2002 to 2010. We defined NEC using Bell's modified criteria IIA and higher and TANEC as NEC occurring within 48h of a packed red blood cell (pRBC) transfusion. We compared demographic and laboratory data for TANEC vs. other NEC infants and the incidence of TANEC pre/post implementation of our peri-transfusion feeding protocol. We also assessed the relationship between pre-transfusion hematocrit and pRBC unit age with TANEC.

RESULTS

A total of 148/1380 (10.7%) infants developed NEC. Incidence of NEC decreased after initiating our peri-transfusion feeding protocol: 126/939 (12%) to 22/293 (7%), P=0.01. The proportion of TANEC did not change: 51/126 (41%) vs. 9/22 (41%), P>0.99. TANEC infants were smaller, more likely to develop surgical NEC, and had lower mean pre-transfusion hematocrits prior to their TANEC transfusions compared with all other transfusions before their NEC episode: 28% vs. 33%, P<0.001. Risk of TANEC was inversely related to pre-transfusion hematocrit: odds ratio 0.87 (0.79-0.95).

CONCLUSIONS

Pre-transfusion hematocrit is inversely related to risk of TANEC, which suggests that temporally maintaining a higher baseline hemoglobin in infants most at risk of NEC may be protective. The lack of difference in TANEC pre-/post-implementation of our peri-transfusion feeding protocol, despite an overall temporal decrease in NEC, suggests that other unmeasured interventions may account for the observed decreased incidence of NEC.

Red cell transfusion management for patients undergoing cardiac surgery for congenital heart disease

BACKGROUND

Congenital heart disease is the most commonly diagnosed neonatal congenital condition. Without surgery, only 30% to 40% of patients affected will survive to 10 years old. Mortality has fallen since the 1990s with 2006 to 2007 figures showing surgical survival at one year of 95%. Patients with congenital heart disease are potentially exposed to red cell transfusion at many points in the surgical pathway. There are a number of risks associated with red cell transfusion that may be translated into increased patient morbidity and mortality.

OBJECTIVES

To evaluate the effects of red cell transfusion on mortality and morbidity on patients with congenital heart disease at the time of cardiac surgery.

SEARCH METHODS

We searched 11 bibliographic databases and three ongoing trials databases including the Cochrane Central Register of Controlled Trials (CENTRAL) (Issue 5, 2013), MEDLINE (Ovid, 1950 to 11 June 2013), EMBASE (Ovid, 1980 to 11 June 2013), ClinicalTrials.gov, World Health Organization (WHO) ICTRP and the ISRCTN Register (to June 2013). We also searched references of all identified trials, relevant review articles and abstracts from between 2006 and 2010 of the most relevant conferences. We did not limit the searches by language of publication.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing red cell transfusion interventions in patients undergoing cardiac surgery for congenital heart disease. We included participants of any age (neonates, paediatrics and adults) and with any type of congenital heart disease (cyanotic or acyanotic). We excluded patients with congenital heart disease undergoing non-cardiac surgery. No co-morbidities were excluded.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. We contacted study authors for additional information.

MAIN RESULTS

We identified 11 trials (862 participants). All trials were in neonatal or paediatric populations. The trials covered only three areas of interest: restrictive versus liberal transfusion triggers (two trials), leukoreduction versus non-leukoreduction (two trials) and standard versus non-standard cardiopulmonary bypass (CPB) prime (seven trials). Owing to the clinical diversity in the participant groups (cyanotic (three trials), acyanotic (four trials) or mixed (four trials)) and the intervention groups, it was not appropriate to pool data in a meta-analysis. No study reported data for all the outcomes of interest to this review. Risk of bias was mixed across the included trials, with only attrition bias being low across all trials. Blinding of study personnel and participants was not always possible, depending on the intervention being used.Five trials (628 participants) reported the primary outcome: 30-day mortality. In three trials (a trial evaluating restrictive and liberal transfusion (125 participants), a trial of cell salvage during CPB (309 participants) and a trial of washed red blood cells during CPB (128 participants)), there was no clear difference in mortality at 30 days between the intervention arms. In two trials comparing standard and non-standard CPB prime, there were no deaths in either randomised group. Long-term mortality was similar between randomised groups in one trial each comparing restrictive and liberal transfusion or standard and non-standard CPB prime.Four trials explored a range of adverse effects following red cell transfusion. Kidney failure was the only adverse event that was significantly different: patients receiving cell salvaged red blood cells during CPB were less likely to have renal failure than patients not exposed to cell salvage (risk ratio (RR) 0.26, 95% confidence interval (CI) 0.09 to 0.79, 1 study, 309 participants). There was insufficient evidence to determine whether there was a difference between transfusion strategies for any other severe adverse events.The duration of mechanical ventilation was measured in seven trials (768 participants). Overall, there was no consistent difference in the duration of mechanical ventilation between the intervention and control arms.The duration of intensive care unit (ICU) stay was measured in six trials (459 participants). There was no clear difference in the duration of ICU stay between the intervention arms in the transfusion trigger and leukoreduction trials. In the standard versus non-standard CPB prime trials, one trial examining the impact of washing transfused bypass prime red blood cells showed no clear difference in duration of ICU stay between the intervention arms, while the trial assessing ultrafiltration of the priming blood showed a shorter duration of ICU stay in the ultrafiltration group.

AUTHORS' CONCLUSIONS

There are only a small number of small and heterogeneous trials so there is insufficient evidence to assess the impact of red cell transfusion on patients with congenital heart disease undergoing cardiac surgery accurately. It is possible that the presence or absence of cyanosis impacts on trial outcomes, which would necessitate different clinical management of two groups. Further adequately powered, specific, high-quality trials are warranted to assess this fully.

Restrictive versus liberal red blood cell transfusion thresholds in very low birth weight infants: a systematic review and meta-analysis

AIM

A systematic review was conducted to examine the effects of restrictive versus liberal red blood cell (RBC) transfusion thresholds on clinically important outcomes in very low birth weight (VLBW) infants.

METHODS

Randomised controlled trials (RCTs) of varying RBC transfusion thresholds in VLBW infants were identified by searching MEDLINE, EMBASE, CINAHL, all of the Cochrane Library and other supplementary sources. Selected studies included one of the following outcomes: total number of red blood cell transfusions, donor exposure rate, cranial ultrasonographically diagnosed brain injury, retinopathy of prematurity, bronchopulmonary dysplasia, necrotising enterocolitis or death. Studies to be included were selected by two reviewers who also assessed the risk of bias of each trial. Data extraction and analyses were independently performed by two reviewers. All data were analysed using RevMan 5.

RESULTS

Six RCTs were identified. One trial did not meet the inclusion criteria, while two had inadequate methodological quality. Pooled analysis of two trials showed that the restrictive transfusion group received a significantly lower mean number of transfusions per infant (mean difference (MD) -1.35, 95% confidence interval (CI) [-2.61, -0.09]) and donor exposure rate (MD -0.54, 95% CI [-0.93, -0.15]). No other statistically significant differences were observed.

CONCLUSION

Restrictive RBC transfusion thresholds in VLBW infants may be utilised without incurring clinically important increases in the risk of death or major short-term neonatal morbidities.

Neurodevelopmental outcome of extremely low-birth-weight infants randomly assigned to restrictive or liberal hemoglobin thresholds for blood transfusion

Surviving extremely low-birth-weight infants are at risk of severe neurodevelopmental disability. Transfusion with packed red cells is almost universal in the care of these infants, but the hemoglobin threshold at which these transfusions should be given is unclear. Different clinical trials of restrictive (low hemoglobin) versus liberal (high hemoglobin) thresholds have addressed either neurodevelopmental outcomes at 18-21 months of corrected gestational age or psychological tests and brain imaging at 8-15 years of age. Early follow-up shows differences in cognitive outcome favoring the liberal strategy, but as a post hoc secondary outcome. The childhood studies favor the restrictive strategy, but include major methodological problems of secondary recruitment. No firm conclusion can be reached, other than to report that serious adverse effects may be attributable to one or other of these strategies, that prudent practice is to remain within trial protocols, and that further redesigned clinical trials are required.

Do transfusions cause necrotizing enterocolitis? The complementary role of randomized trials and observational studies

A systematic review and a meta-analysis of the published literature on the association between transfusions in newborns and the occurrence of transfusion-associated necrotizing enterocolitis were performed. We discuss the differences between findings in randomized trials, and the results of observational studies that first explored this putative link. We suggest the following framework: where observational studies play a hypothesis generating- role for therapies and harm, and randomized studies allow an acid test of that hypothesis. It is acknowledged that not all questions can be subject to a randomized evaluation, but argued that this particular association is amenable to such a test.

International survey of transfusion practices for extremely premature infants

Our objective was to survey neonatologists regarding international practice of red cell transfusion thresholds for premature infants with <1000-g birth weight and/or <28-week gestation. An invitation to fill out an 11-question web-based survey was distributed to neonatologists through their professional societies in 22 countries. Physicians were asked about which specific factors, in addition to hemoglobin levels, influenced their decisions about transfusing premature infants. These factors included gestational age, postnatal age, oxygen need, respiratory support, reticulocyte count, and inotropic support. Physicians were presented with 5 scenarios and asked to identify hemoglobin cutoff values for transfusing infants with <1000-g birth weight and/or <28-week gestation. One thousand eighteen neonatologists responded: the majority were from the United States (67.5%), followed by Germany (10.7%), Japan (8.0%), the United Kingdom (4.9%), Spain (3.9%), Italy (2.6%), Colombia (0.6%), Argentina (0.4%), Canada (0.4%), Belgium (0.1%), and the Netherlands (0.1%). Half of the respondents (51.1%) reported having a written policy with specific red cell transfusion guidelines in their unit. Factors considered "very important" regarding the need to administer blood transfusions included degree of oxygen requirement (44.7%) and need for respiratory support (44.1%). Erythropoietin was routinely used to treat anemia by 26.0% of respondents. Delayed cord clamping or cord milking was practiced by 29.1% of respondents. The main finding was of a wide variation in the hemoglobin values used to transfuse infants, regardless of postnatal age. Step-wise increments in the median hemoglobin cutoffs directly paralleled an increase in the need for levels of respiratory support. In the first week of life, there was a wider range in the distribution of hemoglobin transfusion thresholds for infants requiring no respiratory support and full mechanical ventilation compared with the thresholds used in the second, third, and fourth weeks of life. An international survey using hypothetical scenarios shows that red blood cell transfusion practices vary widely among practicing neonatologists in participating countries.

Effects of anaemia on haemodynamic and clinical parameters in apparently stable preterm infants

BACKGROUND

The criteria for erythrocyte transfusion in stable premature infants are currently controversial. Haemodynamic measurements are not common in transfusion practice. The purpose of this study was to determine whether haemodynamic measurements could be helpful as objective criterion for transfusion decisions. We, therefore, evaluated clinical and haemodynamic changes in stable, anaemic, premature infants before and after transfusion using our current blood transfusion protocol based on a haematocrit threshold (<24%) and the neonatologist's discretion.

MATERIAL AND METHODS

Stable premature infants with a haematocrit level ≤30% were prospectively enrolled into the study. Cerebral, intestinal and renal blood flow velocities, cardiac function parameters and vital signs were measured up to three times following every routine haematocrit analysis. Moreover, transfused infants were evaluated three more times: directly before transfusion, and 24 hours and 72 hours after transfusion.

RESULTS

Thirty-six infants were enrolled and 23 of them were transfused. Subgroup analysis of transfused infants showed a significant decrease in cerebral blood flow velocities, cardiac output and heart rate. These changes persisted after transfusion. In the entire cohort, the degree of anaemia correlated with the increase of cerebral blood flow velocities, heart rate and cardiac output.

DISCUSSION

Cerebral blood velocities in the anterior cerebral artery might represent an objective Doppler sonographic criterion indicating the need for transfusion. The measurement of these velocities is non-invasive and quick and easy to perform. However, a randomised, controlled trial is necessary before a formal recommendation can be made.

The safety and efficacy of red cell transfusions in neonates: a systematic review of randomized controlled trials

Premature neonates commonly receive red blood cell (RBC) transfusions. This study systematically identified and appraised randomized controlled trials (RCTs) where the intervention was 'transfusion of red blood cells' from searches of multiple databases. Primary review outcomes were mortality, neurodevelopmental and respiratory endpoints. Two reviewers extracted data and assigned overall quality. Twenty-seven RCTs were identified and grouped into four predefined categories: trials comparing RBC transfusion versus no transfusion/placebo (n = 3); different thresholds for transfusion (n = 6); differing doses or administration schedule (n = 4), or different types or products of RBC (n = 14). In the threshold group of trials, enrolling 679 neonates, no significant differences in mortality (relative risk 1·22, 95% confidence interval 0·84-1·75) or chronic lung disease were found. Only two trials assessed neurodevelopment outcomes, both within the threshold group, but with differing results. The largest subgroup of RCTs by number evaluated different media for storage of red cells (n = 7), enrolling 221 neonates. The methodological quality of many RCTs was poor. The design of future RCTs can be informed by the lessons from this review. Many trials failed to report on outcomes that would be considered of primary importance to clinicians. Consistent reporting of adverse events is required, and endpoints need to include neurodevelopmental outcomes.

Clinical and research issues in neonatal anemia and thrombocytopenia

PURPOSE OF REVIEW

Anemia and thrombocytopenia are the most common hematological problems in neonates. Red blood cell (RBC) and platelet transfusions are the mainstays of therapy, but data to guide neonatal transfusion practices have been sparse. Recombinant hematopoietic growth factors represent another therapeutic alternative, but their use in this population requires a solid understanding of the developmental differences between fetal and adult hematopoiesis.

RECENT FINDINGS

Recently, follow-up studies from children randomized as neonates to either liberal or restrictive RBC transfusion approaches were published. Results of these studies have so far been contradictory and have generated more questions than answers. New developmental stage-specific problems associated with RBC transfusions were also uncovered, such as the transfusion-associated necrotizing enterocolitis. Finally, two thrombopoietin (Tpo) mimetics were approved by the FDA for the treatment of adults with chronic immune thrombocytopenia, thus offering a novel potential therapeutic alternative for thrombocytopenic neonates.

SUMMARY

In this review, we will discuss the currently available data regarding neonatal RBC and platelet transfusion thresholds, as well as the potential limitations, and concerns associated with the use of erythropoietin and Tpo mimetics in this patient population. Finally, we will point out specific areas wherein additional research is critically needed.

A predictive score for retinopathy of prematurity in very low birth weight preterm infants

AIMS

This study describes the development of a score based on cumulative risk factors for the prediction of severe retinopathy of prematurity (ROP) comparing the performance of the score against the birth weight (BW) and gestational age (GA) in order to predict the onset of ROP.

METHODS

A prospective cohort of preterm infants with BW≤ 1500 g and/or GA≤ 32 weeks was studied. The score was developed based on BW, GA, proportional weight gain from birth to the 6th week of life, use of oxygen in mechanical ventilation, and need for blood transfusions from birth to the 6th week of life. The score was established after linear regression, considering the impact of each variable on the occurrences of any stage and severe ROP. Receiver operating characteristic (ROC) curves were used to determine the best sensitivity and specificity values for the score. All variables were entered into an Excel spreadsheet (Microsoft) for practical use by ophthalmologists during screening sessions.

RESULTS

The sample included 474 patients. The area under the ROC curve for the score was 0.77 and 0.88 to predict any stage and severe ROP, respectively. These values were significantly higher for the score than for BW (0.71) and GA (0.69) when measured separately.

CONCLUSIONS

ROPScore is an excellent index of neonatal risk factors for ROP, which is easy to record and more accurate than BW and GA to predict any stage ROP or severe ROP in preterm infants. The scoring system is simple enough to be routinely used by ophthalmologists during screening examination for detection of ROP.

Low versus high haemoglobin concentration threshold for blood transfusion for preventing morbidity and mortality in very low birth weight infants

BACKGROUND

Infants of very low birth weight often receive multiple transfusions of red blood cells, usually in response to predetermined haemoglobin or haematocrit thresholds. In the absence of better indices, haemoglobin levels are imperfect but necessary guides to the need for transfusion. Chronic anaemia in premature infants may, if severe, cause apnoea, poor neurodevelopmental outcomes or poor weight gain.On the other hand, red blood cell transfusion may result in transmission of infections, circulatory or iron overload, or dysfunctional oxygen carriage and delivery.

OBJECTIVES

To determine if erythrocyte transfusion administered to maintain low as compared to high haemoglobin thresholds reduces mortality or morbidity in very low birth weight infants enrolled within three days of birth.

SEARCH METHODS

Two review authors independently searched the Cochrane Central Register of Controlled Trials (The Cochrane Library) , MEDLINE,EMBASE, and conference proceedings through June 2010.

SELECTION CRITERIA

We selected randomised controlled trials (RCTs) comparing the effects of early versus late, or restrictive versus liberal erythrocyte transfusion regimes in low birth weight infants applied within three days of birth, with mortality or major morbidity as outcomes.

Long-term outcome in relationship to neonatal transfusion volume in extremely premature infants: a comparative cohort study

Background

In premature born infants red blood cell (RBC) transfusions have been associated with both beneficial and detrimental sequels. Upon RBC transfusion, improvement in cerebral blood flow and oxygenation have been observed, while a more liberal transfusion policy may be associated with a better developmental outcome. The effect of the transfusion volume on long-term outcome is not known.

Methods

Observational follow-up study of a cohort of extremely premature born infants, treated in 2 neonatal intensive care units using a different transfusion volume (15 ml/kg in Unit A and 20 ml/kg in Unit B). The primary outcome was a composite of post discharge mortality, neuromotor developmental delay, blindness or deafness, evaluated at a mean corrected age (CA) of 24 months related to the transfusion volume/kg bodyweight administered during the postnatal hospital stay.

Results

Despite the difference in transfusion volume in clinically comparable groups of infants, they received a similar number of transfusions (5.5 ± 3.2 versus 5.5 ± 2.3 respectively in Unit A and B). The total transfused volume in unit A was 79 ± 47 ml/kg and 108 ± 47 ml/kg in unit B (p = 0.02). Total transfused RBC volume per kg bodyweight was not an independent predictor of the composite outcome (p = 0.96, OR 1.0 (CI 0.9-1.1).

Conclusion

There was no relationship between the composite outcome at 24 months CA and transfusion volume received during the post natal hospital stay. As there was no clinical advantage of the higher transfusion volume, a more restrictive volume will reduce total transfusion volume and donor exposure. Future research on the optimal transfusion volume per event to extreme preterm infants should include larger, prospective studies with a longer follow-up period through to childhood or even adolescence.

Learning to live with patency of the ductus arteriosus in preterm infants

Treatment of persistent patency of the ductus arteriosus in preterm infants remains heterogeneous and controversial. Routine early treatment to induce ductal closure is not beneficial, but the potential criteria for, timing of, methods for and benefits of later ductal closure have not been determined. Management strategies for infants awaiting spontaneous closure or meeting criteria for treatment may be based on pathophysiological considerations but require evaluation in clinical trials. Better diagnostic tools allowing the identification of infants who might benefit from ductal closure, supplemented by data from clinical trials confirming realization of that potential, are urgently needed.

Long-term outcome of brain structure in premature infants: effects of liberal vs restricted red blood cell transfusions

OBJECTIVE

To assess the long-term outcome of brain structure in preterm infants, at an average age of 12 years, who received a red blood cell transfusion for anemia of prematurity.

DESIGN

As neonates, this cohort of infants participated in a clinical trial in which they received red blood cell transfusions based on a high pretransfusion hematocrit threshold (liberal group) or a low hematocrit threshold (restricted group). These 2 preterm groups were compared with a group of full-term healthy control children.

SETTING

Tertiary care hospital.

PARTICIPANTS

Magnetic resonance imaging scans for 44 of the original 100 subjects were obtained.

INTERVENTION

Liberal vs restricted transfusion.

MAIN OUTCOME MEASURES

Intracranial volume, total brain tissue, total cerebrospinal fluid, cerebral cortex and cerebral white matter volume, subcortical nuclei volume, and cerebellum volume.

RESULTS

Intracranial volume was substantially smaller in the liberal group compared with controls. Intracranial volume in the restricted group was not different from controls. Whole-cortex volume was not different in either preterm group compared with controls. Cerebral white matter was substantially reduced in both preterm groups, more so for the liberal group. The subcortical nuclei were substantially decreased in volume, equally so for both preterm groups compared with controls. When sex effects were evaluated, the girls in the liberal group had the most significant abnormalities.

CONCLUSION

Red blood cell transfusions affected the long-term outcome of premature infants as indicated by reduced brain volumes at 12 years of age for neonates who received transfusions using liberal guidelines.

Blood transfusion risks and alternative strategies in pediatric patients

Although the safety of the blood supply has been greatly improved, there still remain both infectious and noninfectious risks to the patient. The incidence of noninfectious transfusion reactions is greater than that of infectious complications. Furthermore, the mortality associated with noninfectious risks is significantly higher. In fact, noninfectious risks account for 87-100% of fatal complications of transfusions. It is concerning to note that the majority of pediatric reports relate to human error such as overtransfusion and lack of knowledge of special requirements in the neonatal age group. The second most frequent category is acute transfusion reactions, majority of which are allergic in nature. It is estimated that the incidence of adverse outcome is 18:100,000 red blood cells issued for children aged less than 18 years and 37:100,000 for infants. The comparable adult incidence is 13:100,000. In order to decrease the risks associated with transfusion of blood products, various blood-conservation strategies can be utilized. Modalities such as acute normovolemic hemodilution, hypervolemic hemodilution, deliberate hypotension, antifibrinolytics, intraoperative blood salvage, and autologous blood donation are discussed and the pediatric literature is reviewed. A discussion of transfusion triggers, and algorithms as well as current research into alternatives to blood transfusions concludes this review.

A rational approach to red blood cell transfusion in the neonatal ICU

PURPOSE OF REVIEW

There have been several recent randomized controlled trials collectively aimed at either the prevention or the management of anemia of prematurity. We aim to summarize evidence on prevention, management and long-term outcomes.

RECENT FINDINGS

Current guidelines for red blood cell transfusion are based on expert opinion and vary. Conservative transfusion policies can reduce the number of transfusions, but other benefits are more uncertain. Delivery room prevention by using delayed cord clamping or cord milking is promising, but requires long-term outcome assessments in preterms. Some measures of hypoxemia to guide 'need' for transfusion have potential, but are not yet ready for general use. Pragmatic management trials have compared a 'restrictive' with a 'liberal' policy with respect to effects on clinically relevant outcomes by neonatal ICU discharge, but conclusions have differed. Follow-up data to 24 months is available for only one study, which showed no benefit in the primary outcome of death and or neurodisability. However, an a-priori subgroup analysis shows benefit in the cognitive Bayley scores, favoring high hemoglobins.

SUMMARY

This field is plagued by lack of replication, small studies and speculative findings. Hence, the risk-benefit ratio of blood transfusions for preterms still needs adequate definition. Evidence suggests that a restrictive hemoglobin, hematocrit threshold or both for transfusion decreases the number of blood transfusions in preterm infants. However, uncertainty remains on long-term outcomes. Large randomized controlled trials are needed to clarify the safety of a lower threshold or the longer-term benefit of a high threshold.