Strict red blood cell transfusion guideline reduces the need for transfusions in very-low-birthweight infants in the first 4 weeks of life: a multicentre trial

Frequency of red blood cell transfusions in preterm neonates in Brazil: A systematic review and meta-analysis

BACKGROUND AND OBJECTIVES

Red blood cell transfusions are frequent in preterm neonates. The proportion of preterm neonates transfused in Brazil remains unknown. We systematically reviewed the literature to estimate the frequency of red blood cell transfusions in preterm neonates in Brazil.

MATERIALS AND METHODS

The LILACS, EMBASE, Cochrane, SciELO, MEDLINE (PubMed), Web of Science, Scopus, BDTD and 27 national university institutional databases were searched for studies that analysed red blood cell transfusion in preterm neonates in Brazil without period restriction. The Preferred Reporting Items in Systematic Reviews and Meta-Analyses guidelines were followed, and the GRADE methodology was applied. A random-effects model along with the restricted maximum likelihood method was used, and the Freeman-Tukey transformed proportion was used to estimate effect size.

RESULTS

Nine studies, representing 6548 preterm neonates, were included in the qualitative and quantitative analyses. The mean gestational age ranged from 26.0 to 31.6 weeks. Most of the studies were from the Southeast region. The pooled estimated frequency of red blood cell transfusions was 58.0% (95% confidence interval = 52.0%-64.0%, p < 0.001) with low certainty. There was statistically significant heterogeneity among studies (I2  = 92.5%, p < 0.001).

CONCLUSION

In this current meta-analysis of the evidence available, which included moderate and extremely preterm neonates, the observed frequency of red blood cell transfusions in preterm neonates in Brazil was 58.0% and this estimate can help health programming. Some Brazilian regions were not included in this study, and further research is needed to provide a more representative overview of Brazil.

Red Blood Cell Transfusion Thresholds for Anemia of Prematurity

Anemia of prematurity affects the majority of preterm infants, particularly extremely low birthweight infants. Anemia of prematurity arises from both innate and iatrogenic causes and results in more than 80% of extremely preterm infants receiving red blood cell transfusions during the first month after birth. Multiple randomized controlled trials were conducted to evaluate the effect of using lower versus higher transfusion thresholds based on hemoglobin levels. These trials showed no difference in the primary outcome of neurodevelopmental impairment at 2 years of age between lower and higher thresholds. However, some uncertainties about transfusion thresholds remain. This review elaborates the following: 1) the etiology, prevention, and treatment of anemia of prematurity with a focus on red blood cell transfusions, 2) the history of randomized controlled trials on the treatment of anemia of prematurity, and 3) limitations of the evidence and remaining questions about thresholds for red blood cell transfusions in preterm infants.

Red cell transfusion thresholds for preterm infants: finally some answers

Extremely low birthweight infants become anaemic during their care in the neonatal intensive care unit because of the physiological anaemia experienced by all newborn infants compounded by early umbilical cord clamping, blood loss by phlebotomy for laboratory monitoring and delayed erythropoiesis. The majority of these infants receive transfusions of packed red blood cells, usually based on haemoglobin values below a certain threshold. The haemoglobin or haematocrit thresholds used to guide transfusion practices vary with infant status and among institutions and practitioners. Previous smaller studies have not given clear guidance with respect to the haemoglobin thresholds that should trigger transfusions or even if this is the best way to decide when to transfuse an infant. Two large clinical trials of similar design comparing higher and lower haemoglobin thresholds for transfusing extremely low birthweight infants were recently published, the ETTNO and TOP trials. These trials found reassuringly conclusive and concordant results. Within the range of haemoglobin transfusion thresholds studied, there was no difference in the primary outcome (which was the same in both studies), neurodevelopmental impairment at 2 years' corrected age or death before assessment, in either study. In addition, there was no difference in either study in either of the components of the primary outcome. In conclusion, haemoglobin transfusion thresholds within the ranges used in these trials, 11-13 g/dL for young critically ill or ventilated infants and 7-10 g/dL for stable infants not requiring significant respiratory support, can be safely used without expecting adverse consequences on survival or neurodevelopment.

Multiple red blood cell transfusions and iron overload in very low birthweight infants

BACKGROUND AND OBJECTIVES

To estimate the risk of iron overload in very low birthweight (VLBW) infants who receive more than two red blood cell (RBC) transfusions, in comparison with those who receive two or less during their hospital stay.

MATERIALS AND METHODS

Prospective open cohort study in VLBW infants with >2 (exposed) and ≤2 (non-exposed) RBC transfusions. Ferritin, alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured at birth and after each RBC transfusion. The incidence of iron overload was determined. Risk factors were analysed using a logistic regression model. RBC transfusion volume correlations with ferritin, ALT and AST were calculated with Spearman's rank correlation coefficient, as well as correlations between ferritin and aminotransferases.

RESULTS

A total of 63 patients were enrolled, 18 of which were exposed and 45 non-exposed. Twelve patients developed severe iron overload, eight exposed (44·5%) vs. four (8·8%) non-exposed (RR: 5, 95% CI: 1·7-14·6). Multivariate analysis showed that the number of transfusions increased the risk of iron overload (OR: 2·07, 95% CI: 1·36-2·14) while a higher one-minute Apgar score was associated with a lower risk (OR: 0·56, 95% CI: 0·32-0·99). Severe iron overload mainly occurred with a transfusion volume higher than 120 ml/kg. There was a positive correlation between ferritin and transfusion (r = 0·53; P < 0·001).

CONCLUSION

There was a higher risk of iron overload in exposed infants in comparison with non-exposed infants. Severe iron overload in VLBW infants may occur with a total transfusion volume >120 ml/kg.

Factors associated with red blood cell transfusions in very-low-birth-weight preterm infants in Brazilian neonatal units

BACKGROUND

Preterm infants in neonatal intensive care units frequently receive red blood cells (RBC) transfusions due to the anemia of prematurity. A number of variables related to gestational age, severity of illness and transfusion practices adopted in the neonatal unit where the neonate was born may contribute to the prescription of RBC transfusions. This study aimed to analyse the frequency and factors associated with RBC transfusions in very-low-birth-weight preterm infants.

METHODS

A prospective cohort of 4283 preterm infants (gestational age: 29.9 ± 2.9 weeks; birth weight: 1084 ± 275 g) carried out at 16 university hospitals in Brazil between January 2009 and December 2011 was analysed. Factors associated with RBC transfusions were evaluated using univariate and multiple logistic regression analysis.

RESULTS

A total of 2208 (51.6%) infants received RBC transfusions (variation per neonatal unit: 34.1% to 66.4%). RBC transfusions were significantly associated with gestational age (OR: -1.098; 95%CI: -1.12 to -1.04), SNAPPE II score (1.01; 1.00-1.02), apnea (1.69; 1.34-2.14), pulmonary hemorrhage (2.65; 1.74-4.031), need for oxygen at 28 days of life (1.56; 1.17-2.08), clinical sepsis (3.22; 2.55-4.05), necrotising enterocolitis (3.80; 2.26-6.41), grades III/IV intraventricular hemorrhage (1.64; 1.05-2.58), mechanical ventilation (2.27; 1.74-2.97), use of umbilical catheter (1.86; 1.35-2.57), parenteral nutrition (2.06; 1.27-3.33), >60 days of hospitalization (5.29; 4.02-6.95) and the neonatal unit where the neonate was born.

CONCLUSIONS

The frequency of RBC transfusions varied among neonatal intensive care units. Even after adjusting for adverse health conditions and therapeutic interventions, the neonatal unit continued to influence transfusion practices in very-low birth-weight infants.

Reduction of exposure to blood donors in preterm infants submitted to red blood cell transfusions using pediatric satellite packs

OBJECTIVE

In preterm newborn infants transfused with erythrocytes stored up to 28 days, to compare the reduction of blood donor exposure in two groups of infants classified according to birth weight.

METHODS

A prospective study was conducted with preterm infants with birth weight <1000 g (Group 1) and 1000-1499 g (Group 2), born between April, 2008 and December, 2009. Neonates submitted to exchange transfusions, emergency erythrocyte transfusion, or those who died in the first 24 hours of life were excluded. Transfusions were indicated according to the local guideline using pediatric transfusion satellite bags. Demographic and clinical data, besides number of transfusions and donors were assessed. . Logistic regression analysis was performed to determine factors associated with multiple transfusions.

RESULTS

30 and 48 neonates were included in Groups 1 and 2, respectively. The percentage of newborns with more than one erythrocyte transfusion (90 versus 11%), the median number of transfusions (3 versus 1) and the median of blood donors (2 versus 1) were higher in Group 1 (p<0.001), compared to Group 2. Among those with multiple transfusions, 14 (82%) and one (50%) presented 50% reduction in the number of blood donors, respectively in Groups 1 and 2. Factors associated with multiple transfusions were: birth weight <1000 g (OR 11.91; 95%CI 2.14-66.27) and presence of arterial umbilical catheter (OR 8.59; 95%CI 1.94-38.13), adjusted for confounders.

CONCLUSIONS

The efficacy of pediatrics satellites bags on blood donor reduction was higher in preterm infants with birth weight <1000 g.

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.

Red blood cell transfusions are independently associated with intra-hospital mortality in very low birth weight preterm infants

OBJECTIVE

To test the hypothesis that red blood cell (RBC) transfusions in preterm infants are associated with increased intra-hospital mortality.

STUDY DESIGN

Variables associated with death were studied with Cox regression analysis in a prospective cohort of preterm infants with birth weight <1500 g in the Brazilian Network on Neonatal Research. Intra-hospital death and death after 28 days of life were analyzed as dependent variables. Independent variables were infant demographic and clinical characteristics and RBC transfusions.

RESULTS

Of 1077 infants, 574 (53.3%) received at least one RBC transfusion during the hospital stay. The mean number of transfusions per infant was 3.3 ± 3.4, with 2.1 ± 2.1 in the first 28 days of life. Intra-hospital death occurred in 299 neonates (27.8%), and 60 infants (5.6%) died after 28 days of life. After adjusting for confounders, the relative risk of death during hospital stay was 1.49 in infants who received at least one RBC transfusion in the first 28 days of life, compared with infants who did not receive a transfusion. The risk of death after 28 days of life was 1.89 times higher in infants who received more than two RBC transfusions during their hospital stay, compared with infants who received one or two transfusions.

CONCLUSION

Transfusion was associated with increased death, and transfusion guidelines should consider risks and benefits of transfusion.

Neonatal red blood cell transfusions: searching for better guidelines

BACKGROUND

Packed red blood cell (RBC) transfusions are often administered to patients in the neonatal intensive care unit. The purpose of this study was to determine whether current blood transfusion guidelines are as useful as care givers' perception in identifying patients in need of a packed RBC transfusion.

DESIGN AND METHODS

Health care providers were asked to complete a pre- and post-transfusion survey on neonates receiving a packed RBC transfusion. These patients were divided into three groups based on reasons for transfusion: (i) guidelines; (ii) care-givers' perceptions of need for packed RBC transfusion; or (iii) both. These three groups were further subdivided into two cohorts according to whether they had a clinical improvement or not. Demographic data and clinical variables were compared between the groups.

RESULTS

Seventy-eight care-givers were surveyed. Eighteen patients (23%) were transfused based on guidelines, 36 (46%) based on care givers' perception and 24 (31%) based on both. Neonates transfused based on guidelines alone were more likely to have received the transfusion in the first week of life, had a higher pre-transfusion haematocrit, were less symptomatic and had a higher trend to require mechanical ventilation. Neonates transfused based on caregivers' perception were more likely to be on non-invasive ventilatory support and were more symptomatic. Neonates who improved after a transfusion had a lower pre-transfusion haematocrit (p=0.02), were more symptomatic (p=0.01) and were more likely to be on non-invasive ventilatory support (p=0.002) when compared to the group without a clinical improvement. The group without improvement had an increase in oxygen requirement (+2.8±6.4) after the transfusion (p=0.0004). Tachycardia was the most sensitive predictor of a benefit from packed RBC transfusion [OR 6.48: p=0.005].

DISCUSSION

Guidelines on when to transfuse stable growing neonates with packed RBC should be re-evaluated to include more care giver judgement and perhaps be more restrictive for critically ill neonates.

When to transfuse preterm babies

The physiological anaemia experienced by preterm babies is exacerbated by common care practices such as early clamping of the umbilical cord at birth and gradual exsanguination by phlebotomy for laboratory monitoring. The need for subsequent transfusion with red blood cells can be reduced by delaying cord clamping for 30-60 s in infants who do not require immediate resuscitation. The need for transfusions can be further reduced by limiting phlebotomy losses, providing good nutrition, and using standard guidelines for transfusion based on haemoglobin or haematocrit. What those guidelines should be is not clear. Analysis of two recent large clinical trials comparing restrictive and liberal transfusion guidelines leads to several conclusions. Restrictive transfusion guidelines may reduce the number of transfusions given, but there is no reduction in donor exposures if a single-donor transfusion programme is used. There is some evidence that more liberal transfusion guidelines may help to prevent brain injury, but information on the impact of transfusion practice on long-term outcome is lacking. Until further guidance emerges, transfusion thresholds lower than those used in the two trials should not be used, as there is no evidence that lower thresholds are safe.

The use of blood products in perinatal medicine

Fetal and neonatal medicine is a field with many new procedures and techniques. An increasing number of centres worldwide give intrauterine transfusions, which are considered to be standard-of-care treatment for severe fetal anaemia. The survival of very prematurely born neonates, in particular of a gestational age of <28 weeks, has greatly improved over the last decade but almost all these children need transfusions. Although in many cases such blood transfusions are life saving, randomized, controlled studies investigating appropriate indications, transfusion volume and type of blood product have not been performed. Most of the protocols used are expert based.

Adherence to NICU transfusion guidelines: data from a multihospital healthcare system

OBJECTIVE

We critically reviewed every NICU blood component transfusion (packed erythrocytes, platelets, frozen plasma (FP) and cryoprecipitate) administered during a one-year period. This was done to determine the proportion of transfusions given out of compliance with the Intermountain Healthcare transfusion guidelines, and to look for patterns of non-compliance that could be addressed by quality improvement measures.

STUDY DESIGN

A detailed review was made of every transfusion administered to patients with a date of birth of 1 January 2006 through 31 December 2006, in any of three level III, perinatal-center-associated NICUs within Intermountain Healthcare.

RESULT

During 2006 the three NICUs cared for 1759 neonates. Seventeen percent of these received one or more (median 3) erythrocyte transfusions, 4% received one or more (median 3) platelet transfusions, 6% received one or more (median 1) FP infusions and 2% received cryoprecipitate (median 1 dose). Seventy percent of the erythrocyte transfusions were given in compliance with the guidelines, as were 69% of the platelet transfusions, 65% of the FP transfusions and 94% of the cryoprecipitate administrations. Patients who received large numbers of transfusions were more likely to receive transfusion that violated the guidelines. Forty-five percent of patients who received 1 to 3 transfusions received all transfusions within guidelines. However, only 18% of patients who received 4 to 10 transfusions received all within guidelines. No patient who received >10 transfusions received all within the guidelines. Erythrocyte transfusions given early in the hospital course were likely to be within guidelines; 72% (588/818) in the first 29 days were compliant with guidelines, but compliance fell to 61% (144/237) for transfusions administered after 29 days (P=0.002). About half of the platelet transfusions given early in the hospital course were in violation of guidelines, but after day 9, 83% of platelet transfusions were compliant with guidelines (P=0.000).

CONCLUSION

Opportunities exist in our healthcare system to improve compliance with our transfusion guidelines. Such opportunities are greatest among neonates receiving multiple transfusions, among those receiving erythrocyte transfusions late in their NICU course and among those receiving platelet transfusions early in their NICU course.

Advances and controversies in neonatal ICU platelet transfusion practice

Some of the platelet transfusions currently given to NICU patients are unnecessary and convey no benefits. Although ordered with good intentions, unnecessary platelet transfusions carry known and unknown risks. Identifying and eliminating any unnecessary platelet transfusions in NICUs would be a step toward better care, lower costs, and more careful preservation of blood component resources. A renewed interest in platelet transfusion studies is needed, if essential data is to be gathered to improve NICU platelet transfusion practice. Retrospective studies can be of value: for instance, seeking associations between bleeding events and platelet counts can suggest the possibility of cause and effect relationships. Such studies might identify approximate platelet count levels that convey high hemorrhagic risk and might help focus future prospective trials. Prospective indirect studies also can be of value, for instance, measuring the template bleeding time and the PFA-100 closure time as a function of platelet count and perhaps as a function of circulating platelet mass, and would provide new information with relevance to platelet transfusion benefits. Such studies might give a better awareness of how low the platelet count can fall before platelet plug formation is impaired. It seems inescapable, however, that new, multicentered, randomized, prospective studies are needed, where NICU patients are assigned different platelet transfusion triggers and then carefully tracked for bleeding events and long-term neurodevelopmental outcomes. Only that type of study is likely to generate the evidence base needed for widespread implementation of improvements in NICU platelet transfusion practice.

Transfusions of CPDA-1 red blood cells stored for up to 28 days decrease donor exposures in very low-birth-weight premature infants

The goal of this research was to study the safety and the efficacy of transfusing citrate-phosphate-adenine anticoagulant-preservative (CPDA-1) RBC stored for up to 28 days to reduce donor exposures in premature infants. A prospective randomized two-group study was conducted with very low-birth-weight premature infants that received at least one RBC transfusion during hospital stay. Neonates randomly assigned to Group 1 (26 infants) were transfused with CPDA-1 RBC stored for up to 28 days; those assigned to Group 2 (26 infants) received CPDA-1 RBC stored for up to 3 days. Demographic and transfusion-related data were collected. Neonates from both groups showed similar demographics and clinical characteristics. The number of transfusions per infant transfused was 4.4 +/- 4.0 in Group 1 and 4.2 +/- 3.1 in Group 2, and the number of donors per infant transfused was 1.5 +/- 0.8 (Group 1) and 4.3 +/- 3.4 (Group 2), P < 0.001. RBC transfusions containing 29.7 +/- 18.3 mmol L(-1) of potassium (RBC stored for up to 28 days) did not cause clinical or biochemical changes and reduced donor exposures by 70.2%, compared to transfusions containing 19.8 +/- 12.3 mmol L(-1) of potassium (RBC stored for up to 3 days), P < 0.001. In conclusion, RBC stored for up to 28 days safely reduced donor exposures in premature infants.