Coagulation in pediatric extracorporeal membrane oxygenation: A systematic review of studies shows lack of standardized reporting
Research and practice in thrombosis and haemostasis. 2022;6(2):e12687
OBJECTIVES Extracorporeal membrane oxygenation (ECMO) involves complex coagulation management and frequent hemostatic complications. ECMO practice between centers is variable. To compare results between coagulation studies, standardized definitions and clear documentation of ECMO practice is essential. We assessed how study population, outcome definitions, and ECMO-, coagulation-, and transfusion-related parameters were described in pediatric ECMO studies. DATA SOURCES Embase, Medline, Web of Science, Cochrane Library and Google Scholar. STUDY SELECTION English original studies of pediatric ECMO patients describing hemostatic tests or outcome. DATA EXTRACTION Eligibility was assessed following PRISMA guidelines. Study population, outcome and ECMO-, coagulation, and transfusion parameters were summarized. DATA SYNTHESIS A total of 107 of 1312 records were included. Study population parameters most frequently included (gestational) age (79%), gender (60%), and (birth) weight (59%). Outcomes, including definitions of bleeding (29%), thrombosis (15%), and survival (43%), were described using various definitions. Description of pump type, oxygenator and cannulation mode occurred in 49%, 45%, and 36% of studies, respectively. The main coagulation test (53%), its reference ranges (49%), and frequency of testing (24%) were the most prevalent reported coagulation parameters. The transfusion thresholds for platelets, red blood cells, and fibrinogen were described in 27%, 18%, and 18% of studies, respectively. CONCLUSIONS This systematic review demonstrates a widespread lack of detail or standardization of several parameters in coagulation research of pediatric ECMO patients. We suggest several parameters that might be included in future coagulation studies. We encourage the ECMO community to adopt and refine this list of parameters and to use standardized definitions in future research.
Fresh frozen plasma transfusion in the neonatal population: A systematic review
Blood reviews. 2022;:100951
Although fresh frozen plasma (FFP) transfusions are common practice in neonatology, robust evidence on their use is lacking. The aim of this study was to systematically review the literature for data on the practice of FFP transfusions in neonates and their association with neonatal morbidity and mortality. The authors identified 40 studies, which met the inclusion criteria for this review. It was demonstrated that the practice of FFP transfusions significantly varies throughout the world. The majority of FFP transfusions are administered "prophylactically", without evidence of active bleeding. Although FFP transfusions may restore coagulation tests results, they do not alter the clinical outcome of the neonates. Reactions following transfusions are probably underestimated in neonates, often undiagnosed and thus, underreported. High quality RCTs aiming to evaluate the effectiveness of FFP in specific clinical conditions are urgently needed, as they could change long-standing FFP transfusion practices, and help reduce neonatal morbidity and mortality.
Restrictive Transfusion Strategy after Cardiac Surgery
BACKGROUND Recent guidelines on transfusion in cardiac surgery suggest that hemoglobin might not be the only criterion to trigger transfusion. Central venous oxygen saturation (Svo2), which is related to the balance between tissue oxygen delivery and consumption, may help the decision process of transfusion. We designed a randomized study to test whether central Svo2-guided transfusion could reduce transfusion incidence after cardiac surgery. METHODS This single center, single-blinded, randomized controlled trial was conducted on adult patients after cardiac surgery in the intensive care unit (ICU) of a tertiary university hospital. Patients were screened preoperatively and were assigned randomly to two study groups (control or Svo2) if they developed anemia (hemoglobin less than 9 g/dl), without active bleeding, during their ICU stay. Patients were transfused at each anemia episode during their ICU stay except the Svo2 patients who were transfused only if the pretransfusion central Svo2 was less than or equal to 65%. The primary outcome was the proportion of patients transfused in the ICU. The main secondary endpoints were (1) number of erythrocyte units transfused in the ICU and at study discharge, and (2) the proportion of patients transfused at study discharge. RESULTS Among 484 screened patients, 100 were randomized, with 50 in each group. All control patients were transfused in the ICU with a total of 94 transfused erythrocyte units. In the Svo2 group, 34 (68%) patients were transfused (odds ratio, 0.031 [95% CI, 0 to 0.153]; P < 0.001 vs. controls), with a total of 65 erythrocyte units. At study discharge, eight patients of the Svo2 group remained nontransfused and the cumulative count of erythrocyte units was 96 in the Svo2 group and 126 in the control group. CONCLUSIONS A restrictive transfusion strategy adjusted with central Svo2 may allow a significant reduction in the incidence of transfusion.
FEEding DURing red cell transfusion (FEEDUR RCT): a multi-arm randomised controlled trial
BMC Pediatr. 2020;20(1):346
BACKGROUND Necrotising Enterocolitis (NEC) is a devastating neonatal disease. A temporal association between red cell transfusion and NEC has been recognized and there have been concerns about the effects of feeding during transfusion. We aimed to assess the effect of different enteral feeding regimens on splanchnic oxygenation in preterm infants receiving red cell transfusions. METHODS This was an open, multi-arm, parallel-group, randomised controlled trial conducted in a single centre in Australia. We compared three different enteral feeding regimes during a single red cell transfusion in preterm infants < 35 weeks gestational age at birth. Infants were randomised to either: (1) Withholding enteral feeds for 12 h from the start of transfusion or; (2) Continuing enteral feeds or; (3) Restriction of enteral feed volume to 120 ml/kg/day (maximum 20 kcal/30 ml) for 12 h. The primary outcome was mean splanchnic-cerebral oxygenation ratio (SCOR) and mean splanchnic fractional oxygen extraction (FOE) before (1 h prior), during (1 h into transfusion) and after (end of transfusion; 12 and 24 h post) transfusion. RESULTS There were 60 transfusion episodes (20 transfusion episodes in each group) included in the analysis. 41 infants with a median gestational age at birth of 27 weeks (range 23-32 weeks) were enrolled. The median postnatal age was 43 days (range 19-94 days) and the median pre-transfusion haematocrit was 0.27 (range 0.22-0.32). All three groups were similar at baseline. There were no differences in mean SCOR and mean splanchnic FOE at any of the pre-specified time points. There were also no differences in clinical outcomes. There were no episodes of NEC in any infant. Across all groups the mean SCOR increased from the start to the end of each transfusion (0.97 [CI95% 0.96-0.98] vs 1.00 [CI95% 0.99-1.01]; p = 0.04) and the mean FOE decreased from the start to the end of each transfusion (0.22 [CI95% 0.21-0.23] vs 0.17 [CI95% 0.16-0.18]; p < 0.001). CONCLUSIONS There were no differences in splanchnic oxygenation when enteral feeds were either withheld, continued or restricted during a transfusion. However, the successful conduct of this study supports the feasibility of a large trial powered to assess clinical outcomes. TRIAL REGISTRATION ANZCTR, ACTRN12616000160437. Registered 10 February 2016, https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=370069.
Preterm infants receiving red cell transfusions enrolled in the FEEding DURing red cell transfusion (FEEDUR RCT) trial, (n= 41).
Enteral feeds withheld for 12 hours from the start of transfusion (n= 19).
Enteral feeds continued (n= 18). Enteral feed volume restricted to 120 ml/kg/day for 12 hours (n= 17).
Sixty transfusion episodes (20 transfusion episodes in each group) were included in the analysis. There were no differences in mean splanchnic-cerebral oxygenation ratio (SCOR) and mean splanchnic fractional oxygen extraction (FOE) at any of the pre-specified time points. There were also no differences in clinical outcomes. There were no episodes of necrotising enterocolitis in any infant. Across all groups the mean SCOR increased from the start to the end of each transfusion (0.97 vs 1.00) and the mean FOE decreased from the start to the end of each transfusion (0.22 vs 0.17). There were no differences in splanchnic oxygenation when enteral feeds were either withheld, continued or restricted during a transfusion.
Challenges in Maintaining the Hemostatic Balance in Children Undergoing Extracorporeal Membrane Oxygenation: A Systematic Literature Review
Frontiers in pediatrics. 2020;8:612467
Background: Despite advances in technology and clinical experience, the incidence of hemostatic complications, including bleeding and thrombosis, remains high in children supported with extracorporeal membrane oxygenation (ECMO). These hemostatic complications are important to prevent, since they are associated with increased morbidity and mortality. This systematic literature review aims to outline the most important risk factors for hemostatic complications in children undergoing ECMO treatment, to summarize the reported alternative anticoagulant drugs used in pediatric ECMO and to describe studied associations between coagulation tests and hemostatic complications. Methods: A literature search was performed in Embase, Medline, Web of Science Core Collection, Cochrane Central Register of Controlled Trials, and Google Scholar in February 2020. Included studies were studies evaluating children (<18 years old) treated with ECMO, and studies evaluating risk factors for hemostatic complications, alternative anticoagulants, or the association between coagulation tests and hemostatic complications. Results: Out of 1,152 articles, 35 studies were included. Thirteen out of 49 risk factors were investigated in three or more studies. Most consistent results were found regarding ECMO duration and pH. However, evidence for risk factors was equivocal in the majority of studies, which is explained by the variability of populations studied, definitions of hemostatic complications, ECMO circuits, anticoagulation protocols, transfusion triggers and monitoring of anticoagulation. Five studies described alternative anticoagulants, including bivalirudin (n = 3), argatroban (n = 1) and FUT (n = 1). Higher anti-factor Xa levels were associated with less clotting events in one of nine studies, investigating the association between tests and hemostatic complications. Two studies revealed an association between anti-factor Xa assay-based protocols and a decreased number of transfusions, bleedings and need for circuit change. Conclusion: Studies regarding risk factors showed conflicting results and a few retrospective studies reported the use of new anticoagulants and data on coagulation tests in relation to hemostatic complications. To decrease hemostatic complications in ECMO children, prospective multicenter studies are needed with clear bleeding and thrombotic definitions, and the best possible standardization of ECMO circuits used, anticoagulation protocols, and transfusion triggers.
Stopping enteral feeds for prevention of transfusion-associated necrotising enterocolitis in preterm infants
The Cochrane database of systematic reviews. 2019;2019(10)
BACKGROUND Feeding practices around the time of packed red blood cell transfusion have been implicated in the subsequent development of necrotising enterocolitis (NEC) in preterm infants. Specifically, it has been suggested that withholding feeds around the time of transfusion may reduce the risk of subsequent NEC. It is important to determine if withholding feeds around transfusion reduces the risk of subsequent NEC and associated mortality. OBJECTIVES * To assess the benefits and risks of stopping compared to continuing feed management before, during, and after blood transfusion in preterm infants * To assess the effects of stopping versus continuing feeds in the following subgroups of infants: infants of different gestations; infants with symptomatic and asymptomatic anaemia; infants who received different feeding schedules, types of feed, and methods of feed delivery; infants who were transfused with different blood products, at different blood volumes, via different routes of delivery; and those who received blood transfusion with and without co-interventions such as use of diuretics * To determine the effectiveness and safety of stopping feeds around the time of a blood transfusion in reducing the risk of subsequent necrotising enterocolitis (NEC) in preterm infants SEARCH METHODS We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL; 2018, Issue 11), in the Cochrane Library; MEDLINE (1966 to 14 November 2018); Embase (1980 to 14 November 2018); and the Cumulative Index to Nursing and Allied Health Literature (CINAHL; 1982 to 14 November 2018). We also searched clinical trials databases, conference proceedings, and reference lists of retrieved articles for randomised controlled trials (RCTs), cluster-RCTs, and quasi-RCTs. SELECTION CRITERIA Randomised and quasi-randomised controlled trials that compared stopping feeds versus continuing feeds around the time of blood transfusion in preterm infants. DATA COLLECTION AND ANALYSIS Two review authors independently selected trials, assessed trial quality, and extracted data from the included studies. MAIN RESULTS The search revealed seven studies that assessed effects of stopping feeds during blood transfusion. However, only one RCT involving 22 preterm infants was eligible for inclusion in the review. This RCT had low risk of selection bias but high risk of performance bias, as care personnel were not blinded to the study allocation. The primary objective of this trial was to investigate changes in mesenteric blood flow, and no cases of NEC were reported in any of the infants included in the trial. We were unable to draw any conclusions from this single study. The overall GRADE rating for quality of evidence was very low. AUTHORS' CONCLUSIONS Randomised controlled trial evidence is insufficient to show whether stopping feeds has an effect on the incidence of subsequent NEC or death. Large, adequately powered RCTs are needed to address this issue.
Interventions to reduce blood loss from laboratory testing in critically ill patients and impact on transfusion: a systematic review
Blood. 2015;: Abstract No. 40.
Interventions to reduce blood loss from laboratory testing in critically ill patients and impact on transfusion: a systematic review
Journal of Thrombosis and Haemostasis. 2015;13((Suppl. 2)):974-975.. Abstract No. PO616-WED.
Closed system for blood sampling and transfusion in critically ill patients
Revista Brasileira de Terapia Intensiva. 2010;22((1)):5-10.
OBJECTIVE Anemia is common in severely ill patients, and blood sampling plays a relevant causative role. Consequently, blood transfusions are frequent an related to several complications. Trying to reduce the transfusion-related risk, minimizing blood loss is mandatory. Thus, this work aimed to evaluate a closed blood sampling system as a strategy to spare unnecessary blood losses and transfusions. METHODS This was a prospective, randomized, controlled, multicenter, 6 months, clinical trial. The patients were assigned to either VAMP (Venous Arterial Blood Management Protection) group, using a closed blood sampling system, or control group. The groups' transfusion rate, as well as hemoglobin (Hb) and Hematocrit (Ht) changes were compared for 14 days. RESULTS Were included 127 patients, 65 assigned to the control group, and 62 to VAMP. During the intensive care unit stay, both groups experienced both hemoglobin and hematocrit drops. However, when the final Ht and Hb were compared between the groups, a difference was identified with higher values in the VAMP group (p=0.03; p=0.006, respectively). No statistical difference was found for both groups transfusion rates, although the VAMP group had an absolute 12% blood transfusion reduction. CONCLUSION The use of a closed blood sampling system was able to minimize blood count values changes, however failed to reduce transfusions rate.