Reference intervals for common coagulation tests of preterm infants (CME)

The value of thromboelastography to neonatology

Hemostatic derangements are common in critically ill and premature neonates. Nevertheless, hemostasis assessment in neonates is still challenging. The hemostatic system undergoes age-related physiological changes during its maturation and exhibits quantitative and qualitative differences between infants and adults. Conventional coagulation tests are mainly responsive to procoagulant factors, regardless of the contribution of cellular elements, anticoagulants and fibrinolytic contributors and, therefore, their role in predicting bleeding in neonatal acquired coagulopathy is somewhat limited. Viscoelastic coagulation tests offer a promising alternative, enabling a bedside and real-time assessment of the entire hemostatic process in short turn-around times with a limited amount of blood. These tests allow a targeted hemostatic monitoring and a tailored management of blood products and anticoagulation. The routine use of VCTs in the NICU remains limited, especially for premature infants, due to the lack of established normative ranges. In this review we will provide an overview of the main evidence related to the clinical application of viscoelastic monitoring in the neonatal setting.

Plasma transfusions in neonatal intensive care units: a prospective observational study

OBJECTIVE

Despite lack of evidence supporting efficacy, prophylactic fresh frozen plasma and Octaplas transfusions may be administered to very preterm infants to reduce bleeding risk. International variation in plasma transfusion practices in neonatal intensive care units (NICUs) is poorly understood, therefore, we aimed to describe neonatal plasma transfusion practice in Europe.

DESIGN

Prospective observational study.

SETTING

64 NICUs in 22 European countries, with a 6-week study period per centre between September 2022 and August 2023.

PATIENTS

Preterm infants born below 32 weeks of gestational age.

INTERVENTIONS

Admission to the NICU.

MAIN OUTCOME MEASURES

Plasma transfusion prevalence, cumulative incidence, indications, transfusion volumes and infusion rates and adverse effects.

RESULTS

A total of 92 of 1143 infants included (8.0%) received plasma during the study period, collectively receiving 177 transfusions. Overall prevalence was 0.3 plasma transfusion days per 100 admission days, and rates varied substantially across Europe. By day 28 of life, 13.5% (95% CI 10.0% to 16.9%) of infants received at least one plasma transfusion, accounted for competing risks of death or discharge. Transfusions were given for a broad range of indications, including active bleeding (29.4%), abnormal coagulation screen results (23.7%) and volume replacement/hypotension (21.5%). Transfusion volumes and infusion rates varied significantly; the most common volume was 15 mL/kg (range: 5-30 mL/kg) and the most common duration was 2 hours (range: 30 min to 6 hours).

CONCLUSIONS

We found wide variation in plasma transfusion practices in Europe, highlighting the need for evidence to inform neonatologists in daily practice and guidelines, in particular for non-bleeding indications.

TRIAL REGISTRATION NUMBER

ISRCTN17267090.

Coagulation assay results at birth in preterm infants: A cohort study highlighting the relevance of local reference values for interpretation

BACKGROUND AND OBJECTIVES

Routine coagulation screens at birth are still standard in some European neonatal intensive care units (NICUs), although interpretation of these results is complex in preterm infants. It is unclear to what extent local coagulation assay results agree with published reference ranges when using different analysers and reagents. We aimed to assess coagulation assay results on day 1 of life in very preterm infants admitted to the NICU.

MATERIALS AND METHODS

We included all preterm infants born below 32 weeks gestational age (GA) admitted to the Leiden University Medical Center between 2004 and 2020 in whom coagulation assays (prothrombin time [PT] and activated partial thromboplastin time [APTT]) were obtained during the first 24 h of life. Infants either diagnosed with major intraventricular haemorrhage or who received plasma transfusion before coagulation assay were excluded. We assessed coagulation assay results and compared the results between <28 weeks (extremely preterm) and 28-32 weeks (very preterm) GA groups.

RESULTS

Coagulation assays were obtained at birth in 144 infants (144/2577; 5.5%) of whom 104 fulfilled the inclusion criteria. We found similar median PT and APTT values for extremely and very preterm infants (PT: 18.1 vs. 18.7 s [p-value = 0.400]; APTT: 44.2 vs. 47.7 s [p-value = 0.252], respectively).

CONCLUSION

We found similar coagulation assay results at birth for extremely and very preterm infants; however, results deviated considerably from some of the published reference ranges. This may be due to differences between analysers and reagents, underlining the need for reference ranges calibrated to the equipment used per NICU.

Estimation of gestational age-specific reference intervals for coagulation assays in a neonatal intensive care unit using real-world data

BACKGROUND

Interpretation of coagulation testing in neonates currently relies on reference intervals (RIs) defined from older patient cohorts. Direct RI studies are difficult, but indirect estimation may allow us to infer normative neonatal distributions from routinely collected clinical data.

OBJECTIVE

Assess the utility of indirect reference interval methods in estimating coagulation reference intervals in critically ill neonates.

METHODS

We analyzed first-in-life coagulation testing results from all patients admitted to a level IV neonatal intensive care unit between January 1, 2018, and January 1, 2024. Results obtained after transfusion of any blood product were excluded. Indirect RIs were estimated across gestational age groups using refineR and compared with currently reported intervals for patients less than 1 year of age.

RESULTS

Prothrombin times (PTs) and international normalized ratios (INRs) were available for 1128 neonates, while activated partial thromboplastin times (APTTs) were available for 790 neonates. The indirect RI was 10 to 25 seconds in preterm, 10 to 22 seconds in term, and 10 to 24 seconds in all neonates for PT; 0.7 to 2.1 in preterm, 0.8 to 1.8 in term, and 0.8 to 1.9 in all neonates for INR; and 25 to 68 seconds in preterm, 25 to 58 seconds in term, and 25 to 62 seconds in all neonates for APTT. Compared with our current intervals, the indirect RIs would flag 58% fewer PT, 43% fewer INR, and 17% fewer APTT results as abnormal.

CONCLUSION

Indirectly estimated RIs in neonates admitted to intensive care show substantial divergence from current, first-year-of-life RIs, leading to an abundance of abnormal flags. The associations between these flags and provider behavior, transfusion practice, or clinical outcomes are areas of future exploration.

Contemporary tools for evaluation of hemostasis in neonates. Where are we and where are we headed?

The assessment of hemostatic disorders in neonates is crucial, but remains challenging for clinicians. Although the concept of developmental hemostasis is widely accepted among hemostasis specialists globally, it is probably under-recognized by clinicians and laboratory practitioners. In parallel with age-dependent hemostatic status maturation, comprehension of the differences between normal values is crucial for the accurate diagnosis of potential hemorrhagic and thrombotic disorders of the vulnerable neonatal population. This review outlines the basics of developmental hemostasis and the features of the available coagulation testing methods, with a focus on novel tools for evaluating the neonatal hemostatic profile. Common errors, issues, and pitfalls during the assessment of neonatal hemostasis are discussed, along with their impact on patient management. Current knowledge gaps and research areas are addressed. Further studying to improve our understanding of developmental hemostasis and its reflection on everyday clinical practice is warranted.

Neonatal Thrombocytopenia: Factors Associated With the Platelet Count Increment Following Platelet Transfusion

OBJECTIVE

To understand better those factors relevant to the increment of rise in platelet count following a platelet transfusion among thrombocytopenic neonates.

STUDY DESIGN

We reviewed all platelet transfusions over 6 years in our multi-neonatal intensive care unit system. For every platelet transfusion in 8 neonatal centers we recorded: (1) platelet count before and after transfusion; (2) time between completing the transfusion and follow-up count; (3) transfusion volume (mL/kg); (4) platelet storage time; (5) sex and age of platelet donor; (6) gestational age at birth and postnatal age at transfusion; and magnitude of rise as related to (7) pre-transfusion platelet count, (8) method of enhancing transfusion safety (irradiation vs pathogen reduction), (9) cause of thrombocytopenia, and (10) donor/recipient ABO group.

RESULTS

We evaluated 1797 platelet transfusions administered to 605 neonates (median one/recipient, mean 3, and range 1-52). The increment was not associated with gestational age at birth, postnatal age at transfusion, or donor sex or age. The rise was marginally lower: (1) with consumptive vs hypoproductive thrombocytopenia (P < .001); (2) after pathogen reduction (P < .01); (3) after transfusing platelets with a longer storage time (P < .001); and (4) among group O neonates receiving platelets from non-group O donors (P < .001). Eighty-seven neonates had severe thrombocytopenia (<20 000/μL). Among these infants, poor increments and death were associated with the cause of the thrombocytopenia.

CONCLUSION

The magnitude of post-transfusion rise was unaffected by most variables we studied. However, the increment was lower in neonates with consumptive thrombocytopenia, after pathogen reduction, with longer platelet storage times, and when not ABO matched.

Coagulation parameters in very preterm infants

The aim of this study was to define normal percentile values of coagulation parameters in preterm infants below 32 weeks of gestational age. This retrospective cohort study was conducted at Istanbul Medical Faculty. Preterm infants who were born prior to 32 weeks of gestation, between 2011 and 2021 were included and evaluated for coagulation parameters. Blood samples obtained through umbilical catheters prior to administration of heparinized flushes/fluids, vitamin K or fresh frozen plasma (FFP). Infants with a major bleeding disorder, intrapartum asphyxia or a history of familial bleeding disorders were excluded. Infants were grouped according to their gestational ages and birth weights: less than 24, 25-26, 27-28, 29-30, 31-32 weeks and <500, 500-749, 750-999, 1000-1249, 1250-1499, more than 1500 g. Third to 97th percentile values of both prothrombin time (PT) and activated partial thromboplastin time (aPTT) were defined. A total of 420 preterm infants were included. The median value and range of gestational age and birth weight of the infants were 29 (22.3-32.9) weeks and 1150 (395-2790) g, respectively. PT values were similar between subgroups according to gestational age but longer in infants with a birth weight less than 1000 g. aPTT values in infants born less than 24 weeks of gestation were found significantly longer. As maturation of the coagulation system increases by gestational age, very preterm infants (<32 gestational week (GW)) are under increased risk of bleeding. Determination of normal percentile distribution of coagulation parameters for preterm infants will shed light on the interpretation of coagulation parameters of these infants and minimize unnecessary FFP administrations.

Fresh frozen plasma and cryoprecipitate: Can we safely reduce their use in the NICU?

OBJECTIVE

To study patterns of use of Fresh Frozen Plasma (FFP) and Cryoprecipitate (CRYO) in a level 4 NICU and assess what proportions were not supported by literature.

STUDY DESIGN

single centered retrospective observational. Charts of neonates admitted between 1/1/2010 to 12/31/2017 to CT Children's level 4 NICU were reviewed. Transfusions were assigned as "supported" or "non-supported" based on available evidence. Groups were compared using T-tests and chi-squared analyses.

RESULTS

of 4110 total admissions, 197 (4.8%) received a total of 461 transfusions (374 FFP, 87 CRYO). Only 59% of FFP and 60% CRYO were supported by literature. Within the "non-supported" group the largest category was neonates transfused prophylactically.

CONCLUSION

A large proportion of transfusions administered to neonates was not evidence-based, suggesting there are opportunities for improvement in use of these products.

Use of Cryoprecipitate in Newborn Infants

Cryoprecipitate is a transfusion blood product derived from fresh-frozen plasma (FFP), comprised mainly of the insoluble precipitate that gravitates to the bottom of the container when plasma is thawed and refrozen. It is highly enriched in coagulation factors I (fibrinogen), VIII, and XIII; von Willebrand factor (vWF); and fibronectin. In this article, we have reviewed currently available information on the preparation, properties, and clinical importance of cryoprecipitate in treating critically ill neonates. We have searched extensively in the databases PubMed, Embase, and Scopus after short-listing keywords to describe the current relevance of cryoprecipitate.

Use of Fresh-frozen Plasma in Newborn Infants

Nearly 10% of premature and critically ill infants receive fresh-frozen plasma (FFP) transfusions to reduce their high risk of bleeding. The authors have only limited data to identify relevant clinical predictors of bleeding and to evaluate the efficacy of FFP administration. There is still no consensus on the optimal use of FFP in infants who have abnormal coagulation parameters but are not having active bleeding. The aims of this review are to present current evidence derived from clinical studies focused on the use of FFP in neonatology and then use these data to propose best practice recommendations for the safety of neonates receiving FFP.

Reference Values of Thromboelastometry Parameters in Healthy Term Neonates Using NATEM in Cord Blood Samples

Background: ROTEM assay has gained increasing acceptance as a method for rapid and specific coagulation pathway assessment. However, its use in the neonatal population remains limited since reference ranges have not yet been established. Aims: (1) to determine reference ranges for healthy term neonates of ROTEM parameters using non-activated assay (NATEM) in cord blood samples; (2) to assess whether delivery mode, gender, gestational age, birth weight and blood group (ABO and Rhesus) of the neonate, coagulation disorder and anticoagulant medication of the mother have an impact on NATEM parameters. Methods: NATEM assay was conducted in cord blood samples of 189 term neonates without any medical history. Results: Reference ranges (2.5th and 97.5th percentiles) are established for clotting time (CT), clot formation time (CFT), α-angle, clot amplitude at 5, 10 and 20 min (A5, A10, A20), maximum clot firmness (MCF), lysis index at 30 and 60 min (LI30, LI60, %) and maximum clot elasticity (MCE). Reference ranges for NATEM are CT 182-499 s, CFT 63-176 s, α-angle 58-78°, A5 28-52 mm, A10 37-61 mm, A20 42-66 mm, MCF 43-67 mm, LI30 97-100%, LI60 87-98% and MCE 75-203. Male neonates appear to be more hypocoagulable than females. Conclusions: We demonstrate reference ranges for healthy term neonates in NATEM assay that could be used as a reference group for future studies of neonates with an underlying pathology.

Optimizing fresh-frozen plasma transfusion in surgical neonates through thromboelastography: a quality improvement study

Fresh frozen plasma (FFP) is largely misused in the neonatal setting. The aim of the study is to evaluate the impact of a Thromboelastography (TEG)-based Quality Improvement (QI) project on perioperative FFP use and neonatal outcomes. Retrospective pre-post implementation study in a level-III NICU including all neonates undergoing major non-cardiac surgery before (01-12/2017) and after (01-12/2019) the intervention. In 2018, the intervention included the following: (1) Training on TEG, (2) Implementation of TEG, and (3) Algorithm for TEG-directed FFP administration in surgical neonates. We compared pre- vs post-intervention patient characteristics, hemostasis, and clinical management. Linear and logistic regression models were used to evaluate the impact of the project on main outcomes. We analyzed 139 neonates (pre-intervention: 72/post-intervention: 67) with a mean (± SD) gestational age (GA) 34.9 (± 5) weeks and birthweight 2265 (± 980) grams which were exposed to 184 surgical procedures (pre-intervention: 91/post-intervention: 93). Baseline characteristics were similar between periods. In 2019, prothrombin time (PT) was longer (14.3 vs 13.2 s; p < 0.05) and fibrinogen was lower (229 vs 265 mg/dl; p < 0.05), if compared to 2017. In 2019, the intraoperative exposure to FFP decreased (31% vs 60%, p < 0.001), while the pre-operative FFP use did not change. The reduction of intraoperative FFP did not impact on mortality and morbidity. Intraoperative FFP use was lower in the post-intervention even after controlling for GA, American Society of Anesthesiologists score, PT, and fibrinogen (Odds ratio: 0.167; 95% CI: 0.070, 0.371).   Conclusion: The TEG-based QI project for the management of FFP during neonatal surgery reduced intraoperative FFP exposure. What is Known: • PT and aPTT are poor predictors of bleeding risk in acquired neonatal coagulopathy, leading to likely unnecessary fresh frozen plasma (FFP) transfusion in the Neonatal Intensive Care Setting.  • As neonatal hemostasis is a delicate balance between the concomitant reduction of pro- and anti-coagulants drivers, thromboelastography (TEG) is a promising alternative for coagulation monitoring. What is New: • The implementation of TEG, training, and shared protocols contributed to reduced intraoperative FFP use, which was not associated with increased mortality or bleeding events. • These findings inform future research showing that there is clinical equipoise to allow for larger studies to confirm the use of TEG in NICUs and to identify TEG cut-offs for transfusion practice.

Plasma and Platelet Transfusion Strategies in Critically Ill Children With Malignancy, Acute Liver Failure and/or Liver Transplantation, or Sepsis: From the Transfusion and Anemia EXpertise Initiative-Control/Avoidance of Bleeding

OBJECTIVES

To present the consensus statements with supporting literature for plasma and platelet transfusions in critically ill neonates and children with malignancy, acute liver disease and/or following liver transplantation, and sepsis and/or disseminated intravascular coagulation from the Transfusion and Anemia EXpertise Initiative-Control/Avoidance of Bleeding.

DESIGN

Systematic review and consensus conference of international, multidisciplinary experts in platelet and plasma transfusion management of critically ill children.

SETTING

Not applicable.

PATIENTS

Critically ill neonates and children with malignancy, acute liver disease and/or following liver transplantation, and sepsis and/or disseminated intravascular coagulation.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A panel of 13 experts developed evidence-based and, when evidence was insufficient, expert-based statements for plasma and platelet transfusions in critically ill neonates and children with malignancy, acute liver disease and/or following liver transplantation, and sepsis and/or disseminated intravascular coagulation. These statements were reviewed and ratified by the 29 Transfusion and Anemia EXpertise Initiative-Control/Avoidance of Bleeding experts. A systematic review was conducted using MEDLINE, EMBASE, and Cochrane Library databases, from inception to December 2020. Consensus was obtained using the Research and Development/University of California, Los Angeles Appropriateness Method. Results were summarized using the Grading of Recommendations Assessment, Development, and Evaluation method. We developed 12 expert consensus statements.

CONCLUSIONS

In the Transfusion and Anemia EXpertise Initiative-Control/Avoidance of Bleeding program, the current absence of evidence for use of plasma and/or platelet transfusion in critically ill children with malignancy, acute liver disease and/or following liver transplantation, and sepsis means that only expert consensus statements are possible for these areas of practice.

The role of the calibrated automated thrombogram in neonates: describing mechanisms of neonatal haemostasis and evaluating haemostatic drugs

Premature infants are at high risk of haemorrhage and thrombosis. Our understanding of the differences between the neonatal and adult haemostatic system is evolving. There are several limitations to the standard coagulation tests used in clinical practice, and there is currently a lack of evidence to support many of the transfusion practices in neonatal medicine. The evaluation of haemostasis is particularly challenging in neonates due to their limited blood volume. The calibrated automated thrombogram (CAT) is a global coagulation assay, first described in 2002, which evaluates both pro- and anti-coagulant pathways in platelet-rich or platelet-poor plasma. In this review, the current applications and limitations of CAT in the neonatal population are discussed.Conclusion: CAT has successfully elucidated several differences between haemostatic mechanisms in premature and term neonates compared with adults. Moreover, it has been used to evaluate the effect of a number of haemostatic drugs in a pre-clinical model. However, the lack of evidence of CAT as an accurate predictor of neonatal bleeding, blood volume required and the absence of an evidence-based treatment algorithm for abnormal CAT results limit its current application as a bedside clinical tool for the evaluation of sick neonates. What is Known: • The Calibrated automated thrombogram (CAT) is a global coagulation assay which evaluates pro- and anti-coagulant pathways. • CAT provides greater information than standard clotting tests and has been used in adults to evaluate bleeding risk. What is New: • This review summarises the physiological differences in haemostasis between neonates and adults described using CAT. • The haemostatic effect of several drugs has been evaluated in neonatal plasma using CAT.

Hemostasis in neonatal ECMO

Extracorporeal membrane oxygenation (ECMO) is a life-saving support for cardio-respiratory function. Over the last 50 years, the extracorporeal field has faced huge technological progress. However, despite the improvements in technique and materials, coagulation problems are still the main contributor to morbidity and mortality of ECMO patients. Indeed, the incidence and survival rates of the main hemorrhagic and thrombotic complications in neonatal respiratory ECMO are relevant. The main culprit is related to the intrinsic nature of ECMO: the contact phase activation. The exposure of the human blood to the non-endothelial surface triggers a systemic inflammatory response syndrome, which chronically activates the thrombin generation and ultimately leads to coagulative derangements. Pre-existing illness-related hemostatic dysfunction and the peculiarity of the neonatal clotting balance further complicate the picture. Systemic anticoagulation is the management's mainstay, aiming to prevent thrombosis within the circuit and bleeding complications in the patient. Although other agents (i.e., direct thrombin inhibitors) have been recently introduced, unfractionated heparin (UFH) is the standard of care worldwide. Currently, there are multiple tests exploring ECMO-induced coagulopathy. A combination of the parameters mentioned above and the evaluation of the patient's underlying clinical context should be used to provide a goal-directed antithrombotic strategy. However, the ideal algorithm for monitoring anticoagulation is currently unknown, resulting in a large inter-institutional diagnostic variability. In this review, we face the features of the available monitoring tests and approaches, mainly focusing on the role of point-of-care (POC) viscoelastic assays in neonatal ECMO. Current gaps in knowledge and areas that warrant further study will also be addressed.

Hemostatic Evaluation With Viscoelastic Coagulation Monitor: A Nicu Experience

BACKGROUND

Viscoelastic coagulation tests provide valuable information in neonatal intensive care units (NICUs), but the lack of reference intervals still limits their decision-making power according to gestational age. The aim of the present study is to evaluate the hemostasis of a cohort of full-term (FT) and late-preterm (LP) infants using the viscoelastic coagulation monitor (VCM®) system, a new portable device that uses untreated whole blood.

METHODS

An observational study was performed to identify non-coagulopathic FT and LP infants admitted to III° level NICU (January 2020 to December 2021) with a VCM test in the first 72 h of life.

RESULTS

Forty-five patients were enrolled, 26 FT and 19 LP. No statistical differences in hemostatic parameters were observed between FT and LP nor between stable and unstable neonates. Clotting time (CT) was positive correlated with PT (p = 0.032), not with aPTT (p = 0.185). From linear regression, platelet resulted associated with: clot formation time (CTF, p = 0.003), alpha angle (Alpha, p = 0.010), amplitude at 10 (A10, p = 0.001), amplitude at 20 min (A20, p < 0.001), maximum clot firmness (MCF, p < 0.001); and fibrinogen was associated with: A10 (p = 0.008), A20 (p = 0.015) and MCF (p = 0.024). Compared to the adult reference population, neonates showed shorter CT (mean (SD): 5.3 (1.4) vs. 7.0 (0.9) min, p < 0.001), CFT (2.4 (0.7) vs. 2.8 (0.6) minutes, p < 0.001) and higher Alpha (60.8 (6.3) vs. 55 (5)°, p < 0.001). In addition, the neonatal cohort showed an early transient difference in amplitude and fibrinolysis, as follows: A10 (28.0 (5.0) vs. 26 (4) VCM units, p =0.004), A20 (34.8 (5.0) vs. 33 (4) VCM units, p =0.012), and LI30 (99.8 (0.5) vs. 99 (1)%, p <0.001).

CONCLUSIONS

The viscoelastic profile of FT and LP infants assessed with VCM showed a hemostatic competence characterized by accelerated coagulation and clot formation time, in line with other viscoelastic techniques. VCM system provides promising applications in the NICU setting.

Nucleated Red Blood Cell Counts of Neonates Born Emergently 1-4 h after a Maternal Cardiac Arrest

A high nucleated red blood cell (NRBC) count in a newborn infant at birth is sometimes used to imply that fetal hypoxia occurred. However, it is debated whether many hours are required between fetal hypoxia and the appearance of high NRBC or alternatively, whether this can occur very quickly, with fetal hypoxia within minutes to a few hours before birth. We sought relevant information from four unfortunate cases, where during a previously healthy pregnancy, the mother had a sudden cardiac arrest, with cardiopulmonary resuscitation begun at the incident scene and continued through emergent cesarean section delivery.

Individualized Bleeding Risk Assessment through Thromboelastography: A Case Report of May-Hegglin Anomaly in Preterm Twin Neonates

May–Hegglin anomaly (MHA) is a rare autosomal dominant disorder in the spectrum of myosin heavy chain-related disorders (MYH9-RD), characterized by congenital macrothrombocytopenia and white blood cell inclusions. MHA carries a potential risk of hemorrhagic complications. Bleeding diathesis is usually mild, but sporadic, life-threatening events have been reported. Data regarding the clinical course and outcomes of neonatal MYH9-RD are limited, and specific guidelines on platelet transfusion in asymptomatic patients are lacking. We present monochorionic twins born preterm at 32 weeks of gestation to an MHA mother; both presented with severe thrombocytopenia at birth. Peripheral blood smear demonstrated the presence of macrothrombocytes, and immunofluorescence confirmed the diagnosis of MHA. Close clinical monitoring excluded bleeding complications, and serial hemostatic assessments through a viscoelastic system demonstrated functionally normal primary hemostasis in both patients. Therefore, prophylactic platelet transfusions were avoided. Whole DNA sequencing confirmed the pathogenetic variant of MHA of maternal origin in both twins. Thromboelastography allowed real-time bedside bleeding risk assessment and supported individualized transfusion management in preterm newborns at risk of hemostatic impairment. This report suggests that dynamic and appropriate clotting monitoring may contribute to the more rational use of platelets’ transfusions while preserving patients with hemorrhagic complications and potential transfusion-related side effects.

Establishing reference ranges of cord blood: point-of-care hemostatic function assessment in preterm and term neonates

BACKGROUND

Thrombelastometry, allowing timely assessment of global hemostatic function, is increasingly used to guide hemostatic interventions in bleeding patients. Reference values are available for adults and children, including infants but not neonates immediately after birth.

METHODS

Neonates were grouped as preterm (30 + 0 to 36 + 6 weeks/days) and term (37 + 0 to 39 + 6 weeks/days). Blood samples were drawn from the umbilical cord immediately after cesarean section and analyzed by thrombelastometry. Reference ranges were determined for the extrinsic and intrinsic coagulation pathways, fibrin polymerization, and hyperfibrinolysis detection.

RESULTS

All extrinsically activated test parameters, but maximum lysis (P = 0.139) differed significantly between both groups (P ≤ 0.001). Maximum clot firmness in the fibrin polymerization test was comparable (P = 0.141). All intrinsically activated test parameters other than coagulation time (P = 0.537) and maximum lysis (P = 0.888) differed significantly (P < 0.001), and so did all aprotinin-related test parameters (P ≤ 0.001) but maximum lysis (P = 0.851).

CONCLUSIONS

This is the first study to identify reference ranges for thrombelastometry in preterm and term neonates immediately after birth. We also report differences in clot initiation and clot strength in neonates born <37 versus ≤40 weeks of gestation, mirroring developmental hemostasis.

IMPACT

Impact: This prospective observational study is the first to present reference ranges in preterm and term infants for all types of commercially available tests of thrombelastometry, notably also including the fibrin polymerization test.

IMPORTANCE

Viscoelastic coagulation assays such as thrombelastometry have become integral to the management of perioperative bleeding by present-day standards. Reference values are available for adults, children, and infants but not for neonates. Key message: Clot initiation and formation was faster and clot strength higher in the term than in the preterm group. Parameters of thrombelastometry obtained from cord blood do not apply interchangeably to preterm and term neonates.

Hot topics in coagulation testing: Important considerations for testing children for bleeding/thrombotic disorders

The accurate use and interpretation of diagnostic investigations are essential for safe and effective patient care. Appropriate application and interpretation of coagulation testing can be challenging, and many controversies exist relating to the standardization of testing procedures, the application of relevant tests to different patient populations and the interpretation of test results. We present a list of the most prominent controversies in coagulation testing and have selected three specific examples (age-appropriate reference ranges, therapeutic anticoagulation monitoring and tests of thrombin generation) for closer discussion, highlighting examples with a paediatric framework. We discuss the limitations of discrete age-partitioned reference intervals, given the established principle of developmental haemostasis; the difficulties in establishing normative data across different laboratories; important pre-analytical variables affecting coagulation testing; the challenges in interpreting APTT and anti-Xa assays for monitoring unfractionated heparin therapy in different clinical situations; and the limitations in interpreting tests of thrombin generation due to current available thrombin-specific substrates and the complicating factor of variable alpha2-macroglobulin levels. These controversies are demonstrated using paediatric examples, but raise important implications for coagulation testing in patients of all ages and highlight the pressing need for further research in these areas.

Hemostatic Challenges in Neonates

The neonatal hemostatic system is strikingly different from that of adults. Among other differences, neonates exhibit hyporeactive platelets and decreased levels of coagulation factors, the latter translating into prolonged clotting times (PT and PTT). Since pre-term neonates have a high incidence of bleeding, particularly intraventricular hemorrhages, neonatologists frequently administer blood products (i.e., platelets and FFP) to non-bleeding neonates with low platelet counts or prolonged clotting times in an attempt to overcome these "deficiencies" and reduce bleeding risk. However, it has become increasingly clear that both the platelet hyporeactivity as well as the decreased coagulation factor levels are effectively counteracted by other factors in neonatal blood that promote hemostasis (i.e., high levels of vWF, high hematocrit and MCV, reduced levels of natural anticoagulants), resulting in a well-balanced neonatal hemostatic system, perhaps slightly tilted toward a prothrombotic phenotype. While life-saving in the presence of active major bleeding, the administration of platelets and/or FFP to non-bleeding neonates based on laboratory tests has not only failed to decrease bleeding, but has been associated with increased neonatal morbidity and mortality in the case of platelets. In this review, we will present a clinical overview of bleeding in neonates (incidence, sites, risk factors), followed by a description of the key developmental differences between neonates and adults in primary and secondary hemostasis. Next, we will review the clinical tests available for the evaluation of bleeding neonates and their limitations in the context of the developmentally unique neonatal hemostatic system, and will discuss current and emerging approaches to more accurately predict, evaluate and treat bleeding in neonates.

Pediatric Fibrinogen PART I-Pitfalls in Fibrinogen Evaluation and Use of Fibrinogen Replacement Products in Children

Fibrinogen is a key coagulation protein, playing a critical role in hemostasis. It is the first factor to decrease to critical levels during bleeding. Hypofibrinogenemia is an important risk factor for bleeding in clinical settings, including pediatric surgery. Yet, the optimal measurement of fibrinogen levels is subject to debate, as is the critical threshold for intervention. Fibrinogen replacement may be provided by cryoprecipitate and fibrinogen concentrate. Whilst both products contain fibrinogen, they are not equivalent, each has its own advantages and disadvantages, especially for pediatric use. Unfortunately, medical literature to support fibrinogen replacement in children is limited. In this article we review the current diagnostic tools to measure fibrinogen, with respect to their use in the pediatric critical care setting. Secondly, we evaluate the different fibrinogen replacement therapies, focusing on cryoprecipitate and fibrinogen concentrate and examine their individual product characteristics, associated risks and benefits, different dosing strategies and specific pitfalls for use in children. We summarize by highlighting current knowledge gaps and areas for future research.

Transfusion in Neonatal Patients: Review of Evidence-Based Guidelines

Transfusion of red blood cells, platelets, and fresh frozen plasma in neonatal patients has not been well characterized in the literature, with guidelines varying greatly between institutions. However, anemia and thrombocytopenia are highly prevalent, especially in preterm neonates. When transfusing a neonatal patient, clinicians must take into consideration physiologic differences, gestational and postnatal age, congenital disorders, and maternal factors while weighing the risks and benefits of transfusion. This review of existing literature summarizes current evidence-based neonatal transfusion guidelines and highlights areas of current ongoing research and those in need of future studies.

Changes in the Use of Fresh-Frozen Plasma Transfusions in Preterm Neonates: A Single Center Experience

The aim of this study was to evaluate changes in the use of fresh-frozen plasma (FFP) transfusions and the use of clotting tests in preterm neonates in our center over the past two decades. In this retrospective cohort analysis, we included all consecutive neonates with a gestational age at birth between 24 + 0 and 31 + 6 weeks admitted to our neonatal intensive care unit (NICU) between 2004 and 2019. We divided all included neonates into three consecutive time epochs according to date of birth: January 2004 to April 2009, May 2009 to August 2014 and September 2014 to December 2019. The main outcomes were the use of FFP transfusion, coagulation testing and the indications for FFP transfusion. The percentage of preterm neonates receiving FFP transfusion decreased from 5.7% (47/824) to 3.7% (30/901) to 2.0% (17/852) from the first epoch to the last epoch (p < 0.001). Additionally, the rate of neonates undergoing coagulation testing decreased from 24.3% (200/824) to 14.5% (131/901) to 8% (68/852) over the epochs (p < 0.001). Most FFP transfusions were prescribed prophylactically based on prolongation of activated partial thromboplastin time (aPTT) or prothrombin time (PT) (56%). In conclusion, both the use of FFP transfusions and the use of coagulation tests decreased significantly over the years. The majority of the FFP transfusions were administrated prophylactically for abnormal coagulation tests.

Transfusion support: Considerations in pediatric populations

Over 400,000 units of blood and blood products are transfused to pediatric patients annually, yet only sparse high-quality data exist to guide the preparation and administration of blood products in this population. The direct application of data from studies in adult patients should be undertaken with caution, as there are dissimilarities in the pathology and physiology between adult and pediatric patients. We provide an overview of available evidence in the field of pediatric transfusion medicine, summarizing indications for blood product transfusion, thresholds for transfusion and indications for blood product modifications.

Thromboelastographic profiles of healthy very low birthweight infants serially during their first month

OBJECTIVE

We determined thromboelastographic (TEG) profiles of healthy very low birthweight infants (VLBWIs) of the day of birth and at set intervals during their first month.

DESIGN

Prospective observational study with blinded clinical and laboratory follow-up.

SETTING

Level III neonatal intensive care unit (June 2015 to June 2018).

PATIENTS

Consecutive qualifying VLBWIs were enrolled at birth and followed up for 30 days.

INTERVENTIONS AND MAIN OUTCOMES MEASURES

Laboratory (citrated-native TEG, prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen, blood count) and clinical variables were retrieved at birth, 3rd-5th, 10th and 30th day of life. Blood samples temporally related to events with a potential hemostatic impact (sepsis, bleeding, platelets/plasma transfusions, ibuprofen/indomethacin administration) were excluded from analysis.

RESULTS

We enrolled 201 VLBWIs and 72 full-term neonates. Sixty-seven of the healthy VLBWIs completed the 30-day follow-up. 541 TEG traces were analysed.On day 1, the median (minimum-maximum) TEG values were as follows: reaction time (R), 8.2 min (1-21.8); kinetics (K), 2.8 min (0.8-16); α angle, 51° (14.2-80.6); maximum amplitude (MA), 54.9 mm (23.9-76.8). PT and APTT were 15.9 s (11.7-51.2) and 59 s (37.8-97.5), respectively. The above parameters suggest minor hypocoagulability compared with term infants. On day 30, the median (minimum-maximum) R was 5 (1-16.9), K 1 (0.8-4.1), α 74.7 (41.1-86.7) and MA 70.2 (35.8-79.7). PT and APTT were 12.1 (10.4-16.6) and 38.8 (29.6-51.4), respectively. Those parameters are consistent with a relatively hypercoagulable phenotype, compared with term infants.

CONCLUSIONS

Healthy VLBWIs have a prolonged PT and APTT, but their TEG profiles suggest a relatively balanced hemostatic system, with slight hypocoagulability initially (compared with term neonates), gradually evolving to a somewhat more procoagulant phenotype over the first month.

Is placental blood a reliable source for the evaluation of neonatal hemostasis at birth?

BACKGROUND

Phlebotomy is among the main determinants of anemia of prematurity. Blood sparing policies endorsed umbilical cord blood (here called placental) as an alternative source for laboratory testing. Little is known on the suitability of placental blood to evaluate neonatal hemostasis of newborn infants. We aimed to compare the hemostatic profile of paired placental and infant venous blood, by means of prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen, antithrombin, protein C, thromboelastography (TEG) and thrombin generation assay (TGA).

STUDY DESIGN

This was an observational single-center study.

METHODS

We collected at birth venous citrated blood from both placental and infant venous source and performed PT, APTT, fibrinogen, antithrombin, protein C, TEG (reaction time-R; kinetics-K alpha angle-α, maximum amplitude-MA and lysis at 30 minutes-LY30), and TGA (endogenous thrombin potential-ETP).

RESULTS

We enrolled 60 neonates with a median gestational age (range) of 37 weeks (28⁺¹ -41) and birth-weight 2417 g (950-4170). Based on TEG and TGA, placental blood showed a procoagulant imbalance as indicated by lower median R (4.0 vs. 6.1 min; p < 0.001) and K (1.3 vs. 2.2 min; p < 0.001); higher α-angle (69.7 vs. 57.4°; p < 0.001) and ETP (1260 vs. 1078; p = 0.002) than those observed for infant venous blood. PT and APTT did not differ significantly between the two groups.

CONCLUSIONS

While placental and neonatal blood samples are equally suitable to measure the standard coagulation tests PT and APTT, placental blood leads to a procoagulant imbalance when testing is performed with TEG or TGA. These effects should be considered when interpreting results stemming from investigation of neonatal hemostasis.

Procoagulant imbalance in preterm neonates detected by thrombin generation procedures

Preterm newborns are considered at risk of acquired coagulopathy and are often prophylactically infused with fresh frozen plasma (FFP) even in the absence of bleeding. To assess the coagulation asset of preterm neonates and the biological plausibility of such infusions, we investigated at birth 87 very low birth weight (≤1500 g) preterm (gestational age <35 weeks) newborns and 64 full-term newborns. Preterm neonates were also investigated at different time-points up to 30 days after birth. Plasma from preterm and full-term neonates were subjected to the measurement of prothrombin and activated partial thromboplastin time (PT, APTT), pro- and anticoagulant factors as well as to thrombin-generation procedures both with and without thrombomodulin. PT and APTT of preterm newborns were longer than those of full-term neonates [PT: 15.9 s (11.7-51.2)-vs-13.8 (11.0-25.4), p < 0.001. APTT: 59.0 (37.8-97.5)-vs- 47.3 (28.1-71.9), p < 0.001] and tended to shortening after 30 days from birth. Thrombin-generation defined as endogenous thrombin potential (ETP) was increased in preterm as compared to full-term neonates at birth [1322 nM·min (474-2384)-vs-1006 (697-1612), p < 0.001] and did not change appreciably over time up to 30 days from birth. In conclusion, plasma from preterm neonates displays a procoagulant imbalance at birth as shown by increasing ETP, despite the prolongation of PT and APTT. The results define preterm newborns as having hyper- rather than hypo-coagulability and argue against the infusion of FFP when given prophylactically and/or based solely on prolongation of PT or APTT.

Neonates with suspected microangiopathic disorders: performance of standard manual schistocyte enumeration vs. the automated fragmented red cell count

OBJECTIVES

To enhance the diagnosis of schistocyte-producing conditions, we compared routine manual schistocyte enumeration with automated fragmented red cell counts (FRCs).

STUDY DESIGN

In neonates "suspected" of having sepsis, NEC, or DIC we compared manual schistocyte estimates vs. automated FRC counts. When the two disagreed, we used a "gold standard" from a  ≥ 1000 RBC differential. We also assessed the diagnostic accuracy of the FRC count in diagnosing sepsis, NEC, or DIC.

RESULTS

We collected 270 CBCs from 90 neonates. The methods agreed in 63% (95% CI 55%-70%) of the CBCs. Among the 37% where they disagreed, the FRC count was more accurate in 100% (95% CI 88-100%). An elevated FRC count was specific for sepsis, and was sensitive and specific for necrotizing enterocolitis and DIC.

CONCLUSIONS

Automated FRC counts have advantages over routine manual evaluation, larger sample size, lower expense, and superior accuracy in diagnosing schistocyte-producing conditions.

Hemostatic profile of infants with spontaneous prematurity: can we predict intraventricular hemorrhage development?

Background

Defining hemostatic profile for preterm infants is a challenge when severe bleedings are frequent.

Methods

The aim was to define the hemostatic profile at birth of infants with spontaneous prematurity and to evaluate whether characteristic profiles can predict the development of intraventricular hemorrhage (IVH) in prematures.

Results

We included 122 newborns with a median age of 31^5/7 gestational age (GA) [29^2/7;34^0/7] and median weight of 1145 g [785;1490]. Levels of fibrinogen, factor II (FII) and factor V (FV) rose with GA (p = 0.017,p = 0.009, p = 0.001). In the group of 23^0/7 – 28^6/7 GA, the 5th percentile was defined as 0.6 g/L for fibrinogen, 15 IU/dL for FII and 16 IU/dL for factor V (n = 30). In the group of 29^0/7–32^6/7 GA, the 5th percentile was defined as 1.0 g/L for fibrinogen, 24 IU/dL for FII and 41 IU/dL for factor V (n = 46). In the group of 33^0/7–36^6/7 GA, the 5th percentile was defined as 1.0 g/L for fibrinogen, 24 IU/dL for FII and 30 IU/dL for factor V (n = 46). Level of fibrinogen was higher in case of vaginal delivery and lower in case of IUGR. Only lower level of FV at birth was significantly associated with IVH (63.5 [46.0; 76.5] vs 74.0 [58.0; 89.0], p = 0.026) with an unadjusted OR per SD increase in FV of 0.57 (95%CI, 0.34 to 0.96). After adjustment for age, the association between FV level and IVH was slightly attenuated (adjusted OR, 0.70; 95%CI, 0.40 to 1.23) but remained not significant (p = 0.22).There was no correlation with FII and fibrinogen.

Conclusions

We can define hemostastic profile of prematures and corroborate references ranges for studied parameters. Further large studies are still called for, to correlate the grade of hemorrhage and the factor V level at birth.

An iTRAQ-Based Quantitative Proteomic Analysis of Plasma Proteins in Preterm Newborns With Retinopathy of Prematurity

Purpose

Retinopathy of prematurity (ROP) is a vision-threatening complication of a premature birth, in which the etiology still remains unclear. Importantly, the molecular processes that govern these effects can be investigated in a perturbed plasma proteome composition. Thus, plasma proteomics may add new insights into a better understanding of the pathogenesis of this disease.

Methods

The cord and peripheral blood of neonates (≤30 weeks gestational age) was drawn at birth and at the 36th postmenstrual week (PMA), respectively. Blood samples were retrospectively subdivided into ROP(+) and ROP(-) groups, according to the development of ROP.

Results

The quantitative analysis of plasma proteome at both time points revealed 30 protein abundance changes between ROP(+) and ROP(-) groups. After standardization to gestational age, children who developed ROP were characterized by an increased C3 complement component and fibrinogen level at both analyzed time points.

Conclusions

Higher levels of the complement C3 component and fibrinogen, present in the cord blood and persistent to 36 PMA, may indicate a chronic low-grade systemic inflammation and hypercoagulable state that may play a role in the development of ROP.

Predictors of severe intraventricular hemorrhage in preterm infants under 29-weeks gestation

Purpose: Preterm infants <29 weeks of gestation are at risk for severe intraventricular hemorrhage (IVH). Lower gestational age, birth weight, severe illness, as indexed by higher Score for Neonatal Acute Physiology - Perinatal Extension II (SNAPPE-II) are associated with severe IVH. The role of coagulation abnormalities on the first day after birth in severe IVH remains controversial. The present study investigated factors that predict the risk of severe IVH, including SNAPPE-II at 12 h and coagulation parameters on the first day after birth.Materials and methods: A retrospective chart review of infants < 29 weeks of gestation from January 2008 to December 2013 was performed. Prenatal and postnatal characteristics, SNAPPE-II at 12 h, coagulation parameters [prothrombin time (PT), INR, partial thromboplastin time (aPTT), thrombin time (TT), and fibrinogen] on the first day and cranial ultrasound examination records were collected. The association between clinical and laboratory variables and severe IVH was determined. A joint predictive model for the risk of severe IVH (grades 3 and 4) versus no-mild IVH (grades 0, 1, and 2) was developed using multiple regression analysis.Results: Preterm infants of gestational age < 29 weeks were included (n = 101). Fifteen (15%) infants had severe IVH. Lower gestational age (p = .006), birth weight (p = .008), African American race (p = .031) and higher SNAPPE-II at 12 h (p = .001) were associated with severe IVH. Infants with severe IVH had longer PT (p = .004), higher INR (p = .004) and lower platelet count (p = .034) than those with no-mild IVH. Stepwise logistic regression showed that only SNAPPE-II at 12 h was an independent predictor of severe IVH. For each unit increase in SNAPPE-II, the log odds of severe IVH increased by 0.045 (95% CI: [0.017, 0.073]; p = .002). A threshold of 55 on the SNAPPE-II yielded a sensitivity of 60% (9/15), a specificity of 91% (78/86), a positive predictive value (PPV) of 53% (9/17) and a negative predictive value (NPV) of 93% (78/84). All other demographic and clinical variables and coagulation abnormalities had an insignificant coefficient (p > .05) when included in a bivariate logistic model with SNAPPE-II.Conclusion: SNAPPE-II at 12 h after birth is an independent predictor of severe IVH in preterm infants with gestational age < 29 weeks.

Selective prophylactic solvent-detergent plasma and cryoprecipitate transfusion to prevent intraventricular hemorrhage in extreme preterm infants: A case-historical control

BACKGROUND

Contradictory evidence exists whether a prophylactic coagulation factor transfusion in the first hours of life (HOL) prevents intraventricular hemorrhage (IVH) in extreme preterm infants (EPI, <28 weeks gestation). We aimed to determine whether selective prophylactic solvent-detergent plasma and cryoprecipitate transfusion within 12 hours of life (SP-SDP/Cryoprecipitate-T) could prevent IVH in EPI.

METHOD

This is a retrospective analysis, case-historical control, of prospectively collected data from a pre-existing electronic neonatal database at a Saudi tertiary neonatal intensive care unit. We compared the IVH rate in EPI born in the first 4 years (Jan 2010-Dec 2013) of the SP-SDP/Cryoprecipitate-T period with that of EPI born during the last 4 years (Jan 2006-Dec 2009) of the rescue SDP/Cryoprecipitate-T period.

RESULTS

The IVH rate was lower in the SP compared to the rescue- SDP/Cryoprecipitate-T period (30.8% versus 51.2%, odds ratio 0.42, 95% confidence interval 0.21, 0.88, p = 0.02). This difference remained significant after controlling for six other IVH risk factors.

CONCLUSIONS

Early SP-SDP/Cryoprecipitate-T may reduce the IVH rate in EPI. A large multicenter clinical trial is required for confirm the short and long-term benefit and risk of this intervention. Until then, early SP-SDP/Cryoprecipitate-T may be considered by an institution with a persistently high IVH rate.

Ante-, peri- and postnatal factors associated with intraventricular hemorrhage in very premature infants

BACKGROUND

Intraventricular hemorrhage (IVH) is one of the most serious complications in preterm infants and is associated with neurological sequelae and mortality. Over the past few decades, the rate of IVH has decreased due to improved neonatal intensive care. However, up to 15-25% of very and extremely premature infants (<32 and <28weeks of pregnancy (WOP) respectively) still suffer from IVH.

STUDY PURPOSE

The aim of this study was to perform an updated, multicenter analysis to identify ante-, peri, and postnatal factors other than gestational age/birth weight associated with IVH of any grade in a large cohort of very and extremely premature infants.

METHODS

We performed a retrospective analysis in a prospectively conducted multicenter cohort study between 01/01/1998-31/12/2012 at 5 level 3 perinatal centers. All relevant ante-, peri- and neonatal data were collected and univariate as well as multivariate logistic regression analysis was performed.

RESULTS

765 inborn infants with a gestational age<32 WOP were enrolled into this study (369 (48.2%) female; 396 (51.8%) male). Birth weight ranged from 315g to 2200g (mean 1149.7g, SD 371.9g); 279 (36.5%) were born ≤27+6 WOP and 486 (63.5%)≥28+0 WOP. IVH was seen in 177 (23.1%) patients. Multivariate analysis revealed that in addition to higher gestational age (OR 0.7, CI [0.6-0.8]), antenatal steroid treatment (OR 0.3, CI [0.2-0.6]) and caesarian section without uterine contraction (OR 0.6, CI [0.4-0.9]) were associated with a lower rate of IVH while RDS (OR 5.6, CI [1.3-24.2]), pneumothorax (OR 2.8, CI [1.4-5.5]) and use of catecholamines (OR 2.7, CI [1.7-4.5]) were associated with an increased risk of IVH. After exclusion of gestational age and birth weight from multivariate analysis, early onset sepsis (OR 1.6, CI [1.01-2.7]) and patent ductus arteriosus (OR 1.9, CI [1.1-3.1]) were associated with a higher rate of IVH. In addition, univariate analysis revealed that Apgar scores at 5min (p<0.001), BDP/ROP/NEC (p<0.001), mechanical ventilation (p<0.001) and inhalative nitric oxide (p<0.001) were significantly associated with IVH.

CONCLUSIONS

Our comprehensive analysis demonstrated that the occurrence of IVH in very premature infants is significantly associated with ante-, peri- and postnatal factors being either related to the degree of immaturity or indicating a critical clinical course after birth. The analysis reiterates the necessity for a very close cooperation between obstetricians and neonatologists to reduce the incidence of IVH in this susceptible cohort.

Fresh frozen plasma transfusion - a risk factor for pulmonary hemorrhage in extremely low birth weight infants?

AIM

To evaluate risk factors for pulmonary hemorrhage (PH) in extremely low birth weight infants (ELBW) taking into consideration coagulation screens, platelet counts, transfusion of fresh frozen plasma (FFP), and platelet concentrates prior to PH.

PATIENTS AND METHODS

A retrospective case-control study consisting of 20 ELBW infants with PH and 40 matched controls. Coagulation screens, platelet counts at birth and at onset of PH, and transfusion frequencies prior to PH were compared to case-controls at birth and 24-96 h after birth.

RESULTS

While the initial platelet counts, fibrinogen concentrations, and international normalized ratios were similar in PH infants and controls, the activated partial prothrombin time was prolonged (P=0.05). Compared to 28% of case controls (P<0.05), 55% of infants with later PH received FFP prior to PH. Platelet counts were significantly lower at onset of PH (median 81/nL; range: 37-236/nL) compared to controls (166/nL; 27-460/nL; P<0.005). Multivariate analysis indicated a lack of antenatal steroids, supplemental oxygen, and transfusion of FFP as independent risk factors for PH.

CONCLUSION

Prolonged activated partial thromboplastin time (aPTT) might be associated with PH. PH does not primarily depend upon severe thrombocytopenia. A developmental mismatch in hemostasis by transfusion of adult donor plasma should be considered a risk factor for PH.

Use and Future Investigations of Recombinant and Plasma-Derived Coagulation and Anticoagulant Products in the Neonate

Although congenital bleeding disorders can manifest in the newborn period, the most common causes of bleeding and thrombosis in neonates are acquired conditions. Factor concentrates are used for specific diagnoses (hemophilia with inhibitors, specific factor deficiency, von Willebrand disease) and approved indications, and increasingly for off-label indications (bleeding in surgery cardiopulmonary bypass, extracorporeal membrane oxygenation). We will review the approved indications for factor products in the neonate and discuss the evidence and rationale for off-label use of factor products in management of bleeding and thrombosis in the neonate.

Neonatal Plasma Transfusion: An Evidence-Based Review

Several clinical scenarios for plasma transfusion are repeatedly identified in audits, including treatment of bleeding in association with laboratory evidence of coagulopathy, correction of disseminated intravascular coagulation, prevention of intraventricular hemorrhage, management of critically ill neonates (eg, during sepsis or as a volume expander), or correction of markers of prolonged coagulation in the absence of bleeding. The findings of at least one national audit of transfusion practice indicated that almost half of plasma transfusions are given to neonates with abnormal coagulation values with no evidence of active bleeding, despite the limited evidence base to support the effectiveness of this practice. Plasma transfusions to neonates should be considered in the clinical context of bleeding (eg, vitamin K dependent), disseminated intravascular coagulation, and very rare inherited deficiencies of coagulation factors. There seems to be no role for prophylactic plasma to prevent intraventricular hemorrhage or for use as a volume expander.

Clinical Data of Neonatal Systemic Thrombosis

OBJECTIVE

To evaluate clinical data and associated risk conditions of noncerebral systemic venous thromboembolism (VT), arterial thromboembolism (AT), and intracardiac thromboembolism (ICT) in neonates.

STUDY DESIGN

Data analysis of first systemic thromboembolism occurring in 75 live neonates (0-28 days), enrolled in the Italian Registry of Pediatric Thrombosis from neonatology centers between January 2007 and July 2013.

RESULTS

Among 75 events, 41 (55%) were VT, 22 (29%) AT, and 12 (16%) ICT; males represented 65%, and 71% were preterm. In 19 (25%), thromboembolism was diagnosed on the first day of life. In this "early onset" group, prenatal-associated risk conditions (maternal/placental disease) were reported in 70% and inherited thrombophilia in 33%. Postnatal risk factors were present in 73%; infections and central vascular catheters in 56% and 54% VT, respectively, and in 67% ICT vs 27% AT (<.05). Overall mortality rate was 15% and significant thromboembolism-related sequelae were reported in 16% of discharged patients.

CONCLUSIONS

This report from the Registro Italiano Trombosi Infantili, although limited by representing an uncontrolled case series, can be used to develop future clinical trials on appropriate management and prevention of neonatal thrombosis, focusing on obstetrical surveillance and monitoring of critically ill neonates with vascular access. A thrombosis risk prediction rule specific for the neonatal population should be developed through prospective controlled studies.

Cellular and humoral coagulation profiles and occurrence of IVH in VLBW and ELWB infants

BACKGROUND AND STUDY PURPOSE

Intraventricular hemorrhage (IVH) is a major complication in preterm neonates with significant long-term morbidity and an increased mortality rate. The role of the immature coagulation system in the pathogenesis of IVH in these infants is still under debate. The aim of this study was to provide reference values for coagulation studies within the first 24h of life, and to relate these findings to the incidence of IVH.

PATIENTS AND METHODS

In this retrospective study, a total of 250 (male: 123/female: 127; VLBW: 150 and ELBW: 100) infants were included over a 4-year-period. Coagulation studies were performed within the first 24h of life in all infants. Multiple regression analysis was employed to demonstrate a potential association between IVH and a number of known risk and protective factors for IVH (antenatal steroids, birth weight, gender, IUGR, APGAR score at 10minutes, platelet count, INR, PTT, fibrinogen).

RESULTS

Mean birth weight was 1047.9±305.6 (range: 320-1490g). Both cellular (platelets, nucleated red blood cells) and plasmatic coagulation parameters (INR, fibrinogen and antithrombin III) were dependent on birth weight. Moreover, INR levels (p<0.05) were significantly increased in neonates with IVH of any grade. Also, INR was positively correlated with the severity of IVH (Spearman's correlation coefficient: 0.193; p=0.003). While overall fibrinogen levels were not associated with IVH, a fibrinogen level<100mg/dL significantly increased the risk for IVH (p<0.01).

CONCLUSIONS

Our data provide a robust set of reference values for both cellular and humoral coagulation studies in VLBW and ELBW infants for the first 24h of life. The results of our study indicate that abnormal INR levels and fibrinogen levels<100mg/dL are significantly associated with the occurrence of IVH in this susceptible cohort.

Coagulation indices in very preterm infants from cord blood and postnatal samples

BACKGROUND

Very premature infants are at high risk of bleeding complications; however, few data exist on ranges for standard coagulation tests.

OBJECTIVES

The primary objective of this study was to measure standard plasma coagulation tests and thrombin generation in very premature infants compared with term infants. The secondary objective was to evaluate whether an association existed between coagulation indices and intraventricular hemorrhage (IVH).

PATIENTS/METHODS

Cord and peripheral blood of neonates < 30 weeks gestational age (GA) was drawn at birth, on days 1 and 3 and fortnightly until 30 weeks corrected gestational age. Prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen and coagulation factor levels were measured and tissue factor-stimulated thrombin generation was characterized. Control plasma was obtained from cord blood of term neonates.

RESULTS

One hundred and sixteen infants were recruited. Median (range) GA was 27.7 (23.7-29.9) weeks and mean (SD) birth weight was 1020 (255) g. Median (5th-95th percentile) day 1 PT, APTT and fibrinogen were 17.5 (12.7-26.6) s, 78.7 (48.7-134.3) s and 1.4 (0.72-3.8) g L(-1) , respectively. No difference in endogenous thrombin potential between preterm and term plasma was observed, where samples were available. Levels of coagulation factors II, VII, IX and X, protein C, protein S and antithrombin were reduced in preterm compared with term plasma. Day 1 APTT and PT were not associated with IVH.

CONCLUSION

In the largest cross-sectional study to date of very preterm infants, typical ranges for standard coagulation tests were determined. Despite long clotting times, thrombin generation was observed to be similar in very preterm and term infants.

Reference Intervals in Neonatal Hematology

The various blood cell counts of neonates must be interpreted in accordance with high-quality reference intervals based on gestational and postnatal age. Using very large sample sizes, we generated neonatal reference intervals for each element of the complete blood count (CBC). Knowledge of whether a patient has CBC values that are too high (above the upper reference interval) or too low (below the lower reference interval) provides important insights into the specific disorder involved and in many instances suggests a treatment plan.

Fresh Frozen Plasma Administration in the Neonatal Intensive Care Unit: Evidence-Based Guidelines

Neonates receiving fresh frozen plasma (FFP) should do so according to evidence-based guidelines so as to reduce inappropriate use of this life-saving and costly blood product and to minimize associated adverse effects. The consensus-based uses of FFP in neonatology involve neonates with active bleeding and associated coagulopathy. However, because of limited and poor-quality evidence, considerable FFP utilization occurs outside these recommendations. In this review, we describe what we conclude are currently the best practices for the use of FFP in neonates, including interpreting neonatal coagulation tests and strategies for reducing unnecessary FFP transfusions.

Thrombocytopenia in Small-for-Gestational-Age Infants

BACKGROUND

Thrombocytopenia is common among small-for-gestational-age (SGA) neonates (birth weight <10th percentile reference range), but several aspects of this thrombocytopenia are unclear, including the incidence, typical nadir, duration, association with preeclampsia, mechanism, and risk of death.

METHODS

Using 9 years of multihospital records, we studied SGA neonates with ≥2 platelet counts <150,000/μL in their first week.

RESULTS

We found first-week thrombocytopenia in 31% (905 of 2891) of SGA neonates versus 10% of non-SGA matched controls (P < .0001). Of the 905, 102 had a recognized cause of thrombocytopenia (disseminated intravascular coagulation, early-onset sepsis, or extracorporeal membrane oxygenation). This group had a 65% mortality rate. The remaining 803 did not have an obvious cause for their thrombocytopenia, and we called this "thrombocytopenia of SGA." They had a mortality rate of 2% (P < .0001) and a mean nadir count on day 4 of 93,000/μL (SD 51,580/μL, 10th percentile 50,000/μL, 90th percentile 175,000/μL). By day 14, platelet counts were ≥150,000/μL in more than half of the patients. Severely SGA neonates (<1st percentile) had lower counts and longer thrombocytopenia duration (P < .001). High nucleated red cell counts at birth correlated with low platelets (P < .0001). Platelet transfusions were given to 23%, and counts typically more than tripled. Thrombocytopenia was more associated with SGA status than with the diagnosis of maternal preeclampsia.

CONCLUSIONS

SGA neonates with clearly recognized varieties of thrombocytopenia have a high mortality rate. In contrast, thrombocytopenia of SGA is a hyporegenerative condition of moderate severity and 2 weeks' duration and is associated with evidence of intrauterine hypoxia and a low mortality rate.

Fresh Frozen Plasma Use in a Neonatal Unit in South Africa

BACKGROUND

Despite limited evidence, fresh frozen plasma (FFP) transfusions are a relatively common neonatal procedure.

OBJECTIVES

Quantify FFP usage in our unit; determine indications for transfusions and compliance with published guidelines.

METHODS

Data were retrospectively collected on infants who received FFP from January 2009 to December 2013.

RESULTS

Admissions totalled 10 912 infants during the study period. In total, 113 case notes were reviewed and 142 FFP transfusions were administered. Infants receiving FFP had a high mortality rate (54.87%) and an increased odds ratio for mortality 17.9 (95% confidence interval 12.0-26.6). In total, 75% FFP transfusions were compliant with guidelines. The difference between pre- and post-transfusion coagulation profile in 36.3% of infants was not statistically significant.

CONCLUSIONS

FFP was often used in accordance with published guidelines in our neonatal unit. However, the appropriate use and effectiveness of FFP in improving neonatal outcomes undermines the rationale for FFP usage in current guidelines.