Randomized Trial of Platelet-Transfusion Thresholds in Neonates

Maternal Early-onset Preeclampsia Places Preterm Infants at Risk of Thrombocytopenia Requiring Platelet Transfusions

OBJECTIVES

Evaluate the hematological parameters and indices in the blood count collected on the first day of life (D1) in very premature infants born to mothers with early-onset preeclampsia (PE) and their correlation with increased neonatal morbimortality.

BACKGROUND

Changes in hematologic parameters in the blood counts collected after birth associated with PE have been demonstrated by recent studies, although inconsistently.

MATERIALS AND METHODS

Retrospective study between 2008 and 2023, at a level III neonatal intensive care unit, including preterm infants with a gestational age below 30 weeks. A blood count was collected on D1 and a comparison of hematological parameters and indices was made between infants exposed or not to PE.

RESULTS

We included 206 newborns (PE = 39; no PE = 167). The multivariate analyses showed no significant hematological changes. PE-exposed infants required significantly more platelet transfusions (PE: n = 20 [51.8%]; no PE: n = 34 [20.36%]; P < 0.0001).

CONCLUSION

PE-exposed preterms required more platelet transfusions, which increases the risk of associated complications.

Development and implementation of restrictive platelet transfusion thresholds in a neonatal intensive care unit

OBJECTIVE

Thrombocytopenia is a common problem affecting preterm neonates. Recent studies show increased morbidity and mortality with liberal platelet transfusion thresholds. We sought to standardize thrombocytopenia management through a transfusion guideline to reduce excessive transfusions.

STUDY DESIGN

We developed and implemented a guideline using PDSA cycles for infants with birth weights <1000 grams. Platelet transfusions were classified as indicated or non-indicated per the guideline. Severe (grade 3 or 4) intraventricular hemorrhage and pulmonary hemorrhage rates were balancing measures.

RESULTS

We analyzed 101 infants pre-guideline and 96 infants post-guideline. The mean monthly non-indicated transfusions significantly decreased from 13.0 to 2.0, respectively (p-value < 0.01). Incidence of severe grade IVH and pulmonary hemorrhage remained stable.

CONCLUSION

Rapid implementation of an evidence-based, restrictive platelet transfusion guideline significantly reduced non-indicated platelet transfusions without a concomitant increase in major bleeding events.

Aging platelets shift their hemostatic properties to inflammatory functions

ABSTRACT

Platelets are crucial players in hemostasis and thrombosis but also contribute to immune regulation and host defense, using different receptors, signaling pathways, and effector functions, respectively. Whether distinct subsets of platelets specialize in these diverse tasks is insufficiently understood. Here, we used a pulse-labeling method in Mus musculus models for tracking in vivo platelet aging and its functional implications. Using in vitro and in vivo assays, we reveal that young, reticulated platelets show heightened responses in the setting of clot formation, with corresponding, increased responses to agonists, adhesion, and retractile function. Unexpectedly, aged platelets lose their hemostatic proficiency but are more prone to react to inflammatory challenge: compared with reticulated platelets, this cohort was more likely to form platelet-leukocyte aggregates and showed increased adhesion to neutrophils in vitro, as well as enhanced bactericidal function. In vivo, this was reflected in increased pulmonary recruitment of aged platelets in an acute lung injury model. Proteomic analyses confirmed the upregulation of immune pathways in this cohort, including enhanced procoagulant function. In mouse models of prolonged platelet half-life, this resulted in increased pulmonary leukocyte infiltration and inflammation upon acute lung injury. Similarly, human platelet concentrates decreased their hemostatic function and elevated their putative immunomodulatory potential in vitro over time, and in a mouse model of platelet transfusion, aged platelet concentrates resulted in augmented inflammation. In summary, we show that platelets exhibit age-dependent phenotypic shifts, allowing them to fulfill their diverse tasks in the vasculature. Because functional alterations of aging platelets extend to platelet concentrates, this may hold important implications for transfusion medicine.

Association of Anaesthetists guidelines: the use of blood components and their alternatives

BACKGROUND

The administration of blood components and their alternatives can be lifesaving. Anaemia, bleeding and transfusion are all associated with poor peri-operative outcomes. Considerable changes in the approaches to optimal use of blood components and their alternatives, driven by the findings of large randomised controlled trials and improved haemovigilance, have become apparent over the past decade. The aim of these updated guidelines is to provide an evidence-based set of recommendations so that anaesthetists and peri-operative physicians might provide high-quality care.

METHODS

An expert multidisciplinary, multi-society working party conducted targeted literature reviews, followed by a three-round Delphi process to produce these guidelines.

RESULTS

We agreed on 12 key recommendations. Overall, these highlight the importance of organisational factors for safe transfusion and timely provision of blood components; the need for protocols that are targeted to different clinical contexts of major bleeding; and strategies to avoid the need for transfusion, minimise bleeding and manage anticoagulant therapy.

CONCLUSIONS

All anaesthetists involved in the care of patients at risk of major bleeding and peri-operative transfusion should be aware of the treatment options and approaches that are available to them. These contemporary guidelines aim to provide recommendations across a range of clinical situations.

Association between Platelet Count and Bleeding during Central Line Placement in Critically Ill Children

OBJECTIVE

To evaluate the association between platelet count and procedure-related bleeding at the time of central venous line (CVL) placement in critically ill children.

STUDY DESIGN

A retrospective cohort study was performed capturing patient admissions to the pediatric intensive care unit between January 1, 2012 to March 1, 2022. Critically ill children between 0 months and 19 years who underwent bedside CVL placement were included. A total of 363 were included in the final analysis.

RESULTS

Patients' platelet counts prior to line placement ranged from 11 000/uL to 735 000/uL. Bleeding was identified in 26 of 363 (7.2%) of patients, and was categorized as 24 (92%) minimal, 2 (8%) moderate, and none severe. Platelet count and platelet transfusion before line placement were both significantly different between bleeding and non-bleeding patients (P = .04 and P = .032). Patients with lower platelet counts had a higher proportion of bleeding events. There were no significant differences between the bleeding and non-bleeding groups in age, sex, history of bleeding, or number of attempts at CVL. Patients with bleeding were not significantly sicker. Regression analysis determined that female sex and transfusion before CVL placement were both significantly associated with bleeding.

CONCLUSIONS

We found that the platelet count prior to CVL placement was not associated with bleeding events in critically ill pediatric patients. Bleeding was more common in patients receiving platelet transfusions. Additional studies are needed to evaluate further the effect of platelet transfusions on procedure-related bleeding.

Forty-eight-hour cold-stored whole blood in paediatric cardiac surgery: Implications for haemostasis and blood donor exposures

BACKGROUND AND OBJECTIVES

Cold-stored whole blood (CS-WB) in paediatric cardiac surgery is making a resurgence, given its identified benefits compared to conventional blood component therapy (CT).

STUDY DESIGN AND METHODS

A single-centre retrospective study was conducted from January 2018 to October 2018 by including children <18 years of age undergoing cardiac surgery requiring cardiopulmonary bypass. ABO-compatible CS-WB from non-directed random donors was leukoreduced with platelet-sparing filters and compared with CT.

RESULTS

Fifty-seven patients (30, 53% CS-WB; 27, 47% CT) were studied. Patient demographics were similar, although CT patients were cooled to a lower intra-operative temperature. Blood product requirements 24 h post operation were less in the CS-WB group (11.1 vs. 26.7 mL/kg, p = 0.048). Twelve (40%) patients in the CS-WB cohort had more than one donor exposure versus 25 (93%) in the CT group (p < 0.001). CT patients compared to CS-WB patients had a greater decrease in pre-operative versus 48-h post-operative haemoglobin, platelets and prothrombin time. Patients who received CT compared to CS-WB had a trend towards higher median (interquartile range [IQR]) chest-tube output (mL/kg/h) in the first 4 h post cardiac intensive care unit (ICU) admission (2.1 [0.8, 3] vs. 1.6 [0.8, 2.2], p = 0.197). There was no difference in antifibrinolytic use, length of stay, sepsis, acute kidney injury or wound infection. Survival to discharge was similar.

CONCLUSION

CS-WB in paediatric cardiac surgery may reduce donor exposure and improve haemostatic balance. Future multi-centre prospective studies are needed to validate these findings and identify patients who would benefit from CS-WB in paediatric cardiac surgery.

Cord blood for autologous transfusion in infants with congenital anomalies: Volumes, sterility, and stability during storage

BACKGROUND

Neonates with congenital anomalies frequently require perioperative allogeneic red blood cell (RBC) transfusion. Whole cord blood for autologous transfusion to neonates may provide an alternative RBC source, but whether sufficient volumes can be collected after delayed cord clamping to reduce allogeneic RBC requirements is unknown.

STUDY DESIGN AND METHODS

Inclusion criteria were mothers delivering a viable infant >34 weeks' gestation. Sterile cord blood collection from the umbilical cord was performed at delivery as per routine obstetric indications. During storage at 4°C, we performed weekly blood gases. Blood culture, complete blood count, and hemolysis tests were performed at baseline and day 21. We compared the whole cord blood volume collected with each infant's allogeneic transfusion requirements.

RESULTS

54 collection attempts yielded 49 collections with a mean volume of 54.1 mL (±20.3) after median delayed cord clamping of 46 seconds (IQR 12.0, 60.0). Among 39 blood cultures obtained, 3 grew organisms after vaginal delivery (3/27, 11.0% vs. 0/12, 0% cesarean delivery, p = .54). Hemolysis was stable during storage (baseline vs. day 21, median [IQR], 0.7% [0.4%-0.9%] vs. 0.7% [0.6%-1.1%], p = .08).

CONCLUSIONS

Whole cord blood collection following delayed cord clamping was feasible, with volumes equal to 16.7 mL/kg, or one transfusion. Hemolysis was low, and although potassium increased during storage, it was consistent with patterns observed with adult donor stored whole blood. There were no positive blood cultures from collections during cesarean deliveries. Studies are needed to determine whether whole cord blood transfusions improve patient outcomes.

Platelet transfusion and bleeding risk

In neonatal patients, bleeding is a multifactorial event in which several factors may play a pathogenic role. Among these, thrombocytopenia is often considered a risk factor for bleeding, although a causal relationship has never been demonstrated. In fact, major bleeding mainly occurs in non-thrombocytopenic newborns and thrombocytopenic newborns rarely experience major bleeding. Therefore, parameters other than platelet count might better assess the hemostatic function and define bleeding risk. Historically, neonatologists aimed to reduce the risk of bleeding by administering platelet transfusions. However, recent studies demonstrated that transfusing newborns at higher threshold is associated with an increased risk of death, bleeding, bronchopulmonary dysplasia and neurodevelopmental impairment. The mechanism behind this association is not known and various hypotheses have been proposed, including the non-hemostatic effects of adult-derived platelets transfused into neonates. Alternatively, the rapid volume expansion caused by a platelet transfusion might cause hemodynamic instability and cardiocirculatory overload. Guidelines about platelet transfusions should now include this recent evidence and adopt more stringent thresholds. Future research should focus on finding alternative or improved transfusion products more suitable for newborns.

Thrombocytopenia in the intensive care unit: diagnosis and management

BACKGROUND

This narrative review aims to describe the epidemiology and aetiologies of thrombocytopenia in critically ill patients, the bleeding risk assessment in thrombocytopenic patients, and provide an update on platelet transfusion indications.

RESULTS

Thrombocytopenia is a common disorder in critically ill patients. The classic definition relies on an absolute platelet count below 150 × 109/L. Alternatively, the definition has extended to a relative decrease in platelet count (typically within a range of >30->50% decrease) from baseline, yet remaining above 150 × 109/L. Thrombocytopenia may result from multiple mechanisms depending upon the underlying conditions and the current clinical setting. Regardless of the causes, thrombocytopenia accounts as an independent determinant of poor outcomes in critically ill patients, albeit often of unclear interpretation. Nevertheless, it is well established that thrombocytopenia is associated with an increased incidence of bleeding complications. However, alternative factors also contribute to the risk of bleeding, making it difficult to establish definite links between nadir platelet counts at the expense of potential adverse events. Platelet transfusion represents the primary supportive treatment of thrombocytopenia to prevent or treat bleeding. As randomised controlled trials comparing different platelet count thresholds for prophylactic platelet transfusion in the ICU are lacking, the prophylactic transfusion strategy is largely derived from studies performed in stable haematology patients. Similarly, the platelet count transfusion threshold to secure invasive procedures remains based on a low level of evidence. Indications of platelet transfusions for the treatment of severe bleeding in thrombocytopenic patients remain largely empirical, with platelet count thresholds ranging from 50 to 100 × 109/L. In addition, early and aggressive platelet transfusion is part of massive transfusion protocols in the setting of severe trauma-related haemorrhage.

CONCLUSION

Thrombocytopenia in critically ill patients is very frequent with various etiologies, and is associated with worsened prognosis, with or without bleeding complications. Interventional trials focused on critically ill patients are eagerly needed to better delineate the benefits and harms of platelet transfusions.

Most major bleeds in preterm infants occur in the absence of severe thrombocytopenia: an observational cohort study

OBJECTIVE

To describe the incidence of major bleeds according to different platelet counts in very preterm infants, and to explore whether this association is influenced by other risk factors for bleeding.

DESIGN

Observational cohort study.

SETTING

A Dutch tertiary care neonatal intensive care unit.

PATIENTS

All consecutive infants with a gestational age at birth <32 weeks admitted between January 2004 and July 2022.

EXPOSURE

Infants were stratified into nine groups based on their nadir platelet count (×109/L) during admission (<10, 10-24, 25-49, 50-99, 100-149, 150-199, 200-249, 250-299 and ≥300), measured before the diagnosis of a major bleed and before any platelet transfusion was administered.

MAIN OUTCOME MEASURE

Incidence of major bleeds during admission. Logistic regression analysis was used to quantify the relationship between nadir platelet count and incidence of major bleeds.

RESULTS

Among 2772 included infants, 224 (8%) developed a major bleed. Of the infants with a major bleed, 92% (206/224) had a nadir platelet count ≥50×109/L. The incidence of major bleeds was 8% among infants with and without severe thrombocytopenia (platelet count <50×109/L), 18/231 (95% CI 5 to 12) and 206/2541 (95% CI 7 to 9), respectively. Similarly, after adjustment for measured confounders, there was no notable association between nadir platelet counts below versus above 50×109/L and the occurrence of major bleeds (OR 1.09, 95% CI 0.61 to 1.94).

CONCLUSION

In very preterm infants, the vast majority of major bleeds occur in infants without severe thrombocytopenia.

Identifying barriers to complying with new restrictive NICU transfusion guidelines

OBJECTIVES

Our NICU transfusion stewardship group proposed new, more restrictive guidelines for red blood cell and platelet transfusions. To evaluate our clinician's support for these, we conducted a series of structured interviews.

STUDY DESIGN

We presented 11 scenarios involving the new guidelines to each of 24 clinicians. After every scenario we asked whether they would abide by the guideline, and if not, why.

RESULTS

For 88% of scenarios, participants said they supported the guideline and would not transfuse. The most common reasons for wanting to transfuse when the guidelines said not to were; 1) the scenario-patient did not meet the guideline but was "close" and 2) the guideline was insufficiently explicit.

CONCLUSIONS

Structured interviews like these can identify barriers to complying with transfusion guidelines and can suggest guideline modifications. Future studies will determine the effect of this discovery process on guideline adherence and patient outcomes.

The number of blood transfusions received and the incidence and severity of chronic lung disease among NICU patients born >31 weeks gestation

OBJECTIVE

We previously reported the possible pathogenic role, among infants born ≤29 weeks, of transfusions in bronchopulmonary dysplasia. The present study examined this association in infants born >31 weeks.

STUDY DESIGN

Analysis of red blood cell (RBC) and platelet transfusions in five NICUs to infants born >31 weeks, and chronic neonatal lung disease (CNLD) at six-weeks of age.

RESULTS

Seven-hundred-fifty-one infants born >31 weeks were still in the NICU when six-weeks of age. CNLD was identified in 397 (53%). RBC and platelet transfusions were independently associated with CNLD after controlling for potential confounders. For every transfusion, the adjusted odds of developing CNLD increased by a factor of 1.64 (95% CI, 1.38-2.02; p < 0.001).

CONCLUSIONS

Among NICU patients born >31 weeks, transfusions received by six weeks are associated with CNLD incidence and severity. Though we controlled for known confounding variables in our regression models, severity of illness is an important confounder that limits our conclusions.

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.

Platelet transfusion

PURPOSE OF REVIEW

Platelet transfusions, used as prophylaxis or treatment for bleeding, are potentially life-saving. In many countries, demand for platelet transfusion is rising. Platelets are a limited and costly resource, and it is vital that they are used appropriately. This study will explore the evidence behind platelet transfusions in different contexts, in particular recent and important research in this area.

RECENT FINDINGS

Recent randomized clinical trials demonstrate the efficacy of platelet transfusions in some contexts but potential detrimental effects in others. Platelet transfusions also carry risk of transfusion reactions, bacterial contamination and platelet transfusion refractoriness. Observational and clinical studies, which highlight approaches to mitigate these risks, will be discussed. There is growing interest in cold-stored or cryopreserved platelet units, which may improve platelet function and availability. Clinical trials also highlight the efficacy of other supportive measures such as tranexamic acid or thrombopoietin receptor agonists in patients with bleeding.

SUMMARY

Although platelet transfusions are beneficial in many patients, there remain many settings in which the optimal use of platelet transfusions is unclear, and some situations in which they may have detrimental effects. Future clinical trials are needed to determine optimal use of platelet transfusions in different patient populations.

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.

[The current situation and the future of pediatric blood transfusion]

With advancements in clinical medicine, pediatric blood transfusion has evolved from traditional empirical practices to evidence-based approaches grounded in clinical research data. To better guide pediatric blood transfusion practices and improve clinical outcomes for pediatric patients, the National Health Commission has developed and issued "Guideline for pediatric transfusion". This article summarizes the unique aspects of pediatric blood transfusion, the application of blood component therapy in treating pediatric patients, the significance of interpreting the "Guideline for pediatric transfusion", and anticipates future developments in pediatric blood transfusion medicine.

[Explanation and interpretation of the compilation of neonatal blood transfusion in the national health standard "Guideline for pediatric transfusion"]

In order to guide clinical blood transfusion practices for pediatric patients, the National Health Commission has released the health standard "Guideline for pediatric transfusion" (WS/T 795-2022). Considering the physiological particularities of the neonatal period, blood transfusion practices for neonates are more complex than those for other children, the guidelines include a separate chapter dedicated to neonatal blood transfusion. This paper interprets the background and evidence for the compilation of the neonatal blood transfusion provisions, hoping to aid in the understanding and implementation of the neonatal blood transfusion section of the guidelines.

Platelet transfusion in neonatal intensive care units of 22 European countries: a prospective observational study

Background

Platelet transfusions are given to preterm infants with severe thrombocytopenia aiming to prevent haemorrhage. The PlaNeT2/MATISSE trial revealed higher rates of mortality and/or major bleeding in preterm infants receiving prophylactic platelet transfusions at a platelet count threshold of 50 × 109/L compared to 25 × 109/L. The extent to which this evidence has been incorporated into clinical practice is unknown, thus we aimed to describe current neonatal platelet transfusion practices in Europe.

Methods

We performed a prospective observational study in 64 neonatal intensive care units across 22 European countries between September 2022 and August 2023. Outcome measures included observed transfusion prevalence rates (per country and overall, pooled using a random effects Poisson model), expected rates based on patient-mix (per country, estimated using logistic regression), cumulative incidence of receiving a transfusion by day 28 (with death and discharge considered as competing events), transfusion indications, volumes and infusion rates, platelet count triggers and increment, and adverse effects.

Findings

We included 1143 preterm infants, of whom 71 (6.2%, [71/1143]) collectively received 217 transfusions. Overall observed prevalence rate was 0.3 platelet transfusion days per 100 admission days. By day 28, 8.3% (95% CI: 5.5-11.1) of infants received a transfusion. Most transfusions were indicated for threshold (74.2%, [161/217]). Pre-transfusion platelet counts were above 25 × 109/L in 33.1% [53/160] of these transfusions. There was significant variability in volume and duration.

Interpretation

The restrictive threshold of 25 × 109/L is being integrated into clinical practice. Research is needed to explore existing variation and generate evidence for various aspects including optimal volumes and infusion rates.

Funding

Sanquin, EBA, and ESPR.

A Finnish nationwide register-based study shows a further 50% decline in already low child mortality

AIM

Child mortality declined significantly in Finland in 1969-2004. We investigated whether the already low mortality rate could still decline from 2005 to 2020.

METHODS

This was a nationwide register-based study. The subjects were children under 16 years of age who had resided in Finland between 2005 and 2020. The study population was identified from Finland's Population Information System of the Digital and Population Data Services Agency. Causes of death were obtained from Statistics Finland. Changes in annual overall and cause-specific mortality rates were evaluated.

RESULTS

3685 children (55% boys) under 16 years of age died in Finland in 2005-2020 from 325 causes. Overall annual child mortality declined by 50% (95% confidence interval 37 to 64%) during the study period, from 0.31/1000 in 2005 to 0.16/1000 in 2020. The mortality rate in children under one year of age declined from 3.1/1000 in 2005 to 1.8/1000 in 2020. The deaths from sudden infant death syndrome fell by 84%, congenital malformations by 62%, infectious diseases by 60%, external causes by 52%, and perinatal disorders by 41%.

CONCLUSION

Finland's low child mortality further declined over the past two decades. Contributing factors likely include achievements in paediatric research, public health, and clinical practice.

If things were simple, word would have gotten around. Can complexity science help us improve pediatric research?

Complexity science is a discipline which explores how complex systems behave and how we interact with them. Though it is widely implemented outside medicine, particularly in the sciences involving human behavior, but also in the natural sciences such as physics and biology, there are only a few applications within medical research. We propose that complexity science can provide new and helpful perspectives on complex pediatric medical problems. It can help us better understand complex systems and develop ways to cope with their inherent unpredictabilities. In this article, we provide a brief introduction of complexity science, explore why many medical problems can be considered 'complex', and discuss how we can apply this perspective to pediatric research. IMPACT: Current methods in pediatric research often focus on single mechanisms or interventions instead of systems, and tend to simplify complexity. This may not be appropriate. Complexity science provides a framework and a toolbox to better address complex problems. This review provides a starting point for the application of complexity science in pediatric research.

Approach to neonatal thrombocytopenia

A low platelet count (thrombocytopenia) is a common finding especially in neonates who are admitted to the neonatal intensive care unit. Due to the varied causes that can lead to neonatal thrombocytopenia, assessment and management can be challenging. Having an understanding of the causes of neonatal thrombocytopenia and their natural progression would help guide subsequent management. Therefore, we will be exploring the different circumstances where thrombocytopenia occurs and how to interpret and manage the neonate with thrombocytopenia in this interpretations article.

Lowering platelet-count threshold for transfusion in preterm neonates decreases the number of transfusions without increasing severe hemorrhage events

Thrombocytopenia is common in preterm neonates and can be associated with hemorrhage. Most platelet transfusions are prophylactic. Previously, higher platelet-count thresholds were recommended for neonates, but this recommendation has been questioned in recent studies. In the PlaNeT2 trial, mortality and serious bleeding were more frequent in neonates with the highest platelet-count threshold than in others. Following this trial, we changed our platelet transfusion practice by lowering the platelet-count threshold for prophylactic transfusion from 50,000 to 25,000/mm3. We conducted a before-after retrospective cohort study to quantify the frequency of platelet transfusions and assess the new protocol by analyzing death and serious hemorrhage events. This retrospective monocentric study included neonates born before 37 weeks of gestation with platelet count < 150,000/mm3 during the 2 years preceding the new platelet transfusion protocol (high prophylactic transfusion threshold, 50,000/mm3) and during the 2 years after the new platelet transfusion protocol (low prophylactic transfusion threshold, 25,000/mm3). The primary outcome was the proportion of neonates receiving at least one platelet transfusion in both groups. We also compared the proportion of deaths and severe hemorrhage events. A total of 707 neonates with thrombocytopenia were identified. In the high-threshold group, 99/360 (27.5%) received at least one platelet transfusion as compared with 56/347 (16.1%) in the low-threshold group (p < 0.001). The groups did not differ in proportion of deaths or severe hemorrhage events.

CONCLUSIONS

A reduced platelet-count threshold for transfusion allowed for a significant reduction in the number of platelet transfusions without increasing severe hemorrhage events.

WHAT IS KNOWN

• A recent randomized trial suggested that restrictive platelet-count thresholds for platelet transfusion could be beneficial for preterm neonates.

WHAT IS NEW

• On lowering the platelet-count threshold for transfusion from 50,000 to 25,000/mm3, the number of transfusions significantly decreased without increasing severe hemorrhage events in a neonatal intensive care unit.

Storage properties of platelet concentrates from umbilical cord blood prepared using three different methods

BACKGROUND

Thrombocytopenia, common in preterm newborns, may increase bleeding risk and is often treated with transfusions. Recent studies reveal that transfusing platelets at a high threshold worsens outcomes, possibly due to a "developmental mismatch" between adult-derived platelets and neonatal hemostatic system. Cord blood-derived platelet concentrates (CBPCs) could be an alternative for newborns. Our study aims to produce and evaluate the quality parameters of CBPCs during storage.

STUDY DESIGN AND METHODS

Cord blood was collected from placentas after near-term and full-term pregnancies. Several production methods were attempted to obtain CBPCs, varying centrifugation settings, filtration, and dilution procedures. Adult-derived platelet concentrates (PCs) processed with the same methods, and standard PCs from five buffy-coats were used as controls. Storage tests were performed on days 2, 4-5, 7 from the collection.

RESULTS

CBPCs parameters were compared with adult-derived PCs, and no significant differences were found for mean platelet volume (MPV), swirling, morphology, glucose, lactate, pCO2, and pO2. pH and bicarbonate were lower in CBPCs. Some significant differences between methods in CD62P expression and JC-1 ratio were observed. Compared with standard PCs, CBPCs showed lower platelet concentration, pH, and JC-1. Additionally, both in CBPCs as well as in control PCs, the apoptosis marker phosphatidylserine was elevated.

DISCUSSION

CBPCs were of comparable quality to control PCs during storage. However, apoptosis markers in both groups were elevated, suggesting processing and storage of low volumes of PCs require further optimization. Also, filtration of low volumes leads to significant platelet loss, an issue that requires remedy.

Blood product transfusion practices in neonates with hypoxic-ischemic encephalopathy

OBJECTIVE

Blood product transfusion is a common practice in infants with hypoxic-ischemic encephalopathy (HIE) undoing therapeutic hypothermia (TH). The advantages and disadvantages of conservative or liberal transfusion practices in this fragile population are unknown. Study aims to characterize the transfusion practices in infants with HIE and investigate the association with outcome.

STUDY DESIGN

We conducted a retrospective cohort study at a single level IV NICU, evaluating transfusion thresholds, as well as the association between hematological abnormalities or blood product transfusions and outcomes in infants admitted with HIE.

RESULT

By univariate analysis, FFP transfusion was associated with increased in-hospital death. However, multivariate analysis adjusting for HIE severity demonstrated no association between hematological abnormality or blood product transfusion and death, nor with neurodevelopmental impairment.

CONCLUSION

No association was found between hematological blood product transfusion and death or neurodevelopmental impairment in a retrospective single NICU study of infants with HIE.

Implementing evidence-based restrictive neonatal intensive care unit platelet transfusion guidelines

Platelet transfusions are life-saving treatments for specific populations of neonates. However, recent evidence indicates that liberal prophylactic platelet transfusion practices cause harm to premature neonates. New efforts to better balance benefits and risks are leading to the adoption of more restrictive platelet transfusion guidelines in neonatal intensive care units (NICU). Although restrictive guidelines have the potential to improve outcomes, implementation barriers exist. We postulate that as neonatologists become more familiar with the data on the harm of liberal platelet transfusions, enthusiasm for restrictive guidelines will increase and barriers to implementation will decrease. Thus, we focused this educational review on; (1) the adverse effects of platelet transfusions to neonates, (2) awareness of platelet transfusion "refractoriness" in thrombocytopenic neonates and its association with poor outcomes, and (3) the impetus to find alternatives to transfusing platelets from adult donors to NICU patients.

Platelet transfusions in adult ICU patients with thrombocytopenia: A sub-study of the PLOT-ICU inception cohort study

BACKGROUND

Platelet transfusions are frequently used in the intensive care unit (ICU), but current practices including used product types, volumes, doses and effects are unknown.

STUDY DESIGN AND METHODS

Sub-study of the inception cohort study 'Thrombocytopenia and Platelet Transfusions in the ICU (PLOT-ICU)', including acutely admitted, adult ICU patients with thrombocytopenia (platelet count <150 × 109/L). The primary outcome was the number of patients receiving platelet transfusion in ICU by product type. Secondary outcomes included platelet transfusion details, platelet increments, bleeding, other transfusions and mortality.

RESULTS

Amongst 504 patients with thrombocytopenia from 43 hospitals in 10 countries in Europe and the United States, 20.8% received 565 platelet transfusions; 61.0% received pooled products, 21.9% received apheresis products and 17.1% received both with a median of 2 (interquartile range 1-4) days from admission to first transfusion. The median volume per transfusion was 253 mL (180-308 mL) and pooled products accounted for 59.1% of transfusions, however, this varied across countries. Most centres (73.8%) used fixed dosing (medians ranging from 2.0 to 3.5 × 1011 platelets/transfusion) whilst some (mainly in France) used weight-based dosing (ranging from 0.5 to 0.7 × 1011 platelets per 10 kg body weight). The median platelet count increment for a single prophylactic platelet transfusion was 2 (-1 to 8) × 109/L. Outcomes of patients with thrombocytopenia who did and did not receive platelet transfusions varied.

CONCLUSIONS

Among acutely admitted, adult ICU patients with thrombocytopenia, 20.8% received platelet transfusions in ICU of whom most received pooled products, but considerable variation was observed in product type, volumes and doses across countries. Prophylactic platelet transfusions were associated with limited increases in platelet counts.

Diagnosis and Management of Neonatal Bacterial Sepsis: Current Challenges and Future Perspectives

Sepsis remains the second cause of death among neonates after the pathological consequences of extreme prematurity. In this review we summarized knowledge about pathogens causing early-onset sepsis (EOS) and late-onset sepsis (LOS), the role of perinatal risk factors in determining the EOS risk, and the tools used to reduce unnecessary antibiotics. New molecular assays could improve the accuracy of standard blood cultures, providing the opportunity for a quick and sensitive tool. Different sepsis criteria and biomarkers are available to date, but further research is needed to guide the use of antibiotics according to these tools. Beyond the historical antibiotic regimens in EOS and LOS episodes, antibiotics should be based on the local flora and promptly modulated if specific pathogens are identified. The possibility of an antibiotic lock therapy for central venous catheters should be further investigated. In the near future, artificial intelligence could help us to personalize treatments and reduce the increasing trend of multidrug-resistant bacteria.

Impact of restrictive platelet transfusion strategies on transfusion rates: A cohort study in very preterm infants

BACKGROUND

Evidence supports a restrictive platelet transfusion threshold in preterm neonates. We aimed to describe the effect of implementing this threshold on transfusion rates.

STUDY DESIGN AND METHODS

This retrospective observational cohort study included all very preterm infants (born <32 weeks' gestation) admitted to a neonatal intensive care unit between 2004 and 2022, divided into three epochs. Platelet transfusion thresholds changed from 30 × 109/L for stable neonates and 50 × 109/L for unstable neonates (January 2004 to December 2009) to 20 × 109/L for stable neonates and 50 × 109/L for unstable neonates (January 2010 to June 2019) to 25 × 109/L for non-bleeding neonates and 50 × 109/L for neonates with major bleeding (July 2019 to July 2022). The primary outcome was the percentage of transfused neonates in each epoch. Secondary outcomes included the median number of transfusions per neonate, the percentage of transfusions given above 25 or 50 × 109/L, and major bleeding and mortality rates.

RESULTS

The percentage of neonates transfused was 12.2% (115/939), 5.8% (96/1660), and 4.8% (25/525) in Epoch I, II, and III, respectively (p < .001), a relative reduction of 61%. The median number of transfusions per transfused neonate was 2.0 (interquartile range [IQR]: 1.0-3.0) in Epoch I, and 1.0 (IQR: 1.0-2.0) in subsequent Epochs (p = .04). The percentage of infants receiving at least one transfusion above 50 × 109/L in Epoch I, II, and III was 51.3% (59/115), 17.7% (17/96), and 20.0% (5/25; p < .001). Mortality and bleeding rates did not significantly differ between epochs.

DISCUSSION

Implementation of restrictive platelet guidelines led to reduction of the rate and number of platelet transfusions.

Judicious Transfusion of Platelets Among Neonates: A Systematic Review

In newborns, especially premature babies, there is a high association between thrombocytopenia and bleeding, particularly intraventricular hemorrhage, which may be due to immaturity. It was usual clinical practice that neonates should be transfused with higher platelet counts than older children or adults to reduce their risk of bleeding. However, after keen observations, we noticed that bleeding and mortality were more common in newborns who received more platelet transfusions. The mechanisms underlying the adverse effects of platelet transfusions in neonates may be due to higher antigenicity and immunological factors. We know that neonatal platelets are hyporeactive; this hyporeactivity is balanced by factors in the neonatal blood that promote coagulation, such as increased hematocrit, von Willebrand factor, and fibrinogen, which, on balance, leads to normal primary neonatal hemostasis. Platelets are very similar to adults in number, but functional capabilities were less, and for the reasons mentioned above, particularly bleeding time was short. Theologically, neonatal platelet lifespan was high to compensate for less production. We started this review because we observed that many babies were not having bleeding symptoms in some instances of severe thrombocytopenia. Many well-active babies are receiving unnecessary transfusions, as human blood is precious, and many young neonatologists are going on protocol-based excessive transfusions. This stimulated us to write a review.

Prophylactic Transfusion Strategies in Children Supported by Extracorporeal Membrane Oxygenation: The Pediatric Extracorporeal Membrane Oxygenation Anticoagulation CollaborativE Consensus Conference

OBJECTIVES

To derive systematic-review informed, modified Delphi consensus regarding prophylactic transfusions in neonates and children supported with extracorporeal membrane oxygenation (ECMO) from the Pediatric ECMO Anticoagulation CollaborativE.

DATA SOURCES

A structured literature search was performed using PubMed, EMBASE, and Cochrane Library (CENTRAL) databases from January 1988 to May 2020, with an update in May 2021.

STUDY SELECTION

Included studies assessed use of prophylactic blood product transfusion in pediatric ECMO.

DATA EXTRACTION

Two authors reviewed all citations independently, with a third independent reviewer resolving conflicts. Thirty-three references were used for data extraction and informed recommendations. Evidence tables were constructed using a standardized data extraction form.

MEASUREMENTS AND MAIN RESULTS

The evidence was evaluated using the Grading of Recommendations Assessment, Development and Evaluation system. Forty-eight experts met over 2 years to develop evidence-informed recommendations and, when evidence was lacking, expert-based consensus statements or good practice statements for prophylactic transfusion strategies for children supported with ECMO. A web-based modified Delphi process was used to build consensus via the Research And Development/University of California Appropriateness Method. Consensus was based on a modified Delphi process with agreement defined as greater than 80%. We developed two good practice statements, 4 weak recommendations, and three expert consensus statements.

CONCLUSIONS

Despite the frequency with which pediatric ECMO patients are transfused, there is insufficient evidence to formulate evidence-based prophylactic transfusion strategies.

Prevention of Inflammatory Disorders in the Preterm Neonate: An Update with a Special Focus on Bronchopulmonary Dysplasia

BACKGROUND

The rates of major neonatal morbidities, such as bronchopulmonary dysplasia, necrotizing enterocolitis, preterm white matter disease, and retinopathy of prematurity, remain high among surviving preterm infants. Exposure to inflammatory stimuli and the subsequent host innate immune response contribute to the risk of developing these complications of prematurity. Notably, the burden of inflammation and associated neonatal morbidity is inversely related to gestational age - leaving primarily but not exclusively the tiniest babies at highest risk.

SUMMARY

Avoidance, prevention, and treatment of inflammation to reduce this burden remain a major goal for neonatologists worldwide. In this review, we discuss the link between the host response to inflammatory stimuli and the disease state. We argue that inflammatory exposures play a key role in the pathobiology of preterm birth and that preterm neonates hereafter are highly susceptible to immune stimulation not only from their surrounding environment but also from therapeutic interventions employed in clinical care. Using bronchopulmonary dysplasia as an example, we report clinical studies demonstrating the potential utility of targeting inflammation to prevent this neonatal morbidity. On the contrary, we highlight limitations in our current understanding of how inflammation contributes to disease prevention and treatment.

KEY MESSAGE

To be successful in preventing and treating inflammation-driven morbidity in neonatal intensive care, it may be necessary to better identify at-risk patients and pair therapeutic interventions to key pathways and mediators of inflammation-associated neonatal morbidity identified in pre-clinical and translational studies.

Clinical Practice Guideline for Red Blood Cell Transfusion Thresholds in Very Preterm Neonates

Importance

Red blood cell (RBC) transfusion is a common medical intervention to treat anemia in very preterm neonates; however, best transfusion practices, such as thresholds, remain uncertain.

Objective

To develop recommendations for clinicians on the use of RBC transfusions in very preterm neonates.

Evidence Review

An international steering committee reviewed evidence from a systematic review of 6 randomized clinical trials (RCTs) that compared high vs low hemoglobin-based or hematocrit-based transfusion thresholds. The steering committee reached consensus on certainty-of-evidence ratings and worked with a panel from stakeholder organizations on reviewing the evidence. With input from parent representatives and the stakeholder panel, the steering committee used the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach to develop recommendations.

Findings

A systematic review of 6 RCTs encompassing 3483 participants (1759 females [51.3%]; mean [SD] age range, 25.9-29.8 [1.5-3.0] weeks) was used as the basis of the recommendations. The ranges for higher hemoglobin concentration (liberal) vs lower hemoglobin concentration (restrictive) threshold study arms were similar across the trials. However, specific thresholds differed based on the severity of illness, which was defined using variable criteria in the trials. There was moderate certainty of evidence that low transfusion thresholds likely had little to no difference in important short-term and long-term outcomes. The recommended hemoglobin thresholds varied on the basis of postnatal week and respiratory support needs. At postnatal weeks 1, 2, and 3 or more, for neonates on respiratory support, the recommended thresholds were 11, 10, and 9 g/dL, respectively; for neonates on no or minimal respiratory support, the recommended thresholds were 10, 8.5, and 7 g/dL, respectively (to convert hemoglobin to grams per liter, multiply by 10.0).

Conclusions and Relevance

This consensus statement recommends a restrictive RBC transfusion strategy, with moderate certainty of evidence, for preterm neonates with less than 30 weeks' gestation.

Bleeding Scoring Systems in Neonates: A Systematic Review

We conducted a systematic review aiming to summarize the data on the current hemorrhage prediction models and evaluate their potential for generalized application in the neonatal population. The electronic databases PubMed and Scopus were searched, up to September 20, 2023, for studies that focused on development and/or validation of a prediction model for bleeding risk in neonates, and described the process of model building. Nineteen studies fulfilled the inclusion criteria for the present review. Eighteen bleeding risk prediction models in the neonatal population were identified, four of which were internally validated, one temporally and one externally validated. The existing prediction models for neonatal hemorrhage are mostly based on clinical variables and do not take into account the clinical course and hemostatic profile of the neonates. Most studies aimed at predicting the risk of intraventricular hemorrhage (IVH) reflecting the fact that IVH is the most frequent and serious bleeding complication in preterm neonates. A justification for the study sample size for developing the prediction model was given only by one study. Prediction and stratification of risk of hemorrhage in neonates is yet to be optimized. To this end, qualitative standards for model development need to be further improved. The assessment of the risk of bleeding incorporating platelet count, coagulation parameters, and a set of relevant clinical variables is crucial. Large, rigorous, collaborative cohort studies are warranted to develop a robust prediction model to inform the need for transfusion, which is a fundamental step towards personalized transfusion therapy in neonates.

Platelet dysfunction reversal with cold-stored vs room temperature-stored platelet transfusions

ABSTRACT

Platelets are stored at room temperature for 5 to 7 days (room temperature-stored platelets [RSPs]). Because of frequent and severe shortages, the US Food and Drug Administration recently approved up to 14-day cold-stored platelets (CSPs) in plasma. However, the posttransfusion function of CSPs is unknown and it is unclear which donors are best suited to provide either RSPs or CSPs. In this study, we sought to evaluate the posttransfusion platelet function and its predictors for platelets stored for the maximum approved storage times (7-day RSPs and 14-day CSPs) in healthy volunteers on acetylsalicylic acid (ASA). We conducted a randomized crossover study in 10 healthy humans. Individuals donated 1 platelet unit, stored at either 22°C or 4°C based on randomization. Before transfusion, participants ingested ASA to inhibit endogenous platelets. Transfusion recipients were tested for platelet function and lipid mediators. Platelet units were tested for lipid mediators only. A second round of transfusion with the alternative product was followed by an identical testing sequence. RSPs reversed platelet inhibition significantly better in αIIbβ3 integrin activation-dependent assays. In contrast, CSPs in recipients led to significantly more thrombin generation, which was independent of platelet microparticles. Lysophosphatidylcholine-O species levels predicted the procoagulant capacity of CSPs. In contrast, polyunsaturated fatty acid concentrations predicted the aggregation response of RSPs. In summary, we provide, to our knowledge, the first efficacy data of extended-stored CSPs in plasma. Our results suggest that identifying ideal RSP and CSP donors is possible, and pave the way for larger studies in the future. This trial is registered at www.ClinicalTrials.gov as #NCT0511102.

Platelets: Orchestrators of immunity in host defense and beyond

Platelets prevent blood loss during vascular injury and contribute to thrombus formation in cardiovascular disease. Beyond these classical roles, platelets are critical for the host immune response. They guard the vasculature against pathogens via specialized receptors, intracellular signaling cascades, and effector functions. Platelets also skew inflammatory responses by instructing innate immune cells, support adaptive immunosurveillance, and influence antibody production and T cell polarization. Concomitantly, platelets contribute to tissue reconstitution and maintain vascular function after inflammatory challenges. However, dysregulated activation of these multitalented cells exacerbates immunopathology with ensuing microvascular clotting, excessive inflammation, and elevated risk of macrovascular thrombosis. This dichotomy underscores the critical importance of precisely defining and potentially modulating platelet function in immunity.

Neonatal Intensive Care Unit Patients Receiving More Than 25 Platelet Transfusions

OBJECTIVE

A few patients in neonatal intensive care units (NICU) receive numerous platelet transfusions. These patients can become refractory, defined as transfusions of ≥10 mL/kg failing to increase the platelet count by at least 5,000/µL. Causes of, and best treatments for, platelet transfusion refractoriness in neonates have not been defined.

STUDY DESIGN

Multi-NICU multiyear retrospective analysis of neonates receiving >25 platelet transfusions.

RESULTS

Eight neonates received 29 to 52 platelet transfusions. All eight were blood group O. Five had sepsis, four were very small for gestational age, four had bowel resections, two Noonan syndrome, two had cytomegalovirus infection. All eight had some (19-73%) refractory transfusions. Many (2-69%) of the transfusions were ordered when the platelet count was >50,000/µL. Higher posttransfusion counts occurred after ABO-identical transfusions (p = 0.026). Three of the eight had late NICU deaths related to respiratory failure; all five survivors had severe bronchopulmonary dysplasia requiring tracheostomy for prolonged ventilator management.

CONCLUSION

Neonates who are high users of platelet transfusions appear to be at high risk for poor outcomes, especially respiratory failure. Future studies will examine whether group O neonates are more likely to develop refractoriness and whether certain neonates would have a higher magnitude of posttransfusion rise if they received ABO-identical donor platelets.

KEY POINTS

· Many of the platelet transfusions given in the NICU are given to a small subset of patients.. · Refractoriness to platelet transfusions is common among these very high recipients.. · Neonates who are high users of platelet transfusions appear to be at high risk for poor outcomes..

Increased platelet to red blood cell transfusion ratio associated with acute kidney injury in children with life-threatening bleeding

INTRODUCTION

Transfusion may increase the risk of organ failure through immunomodulatory effects. The primary objective of this study was to assess for patient or transfusion-related factors that are independently associated with the risk of acute kidney injury (AKI) and acute respiratory distress syndrome (ARDS) in a cohort of children with life-threatening bleeding from all etiologies.

METHODS

In a secondary analysis of the prospective observational massive transfusion in children (MATIC) study, multivariable logistic regression was performed in an adjusted analysis to determine if blood product ratios or deficits were independently associated with AKI or ARDS in children with life-threatening bleeding.

RESULTS

There were 449 children included with a median (interquartile range, IQR) age of 7.3 years (1.7-14.7). Within 5 days of the life-threatening bleeding event, AKI occurred in 18.5% and ARDS occurred in 20.3% of the subjects. Every 10% increase in the platelet to red blood cell transfusion ratio is independently associated with a 12.7% increase in the odds of AKI (adjusted odds ratio 1.127; 95% confidence interval 1.025-1.239; p-value .013). Subjects with operative or medical etiologies were independently associated with an increased risk of AKI compared to those with traumatic injury. No transfusion-related variables were independently associated with the risk of developing ARDS.

CONCLUSION

The use of increased platelet to red blood cell transfusion ratios in children with life-threatening bleeding of any etiology may increase the risk of AKI but not ARDS. Prospective trials are needed to determine if increased platelet use in this cohort increases the risk of AKI to examine possible mechanisms.

Assessment of hemostatic profile in neonates with necrotizing enterocolitis using Rotational Thromboelastometry (ROTEM)

BACKGROUND

This study aimed to explore the hemostatic profile of neonates with necrotizing enterocolitis (NEC) using Rotational Thromboelastometry (ROTEM) and to investigate if ROTEM parameters have the capacity to play a role in the differentiation of NEC from sepsis at the disease onset.

METHODS

This observational study included 62 neonates (mean gestational age 31.6 weeks and mean birth weight 1620g) hospitalized in a neonatal intensive care unit. The neonates were categorized in three groups: neonates with NEC (Bell stage II and above), neonates with sepsis and healthy neonates and they were matched 1:1:1 with regards to gestational age, delivery mode, and sex. Clinical, laboratory data as well as measurements of ROTEM parameters at disease onset were recorded.

RESULTS

ROTEM parameters differed between neonates with NEC and neonates with sepsis, indicating that NEC results in accelerated clot formation and higher clot strength compared to sepsis. The EXTEM CFT and A10 parameters demonstrated the highest diagnostic performance for NEC in terms of discrimination between NEC and sepsis (AUC, 0.997; 95% CI: 0.991-1.000 and 0.973; 95% CI: 0.932-1.000, respectively).

CONCLUSIONS

Neonates with NEC manifested accelerated clot formation and higher clot strength compared to septic and healthy neonates, as these were expressed by ROTEM parameters.

IMPACT

This work reports data on the hemostatic profile of neonates with necrotizing enterocolitis (NEC) using Rotational Thromboelastometry (ROTEM) and the capacity of ROTEM parameters in differentiating of NEC from sepsis at the disease onset. Neonates with NEC present acceleration of coagulation and exhibit a hypercoagulable profile, as this is expressed by ROTEM parameters, in comparison to septic and healthy neonates. ROTEM parameters demonstrated a good diagnostic capacity in differentiating NEC from sepsis at the disease onset.

Quantitative label-free mass spectrometry reveals content and signaling differences between neonatal and adult platelets

BACKGROUND

Recent clinical studies have shown that transfusions of adult platelets increase morbidity and mortality in preterm infants. Neonatal platelets are hyporesponsive to agonist stimulation, and emerging evidence suggests developmental differences in platelet immune functions.

OBJECTIVES

This study was designed to compare the proteome and phosphoproteome of resting adult and neonatal platelets.

METHODS

We isolated resting umbilical cord blood-derived platelets from healthy full-term neonates (n = 8) and resting blood platelets from healthy adults (n = 6) and compared protein and phosphoprotein contents using data-independent acquisition mass spectrometry.

RESULTS

We identified 4770 platelet proteins with high confidence across all samples. Adult and neonatal platelets were clustered separately by principal component analysis. Adult platelets were significantly enriched in immunomodulatory proteins, including β2 microglobulin and CXCL12, whereas neonatal platelets were enriched in ribosomal components and proteins involved in metabolic activities. Adult platelets were enriched in phosphorylated GTPase regulatory enzymes and proteins participating in trafficking, which may help prime them for activation and degranulation. Neonatal platelets were enriched in phosphorylated proteins involved in insulin growth factor signaling.

CONCLUSION

Using label-free data-independent acquisition mass spectrometry, our findings expanded the known neonatal platelet proteome and identified important differences in protein content and phosphorylation between neonatal and adult platelets. These developmental differences suggested enhanced immune functions for adult platelets and presence of molecular machinery related to platelet activation. These findings are important to understanding mechanisms underlying key platelet functions as well as the harmful effects of adult platelet transfusions given to preterm infants.

Patient-tailored platelet transfusion practices for children supported by extracorporeal membrane oxygenation

BACKGROUND AND OBJECTIVES

Extracorporeal membrane oxygenation (ECMO) serves as cardiopulmonary therapy in critically ill patients with respiratory/heart failure and often necessitates multiple blood product transfusions. The administration of platelet transfusions during ECMO is triggered by the presence or risk of significant bleeding. Most paediatric ECMO programmes follow guidelines that recommend a platelet transfusion threshold of 80-100 × 109/L. To reduce exposure to platelets, we developed a practice to dynamically lower the threshold to ~20 × 109/L. We describe our experience with patient-tailored platelet thresholds and related bleeding outcomes.

MATERIALS AND METHODS

We retrospectively evaluated our platelet transfusion policy, bleeding complications and patient outcome in 229 ECMO-supported paediatric patients in our unit.

RESULTS

We found that more than 97.4% of patients had a platelet count <100 × 109/L at some point during their ECMO course. Platelets were transfused only on 28.5% of ECMO days; and 19.2% of patients never required a platelet transfusion. The median lowest platelet count in children who had bleeding events was 25 × 109/L as compared to 33 × 109/L in children who did not bleed (p < 0.001). Our patients received fewer platelet transfusions and did not require more red blood cell transfusions, nor did they experience more haemorrhagic complications.

CONCLUSION

We have shown that a restrictive, 'patient-tailored' rather than 'goal-directed' platelet transfusion policy is feasible and safe, which can greatly reduce the use of platelet products. Although there was a difference in the lowest platelet counts in children who bled versus those who did not, the median counts were much lower than current recommendations.

Cold temperature induces a TRPM8-independent calcium release from the endoplasmic reticulum in human platelets

The detection of temperature by the human sensory system is life-preserving and highly evolutionarily conserved. Platelets are sensitive to temperature changes and are activated by a decrease in temperature, akin to sensory neurons. However, the molecular mechanism of this temperature-sensing ability is unknown. Yet, platelet activation by temperature could contribute to numerous clinical sequelae, most importantly to reduced quality of ex vivo-stored platelets for transfusion. In this multidisciplinary study, we present evidence for the expression of the temperature-sensitive ion channel transient receptor potential cation channel subfamily member 8 (TRPM8) in human platelets and precursor cells. We found the TRPM8 mRNA and protein in MEG-01 cells and platelets. Inhibition of TRPM8 prevented temperature-induced platelet activation and shape change. However, chemical agonists of TRPM8 did not seem to have an acute effect on platelets. When exposing platelets to below-normal body temperature, we detected a cytosolic calcium increase which was independent of TRPM8 but was completely dependent on the calcium release from the endoplasmic reticulum. Because of the high interindividual variability of TRPM8 expression, a population-based approach should be the focus of future studies. Our study suggests that the cold response of platelets is complex and TRPM8 appears to play a role in early temperature-induced activation of platelets, while other mechanisms likely contribute to later stages of temperature-mediated platelet response.

Transfusion strategies for neonates: current perspectives

Background

Blood transfusion intervention has been proven to be a crucial therapeutic aid for preterm infants with serious morbidities such as sepsis, intraventricular hemorrhage, and cardiopulmonary insufficiencies. However, blood transfusion practices have also been shown to cause significant adverse outcomes, which may negate the therapeutic effect of the intervention. To address the varying policies regarding the administration of blood products, healthcare professionals have adopted a consensus-based approach. The absence of a standard protocol has resulted in conflicting outcomes in previous clinical studies.

Objective

This study aimed to evaluate the effectiveness of blood transfusion practices in preterm infants by analyzing past clinical research and identifying the current trends that have emerged as a result of recent trials.

Results

Recent trials have demonstrated comparable trends in mortality rates and other primary outcomes, including retinopathy of prematurity, intraventricular hemorrhage, bronchopulmonary dysplasia, and brain injury, following transfusion of blood products in both groups. Nevertheless, employing restrictive thresholds rather than adopting a liberal approach can reduce these outcomes.

Conclusion

The current literature does not provide clear support for either technique as opposing and contradictory results are evident. However, there is a slight inclination toward the restrictive transfusion threshold due to recent trials, which warrants further in-depth investigation into this issue.