Kinetic principles of ParA2-ATP cycling guide dynamic subcellular localizations in Vibrio cholerae.

Dynamic protein gradients are exploited for the spatial organization and segregation of replicated chromosomes. However, mechanisms of protein gradient formation and how that spatially organizes chromosomes remain poorly understood. Here, we have determined the kinetic principles of subcellular localizations of ParA2 ATPase, an essential spatial regulator of chromosome 2 segregation in the multichromosome bacterium, Vibrio cholerae. We found that ParA2 gradients self-organize in V. cholerae cells into dynamic pole-to-pole oscillations. We examined the ParA2 ATPase cycle and ParA2 interactions with ParB2 and DNA. In vitro, ParA2-ATP dimers undergo a rate-limiting conformational switch, catalysed by DNA to achieve DNA-binding competence. This active ParA2 state loads onto DNA cooperatively as higher order oligomers. Our results indicate that the midcell localization of ParB2-parS2 complexes stimulate ATP hydrolysis and ParA2 release from the nucleoid, generating an asymmetric ParA2 gradient with maximal concentration toward the poles. This rapid dissociation coupled with slow nucleotide exchange and conformational switch provides for a temporal lag that allows the redistribution of ParA2 to the opposite pole for nucleoid reattachment. Based on our data, we propose a 'Tug-of-war' model that uses dynamic oscillations of ParA2 to spatially regulate symmetric segregation and positioning of bacterial chromosomes.

Construction of a decision model for donor testing in cases of suspected antibody-mediated transfusion-related-acute-lung-injury.

OBJECTIVE: To propose a rational basis for donor testing in cases of suspected antibody-mediated transfusion-related lung injury (AMT). BACKGROUND: Anti-leukocyte antibodies in donated blood are established causes of transfusion-related lung injury (TRALI). However, the question of whether to test donors for antibodies is not identical to whether the case meets definition criteria for TRALI. There is a balance between the potential benefits of testing and the costs of donor deferral and investigation. We propose that a decision-making process based on optimising the balance between risk and benefit requires a subjective choice of the relative value of different outcomes of testing. METHODS: We have developed a formal decision model to illustrate how these choices affect testing decisions. RESULTS: Using a Bayesian probability model, we show that the diagnostic benefit and TRALI prevention benefit of testing donors have a complex interrelationship with the number of implicated donors and clinical suspicion of antibody-mediated TRALI (AMT) and that rational testing choices vary according to value assigned to outcomes. CONCLUSIONS: The challenges to the use of a formal decision model for clinical testing are discussed and conclude that a formal model is a useful consensus-building tool for improving consistency and openness in decision making.

Understanding the co-construction of safety in the paediatric intensive care unit: A meta-ethnography of parents' experiences.

BACKGROUND: Children experiencing critical illness or injury may require admission to a paediatric intensive care unit (PICU) to receive life-sustaining or life-saving treatment. Studies have explored the experience of parents with a child in PICU but tend to focus on subgroups of children or specific healthcare systems. Therefore, we aimed to undertake a meta-ethnography to draw together the published research. METHODS: A systematic search strategy was developed to identify qualitative studies, which had explored the experiences of parents with a critically ill child treated in a PICU. A meta-ethnography was undertaken following the structured steps of identifying the topic; undertaking a systematic search; reading the research; determining how the studies relate and translate into each other; and synthesising and expressing the results. RESULTS: We identified 2989 articles from our search and after a systematic series of exclusions, 15 papers remaining for inclusion. We explored the original parent voices (first order) and the interpretation of the study authors (second order) to identify three third-order concepts (our interpretation of the findings), which related to technical, relational and temporal factors. These factors influenced parents' experiences, providing both barriers and facilitators to how parents and caregivers experienced the time their child was in the PICU. The dynamic and co-constructed nature of safety provided an analytical overarching frame of reference. CONCLUSION: This synthesis demonstrates novel ways in which parents and caregivers can contribute to the vital role of ensuring a co-created safe healthcare environment for their child when receiving life-saving care within the PICU.

Molecular basis for substrate recognition and septum cleavage by AtlA, the major N-acetylglucosaminidase of Enterococcus faecalis.

The cleavage of septal peptidoglycan at the end of cell division facilitates the separation of the two daughter cells. The hydrolases involved in this process (called autolysins) are potentially lethal enzymes that can cause cell death; their activity, therefore, must be tightly controlled during cell growth. In Enterococcus faecalis, the N-acetylglucosaminidase AtlA plays a predominant role in cell separation. atlA mutants form long cell chains and are significantly less virulent in the zebrafish model of infection. The attenuated virulence of atlA mutants is underpinned by a limited dissemination of bacterial chains in the host organism and a more efficient uptake by phagocytes that clear the infection. AtlA has structural homologs in other important pathogens, such as Listeria monocytogenes and Salmonella typhimurium, and therefore represents an attractive model to design new inhibitors of bacterial pathogenesis. Here, we provide a 1.45 Å crystal structure of the E. faecalis AtlA catalytic domain that reveals a closed conformation of a conserved ß-hairpin and a complex network of hydrogen bonds that bring two catalytic residues to the ideal distance for an inverting mechanism. Based on the model of the AtlA-substrate complex, we identify key residues critical for substrate recognition and septum cleavage during bacterial growth. We propose that this work will provide useful information for the rational design of specific inhibitors targeting this enterococcal virulence factor and its orthologs in other pathogens.

Good clinical research practice (GCRP) in pharmacodynamic studies of neuromuscular blocking agents III: The 2023 Geneva revision.

The set of guidelines for good clinical research practice in pharmacodynamic studies of neuromuscular blocking agents was developed following an international consensus conference in Copenhagen in 1996 (Viby-Mogensen et al., Acta Anaesthesiol Scand 1996, 40, 59-74); the guidelines were later revised and updated following the second consensus conference in Stockholm in 2005 (Fuchs-Buder et al., Acta Anaesthesiol Scand 2007, 51, 789-808). In view of new devices and further development of monitoring technologies that emerged since then, (e.g., electromyography, three-dimensional acceleromyography, kinemyography) as well as novel compounds (e.g., sugammadex) a review and update of these recommendations became necessary. The intent of these revised guidelines is to continue to help clinical researchers to conduct high-quality work and advance the field by enhancing the standards, consistency, and comparability of clinical studies. There is growing awareness of the importance of consensus-based reporting standards in clinical trials and observational studies. Such global initiatives are necessary in order to minimize heterogeneous and inadequate data reporting and to improve clarity and comparability between different studies and study cohorts. Variations in definitions of endpoints or outcome variables can introduce confusion and difficulties in interpretation of data, but more importantly, it may preclude building of an adequate body of evidence to achieve reliable conclusions and recommendations. Clinical research in neuromuscular pharmacology and physiology is no exception.

Increased reports of severe myocarditis associated with enterovirus infection in neonates, United Kingdom, 27 June 2022 to 26 April 2023.

Enteroviruses are a common cause of seasonal childhood infections. The vast majority of enterovirus infections are mild and self-limiting, although neonates can sometimes develop severe disease. Myocarditis is a rare complication of enterovirus infection. Between June 2022 and April 2023, twenty cases of severe neonatal enteroviral myocarditis caused by coxsackie B viruses were reported in the United Kingdom. Sixteen required critical care support and two died. Enterovirus PCR on whole blood was the most sensitive diagnostic test. We describe the initial public health investigation into this cluster and aim to raise awareness among paediatricians, laboratories and public health specialists.

Effect of High-Flow Nasal Cannula Therapy vs Continuous Positive Airway Pressure Therapy on Liberation From Respiratory Support in Acutely Ill Children Admitted to Pediatric Critical Care Units: A Randomized Clinical Trial.

Importance: The optimal first-line mode of noninvasive respiratory support for acutely ill children is not known. Objective: To evaluate the noninferiority of high-flow nasal cannula therapy (HFNC) as the first-line mode of noninvasive respiratory support for acute illness, compared with continuous positive airway pressure (CPAP), for time to liberation from all forms of respiratory support. Design, Setting, and Participants: Pragmatic, multicenter, randomized noninferiority clinical trial conducted in 24 pediatric critical care units in the United Kingdom among 600 acutely ill children aged 0 to 15 years who were clinically assessed to require noninvasive respiratory support, recruited between August 2019 and November 2021, with last follow-up completed in March 2022. Interventions: Patients were randomized 1:1 to commence either HFNC at a flow rate based on patient weight (n = 301) or CPAP of 7 to 8 cm H2O (n = 299). Main Outcomes and Measures: The primary outcome was time from randomization to liberation from respiratory support, defined as the start of a 48-hour period during which a participant was free from all forms of respiratory support (invasive or noninvasive), assessed against a noninferiority margin of an adjusted hazard ratio of 0.75. Seven secondary outcomes were assessed, including mortality at critical care unit discharge, intubation within 48 hours, and use of sedation. Results: Of the 600 randomized children, consent was not obtained for 5 (HFNC: 1; CPAP: 4) and respiratory support was not started in 22 (HFNC: 5; CPAP: 17); 573 children (HFNC: 295; CPAP: 278) were included in the primary analysis (median age, 9 months; 226 girls [39%]). The median time to liberation in the HFNC group was 52.9 hours (95% CI, 46.0-60.9 hours) vs 47.9 hours (95% CI, 40.5-55.7 hours) in the CPAP group (absolute difference, 5.0 hours [95% CI -10.1 to 17.4 hours]; adjusted hazard ratio 1.03 [1-sided 97.5% CI, 0.86-∞]). This met the criterion for noninferiority. Of the 7 prespecified secondary outcomes, 3 were significantly lower in the HFNC group: use of sedation (27.7% vs 37%; adjusted odds ratio, 0.59 [95% CI, 0.39-0.88]); mean duration of critical care stay (5 days vs 7.4 days; adjusted mean difference, -3 days [95% CI, -5.1 to -1 days]); and mean duration of acute hospital stay (13.8 days vs 19.5 days; adjusted mean difference, -7.6 days [95% CI, -13.2 to -1.9 days]). The most common adverse event was nasal trauma (HFNC: 6/295 [2.0%]; CPAP: 18/278 [6.5%]). Conclusions and Relevance: Among acutely ill children clinically assessed to require noninvasive respiratory support in a pediatric critical care unit, HFNC compared with CPAP met the criterion for noninferiority for time to liberation from respiratory support. Trial Registration: ISRCTN.org Identifier: ISRCTN60048867.

Effect of High-Flow Nasal Cannula Therapy vs Continuous Positive Airway Pressure Following Extubation on Liberation From Respiratory Support in Critically Ill Children: A Randomized Clinical Trial.

Importance: The optimal first-line mode of noninvasive respiratory support following extubation of critically ill children is not known. Objective: To evaluate the noninferiority of high-flow nasal cannula (HFNC) therapy as the first-line mode of noninvasive respiratory support following extubation, compared with continuous positive airway pressure (CPAP), on time to liberation from respiratory support. Design, Setting, and Participants: This was a pragmatic, multicenter, randomized, noninferiority trial conducted at 22 pediatric intensive care units in the United Kingdom. Six hundred children aged 0 to 15 years clinically assessed to require noninvasive respiratory support within 72 hours of extubation were recruited between August 8, 2019, and May 18, 2020, with last follow-up completed on November 22, 2020. Interventions: Patients were randomized 1:1 to start either HFNC at a flow rate based on patient weight (n = 299) or CPAP of 7 to 8 cm H2O (n = 301). Main Outcomes and Measures: The primary outcome was time from randomization to liberation from respiratory support, defined as the start of a 48-hour period during which the child was free from all forms of respiratory support (invasive or noninvasive), assessed against a noninferiority margin of an adjusted hazard ratio (HR) of 0.75. There were 6 secondary outcomes, including mortality at day 180 and reintubation within 48 hours. Results: Of the 600 children who were randomized, 553 children (HFNC, 281; CPAP, 272) were included in the primary analysis (median age, 3 months; 241 girls [44%]). HFNC failed to meet noninferiority, with a median time to liberation of 50.5 hours (95% CI, 43.0-67.9) vs 42.9 hours (95% CI, 30.5-48.2) for CPAP (adjusted HR, 0.83; 1-sided 97.5% CI, 0.70-∞). Similar results were seen across prespecified subgroups. Of the 6 prespecified secondary outcomes, 5 showed no significant difference, including the rate of reintubation within 48 hours (13.3% for HFNC vs 11.5 % for CPAP). Mortality at day 180 was significantly higher for HFNC (5.6% vs 2.4% for CPAP; adjusted odds ratio, 3.07 [95% CI, 1.1-8.8]). The most common adverse events were abdominal distension (HFNC: 8/281 [2.8%] vs CPAP: 7/272 [2.6%]) and nasal/facial trauma (HFNC: 14/281 [5.0%] vs CPAP: 15/272 [5.5%]). Conclusions and Relevance: Among critically ill children requiring noninvasive respiratory support following extubation, HFNC compared with CPAP following extubation failed to meet the criterion for noninferiority for time to liberation from respiratory support. Trial Registration: isrctn.org Identifier: ISRCTN60048867.

In the eye of the storm: impact of COVID-19 pandemic on admission patterns to paediatric intensive care units in the UK and Eire.

BACKGROUND: The coronavirus disease-19 (COVID-19) pandemic had a relatively minimal direct impact on critical illness in children compared to adults. However, children and paediatric intensive care units (PICUs) were affected indirectly. We analysed the impact of the pandemic on PICU admission patterns and patient characteristics in the UK and Ireland. METHODS: We performed a retrospective cohort study of all admissions to PICUs in children < 18 years during Jan-Dec 2020, using data collected from 32 PICUs via a central database (PICANet). Admission patterns, case-mix, resource use, and outcomes were compared with the four preceding years (2016-2019) based on the date of admission. RESULTS: There were 16,941 admissions in 2020 compared to an annual average of 20,643 (range 20,340-20,868) from 2016 to 2019. During 2020, there was a reduction in all PICU admissions (18%), unplanned admissions (20%), planned admissions (15%), and bed days (25%). There was a 41% reduction in respiratory admissions, and a 60% reduction in children admitted with bronchiolitis but an 84% increase in admissions for diabetic ketoacidosis during 2020 compared to the previous years. There were 420 admissions (2.4%) with either PIMS-TS or COVID-19 during 2020. Age and sex adjusted prevalence of unplanned PICU admission reduced from 79.7 (2016-2019) to 63.1 per 100,000 in 2020. Median probability of death [1.2 (0.5-3.4) vs. 1.2 (0.5-3.4) %], length of stay [2.3 (1.0-5.5) vs. 2.4 (1.0-5.7) days] and mortality rates [3.4 vs. 3.6%, (risk-adjusted OR 1.00 [0.91-1.11, p = 0.93])] were similar between 2016-2019 and 2020. There were 106 fewer in-PICU deaths in 2020 (n = 605) compared with 2016-2019 (n = 711). CONCLUSIONS: The use of a high-quality international database allowed robust comparisons between admission data prior to and during the COVID-19 pandemic. A significant reduction in prevalence of unplanned admissions, respiratory diseases, and fewer child deaths in PICU observed may be related to the targeted COVID-19 public health interventions during the pandemic. However, analysis of wider and longer-term societal impact of the pandemic and public health interventions on physical and mental health of children is required.

Effect of platelet storage duration on clinical outcomes and incremental platelet change in critically ill children.

The safety of platelet (PLT) concentrates with longer storage duration has been questioned due to biochemical and functional changes that occur during blood collection and storage. Some studies have suggested that transfusion efficacy is decreased and immune system dysfunction is worsened with increased storage age. We sought to describe the effect of PLT storage age on laboratory and clinical outcomes in critically ill children receiving PLT transfusions. STUDY DESIGN AND METHODS: We performed a secondary analysis of a prospective, observational point-prevalence study. Children (3 days to 16 years of age) from 82 pediatric intensive care units in 16 countries were enrolled if they received a PLT transfusion during one of the predefined screening weeks. Outcomes (including PLT count increments, organ dysfunction, and transfusion reactions) were evaluated by PLT storage age. RESULTS: Data from 497 patients were analyzed. The age of the PLT transfusions ranged from 1 to 7 days but the majority were 4 (24%) or 5 (36%) days of age. Nearly two-thirds of PLT concentrates were transfused to prevent bleeding. The indication for transfusion did not differ between storage age groups (P = .610). After patient and product variables were adjusted for, there was no association between storage age and incremental change in total PLT count or organ dysfunction scoring. A significant association between fresher storage age and febrile transfusion reactions (P = .002) was observed. CONCLUSION: The results in a large, diverse cohort of critically ill children raise questions about the impact of storage age on transfusion and clinical outcomes which require further prospective evaluation.

Sedation practices in pediatric patients with acute lymphoblastic leukemia.

BACKGROUND: The 5-year survival for pediatric acute lymphoblastic leukemia (ALL) is greater than 90%. One late effect of pediatric ALL associated with numerous long-term difficulties is neurocognitive deficits. The experience at our institution, as well as conversations with oncologists at other institutions, suggests an increase in the use of sedation during lumbar punctures (LPs) for treatment of pediatric ALL. Among the most common Children's Oncology Group (COG) ALL protocols, approximately 30 LPs are performed over 2-3 years. Studies in animals reveal that sedation drugs may harm the developing brain. Gaps in knowledge exist regarding their use in children, particularly repeated exposures. The purpose of this study is to summarize sedation practices for LPs related to the treatment of ALL at COG institutions. METHODS: Responsible Individuals (RIs) of the Cancer Control Committee of COG were invited to complete an internet-based survey about sedation practices at their institutions. RESULTS: Surveys were sent to 103 RIs with a 62% response rate (N = 64). A combined 2018 new patients with ALL were seen each year (mean = 31.5, range = 3-110) at the participating institutions. The majority (96%) of children with ALL received sedation for LPs. While there was considerable variability across institutions in the type of sedation given, the most common was propofol alone (n = 36, 56%). CONCLUSIONS: A substantial number of children with ALL receive sedation for LPs; however, there is variation in the medication used. Better understanding of sedation practices in children with ALL may inform future research to investigate which methods are the safest, with an emphasis on long-term neurocognitive late effects.

Where Should Critically Ill Adolescents Receive Care? A Qualitative Interview-Based Study of Perspectives of Staff Working in Adult and Pediatric Intensive Care Units.

PURPOSE: In the United Kingdom, critically ill adolescents are treated in either adult or pediatric intensive care units (AICUs or PICUs). This study explores staff perspectives on where and how best to care for this distinct group. MATERIALS AND METHODS: Semistructured interviews were conducted with 12 members of staff (3 medical, 6 nursing, and 3 allied health professionals) working in 4 ICUs; 2 general hospital AICUs and 2 tertiary centre-based PICUs in England. Interviews were audio-recorded, transcribed, and analyzed using framework analysis. FINDINGS: One overarching theme was identified, reflecting staff understanding of the term "adolescent," and this was linked to 2 further themes, each of which had several subthemes. "Needs of the critically ill adolescent" included medical needs, dignity and privacy, issues around consent, and the impact of intensive care admission. "Implications for staff" included managing parental presence and lack of familiarity, and emotional impact, of dealing with this patient group. Some of these factors are currently better accommodated in adult settings. CONCLUSIONS: Decision-making about the place of care should take into account the individual circumstances of the patient (e.g., nature of their medical condition and previous experiences, maturity, family preference) and not be based only on age at admission. We should work across disciplines to ensure we can discover, and consistently deliver, best practice to meet the needs of critically ill adolescents.

Pediatric Plasma and Platelet Transfusions on Extracorporeal Membrane Oxygenation: A Subgroup Analysis of Two Large International Point-Prevalence Studies and the Role of Local Guidelines.

OBJECTIVES: To describe the indications and thresholds for plasma and platelet transfusions for pediatric extracorporeal membrane oxygenation, to compare responses to these transfusions and to describe institutional protocols directing their administration. DESIGN: Subgroup analysis of two prospective, observational studies paired with survey of sites who enrolled subjects into this cohort. SETTING: Fifty-one PICUs in 13 countries. PATIENTS: Children (3 d to 16 yr old) were enrolled if they received a plasma or platelet transfusion while on extracorporeal membrane oxygenation during one of the predefined screening weeks. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Forty-eight children on extracorporeal membrane oxygenation received plasma transfusions and 90 received platelet transfusions. Sixty percent of plasma transfusions (29/48) and 79% of the platelet transfusions (71/90) were given for prophylaxis of bleeding. The median (interquartile range) international normalized ratio prior to transfusion, known in 75% of the patients (36/48), was 1.45 (1.20-1.85). The median (interquartile range) total platelet count prior to transfusion, known in all of the patients, was 70 × 10/L (52-90 × 10/L). The international normalized ratio and total platelet count values prior to transfusion did not vary based on bleeding versus nonbleeding indications. The median (interquartile range) reduction in international normalized ratio for mild coagulopathies (international normalized ratio ≤ 2.0) was 0.1 (0.4-0), median (interquartile range) increase in fibrinogen was 0.2 g/L (0.1-0.4 g/L) and median increase in total platelet count was 34 × 10/L (10-74 × 10/L). Through the course of their admission, children supported by extracorporeal membrane oxygenation received a total median (interquartile range) dose of 75 mL/kg (36-159 mL/kg) of plasma transfusions and 92 mL/kg (42-239 mL/kg) of platelet transfusions. Institutional protocols varied but provided guidance for platelet transfusions more commonly. CONCLUSIONS: Children supported by extracorporeal membrane oxygenation receive large volumes of plasma and platelet transfusions with some institutional guidance in the form of protocols, but significant variation in practice. Interventional studies are necessary to provide evidence to direct the transfusion of hemostatic products in children supported by extracorporeal membrane oxygenation.

Pediatric Liver Transplantation: Then and Now.

This paper reviews the past 50 years of liver transplantation in children from the perspective of patient demographics, perioperative patient management, surgical techniques, immunosuppression and patient outcomes.

The opioid epidemic in pediatrics: a 2020 update.

PURPOSE OF REVIEW: Over the last 3 years and for the first time in 60 years, life expectancy in the United States has declined across all racial groups primarily because of drug overdoses, alcohol abuse, and suicide. A public health response to the opioid crisis must expand its focus to more broadly include children, adolescents, and young adults while increasing efforts toward preventing new cases of opioid addiction, early identification of individuals with opioid-abuse disorder, and ensuring access to effective opioid addiction treatment, while simultaneously continuing to safely meet the needs of patients experiencing pain. RECENT FINDINGS: Although a multimodal approach to pain management is fundamental in current practice, opioids remain an essential building block in the management of acute and chronic pain and have been for over 5000 years as they work. Left over, unconsumed opioids that were appropriately prescribed for pain have become the gateway for the development of opioid use disorder, particularly in the vulnerable adolescents and young adult patient populations. How to reduce the amount of opioids dispensed, improve methods of disposal in an environmentally safe way, and proactively make naloxone, particularly nasal spray, readily available to patients (and their families) receiving prescription opioids or who are at risk of opioid use disorder are highlighted in this review. SUMMARY: We describe the historical use of opioids and the scope of the current opioid crisis, review the differences between dependence and addiction, and the private and public sectors response to pain management and highlight the issue of adolescent vulnerability. We conclude with a proposal for future directions that address both public and patient health needs.

Bleeding Assessment Scale in Critically Ill Children (BASIC): Physician-Driven Diagnostic Criteria for Bleeding Severity.

OBJECTIVE: Although bleeding frequently occurs in critical illness, no published definition to date describes the severity of bleeding accurately in critically ill children. We sought to develop diagnostic criteria for bleeding severity in critically ill children. DESIGN: Delphi consensus process of multidisciplinary experts in bleeding/hemostasis in critically ill children, followed by prospective cohort study to test internal validity. SETTING: PICU. PATIENTS: Children at risk of bleeding in PICUs. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Twenty-four physicians worldwide (10 on a steering committee and 14 on an expert committee) from disciplines related to bleeding participated in development of a definition for clinically relevant bleeding. A provisional definition was created from 35 descriptors of bleeding. Using a modified online Delphi process and conference calls, the final definition resulted after seven rounds of voting. The Bleeding Assessment Scale in Critically Ill Children definition categorizes bleeding into severe, moderate, and minimal, using organ dysfunction, proportional changes in vital signs, anemia, and quantifiable bleeding. The criteria do not include treatments such as red cell transfusion or surgical interventions performed in response to the bleed. The definition was prospectively applied to 40 critically ill children with 46 distinct bleeding episodes. The kappa statistic between the two observers was 0.74 (95% CI, 0.57-0.91) representing substantial inter-rater reliability. CONCLUSIONS: The Bleeding Assessment Scale in Critically Ill Children definition of clinically relevant bleeding severity is the first physician-driven definition applicable for bleeding in critically ill children derived via international expert consensus. The Bleeding Assessment Scale in Critically Ill Children definition includes clear criteria for bleeding severity in critically ill children. We anticipate that it will facilitate clinical communication among pediatric intensivists pertaining to bleeding and serve in the design of future epidemiologic studies if it is validated with patient outcomes.

Red Blood Cell Transfusion in Pediatric Orthotopic Liver Transplantation: What a Difference a Few Decades Make.

BACKGROUND: Liver transplantation in children is often associated with coagulopathy and significant blood loss. Available data are limited. In this observational retrospective study, we assessed transfusion practices in pediatric patients undergoing liver transplantation at a single institution over the course of 9 years. METHODS: Data were retrospectively collected from patient medical records at the Children's Hospital of Pittsburgh of University of Pittsburgh Medical Center. All patients who underwent liver transplantation from January 2008 to June 2017 were included. Primary and secondary outcomes were volume of red blood cells (RBCs) transfused and mortality, respectively. RESULTS: From January 2008 to June 2017, there were 278 liver transplants in 271 patients. The number of primary transplants were 259, second retransplants 15, and third retransplants 4. Average age at transplantation was 6.9 years. Biliary atresia, maple syrup urine disease, urea cycle defect, and liver tumor were the leading indications accounting for 66 (23.7%), 45 (16.2%), 24 (8.6%), and 23 (8.3%) of transplants, respectively. Seventy-six cases (27.3%) did not require RBC transfusions. Among those transfused, 181 (89.6%) of the cases required <1 blood volume (BV). The median BV transfused among all cases was 0.21 (range, 0-9; Q1, 0; Q3, 0.45). There is a trend toward higher volume transfusions among infants (median, 0.46 BV) compared to children >12 months of age (0.12 BV). By diagnosis, the group requiring the highest median volume transfusion was patients with total parenteral nutrition-related liver failure (3.41 BV) followed by patients undergoing repeat transplants (0.6 BV). Comparison of primary versus repeat transplants shows a trend toward higher volume transfusions in third transplants (median, 2.71 BV), compared to second transplants (0.43 BV) and primary transplants (0.18 BV). Four of 271 patients (1.5%) died during admission involving liver transplantation. Nine of 271 patients (3.3%) died subsequently. Total mortality was 4.8%. CONCLUSIONS: In contrast to historically reported trends, evaluation of current transfusion practices reveals that most patients undergoing liver transplantation receive <1 BV of packed RBCs. More than 1 in 4 transplantations require no transfusion at all. Risk factors for greater transfusion need include younger age, total parenteral nutrition-related liver failure, and repeat transplantation.

Patterns of Use of Heated Humidified High-Flow Nasal Cannula Therapy in PICUs in the United Kingdom and Republic of Ireland.

OBJECTIVES: To 1) describe patterns of use of high-flow nasal cannula therapy, 2) examine differences between patients started on high-flow nasal cannula and those started on noninvasive ventilation, and 3) explore whether patients who failed high-flow nasal cannula therapy were different from those who did not. DESIGN: Retrospective analysis of data collected prospectively by the Paediatric Intensive Care Audit Network. SETTING: All PICUs in the United Kingdom and Republic of Ireland (n = 34). PATIENTS: Admissions to study PICUs (2015-2016) receiving any form of respiratory support at any time during PICU stay. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Eligible admissions were classified into nine groups based on the combination of the first-line and second-line respiratory support modes. Uni- and multivariate analyses were performed to test the association between PICU and patient characteristics and two outcomes: 1) use of high-flow nasal cannula versus noninvasive ventilation as first-line mode and 2) high-flow nasal cannula failure, requiring escalation to noninvasive ventilation and/or invasive ventilation. We analyzed data from 26,423 admissions; high-flow nasal cannula was used in 5,951 (22.5%) at some point during the PICU stay. High-flow nasal cannula was used for first-line support in 2,080 (7.9%) and postextubation support in 978 admissions (4.5% of patients extubated after first-line invasive ventilation). High-flow nasal cannula failure occurred in 559 of 2,080 admissions (26.9%) when used for first-line support. Uni- and multivariate analyses showed that PICU characteristics as well as patient age, primary diagnostic group, and admission type had a significant influence on the choice of first-line mode (high-flow nasal cannula or noninvasive ventilation). Younger age, unplanned admission, and higher admission severity of illness were independent predictors of high-flow nasal cannula failure. CONCLUSIONS: The use of high-flow nasal cannula is common in PICUs in the United Kingdom and Republic of Ireland. Variation in the choice of first-line respiratory support mode (high-flow nasal cannula or noninvasive ventilation) between PICUs reflects the need for clinical trial evidence to guide future practice.

Effects of ABO Matching of Platelet Transfusions in Critically Ill Children.

OBJECTIVES: To determine if transfusing ABO compatible platelets has a greater effect on incremental change in platelet count as compared to ABO incompatible platelets in critically ill children. DESIGN: Secondary analysis of a prospective, observational study. Transfusions were classified as either ABO compatible, major incompatibility, or minor incompatibility. The primary outcome was the incremental change in platelet count. Transfusion reactions were analyzed as a secondary outcome. SETTING: Eighty-two PICUs in 16 countries. PATIENTS: Children (3 d to 16 yr old) were enrolled if they received a platelet transfusion during one of the predefined screening weeks. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Five-hundred three children were enrolled and had complete ABO information for both donor and recipient, as well as laboratory data. Three-hundred forty-two (68%) received ABO-identical platelets, 133 (26%) received platelets with major incompatibility, and 28 (6%) received platelets with minor incompatibility. Age, weight, proportion with mechanical ventilation or underlying oncologic diagnosis did not differ between the groups. After adjustment for transfusion dose, there was no difference in the incremental change in platelet count between the groups; the median (interquartile range) change for ABO-identical transfusions was 28 × 10 cells/L (8-68 × 10 cells/L), for transfusions with major incompatibility 26 × 10 cells/L (7-74 × 10 cells/L), and for transfusions with minor incompatibility 54 × 10 cells/L (14-81 × 10 cells/L) (p = 0.37). No differences in count increment between the groups were noted for bleeding (p = 0.92) and nonbleeding patients (p = 0.29). There were also no differences observed between the groups for any transfusion reaction (p = 0.07). CONCLUSIONS: No differences were seen in the incremental change in platelet count nor in transfusion reactions when comparing major ABO incompatible platelet transfusions with ABO compatible transfusions in a large study of critically ill children. Studies in larger, prospectively enrolled cohorts should be performed to validate whether ABO matching for platelet transfusions in critically ill children is necessary.

International Study of the Epidemiology of Platelet Transfusions in Critically Ill Children With an Underlying Oncologic Diagnosis.

OBJECTIVES: To describe the epidemiology of platelet transfusions in critically ill children with an underlying oncologic diagnosis and to examine effects of prophylactic versus therapeutic transfusions. DESIGN: Subgroup analysis of a prospective, observational study. SETTING: Eighty-two PICUs in 16 countries. PATIENTS: All children (3 d to 16 yr old) who received a platelet transfusion during one of the six predefined screening weeks and had received chemotherapy in the previous 6 months or had undergone hematopoietic stem cell transplantation in the last year. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Of the 548 patients enrolled in the parent study, 237 (43%) had an underlying oncologic diagnosis. In this population, 71% (168/237) of transfusions were given prophylactically, and 59% (139/237) of transfusions were given at a total platelet count greater than 20 × 10/L, higher than the current recommendations. Those with an underlying oncologic diagnosis were significantly older, and received less support including less mechanical ventilation, fewer medications that affect platelet function, and less use of extracorporeal life support than those without an underlying oncologic diagnosis. In this subpopulation, there were no statistically significant differences in median (interquartile range) platelet transfusion thresholds when comparing bleeding or nonbleeding patients (50 × 10/L [10-50 × 10/L] and 30 × 10/L [10-50 × 10/L], respectively [p = 0.166]). The median (interquartile range) interval transfusion increment in children with an underlying oncologic diagnosis was 17 × 10/L (6-52 × 10/L). The presence of an underlying oncologic diagnosis was associated with a poor platelet increment response to platelet transfusion in this cohort (adjusted odds ratio, 0.46; 95% CI, 0.22-0.95; p = 0.035). CONCLUSIONS: Children with an underlying oncologic diagnosis receive nearly half of platelet transfusions prescribed by pediatric intensivists. Over half of these transfusions are prescribed at total platelet count greater than current recommendations. Studies must be done to clarify appropriate indications for platelet transfusions in this vulnerable population.