Epidemiology of Bleeding in Critically Ill Children

Mechanical Thromboprophylaxis and Hospital-Acquired Venous Thromboembolism Among Critically Ill Adolescents: A U.S. Pediatric Health Information Systems Registry Study, 2016-2023

OBJECTIVES

To estimate the rate of mechanical thromboprophylaxis (mTP) prescription among critically ill adolescents using a multicenter administrative database and determine whether mTP prescription is inversely associated with hospital-acquired venous thromboembolism.

DESIGN

Multicenter, observational, retrospective study of the Pediatric Health Information Systems (PHIS) Registry cohort, January 2016 to December 2023.

SETTING

Thirty PICUs located within quaternary pediatric referral centers in the United States.

PATIENTS

Critically ill children 12-17 years old, excluding encounters with a principal diagnosis at admission of venous thromboembolism.

INTERVENTIONS

mTP prescription within the first 24 hours of hospitalization.

MEASUREMENTS AND MAIN RESULTS

A total of 107,804 children met the study criteria, of which 21,124 (19.6%) were prescribed mTP. Hospital center prescribing rates ranged from 1.4% to 65.4% and decreased by 1.6% per year from 28.2% in 2016 to 17.1% in 2023. As compared with those without mTP, those with mTP more frequently had a concurrent central venous catheter (17.2% vs. 9.4%, p < 0.001), underwent invasive mechanical ventilation (37.4% vs. 24.8%, p < 0.001), were admitted for a primary surgical indication (30.9% vs. 12.7%, p < 0.001), and experienced a longer median duration of hospitalization (7 [interquartile range (IQR): 4-15] vs. 4 [IQR: 2-9] d, p < 0.001). Hospital-acquired venous thromboembolism occurred in 2.7% of the study sample and was more common among those with, as compared with without, prescription of mTP (4% vs. 2.4%, p < 0.001). In multivariable logistic regression models for hospital-acquired venous thromboembolism adjusting for salient prothrombotic risk factors, we failed to identify an association between mTP and greater odds of hospital-acquired venous thromboembolism (HA-VTE) among low-, moderate-, and high-risk tiers. However, we cannot exclude the possibility of 17-50% greater odds of HA-VTE in this population.

CONCLUSIONS

In the multicenter PHIS cohort, 2016-2023, the prescribing patterns for mTP among critically ill adolescents showed a low rate of mTP prescription (19.6%) that varied widely across institutions, decreased annually over the study period by 1.6%/year, and was not independently associated with HA-VTE risk reduction.

Assessing the Reliability of the Bleeding Assessment Scale in Critically Ill Children (BASIC) Definition: A Prospective Cohort Study

OBJECTIVES

To determine the reliability of the Bleeding Assessment Scale in critically Ill Children (BASIC) definition of bleeding severity in a diverse cohort of critically ill children.

DESIGN

Prospective cohort study.

SETTING

Eight mixed PICUs in the Netherlands, Israel, and the United States.

SUBJECTS

Children ages 0-18 years admitted to participating PICUs from January 1, 2020, to December 31, 2022, with bleeding noted by bedside nurse.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The bleeding events were classified as minimal, moderate, or severe, according to the BASIC definition, by two independent physicians at two different time points. Patient demographic data, laboratory values, and clinical outcomes were collected. Three hundred twenty-eight patients were enrolled. The overall inter-rater reliability was substantial (weighted kappa coefficient, 0.736; 95% CI, 0.683-0.789), and the intra-rater reliability was "almost-perfect" (weighted kappa coefficient, 0.816; 95% CI, 0.769-0.863). The platelet count ( p = 0.008), prothrombin time ( p = 0.004), activated partial thromboplastin time ( p = 0.025), and fibrinogen levels ( p = 0.035) were associated with the bleeding severity, but the international normalized ratio was not ( p = 0.195). Patients were transfused blood components in response to any bleeding in 31% of cases and received hemostatic medications in 9% of cases. More severe bleeding was associated with increased 28-day mortality, longer hospital length of stay, and more days receiving inotropic support.

CONCLUSIONS

The BASIC definition is a reliable tool for identifying and classifying bleeding in critically ill children. Implementing this definition into clinical and research practice may provide a consistent and reliable evaluation of bleeding.

Short-term neurologic outcomes in pediatric extracorporeal membrane oxygenation are proportional to bleeding severity graded by a novel bleeding scale

INTRODUCTION

This study aimed to characterize the severity of bleeding and its association with short-term neurologic outcomes in pediatric ECMO.

METHODS

Multicenter retrospective cohort study of pediatric ECMO patients at 10 centers utilizing the Pediatric ECMO Outcomes Registry (PEDECOR) database from December 2013-February 2019. Subjects excluded were post-cardiac surgery patients and those with neonatal pathologies. A novel ECMO bleeding scale was utilized to categorize daily bleeding events. Poor short-term neurologic outcome was defined as an unfavorable Pediatric Cerebral Performance Category (PCPC) or Pediatric Overall Performance Category (POPC) (score of >3) at hospital discharge.

RESULTS

This study included 283 pediatric ECMO patients with a median (interquartile range [IQR]) age of 1.3 years [0.1, 9.0], ECMO duration of 5 days [3.0, 9.5], and 44.1% mortality. Unfavorable PCPC and POPC were observed in 48.4% and 51.3% of patients at discharge, respectively. Multivariable logistic regression analysis included patient's age, cannulation type, duration of ECMO, need for cardiopulmonary resuscitation, acute kidney injury, new infection, and vasoactive-inotropic score. As the severity of bleeding increased, there was a corresponding increase in the likelihood of poor neurologic recovery, shown by increasing odds of unfavorable neurologic outcome (PCPC), with an adjusted odds ratio (aOR) of 0.77 (confidence interval [CI] 0.36-1.62), 1.87 (0.54-6.45), 2.97 (1.32-6.69), and 5.56 (0.59-52.25) for increasing bleeding severity (grade 1 to 4 events, respectively). Similarly, unfavorable POPC aOR (CI) was 1.02 (0.48-2.17), 2.05 (0.63-6.70), 5.29 (2.12-13.23), and 5.11 (0.66-39.64) for bleeding grade 1 to 4 events.

CONCLUSION

Short-term neurologic outcomes in pediatric ECMO are proportional to the severity of bleeding events. Strategies to mitigate bleeding events could improve neurologic recovery in pediatric ECMO.

Antithrombin activity and central venous catheter-associated thrombosis in critically ill children at high risk of bleeding

BACKGROUND

Normalization of antithrombin activity may prevent catheter-associated thrombosis in critically ill children at high risk of bleeding.

OBJECTIVES

To characterize the temporal pattern of antithrombin activity, assess its association with catheter-associated thrombosis and clinically relevant bleeding, and evaluate its relationship with thrombin generation in these children.

METHODS

In this prospective cohort study, critically ill children <18 years old at high risk of bleeding with central venous catheter were eligible. Antithrombin activity and thrombin generation were measured from platelet-poor plasma and after in vitro antithrombin supplementation. Systematic surveillance ultrasound was performed to diagnose thrombosis. Children were followed for bleeding.

RESULTS

We enrolled 8 infants (median age: 0.2 years, IQR: 0.2, 0.3 years) and 72 older children (median age: 14.3 years, IQR: 9.1, 16.1 years). Mean antithrombin on the day of catheter insertion was 64 IU/dL (SD: 32 IU/dL) in infants and 83 IU/dL (SD: 35 IU/dL) in older children. Antithrombin normalized by the day of catheter removal. Thrombosis developed in 27 children, while 31 children bled. Thrombosis (regression coefficient: 0.008, 95% CI: -0.01, 0.03) and bleeding (regression coefficient: -0.0007, 95% CI: -0.02, 0.02) were not associated with antithrombin. Antithrombin was not correlated with in vivo change in endogenous thrombin potential (correlation coefficient: -0.07, 95% CI: -0.21, 0.08). In vitro supplementation reduced endogenous thrombin potential (correlation coefficient: -0.78; 95% CI: -0.95, -0.23).

CONCLUSION

These findings may not support normalization of antithrombin activity to prevent catheter-associated thrombosis in critically ill children at high risk of bleeding.

Bleeding in Critically Ill Children With Malignancy or Hematopoietic Cell Transplant: A Single-Center Prospective Cohort Study

OBJECTIVES

To determine the incidence of bleeding in critically ill children with malignancy and to describe associated patient characteristics, interventions, and clinical outcomes.

DESIGN

Prospective cohort study.

SETTING

PICU in a specialized cancer hospital.

PATIENTS

Children with malignancy or hematopoietic cell transplant 0-18 years of age were admitted to the PICU from November 2020 to November 2021.

INTERVENTIONS

None.

MEASUREMENTS

Patient demographic data, laboratory values, and PICU outcome data were collected. Bleeding was classified according to the Bleeding Assessment Scale in Critically Ill Children.

MAIN RESULTS

Ninety-three bleeding patients were enrolled, and a total of 322 bleeding days were recorded. The median (interquartile range [IQR]) age was 5.8 (2.9-11.8) years and 56% (52/93) of the patients were male. There were 121 new bleeding episodes, in 593 at-risk person-days, translating into a 20% incidence rate per day (95% CI, 17-24%). The incidence of severe, moderate, and minimal bleeding was 2% (95% CI, 1-3), 4% (95% CI, 3-6), and 14% (95% CI, 12-17), respectively. Of the new bleeding episodes, 9% were severe, 25% were moderate and 66% were minimal. Thrombocytopenia was the only laboratory value independently associated with severe bleeding ( p = 0.009), as compared to minimal and moderate bleeding episodes. History of radiation therapy was independently associated with severe bleeding ( p = 0.04). We failed to identify an association between a history of stem cell transplant ( p = 0.49) or tumor type ( p = 0.76), and bleeding severity. Patients were transfused any blood product on 28% (95% CI, 22-34) of the bleeding days. Severe bleeding was associated with increased length of mechanical ventilation ( p = 0.003), longer PICU stays ( p = 0.03), and higher PICU mortality ( p = 0.004).

CONCLUSIONS

In this prospective cohort of children with malignancy, the incidence rate of bleeding was 20%. Most events were classified as minimal bleeding. Low platelet count and radiation therapy were variables independently associated with severe bleeding episodes.

Epidemiology of severe bleeding in children following cardiac surgery involving cardiopulmonary bypass: use of Bleeding Assessment Scale for critically Ill Children (BASIC)

OBJECTIVES

To describe the epidemiology of severe bleeding in the immediate post-operative period in children who undergo cardiopulmonary bypass surgery using the Bleeding Assessment Scale for critically Ill Children (BASIC).

STUDY DESIGN

Retrospective cohort study in a paediatric ICU from 2015 to 2020.

RESULTS

356 children were enrolled; 59% were male with median (IQR) age 2.1 (0.5-8) years. Fifty-seven patients (16%) had severe bleeding in the first 24 hours post-operatively. Severe bleeding was observed more frequently in younger and smaller children with longer bypass and cross-clamp times (p-values <0.001), in addition to higher surgical complexity (p = 0.048). Those with severe bleeding received significantly more red blood cells, platelets, plasma, and cryoprecipitate in the paediatric ICU following surgery (all p-values <0.001). No laboratory values obtained on paediatric ICU admission were able to predict severe post-operative bleeding. Those with severe bleeding had significantly less paediatric ICU-free days (p = 0.010) and mechanical ventilation-free days (p = 0.013) as compared to those without severe bleeding.

CONCLUSIONS

Applying the BASIC definition to our cohort, severe bleeding occurred in 16% of children in the first day following cardiopulmonary bypass. Severe bleeding was associated with worse clinical outcomes. Standard laboratory assays do not predict bleeding warranting further study of available laboratory tests.

Thrombosis and hemorrhage experienced by hospitalized children with SARS-CoV-2 infection or MIS-C: Results of the PICNIC registry

INTRODUCTION

Coagulopathy and thrombosis associated with SARS-CoV-2 infection are well defined in hospitalized adults and leads to adverse outcomes. Pediatric studies are limited.

METHODS

An international multicentered (n = 15) retrospective registry collected information on the clinical manifestations of SARS-CoV-2 and multisystem inflammatory syndrome (MIS-C) in hospitalized children from February 1, 2020 through May 31, 2021. This sub-study focused on coagulopathy. Study variables included patient demographics, comorbidities, clinical presentation, hospital course, laboratory parameters, management, and outcomes.

RESULTS

Nine hundred eighty-five children were enrolled, of which 915 (93%) had clinical information available; 385 (42%) had symptomatic SARS-CoV-2 infection, 288 had MIS-C (31.4%), and 242 (26.4%) had SARS-CoV-2 identified incidentally. Ten children (1%) experienced thrombosis, 16 (1.7%) experienced hemorrhage, and two (0.2%) experienced both thrombosis and hemorrhage. Significantly prevalent prothrombotic comorbidities included congenital heart disease (p-value .007), respiratory support (p-value .006), central venous catheter (CVC) (p = .04) in children with primary SARS-CoV-2 and in those with MIS-C included respiratory support (p-value .03), obesity (p-value .002), and cytokine storm (p = .012). Comorbidities prevalent in children with hemorrhage included age >10 years (p = .04), CVC (p = .03) in children with primary SARS-CoV-2 infection and in those with MIS-C encompassed thrombocytopenia (p = .001) and cytokine storm (p = .02). Eleven patients died (1.2%), with no deaths attributed to thrombosis or hemorrhage.

CONCLUSION

Thrombosis and hemorrhage are uncommon events in children with SARS-CoV-2; largely experienced by those with pre-existing comorbidities. Understanding the complete spectrum of coagulopathy in children with SARS-CoV-2 infection requires ongoing research.

Executive Summary of Recommendations and Expert Consensus for Plasma and Platelet Transfusion Practice in Critically Ill Children: From the Transfusion and Anemia EXpertise Initiative-Control/Avoidance of Bleeding (TAXI-CAB)

OBJECTIVES

Critically ill children frequently receive plasma and platelet transfusions. We sought to determine evidence-based recommendations, and when evidence was insufficient, we developed expert-based consensus statements about decision-making for plasma and platelet transfusions in critically ill pediatric patients.

DESIGN

Systematic review and consensus conference series involving multidisciplinary international experts in hemostasis, and plasma/platelet transfusion in critically ill infants and children (Transfusion and Anemia EXpertise Initiative-Control/Avoidance of Bleeding [TAXI-CAB]).

SETTING

Not applicable.

PATIENTS

Children admitted to a PICU at risk of bleeding and receipt of plasma and/or platelet transfusions.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A panel of 29 experts in methodology, transfusion, and implementation science from five countries and nine pediatric subspecialties completed a systematic review and participated in a virtual consensus conference series to develop recommendations. The search included MEDLINE, EMBASE, and Cochrane Library databases, from inception to December 2020, using a combination of subject heading terms and text words for concepts of plasma and platelet transfusion in critically ill children. Four graded recommendations and 49 consensus expert statements were developed using modified Research and Development/UCLA and Grading of Recommendations, Assessment, Development, and Evaluation methodology. We focused on eight subpopulations of critical illness (1, severe trauma, intracranial hemorrhage, or traumatic brain injury; 2, cardiopulmonary bypass surgery; 3, extracorporeal membrane oxygenation; 4, oncologic diagnosis or hematopoietic stem cell transplantation; 5, acute liver failure or liver transplantation; 6, noncardiac surgery; 7, invasive procedures outside the operating room; 8, sepsis and/or disseminated intravascular coagulation) as well as laboratory assays and selection/processing of plasma and platelet components. In total, we came to consensus on four recommendations, five good practice statements, and 44 consensus-based statements. These results were further developed into consensus-based clinical decision trees for plasma and platelet transfusion in critically ill pediatric patients.

CONCLUSIONS

The TAXI-CAB program provides expert-based consensus for pediatric intensivists for the administration of plasma and/or platelet transfusions in critically ill pediatric patients. There is a pressing need for primary research to provide more evidence to guide practitioners.

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

OBJECTIVES

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

DESIGN

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

SETTING

Not applicable.

PATIENTS

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

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

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

CONCLUSIONS

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

Plasma and Platelet Transfusion Strategies in Critically Ill Children Following Noncardiac Surgery and Critically Ill Children Undergoing Invasive Procedures Outside the Operating Room: From the Transfusion and Anemia EXpertise Initiative-Control/Avoidance of Bleeding

OBJECTIVES

To present consensus statements and supporting literature for plasma and platelet transfusions in critically ill children following noncardiac surgery and critically ill children undergoing invasive procedures outside the operating room from the Transfusion and Anemia EXpertise Initiative - Control/Avoidance of Bleeding.

DESIGN

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

SETTING

Not applicable.

PATIENTS

Critically ill children undergoing invasive procedures outside of the operating room or noncardiac surgery.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A panel of 10 experts developed evidence-based and, when evidence was insufficient, expert-based statements for plasma and platelet transfusions in critically ill children following noncardiac surgery or undergoing invasive procedures outside of the operating room. These statements were reviewed and ratified by the 29 Transfusion and Anemia EXpertise Initiative-Control/Avoidance of Bleeding experts. A systematic review was conducted using MEDLINE, EMBASE, and Cochrane Library databases, from inception to December 2020. Consensus was obtained using the Research and Development/University of California, Los Angeles Appropriateness Method. Results were summarized using the Grading of Recommendations Assessment, Development, and Evaluation method. We developed eight expert consensus statements focused on the critically ill child following noncardiac surgery and 10 expert consensus statements on the critically ill child undergoing invasive procedures outside the operating room.

CONCLUSIONS

Evidence regarding plasma and platelet transfusion in critically ill children in this area is very limited. The Transfusion and Anemia EXpertise Initiative-Control/Avoidance of Bleeding Consensus Conference developed 18 pediatric specific consensus statements regarding plasma and platelet transfusion management in these critically ill pediatric populations.

Epidemiology of Bleeding in Critically Ill Children With an Underlying Oncologic Diagnosis

Supplemental Digital Content is available in the text.

Critically ill children with malignancy have significant risk of bleeding but the exact epidemiology is unknown. We sought to describe severe bleeding events and associated risk factors in critically ill pediatric patients with an underlying oncologic diagnosis using the newly developed Bleeding Assessment Scale in Critically Ill Children definition.

Efficacy of Early Prophylaxis Against Catheter-Associated Thrombosis in Critically Ill Children: A Bayesian Phase 2b Randomized Clinical Trial

OBJECTIVES

We obtained preliminary evidence on the efficacy of early prophylaxis on the risk of central venous catheter-associated deep venous thrombosis and its effect on thrombin generation in critically ill children.

DESIGN

Bayesian phase 2b randomized clinical trial.

SETTING

Seven PICUs.

PATIENTS

Children less than 18 years old with a newly inserted central venous catheter and at low risk of bleeding.

INTERVENTION

Enoxaparin adjusted to anti-Xa level of 0.2-0.5 international units/mL started at less than 24 hours after insertion of central venous catheter (enoxaparin arm) versus usual care without placebo (usual care arm).

MEASUREMENTS AND MAIN RESULTS

At the interim analysis, the proportion of central venous catheter-associated deep venous thrombosis on ultrasonography in the usual care arm, which was 54.2% of 24 children, was significantly higher than that previously reported. This resulted in misspecification of the preapproved Bayesian analysis, reversal of direction of treatment effect, and early termination of the randomized clinical trial. Nevertheless, with 30.4% of 23 children with central venous catheter-associated deep venous thrombosis on ultrasonography in the enoxaparin arm, risk ratio of central venous catheter-associated deep venous thrombosis was 0.55 (95% credible interval, 0.24-1.11). Including children without ultrasonography, clinically relevant central venous catheter-associated deep venous thrombosis developed in one of 27 children (3.7%) in the enoxaparin arm and seven of 24 (29.2%) in the usual care arm (p = 0.02). Clinically relevant bleeding developed in one child randomized to the enoxaparin arm. Response profile of endogenous thrombin potential, a measure of thrombin generation, was not statistically different between trial arms.

CONCLUSIONS

These findings suggest the efficacy and safety of early prophylaxis that should be validated in a pivotal randomized clinical trial.

Pediatric Fibrinogen PART II-Overview of Indications for Fibrinogen Use in Critically Ill Children

Bleeding is frequently seen in critically ill children and is associated with increased morbidity and mortality. Fibrinogen is an essential coagulation factor for hemostasis and hypofibrinogenemia is an important risk factor for bleeding in pediatric and adult settings. Cryoprecipitate and fibrinogen concentrate are often given to critically ill children to prevent bleeding and improve fibrinogen levels, especially in the setting of surgery, trauma, leukemia, disseminated intravascular coagulopathy, and liver failure. The theoretical benefit of fibrinogen supplementation to treat hypofibrinogenemia appears obvious, yet the evidence to support fibrinogen supplementation in children is sparce and clinical indications are poorly defined. In addition, it is unknown what the optimal fibrinogen replacement product is in children and neonates or what the targets of treatment should be. As a result, there is considerable variability in practice. In this article we will review the current pediatric and applicable adult literature with regard to the use of fibrinogen replacement in different pediatric critical care contexts. We will discuss the clinical indications for fibrinogen supplementation in critically ill children and the evidence to support their use. We summarize by highlighting current knowledge gaps and areas for future research.

Risks of venous thrombosis and bleeding in critically ill adolescents after trauma or major surgery

BACKGROUND

The risks of venous thromboembolism (VTE) and bleeding in critically ill adolescents based on interventions received and anatomic site of trauma or major surgery may identify a cohort eligible for enrollment in a trial of pharmacologic prophylaxis.

METHODS

This retrospective cohort study using the Virtual Pediatric Systems database included adolescents admitted to pediatric intensive care units after trauma or major surgery between 2013 and 2017. Mixed effects logistic regression was used to determine the adjusted risks of VTE and bleeding with central venous catheterization (CVC), mechanical ventilation (MV) and anatomic site of trauma or major surgery. The adjusted risks were used to identify the cohort eligible for enrollment.

MEASUREMENTS AND MAIN RESULTS

VTE developed in 212 (0.8%) of 27,647 adolescents. The adjusted risk of VTE was >2% with CVC and 2 or more of MV and trauma or major surgery to the brain or abdomen. Excluding those with bleeds present on admission or at high risk of bleeding, 375 (1.4%) adolescents would be eligible for enrollment.

CONCLUSIONS

VTE is generally uncommon in adolescents after trauma or major surgery. The small proportion of adolescents who are at high risk of VTE and at low risk of bleeding impacts the feasibility of a trial.

LEVEL OF EVIDENCE

Prognostic Study Level II.

Bleeding in Critically Ill Children-Review of Literature, Knowledge Gaps, and Suggestions for Future Investigation

Clinically significant bleeding complicates up to 20% of admissions to the intensive care unit in adults and is associated with severe physiologic derangements, requirement for significant interventions and worse outcome. There is a paucity of published data on bleeding in critically ill children. In this manuscript, we will provide an overview of the epidemiology and characteristics of bleeding in critically ill children, address the association between bleeding and clinical outcomes, describe the current definitions of bleeding and their respective limitations, and finally provide an overview of current knowledge gaps and suggested areas for future research.

Epidemiology of Bleeding in Critically Ill Children

Objective: Bleeding can be a severe complication of critical illness, but its true epidemiologic impact on children has seldom been studied. Our objective is to describe the epidemiology of bleeding in critically ill children, using a validated clinical tool, as well as the hemostatic interventions and clinical outcomes associated with bleeding. Design: Prospective observational cohort study. Setting: Tertiary pediatric critical care unit Patients: All consecutive patients (1 month to 18 years of age) admitted to a tertiary pediatric critical care unit Measurements and Main Results: Bleeding events were categorized as minimal, moderate, severe, or fatal, according to the Bleeding Assessment Scale in Critically Ill Children. We collected demographics and severity at admission, as evaluated by the Pediatric Index of Mortality. We used regression models to compare the severity of bleeding with outcomes adjusting for age, surgery, and severity. Over 12 months, 902 critically ill patients were enrolled. The median age was 64 months (IQR 17; 159), the median admission predicted risk of mortality was 0.5% (IQR 0.2; 1.4), and 24% were post-surgical. Eighteen percent of patients experienced at least one bleeding event. The highest severity of bleeding was minimal for 7.9% of patients, moderate for 5.8%, severe for 3.8%, and fatal for 0.1%. Adjusting for age, severity at admission, medical diagnosis, type of surgery, and duration of surgery, bleeding severity was independently associated with fewer ventilator-free days (p < 0.001) and fewer PICU-free days (p < 0.001). Adjusting for the same variables, bleeding severity was independently associated with an increased risk of mortality (adjusted odds ratio for each bleeding category 2.4, 95% CI 1.5; 3.7, p < 0.001). Conclusion: Our data indicate bleeding occurs in nearly one-fifth of all critically ill children, and that higher severity of bleeding was independently associated with worse clinical outcome. Further multicenter studies are required to better understand the impact of bleeding in critically ill children.

Reassessing the Use of Proton Pump Inhibitors and Histamine-2 Antagonists in Critically Ill Children: A Systematic Review and Meta-Analysis

OBJECTIVE

To determine the associations of stress ulcer prophylaxis with gastrointestinal (GI) bleeding, nosocomial pneumonia (NP), mortality, and length of stay in the pediatric intensive care unit (PICU).

STUDY DESIGN

We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) and observational studies in the English language assessing the effects of proton pump inhibitors and histamine-2 receptor antagonists on patients in the PICU published before October 2018 from the PubMed, Embase, CINAHL, and Cochrane Central Register of Controlled Trials databases. A random-effects Mantel-Haenszel risk difference (MHRD) model was used to pool all the selected studies for meta-analysis. Primary outcomes were the incidences of GI bleeding and NP. Secondary outcomes included mortality and length of PICU stay.

RESULTS

Seventeen studies (4 RCTs and 13 observational studies) with a total of 340 763 patients were included. The overall incidence of GI bleeding was 15.2%. There was no difference in the risk of GI bleeding based on stress ulcer prophylaxis status (MHRD, 5.0%; 95% CI, -1.0% to 11.0%; I² = 62%). There was an increased risk of NP in patients who received stress ulcer prophylaxis compared with those who did not (MHRD, 5.3%; 95% CI, 3.5%-7.0%; I² = 0%). An increased risk of mortality was seen in patients receiving stress ulcer prophylaxis (MHRD, 2.1%; 95% CI, 2.0%-2.2%; I² = 0%), although this association was no longer found when 1 large study was removed in a sensitivity analysis. There was no statistically significant difference in length of PICU stay between the groups (standardized mean difference, 0.42 days; 95% CI, -0.16 to 1.01 days; I² = 89.8%).

CONCLUSIONS

Stress ulcer prophylaxis does not show a clear benefit in reducing GI bleeding or length of PICU stay. Observational studies suggest an increased risk of NP and mortality with stress ulcer prophylaxis, which remains to be validated in clinical trials.

Post-operative discharge education for parent caregivers of children with congenital heart disease: a needs assessment

OBJECTIVE

Children with congenital heart disease (CHD) have complex unique post-operative care needs. Limited data assess parents' hospital discharge preparedness and education quality following cardiac surgery. The goals were to identify knowledge gaps in discharge preparedness after congenital heart surgery and to assess the acceptability of an educational mobile application to improve discharge preparedness.

METHODS

Telephonic interviews with parents of children with two-ventricle physiology who underwent cardiac surgery 5-7 days post-discharge and in-person interviews with clinicians were conducted. We collected parent and clinician demographics, parent health literacy information and patient clinical data. We analysed interview transcripts using summative content analysis.

RESULTS

We interviewed 26 parents and 6 clinicians. Twenty-two of the 26 (85%) parents felt ready for discharge; 4 of the 6 (67%) clinicians did not feel most parents were ready for discharge. Fifteen of the 26 parents (58%) reported receiving the majority of discharge teaching on the day of discharge. Eight parents did not feel like all of their questions were answered. Most parents (14/26, 54%) preferred visual educational learning aids and could accurately describe important aspects of care. Most parents (23/26, 88%) and all 6 clinicians felt a mobile application for post-operative care education would be helpful.

CONCLUSIONS

Most parents received education on the day of discharge and could describe the information they received prior to discharge, although there were some preparedness gaps identified after discharge. Clinicians and parents varied in their perceptions of the readiness for discharge. Most responses suggest that a mobile application for discharge education may be helpful for transition to home.

Bayesian analysis of the epidemiology of bleeding in critically ill children

PURPOSE

We updated our findings on the epidemiology of clinically relevant bleeding (CRB) in critically ill children. We also determined the concordance of CRB as defined by the International Society of Thrombosis and Haemostasis, i.e., ISTH definition, and characteristics identified by pediatric intensivists in a recent survey, i.e., survey definition.

METHODS

In a prospective cohort study, we included children <18 years old who were admitted to the pediatric intensive care unit for >1 day. We followed them daily for bleeding. Bayesian inference was used as the primary analytic tool to incorporate our prior findings.

RESULTS

Using the ISTH definition, the estimated frequency of CRB was 10.0% (95% credible interval, CrI: 7.6%, 12.8%) from 41 of 405 children who had CRB. The estimated frequency from 4 of 12 adolescents >13 years old who received mechanical ventilation or vasopressor support and had CRB was 32.9% (95% CrI: 12.0%, 58.8%). Using the survey definition, the estimated frequency of CRB for the entire cohort was 10.8% (95% CrI: 8.3%, 13.8%). Concordance between definitions for each bleeding event was 0.40 (95% confidence interval: 0.27, 0.52).

CONCLUSIONS

Our updated findings highlight the high frequency of CRB regardless of definition used for CRB.

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.

Quantifiable Bleeding in Children Supported by Extracorporeal Membrane Oxygenation and Outcome

OBJECTIVES

To evaluate the association between bleeding from chest tubes and clinical outcomes in children supported by extracorporeal membrane oxygenation.

DESIGN

Secondary analysis of a large observational cohort study.

SETTING

Eight pediatric institutions within the Eunice Kennedy Shriver National Institute of Child Health and Human Development's Collaborative Pediatric Critical Care Research Network.

PATIENTS

Critically ill children supported by extracorporeal membrane oxygenation.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Daily chest tube bleeding, results from hemostatic assays, transfusion volumes, 90-day PICU-free days, and mortality were collected prospectively by trained bedside extracorporeal membrane oxygenation specialists and research coordinators. Extracorporeal membrane oxygenation was employed in the care of 514 consecutive patients. Sixty percent of patients had at least one episode of chest tube bleeding (median chest tube blood volume over the entire extracorporeal membrane oxygenation course was 123 mL/kg [interquartile range, 47-319 mL/kg]). Twenty-six percent had at least 1 day of bleeding from the chest tube greater than 100 mL/kg/d. The number of days with chest tube bleeding greater than 60 mL/kg/d was independently associated with increased in-hospital mortality (adjusted odds ratio, 1.43; 95% CI, 1.05-1.97; p = 0.02) and decreased PICU-free days (beta coefficient, -4.2; 95% CI, -7.7 to -0.6; p = 0.02). The total amount of bleeding from chest tube were independently associated with increased mortality (per mL/kg/extracorporeal membrane oxygenation run; adjusted odds ratio, 1.002; 95% CI, 1.000-1.003; p = 0.04). Fibrinogen, weight, indication for extracorporeal membrane oxygenation, and need for hemodialysis were independently associated with chest tube bleeding, whereas platelet count, coagulation tests, heparin dose, and thrombotic events were not.

CONCLUSIONS

In children supported by extracorporeal membrane oxygenation, chest tube bleeding above 60 mL/kg/d was independently associated with worse clinical outcome. Low fibrinogen was independently associated with chest tube bleeding, whereas platelet count and hemostatic tests were not. Further research is needed to evaluate if interventions to prevent or stop chest tube bleeding influence the clinical outcome.

Protein biomarkers for incident deep venous thrombosis in critically ill adolescents: An exploratory study

BACKGROUND

There are no tests to identify critically ill children at high risk of deep venous thrombosis (DVT). In this exploratory study, we aimed to identify proteins that are associated with incident DVT in critically ill adolescents.

PROCEDURE

Plasma samples were obtained from critically ill adolescents within 24 hours after initiation of cardiopulmonary support. The adolescents were followed with ultrasound to detect the development of DVT of the lower extremity and clinically for bleeding. Thrombin-antithrombin complex and prothrombin fragment 1+2 were measured using immunosorbent assays, whereas procoagulation and anticoagulation factors were measured using multiplex assays. Plasma samples were also analyzed using SOMAscan, an aptamer-based capture assay. The associations between DVT and the log-transformed level of the proteins were assessed using logistic regression adjusting for the presence of femoral venous catheter and severity of illness. Associations were expressed as odds ratio (OR) for every log-fold increase in level of the protein with 95% confidence interval (CI).

RESULTS

Plasma from 59 critically ill adolescents, of whom 9 developed incident DVT, was analyzed. The median age of the adolescents was 15.1 years (interquartile range, 14.0-16.7 years). Higher levels of thrombin-antithrombin complex (OR: 31.54; 95% CI: 2.09-475.92) and lower levels of factor XIII (OR: 0.03; 95% CI: 0.002-0.44) were associated with DVT. CD36, MIC-1, and EpoR were marginally associated with DVT. Only factor XIII was associated with clinically relevant bleeding (OR: 0.27; 95% CI: 0.08-0.97).

CONCLUSIONS

We identified candidate protein biomarkers for incident DVT. We plan to validate our findings in adequately powered studies.

Evaluation of Intravenous Ranitidine on Gastric pH in Critically Ill Pediatric Patients

OBJECTIVE

To determine the dosing regimen of intravenous ranitidine (IVR) most likely to achieve a gastric pH of ≥4 in critically ill pediatric patients.

METHODS

A retrospective cohort study was designed and included patients younger than 19 years with gastric pH samples taken from a nasogastric tube within 24 hours after a dose of IVR in an intensive care unit. Data collection included patient demographics, clinical variables, IVR dosing, and gastric pH samples. Descriptive statistical analysis and multivariable logistic regression analysis with clustering of patients was performed to determine variables associated with odds of obtaining a pH of ≥4.

RESULTS

A total of 628 patients (1356 nasogastric samples) met study criteria (median age 1.3 years [IQR, 0.33, 5.7 years]; 53% male). The IVR dose was 0.90 ± 0.30 mg/kg per dose every 8.1 ± 2.9 hours, and 60.9% of patients (n = 383) had a pH ≥4. Patients with a pH value ≥4 had gastric pH samples taken earlier after a dose of IVR (6.7 ± 5.0 vs. 5.9 ± 4.7 hours, p < 0.001) but had no difference in IVR dose per kilogram (0.88 ± 0.31 vs. 0.88 ± 0.26, p = 0.86) or frequency of dosing (7.9 ± 3.2 vs. 7.9 ± 3.2 hours, p = 0.89). A multivariable logistic regression model identified increasing age, decreased kidney function, and decreased time to pH sample after an IVR dose with significantly greater odds of pH ≥4.

CONCLUSIONS

The IVR dosing to maintain a gastric pH ≥4 in critically ill pediatric patients should occur more frequently than every 8 hours. Gastric pH evaluation may be necessary to assess IVR efficacy.

Epidemiology of Clinically Relevant Bleeding in Critically Ill Adolescents

OBJECTIVES

The epidemiology of clinically relevant bleeding in critically ill adolescents, particularly those who are at high risk of venous thromboembolism, is unclear. In preparation for a randomized clinical trial of pharmacologic prophylaxis against venous thromboembolism, we characterized the epidemiology of clinically relevant bleeding in critically ill adolescents.

DESIGN

Post hoc analysis of data from a pediatric multicenter observational study of venous thromboembolism.

SETTING

Six PICUs.

PATIENTS

Adolescents 13-17 years old who received cardiac or pulmonary support for at least 48 hours were eligible. Those admitted with venous thromboembolism or receiving therapeutic anticoagulation were excluded.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Adolescents (n = 88) were followed daily for the development of any bleeding event. The severity of the event was categorized based on the definitions by the International Society on Thrombosis and Haemostasis. The frequency of clinically relevant bleeding was 29.5% (95% CI, 20.3-40.2%) or 3.7 events (95% CI, 2.5-5.4 events) per 100 patient-days. Adolescents with venous thromboembolism were more likely to develop clinically relevant bleeding (hazard ratio, 2.06; 95% CI, 1.08-3.94). Age was negatively associated with clinically relevant bleeding (hazard ratio for every 1-year increase in age: 0.68; 95% CI, 0.58-0.79). In contrast, predicted risk of mortality (hazard ratio for every 0.10 increase in risk: 1.35; 95% CI, 1.05-1.74) and admission for trauma or surgery (hazard ratio: 2.04; 95% CI, 1.21-3.44) were positively associated with clinically relevant bleeding. The association of clinically relevant bleeding with medications, interventions, or laboratory tests, including mechanical ventilation and pharmacologic prophylaxis with anticoagulation, did not reach statistical significance. Adolescents with clinically relevant bleeding stayed in the hospital longer than those without clinically relevant bleeding.

CONCLUSIONS

Clinically relevant bleeding is common in critically ill adolescents who are at high risk of venous thromboembolism. Admission for trauma or surgery can be used to stratify the risk of clinically relevant bleeding in these adolescents.

Bleeding Scales Applicable to Critically Ill Children: A Systematic Review

OBJECTIVES

To summarize current bleeding scales and their validation to assess applicability to bleeding in critically ill children.

DATA SOURCES

We conducted electronic searches of Ovid MEDLINE, Ovid EMBASE, Cochrane Library, and Web of Science Core Collection databases from database inception to 2017.

STUDY SELECTION

Included studies contained a bleeding score, bleeding measurement tool, or clinical measurement of hemorrhage.

DATA EXTRACTION

We identified 2,097 unique citations; 20 full-text articles were included in the final review.

DATA SYNTHESIS

Of the 18 studies that included subjects (two others were expert consensus definitions), seven (39%) were pediatric-only, seven (39%) were adult-only, and four (22%) included both adults and children. Nine (50%) occurred with inpatients (two studies in critical care units), seven (39%) involved outpatients and two (11%) included both inpatients and outpatients. Thirty-nine percent of the scales were developed for those with idiopathic thrombocytopenic purpura and only two (12%) described critically ill patients. The majority (80%) included need for treatment (either RBC transfusion or surgical intervention). The majority (65%) did not report measures of reliability or validation to clinical outcomes.

CONCLUSIONS

There is a lack of validated bleeding scales to adequately assess bleeding and outcomes in critically ill children. Validated scales of bleeding are necessary and urgently needed.

Aspirin in childhood acute ischemic stroke: The evidence for treatment and efficacy testing

Aspirin is the most commonly prescribed antiplatelet agent worldwide, but evidence supporting its use varies by age and disease process. Despite its frequent use in childhood acute ischemic stroke prevention and management, major knowledge gaps exist about optimal pediatric aspirin use, particularly in this setting, where high-quality clinical trials are urgently needed. This review focuses upon the evidence for aspirin use in childhood acute ischemic stroke, includes a summary of aspirin pharmacology to highlight misconceptions and common clinical situations which may limit its efficacy, and discusses the techniques and potential role of laboratory monitoring of aspirin efficacy in children.

Criteria for Clinically Relevant Bleeding in Critically Ill Children: An International Survey

OBJECTIVES

Bleeding, a feared complication of critical illness, is frequent in critically ill children. However, the concept of clinically relevant bleeding is ill-defined in this population. There are many established diagnostic criteria for bleeding, but only one estimates bleeding in critically ill adults, and none exist for critically ill children. Our objective was to identify the factors that influence pediatric intensivists' perception of clinically relevant bleeding.

DESIGN

Self-administered, web-based survey with 9-point Likert scales, to qualify the clinical significance of 103 bleeding characteristics in critically ill children.

SETTING

Online survey.

SUBJECTS

Pediatric critical care physicians and nurse practitioners.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The response rate was 40%, with 225 respondents from 16 countries. Characteristics most frequently identified as clinically relevant were bleeding in critical locations (e.g., pericardium, pleural space, CNS, and lungs); requiring interventions; leading to physiologic repercussions, including organ failure; and of prolonged duration. Quantifiable bleeding greater than 5 mL/kg/hr for more than 1 hour was frequently considered clinically relevant. Respondents identified the following characteristics as clinically irrelevant: dressings required to be changed no less frequently than every 6 hours, streaks of blood in gastric tubes, streaks of blood in endotracheal tubes or blood in endotracheal tubes only during suctioning, lightly blood-tinged urine, quantifiable bleeding less than 1 mL/kg/hr, and noncoalescing petechiae. Perception of the clinical relevance of bleeding was not associated with the respondent's geographical location of clinical practice or years of experience.

CONCLUSIONS

This international survey provides a better understanding of the factors that influence the pediatric intensivists' assessment of the clinical relevance of bleeding in critically ill children. It provides the foundation for the development of a validated, diagnostic definition of clinically relevant bleeding in this population.

Recommendations on RBC Transfusion in Critically Ill Children With Nonlife-Threatening Bleeding or Hemorrhagic Shock From the Pediatric Critical Care Transfusion and Anemia Expertise Initiative

OBJECTIVES

To present the recommendations and supporting literature for RBC transfusions in critically ill children with bleeding developed by the Pediatric Critical Care Transfusion and Anemia Expertise Initiative.

DESIGN

Consensus conference series of international, multidisciplinary experts in RBC transfusion management of critically ill children.

METHODS

The panel of 38 experts developed evidence-based and, when evidence was lacking, expert-based clinical recommendations as well as research priorities for RBC transfusions in critically ill children. The bleeding subgroup included five experts. Electronic searches were conducted using PubMed, EMBASE, and Cochrane Library databases from 1980 to May 2017. Agreement was obtained using the Research and Development/UCLA Appropriateness Method. Results were summarized using the Grading of Recommendations Assessment, Development, and Evaluation method.

RESULTS

Transfusion and Anemia Expertise Initiative Consensus Conference experts developed a total of six recommendations focused on transfusion in the critically ill child with acute bleeding. In critically ill children with nonlife-threatening bleeding, we recommend giving a RBC transfusion for a hemoglobin concentration less than 5 g/dL, and be considered for a hemoglobin concentration between 5 and 7 g/dL. In critically ill children with hemorrhagic shock, we suggest that RBCs, plasma and platelets transfusion ratio between 2:1:1 to 1:1:1 until the bleeding is no longer life-threatening. We recommend future studies to develop physiologic and laboratory measures to indicate the need for RBC transfusions, and to determine if goal directed hemostatic resuscitation improves survival. Finally, we recommend future studies to determine if low titer group O whole blood is more efficacious and safe compared with reconstituted whole blood in children with hemorrhagic shock.

CONCLUSIONS

The Transfusion and Anemia Expertise Initiative Consensus Conference developed pediatric specific recommendations regarding RBC transfusion management in the critically ill child with acute bleeding, as well as recommendations to help guide future research priorities.