Jennifer McArthur

Incidence and risk factors associated with venous thrombotic events in pediatric intensive care unit patients.

Objective: To evaluate the incidence and risk factors associated with venous thromboembolism (VTE) in children admitted to pediatric intensive care units (PICUs). Design: Prospective observational study. Setting: Eleven tertiary care PICUs in the United States. Patients: Children who were admitted to PICUs and had radiographically confirmed VTE over a rolling 6-month period were enrolled in the study. Demographic, patient-related, and outcomes data were collected and compared with all children admitted during the same period. Interventions: None. Results: Sixty-six symptomatic VTE were documented in sixty-two patients among 6653 patients admitted to 11 PICUs. Thirteen (19.7%) of the thrombi were present on admission. The incidence rate was 0.74% (range, 0–2.7% per PICU) with a point prevalence of 0.93%. Doppler ultrasound was most frequently used to diagnose or confirm a suspected VTE. Variables associated with unadjusted risk for VTE include: younger age (3.8 months for patients with VTE vs. 51 months for non-VTE patients, p < .001), cardiac diagnosis (41% in VTE cases vs. 15% in non-VTE, p < .001), pre-/post-operative status (63% in VTE cases vs. 40% in non-VTE, p = .001), presence of central venous catheter (88% in VTE case vs. 17% in non-VTE, p < .001), or mechanical ventilation (85% in VTE cases vs. 30% non-VTE, p < .001). Multivariate analysis showed increased risk of VTE with CVC (odds ratio 6.9; confidence interval 2.7–17.5) and mechanical ventilation (odds ratio 2.8; confidence interval 0.98–7.93). Children with VTE were sicker (Pediatric Index of Mortality 2 score risk of mortality of 3.0% vs. 0.9%; p<0.0001), stayed longer in the ICU (21.2 days vs. 1.6 days; p < .0001) and had increased mortality (10.2% vs. 2.6; p < .0001). Conclusions: Children admitted to the PICU have an increased risk of VTE. The presence of a CVC is the strongest risk factor for VTE in this PICU population. Children with VTE were younger, sicker, stayed longer in PICU, and had a higher mortality rate.

Lower hospital mortality and complications after pediatric hematopoietic stem cell transplantation.

Objective:To assess protective and risk factors for mortality among pediatric patients during initial care after hematopoietic stem cell transplantation (HSCT) and to evaluate changes in hospital mortality. Design:Retrospective cohort using the 1997, 2000, and 2003 Kids Inpatient Database, a probabilistic sample of children hospitalized in the United States with a procedure code for HSCT. Setting:Hospitalized patients in the United States submitted to the database. Patients:Age, <19 yrs. Interventions:None. Measurements and Main Results:Hospital mortality significantly decreased from 12% in 1997 to 6% in 2003. Source of stem cells changed with increased use of cord blood. Rates of sepsis, graft versus host disease, and mechanical ventilation significantly decreased. Compared with autologous HSCT, patients who received an allogenic HSCT without T-cell depletion were more likely to die (adjusted odds ratio, 2.4; 95% confidence interval, 1.5, 3.9), while children who received cord blood HSCT were at the greatest risk of hospital death (adjusted odds ratio, 4.8; 95% confidence interval, 2.6, 9.1). Mechanical ventilation (adjusted odds ratio, 26.32; 95% confidence interval, 16.3–42.2), dialysis (adjusted odds ratio, 12.9; 95% confidence interval, 4.7–35.4), and sepsis (adjusted odds ratio, 3.9; 95% confidence interval, 2.5–6.1) were all independently associated with death, while care in 2003 was associated with decreased risk (adjusted odds ratio, 0.4; 95% confidence interval, 0.2–0.7) of death. Conclusions:Hospital mortality after HSCT in children decreased over time as did complications including need for mechanical ventilation, graft versus host disease, and sepsis. Prevention of complications is essential as the need for invasive support continues to be associated with high mortality risk.

Clinical Outcomes of Children Receiving Intensive Cardiopulmonary Support During Hematopoietic Stem Cell Transplant

Objective: We investigated the short-term and 1-year clinical outcomes of 129 children who received intensive cardiopulmonary support during hematopoietic stem cell transplant. Intensive cardiopulmonary support was defined as receiving at least one of the following interventions: continuous positive pressure ventilation, dopamine infusion greater than or equal to 10 mcg/kg/minute, or the use of any other vasoactive infusion. Duration of intensive cardiopulmonary support, survival to hospital discharge, and predictors of these outcome variables were compared with 387 hematopoietic stem cell transplant patients who did not receive intensive support during the same period. We also report the 1-year survival; presence of chronic graft-versus-host disease; and renal, cardiac, and pulmonary function for all patients. Design: A multicenter retrospective cohort study. Setting: The ICU and hematopoietic stem cell transplant unit of nine pediatric tertiary care centers. Patients: Children undergoing hematopoietic stem cell transplant who required intensive cardiopulmonary support. Interventions: None. Results: Predictors of the need for intensive support included unrelated donor allogeneic transplant, glomerular filtration rate less than 85 mL/minute/1.73 m2, and nonmalignant disease as the indication for transplant. The survival to discontinuation of intensive support for all patients was 62% and 58% for patients who received invasive mechanical ventilatory support. The duration of mechanical ventilation was not predictive of survival. Predictors of intensive support mortality included macroscopic bleeding, engraftment, and pediatric logistic organ dysfunction score greater than one in two domains. Survival to hospital discharge was 50% for the intensive support group and 99% for the nonintensive support group. Overall 1-year survival was 40% in the intensive support population and 65% in the nonintensive support group. There were no significant differences in the survival, rates of chronic graft-versus-host disease, creatinine, forced expiratory volume in 1-minute, cardiac shortening fraction, or performance status in intensive and nonintensive support patients who survived to hospital discharge. Conclusion: Intensive cardiopulmonary support plays an important and potentially life-saving role in the care of pediatric stem cell transplant patients. Survivors of intensive support do not have compromised 1-year survival or organ function compared with children who did not receive intensive support.

Invasive Mechanical Ventilation and Mortality in Pediatric Hematopoietic Stem Cell Transplantation: A Multicenter Study.

Objective: To establish the current respiratory practice patterns in pediatric hematopoietic stem cell transplant patients and investigate their associations with mortality across multiple centers. Design: Retrospective cohort between 2009 and 2014. Setting: Twelve children’s hospitals in the United States. Patients: Two hundred twenty-two pediatric allogeneic hematopoietic stem cell transplant recipients with acute respiratory failure using invasive mechanical ventilation. Interventions: None. Measurements and Main Results: PICU mortality of our cohort was 60.4%. Mortality at 180 days post PICU discharge was 74%. Length of PICU stay prior to initiation of invasive mechanical ventilation was significantly lower in survivors, and the odds of mortality increased for longer length of PICU stay prior to intubation. A total of 91 patients (41%) received noninvasive ventilation at some point during their PICU stay prior to intubation. Noninvasive ventilation use preintubation was associated with increased mortality (odds ratio, 2.1; 95% CI, 1.2–3.6; p = 0.010). Patients ventilated longer than 15 days had higher odds of death (odds ratio, 2.4; 95% CI, 1.3–4.2; p = 0.004). Almost 40% of patients (n = 85) were placed on high-frequency oscillatory ventilation with a mortality of 76.5% (odds ratio, 3.3; 95% CI, 1.7–6.5; p = 0.0004). Of the 20 patients who survived high-frequency oscillatory ventilation, 18 were placed on high-frequency oscillatory ventilation no later than the third day of invasive mechanical ventilation. In this subset of 85 patients, transition to high-frequency oscillatory ventilation within 2 days of the start of invasive mechanical ventilation resulted in a 76% decrease in the odds of death compared with those who transitioned to high-frequency oscillatory ventilation later in the invasive mechanical ventilation course. Conclusions: This study suggests that perhaps earlier more aggressive critical care interventions in the pediatric hematopoietic stem cell transplant patient with respiratory failure requiring invasive mechanical ventilation may offer an opportunity to improve outcomes.

Pediatric Acute Respiratory Distress Syndrome in Pediatric Allogeneic Hematopoietic Stem Cell Transplants: A Multicenter Study

Objective: Immunodeficiency is both a preexisting condition and a risk factor for mortality in pediatric acute respiratory distress syndrome. We describe a series of pediatric allogeneic hematopoietic stem cell transplant patients with pediatric acute respiratory distress syndrome based on the recent Pediatric Acute Lung Injury Consensus Conference guidelines with the objective to better define survival of this population. Design: Secondary analysis of a retrospective database. Setting: Twelve U.S. pediatric centers. Patients: Pediatric allogeneic hematopoietic stem cell transplant recipients requiring mechanical ventilation. Interventions: None. Measurements and Main Results: During the first week of mechanical ventilation, patients were categorized as: no pediatric acute respiratory distress syndrome or mild, moderate, or severe pediatric acute respiratory distress syndrome based on oxygenation index or oxygen saturation index. Univariable logistic regression evaluated the association between pediatric acute respiratory distress syndrome and PICU mortality. A total of 91.5% of the 211 patients met criteria for pediatric acute respiratory distress syndrome using the Pediatric Acute Lung Injury Consensus Conference definition: 61.1% were severe, 27.5% moderate, and 11.4% mild. Overall survival was 39.3%. Survival decreased with worsening pediatric acute respiratory distress syndrome: no pediatric acute respiratory distress syndrome 66.7%, mild 63.6%, odds ratio = 1.1 (95% CI, 0.3–4.2; p = 0.84), moderate 52.8%, odds ratio = 1.8 (95% CI, 0.6–5.5; p = 0.31), and severe 24.6%, odds ratio = 6.1 (95% CI, 2.1–17.8; p < 0.001). Nonsurvivors were more likely to have multiple consecutive days at moderate and severe pediatric acute respiratory distress syndrome (p < 0.001). Moderate and severe patients had longer PICU length of stay (p = 0.01) and longer mechanical ventilation course (p = 0.02) when compared with those with mild or no pediatric acute respiratory distress syndrome. Nonsurvivors had a higher median maximum oxygenation index than survivors at 28.6 (interquartile range, 15.5–49.9) versus 15.0 (interquartile range, 8.4–29.6) (p < 0.0001). Conclusion: In this multicenter cohort, the majority of pediatric allogeneic hematopoietic stem cell transplant patients with respiratory failure met oxygenation criteria for pediatric acute respiratory distress syndrome based on the Pediatric Acute Lung Injury Consensus Conference definition within the first week of invasive mechanical ventilation. Length of invasive mechanical ventilation, length of PICU stay, and mortality increased as the severity of pediatric acute respiratory distress syndrome worsened.

The Need for Evidence Based Nutritional Guidelines for Pediatric Acute Lymphoblastic Leukemia Patients: Acute and Long-Term Following Treatment

High survival rates for pediatric leukemia are very promising. With regard to treatment, children tend to be able to withstand a more aggressive treatment protocol than adults. The differences in both treatment modalities and outcomes between children and adults make extrapolation of adult studies to children inappropriate. The higher success is associated with a significant number of children experiencing nutrition-related adverse effects both in the short and long term after treatment. Specific treatment protocols have been shown to deplete nutrient levels, in particular antioxidants. The optimal nutrition prescription during, after and long-term following cancer treatment is unknown. This review article will provide an overview of the known physiologic processes of pediatric leukemia and how they contribute to the complexity of performing nutritional assessment in this population. It will also discuss known nutrition-related consequences, both short and long term in pediatric leukemia patients. Since specific antioxidants have been shown to be depleted as a consequence of therapy, the role of oxidative stress in the pediatric leukemia population will also be explored. More pediatric studies are needed to develop evidence based therapeutic interventions for nutritional complications of leukemia and its treatment.

High Variability in the Reported Management of Hepatic Veno-Occlusive Disease in Children after Hematopoietic Stem Cell Transplantation

Veno-occlusive disease (VOD) is a potentially fatal complication of hematopoietic stem cell transplantation (HSCT). Patients with VOD are often critically ill and require close collaboration between transplant physicians and intensivists. We surveyed members of a consortium of pediatric intensive care unit (PICU) and transplant physicians to assess variability in the self-reported approach to the diagnosis and management of VOD. An internet-based self-administered survey was sent to pediatric HSCT and PICU providers from September 2014 to February 2015. The survey contained questions relating to the diagnosis and treatment of VOD. The response rate was 41% of 382 providers surveyed. We found significant variability in the diagnostic and management approaches to VOD in children. Even though ultrasound is not part of the diagnostic criteria, providers reported using reversal of portal venous flow seen on abdominal ultrasound in addition to Seattle criteria (70%) or Baltimore criteria to make the diagnosis of VOD. Almost 40% of respondents did not diagnose VOD in anicteric patients (bilirubin < 2 mg/dL). Most providers (75%) initiated treatment with defibrotide at the time of diagnosis, but 14%, 7%, and 6% of the providers waited for reversal of portal venous flow, renal dysfunction, or pulmonary dysfunction, respectively, to develop before initiating therapy. Only 50% of the providers restricted fluids to 75% of the daily maintenance, whereas 21% did not restrict fluids at all. Albumin with diuretics was used by 95% of respondents. Platelets counts were maintained at 20,000 to 50,000/mm(3) and 10,000 to 20,000/mm(3) by 64% and 20% of the respondents, respectively. Paracentesis was generally initiated in the setting of oliguria or hypoxia, and nearly 50% of the providers used continuous drainage to gravity, whereas the remainder used an intermittent drainage approach. Nearly 73% of the transplant providers used VOD prophylaxis, whereas the remainder did not use any medications for VOD prophylaxis. There was also considerable variation in the management strategies among the transplant and critical care providers. We conclude that there is considerable self-reported variability in the diagnosis and management of VOD in children. The practice variations reported in this study should encourage the development of standard practice guidelines, which will be helpful in improving the outcome of this potentially fatal complication.

Association of IL-1β -511 polymorphism with severe veno-occlusive disease in pediatric-matched allogeneic hematopoietic stem cell transplantation.

Single nucleotide polymorphisms (SNPs) of the interleukin 1 (IL-1) family have been implicated in acute graft-versus-host disease and mortality postallogeneic hematopoietic stem cell transplantation (HSCT) in adults. Hepatic veno-occlusive disease (VOD) is a well-known complication of HSCT and can result in an increased risk of mortality. In this study, we sought to investigate the association of both patient and donor genotypes at the IL-1&bgr; −511 cytidine/thymidine (C/T) polymorphic site with hepatic VOD and mortality in an exclusive pediatric cohort undergoing matched myeloablative allogeneic HSCT. Donor TT genotype was associated with higher cumulative incidence of grade III-IV hepatic VOD at 3 months after transplantation relative to donor CT and CC genotypes (25±13.1% in TT, 2.9±2.9% in CT, and 3.6±3.6% in CC; P=0.024). Neither recipient nor donor IL-1&bgr; −511 single nucleotide polymorphisms genotypes were associated with mortality or relapse. Our findings suggest that donor, rather than host, genotype at the IL-1&bgr; −511 polymorphic site may associate with higher risk for severe VOD after matched allogeneic HSCT. Our findings challenge the assumption that host factors are exclusively responsible for VOD and suggest a novel role for the donor inflammasome pathway in inducing injury and microvascular disease after HSCT, which merits further study in a larger cohort analysis.

Current treatment practices of venous thromboembolism in children admitted to pediatric intensive care units

Objective:  To describe current treatment practices of VTE in patients admitted to a pediatric intensive care unit (PICU) and compare these practices to published guidelines.

Consensus Report by Pediatric Acute Lung Injury and Sepsis Investigators and Pediatric Blood and Marrow Transplantation Consortium Joint Working Committees: Supportive Care Guidelines for Management of Veno-Occlusive Disease in Children and Adolescents, Part 1: Focus on Investigations, Prophylaxis, and Specific Treatment

Veno-occlusive disease (VOD) is a common and potentially fatal complication in children undergoing hematopoietic cell transplantation (HCT). It occurs in about one-third of all patients undergoing transplantation and is fatal in 50% of patients with severe disease. Early intervention and specific treatment with defibrotide are associated with improved outcomes. However, there is a lack of supportive care guidelines for management of the multiorgan dysfunction seen in most cases. There is high variability in the management of VOD, which may contribute to the increased morbidity and mortality. Although there is ample research in the specific treatment of VOD, there is paucity of literature regarding the management of ascites, transfusions requirements, fluids and electrolyte dysfunction, delirium, and investigations in children with VOD. The joint working committees of the Pediatric Acute Lung Injury and Sepsis Investigators and the Pediatric Blood and Marrow Transplantation Consortium collaborated to develop a series of evidence-based supportive care guidelines for management of VOD. The quality of evidence was rated and recommendations were made using Grading of Recommendations, Assessment, Development and Evaluation criteria. This manuscript is part 1 of the series and focuses on the need to develop these guidelines; methodology used to establish the guidelines; and investigations needed for diagnosis, prophylaxis, and treatment of VOD in children.