Microvascular thrombosis in pediatric multiple organ failure: Is it a therapeutic target?

Therapeutic Plasma Exchange Is Associated With Improved Major Adverse Kidney Events in Children and Young Adults With Thrombocytopenia at the Time of Continuous Kidney Replacement Therapy Initiation

Therapeutic plasma exchange (TPE) has been shown to improve organ dysfunction and survival in patients with thrombotic microangiopathy and thrombocytopenia associated with multiple organ failure. There are no known therapies for the prevention of major adverse kidney events after continuous kidney replacement therapy (CKRT). The primary objective of this study was to evaluate the effect of TPE on the rate of adverse kidney events in children and young adults with thrombocytopenia at the time of CKRT initiation.

DESIGN

Retrospective cohort.

SETTING

Two large quaternary care pediatric hospitals.

PATIENTS

All patients less than or equal to 26 years old who received CKRT between 2014 and 2020.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We defined thrombocytopenia as a platelet count less than or equal to 100,000 (cell/mm3) at the time of CKRT initiation. We ascertained major adverse kidney events at 90 days (MAKE90) after CKRT initiation as the composite of death, need for kidney replacement therapy, or a greater than or equal to 25% decline in estimated glomerular filtration rate from baseline. We performed multivariable logistic regression and propensity score weighting to analyze the relationship between the use of TPE and MAKE90. After excluding patients with a diagnosis of thrombotic thrombocytopenia purpura and atypical hemolytic uremic syndrome (n = 6) and with thrombocytopenia due to a chronic illness (n = 2), 284 of 413 total patients (68.8%) had thrombocytopenia at CKRT initiation (51% female). Of the patients with thrombocytopenia, the median (interquartile range) age was 69 months (13-128 mo). MAKE90 occurred in 69.0% and 41.5% received TPE. The use of TPE was independently associated with reduced MAKE90 by multivariable analysis (odds ratio [OR], 0.35; 95% CI, 0.20-0.60) and by propensity score weighting (adjusted OR, 0.31; 95% CI, 0.16-0.59).

CONCLUSIONS

Thrombocytopenia is common in children and young adults at CKRT initiation and is associated with increased MAKE90. In this subset of patients, our data show benefit of TPE in reducing the rate of MAKE90.

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 Filtration Versus Centrifugation in Pediatric Therapeutic Plasma Exchange: Should the Diagnosis Define the Method?†

Therapeutic plasma exchange (TPE) is used for a variety of illnesses in critically ill pediatric patients. Although both centrifugation and filtration are known to be effective methods, to our knowledge, clinical results for TPE by these methods are not compared in pediatric patient populations. One hundred patients who had TPE for a variety of diagnoses were included in the study. In 55 patients plasma exchange was implemented by centrifugation and in 45, by filtration. These two groups were further divided into subgroups according to admittance diagnoses. The demographic information, admittance Pediatric Risk of Mortality scores, Pediatric Logistic Organ Dysfunction (PELOD) scores before beginning of therapy and PELOD at the end of therapy, durations of ventilatory support, pediatric intensive care unit and hospital stay, and outcomes were compared. Although the survival was significantly better in filtration group, it included more patients with neurologic diagnoses. Filtration group standard mortality rate was 0.6. In both groups, the PELOD scores after the termination of TPE were significantly decreased compared to that before beginning of TPE. Within thrombotic microangiopathy and hemophagocytic lymphohistiocytosis subgroups, median PELOD scores before treatment were higher in centrifugation patients but survival was similar with both methods. Both methods of TPE are alike in decreasing PELOD scores. In the filtration group, survival benefit of TPE is evident. In thrombotic microangiopathy patients, despite higher PELOD scores in the centrifugation group, survival is similar for both methods. These findings should be retested in randomized studies and the underlying physiology awaits to be uncovered.

Role of Damage-Associated Molecular Patterns and Uncontrolled Inflammation in Pediatric Sepsis-Induced Multiple Organ Dysfunction Syndrome

The incidence of multiple organ dysfunction syndrome (MODS) in sepsis varies from 17 to 73% and furthermore, increases the risk of death by 60% when controlled for the number of dysfunctional organs. Several MODS phenotypes exist, each unique in presentation and pathophysiology. Common to the phenotypes is the stimulation of the immune response by pathogen-associated molecular patterns (PAMPs), or danger-associated molecular patterns (DAMPs) causing an unremitting inflammation. Two of the MODS phenotypes are discussed in detail, thrombocytopenia-associated multiple organ failure (TAMOF) and the hyperinflammatory phenotype-macrophage activating syndrome (MAS) and hemophagocytic lymphohistiocytosis (HLH). In the end, we will briefly review the role of mitochondrial dysfunction as a significant contributor to the pathogenesis of MODS.

Thrombocytopenia-associated multiple-organ failure (TAMOF): recognition and management

Thrombocytopenia-associated multiple-organ failure (TAMOF) is an increasingly fatal phenomenon that may be associated with sepsis. TAMOF results from immune dysregulation and impaired activity of A Disintegrin And Metalloproteinase with ThromboSpondin type 1 motif, member 13. Early recognition of this premorbid condition and specific management results in a significantly improved outcome. Herein, we report the presentation and management of a 2-year-old child with TAMOF who was successfully treated with plasma exchange and recovered without long-term sequelae.

Plasma Therapies in Thrombotic Syndromes

Background

Plasma therapies are being applied to thombotic syndromes, but there are limited controlled studies.

Objective

To review the evidence and the current practices for plasma therapies in thrombotic syndromes.

Methods

Expert-enhanced evidence-based analysis. Evidence obtained as of Dec 31, 2002 using Pub Med electronic reference library and expert-obtained library for a total of > 3,000 references obtained using the terms plasma therapy or plasma exchange or plasmapheresis or plasmafiltration or sorbents each combined with the words thrombotic syndrome or sepsis or septic shock. The authors screened the abstracts, reviewed the agreed set of papers, and compiled the recommendations.

Results

Plasma therapies, which alter the plasma components in patients, have been applied in thrombotic syndromes worldwide. In these patients, there is a biologic plausibility for plasma therapies since they have molecules that are prothrombotic and/or antifibrinolytic which would put them at risk for microvascular thrombosis and end-organ damage. There are respectively one randomized controlled trial (RCT) in primary thrombotic syndrome, and secondary thrombotic syndrome, which showed an improvement in mortality in applying plasma therapies (plasma exchange by centrifugation). However, there are numerous non-randomized and case series. Plasma exchange is accepted as the standard therapy for primary thrombotic syndrome as in thrombotic thrombocytopenic purpura (TTP). However, no consensus has been reached for plasma exchange in secondary thrombotic syndromes such as in sepsis, hemolytic uremic syndrome (HUS), thrombocytopenia associated multiple organ failure, TTP/HUS, s/p bone marrow or solid organ transplant, HELLP syndrome, immunologic disorders, drug exposure, or pancreatitis.

Conclusions

As we understand more about the pathophysiology of thrombotic syndromes, specific plasma therapies can be applied for the specific need of a particular patient population. There are sufficient preliminary data to recommend a definitive RCT to evaluate the efficacy of the different types of plasma therapies in secondary thrombotic syndromes.

Plasma Filtration on Mediators of Thrombotic Microangiopathy: An in Vitro Study

Objectives.

Sepsis-induced thrombotic microangiopathy is successfully treated by plasma exchange therapy However, certain putative mediators of thrombotic microangiopathy may not be removed by plasma filtration.

Methods.

We conducted an in vitro study to determine whether plasma filtration can remove ultra-large von Willebrand factor (ULvWF) multimers and other mediators. In separate experiments, human umbilical venous endothelial cell (HUVEC) supernatant enriched with ULvWF or human whole blood was passed through a therapeutic plasma exchange (TPE 2000, PRISMA) filter and samples were taken for measurement of ULvWF, vWF ristocetin cofactor, vWF antigen and PAI-1.

Results.

The sieving coefficients for vWF and PAI-1 were above 0.9. The ULvWF was gradually eliminated, and nearly disappeared after four circulations.

Conclusion.

The TPE 2000 filter can directly remove potential mediators of sepsis-induced thrombotic microangiopathy.

Platelet Transfusions in Pediatric Intensive Care

OBJECTIVES

To characterize the determinants of platelet transfusion in a PICU and determine whether there exists an association between platelet transfusion and adverse outcomes.

DESIGN

Prospective observational single center study, combined with a self-administered survey.

SETTING

PICU of Sainte-Justine Hospital, a university-affiliated tertiary care institution.

PATIENTS

All children admitted to the PICU from April 2009 to April 2010.

INTERVENTION

None.

MEASUREMENTS AND MAIN RESULTS

Among 842 consecutive PICU admissions, 60 patients (7.1%) received at least one platelet transfusion while in PICU. In the univariate analysis, significant determinants for platelet transfusion were admission Pediatric Risk of Mortality Score greater than 10 (odds ratio, 6.80; 95% CI, 2.5-18.3; p < 0.01) and Pediatric Logistic Organ Dysfunction scores greater than 20 (odds ratio, 26.9; 95% CI, 8.88-81.5; p < 0.01), history of malignancy (odds ratio, 5.08; 95% CI, 2.43-10.68; p < 0.01), thrombocytopenia (platelet count, < 50 × 10/L or < 50,000/mm) (odds ratio, 141; 95% CI, 50.4-394.5; p < 0.01), use of heparin (odds ratio, 3.03; 95% CI, 1.40-6.37; p < 0.01), shock (odds ratio, 5.73; 95% CI, 2.85-11.5; p < 0.01), and multiple organ dysfunction syndrome (odds ratio, 10.41; 95% CI, 5.89-10.40; p < 0.01). In the multivariate analysis, platelet count less than 50 × 10/L (odds ratio, 138; 95% CI, 42.6-449; p < 0.01) and age less than 12 months (odds ratio, 3.06; 95% CI, 1.03-9.10; p = 0.02) remained statistically significant determinants. The attending physicians were asked why they gave a platelet transfusion; the most frequent justification was prophylactic platelet transfusion in presence of thrombocytopenia with an average pretransfusion platelet count of 32 ± 27 × 10/L (median, 21), followed by active bleeding with an average pretransfusion platelet count of 76 ± 39 × 10/L (median, 72). Platelet transfusions were associated with the subsequent development of multiple organ dysfunction syndrome (odds ratio, 2.53; 95% CI, 1.18-5.43; p = 0.03) and mortality (odds ratio, 10.1; 95% CI, 4.48-22.7; p < 0.01).

CONCLUSIONS

Among children, 7.1% received at least one platelet transfusion while in PICU. Thrombocytopenia and active bleeding were significant determinants of platelet transfusion. Platelet transfusions were associated with the development of multiple organ dysfunction syndrome and increased mortality.

Thrombocytopenia-associated multi-organ failure caused by diabetic ketoacidosis

Thrombocytopenia-associated multi-organ failure (TAMOF) is an increasingly reported entity in the pediatric intensive care unit. The clinical presentation is similar to thrombotic thrombocytopenic purpura, but with no evidence of hemolysis and no schistocytes on peripheral smear. We report a case of TAMOF induced by diabetic ketoacidosis and treated with therapeutic plasma exchange (TPE). Early diagnosis and initiation of TPE significantly decrease the morbidity associated with TAMOF.

Biology of sepsis: its relevance to pediatric nephrology

Because of its multi-organ involvement, the syndrome of sepsis provides clinical challenges to a wide variety of health care providers. While multi-organ dysfunction triggered by sepsis requires general supportive critical care provided by intensivists, the impact of sepsis on renal function and the ability of renal replacement therapies to modulate its biologic consequences provide a significant opportunity for pediatric nephrologists and related care providers to impact outcomes. In this review, we aim to highlight newer areas of understanding of the pathobiology of sepsis with special emphasis on those aspects of particular interest to pediatric nephrology. As such, we aim to: (1) review the definition of sepsis and discuss advances in our mechanistic understanding of sepsis; (2) review current hypotheses regarding sepsis-induced acute kidney injury (AKI) and describe its epidemiology based on evolving definitions of AKI; (3) review the impact of renal failure on the immune system, highlighting the sepsis risk in this cohort and strategies that might minimize this risk; (4) review how renal replacement therapeutic strategies may impact sepsis-induced AKI outcomes. By focusing the review on these specific areas, we have omitted other important areas of the biology of sepsis and additional interactions with renal function from this discussion; however, we have aimed to provide a comprehensive list of references that provide contemporary reviews of these additional areas.

Use of therapeutic plasma exchange in children with thrombocytopenia-associated multiple organ failure in the Turkish thrombocytopenia-associated multiple organ failure network

OBJECTIVE

Thrombocytopenia-associated multiple organ failure can lead to high mortality in critically ill children, possibly related to consequences of thrombotic microangiopathy. Plasma exchange therapy may improve thrombotic microangiopathy. The purpose of this observational cohort study is to describe whether there is an association between use of plasma exchange therapy and outcome in the Turkish thrombocytopenia-associated multiple organ failure network.

SETTING-INTERVENTIONS

We performed a retrospective cohort analysis in patients with thrombocytopenia-associated multiple organ failure at three different PICUs comparing those who received plasma exchange (+) plus standard therapies with those who did not receive plasma exchange (-) and only received standard therapies.

RESULTS

Among 42 of the enrolled patients with thrombocytopenia-associated multiple organ failure, all had a primary or secondary sepsis diagnosis. Fifteen received plasma exchange therapy (PE [+] group) and 27 received standard medical treatment without plasma exchange (PE [-] group). The mean age was 17.69 months (8.24-54.22) in the PE (+) group and 13.46 months (6.47-20.55) in the PE (-) group. Age (p = 0.232), gender (p = 0.206), thrombocyte count (p = 0.09), Organ Failure Index score (p = 0.111), and pediatric logistic organ dysfunction score (p = 0.177) at admission were not statistically different between groups. The overall 28-day mortality was higher in the PE (-) group (70.37%) compared with the PE (+) group (26.67%) (univariate p = 0.006; multivariate controlling for pediatric logistic organ dysfunction, Organ Failure Index, Pediatric Risk of Mortality scores, and neurological failure p = 0.048). Length of stay was increased in the PE (+) group (p = 0.004).

CONCLUSIONS

The positive association found between use of plasma exchange therapy and improved survival supports the potential of this therapy in Turkish children with thrombocytopenia-associated multiple organ failure. The positive, although less so, associated treatment effect observed after controlling for illness severity provides further rationale for performing a randomized controlled trial in the pediatric Turkish thrombocytopenia-associated multiple organ failure network. Sample size calculations call for a 100-patient trial with a pre hoc interim analysis after enrollment of 50 patients with thrombocytopenia-associated multiple organ failure.

The pediatric multiple organ dysfunction syndrome

OBJECTIVES

To review the epidemiology of pediatric multiple organ dysfunction syndrome (MODS) and summarize current concepts regarding the pathophysiology of shock, organ dysfunction, and nosocomial infections in this population.

DATA SOURCE

A MEDLINE-based literature search using the keywords MODS and child, without any restriction to the idiom.

MAIN RESULTS

Critically ill children may frequently develop multisystemic manifestations during the course of severe infections, multiple trauma, surgery for congenital heart defects, or transplantations. Descriptive scores to estimate the severity of pediatric MODS have been validated. Young age and chronic health conditions have also been recognized as important contributors to the development of MODS. Unbalanced inflammatory processes and activation of coagulation may lead to the development of capillary leak and acute respiratory distress syndrome. Neuroendocrine and metabolic responses may result in insufficient adaptive immune response and the development of nosocomial infections, which may further threaten host homeostasis.

CONCLUSIONS

Over the last 20 yrs, there has been an increasing knowledge on the epidemiology of pediatric MODS and on the physiologic mechanisms involved in the genesis of organ dysfunction. Nevertheless, further studies are needed to more clearly evaluate what is the long-term outcome of pediatric MODS.

Pediatric critical care management of septic shock prior to acute kidney injury and renal replacement therapy

A high index of suspicion for bacterial sepsis and recognition of the potential for rapid deterioration is essential for impacting patient outcome. Meningococcemia produces a stereotypical clinical and biochemical constellation of profound septic shock and purpura fulminans with marked inflammatory disturbance and a complex disruption of coagulation. Meningococcal infections preferentially affect infants and young children, but adolescents are also at risk. Aggressive fluid resuscitation, hemodynamic management, and clinical monitoring are based on understanding of pathophysiologic disturbances typical of the pediatric cardiovascular response and guided by evidence-based guidelines. Appropriate antibiotic choice is important, and corticosteroid use may be beneficial. A variety of efforts to manipulate the coagulation abnormalities may be considered, although evidence is lacking. Extracorporeal support remains a consideration both for the failing cardiorespiratory systems but also potentially for the use of plasma exchange. A team approach between the intensivist and subspecialist is important in managing the frequent multiorgan complications seen with meningococcemia.

Bench-to-bedside review: thrombocytopenia-associated multiple organ failure--a newly appreciated syndrome in the critically ill

New onset thrombocytopenia and multiple organ failure (TAMOF) presages poor outcome in critical illness. Patients who resolve thrombocytopenia by day 14 are more likely to survive than those who do not. Patients with TAMOF have a spectrum of microangiopathic disorders that includes thrombotic thrombocytopenic purpura (TTP), disseminated intravascular coagulation (DIC) and secondary thrombotic microanigiopathy (TMA). Activated protein C is effective in resolving fibrin-mediated thrombosis (DIC); however, daily plasma exchange is the therapy of choice for removing ADAMTS 13 inhibitors and replenishing ADAMTS 13 activity which in turn resolves platelet: von Willebrand Factor mediated thrombosis (TTP/secondary TMA).

Extracorporeal Therapies in the Treatment of Sepsis: Experience and Promise

Desire to restore the balance of body elements has enamored physicians since the ancient practice of bloodletting. More recently, extracorporeal techniques have been employed in both adults and children in treating sepsis. Extracorporeal therapies include continuous renal replacement (CRRT), plasma-based removal techniques, and extracorporeal membrane oxygenation (ECMO). These treatments could theoretically 1) provide immunohomeostasis of pro- and anti-inflammatory cytokines and other sepsis mediators, 2) decrease organ microthrombosis through removal of pro-coagulant factors and modulating the impaired septic coagulation response in sepsis, and 3) provide mechanical support of organ perfusion during the acute septic episode to allow time for response to traditional sepsis therapies and antimicrobials. CRRT is beneficial in managing fluid overload and acute renal failure in sepsis. Removal of sepsis mediators through the technique is variable, and the outcome impact of CRRT on sepsis has not been definitively determined. High-flow CRRT has demonstrated benefit in septic adults. Intriguing early results suggest that plasma exchange could improve outcomes in both adults and children. Based on experience, ECMO is recommended for refractory septic shock in neonates and should be considered for use in children. Ongoing trials may help determine whether the promise of extracorporeal therapies translates into outcome improvement in septic children.

Reducing the global burden of sepsis in infants and children: a clinical practice research agenda

OBJECTIVE

Sepsis remains a predominant cause of mortality and morbidity in children in the developing and industrialized world. This review discusses a clinical practice research agenda to reduce this global burden.

DESIGN

Summary of the literature with analysis by experts.

RESULTS

Many interventions have been proven effective in decreasing sepsis. Heterologous immunization with attenuated Bacillus Camille Guerin vaccine reduces all-cause mortality, and specific immunizations further reduce morbidity and mortality from many specific microbes. Antepartum antibiotics reduce the prevalence of cerebral palsy and mortality in infants. Administration of antibiotics to neonates with signs of sepsis reduces all-cause mortality five-fold and can also reduce mortality in the big four killers of children: severe pneumonia, diarrhea, malaria, or measles. Immunonutrition with zinc and vitamin A can further reduce morbidity in diarrhea and pneumonia and reduce mortality in measles. First-hour rapid intravenous fluid resuscitation achieves 100% survival in dengue shock, and time-sensitive fluid resuscitation and inotropic support reduces mortality ten-fold in meningococcal septic shock. Multiple organ failure occurs when late or inadequate resuscitation results in systemic thrombosis or when infection is not eradicated because of immunosuppression or inadequate source control.

CONCLUSIONS

The global burden of sepsis can be reduced by 1) prevention with improved heterologous or specific vaccines and vitamin or mineral supplement programs; 2) early recognition and treatment with appropriate antibiotics, intravenous fluid resuscitation, and inotropic support in organized healthcare-delivery systems; and 3) development of new diagnostics and therapeutics that reduce systemic thrombosis, improve immune function, and kill resistant organisms.

Validation of the paediatric logistic organ dysfunction (PELOD) score: prospective, observational, multicentre study

BACKGROUND

Multiple organ dysfunction syndrome is more frequent than death in paediatric intensive care units. Estimation of the severity of this syndrome could be a useful additional outcome measure in clinical trials in such units. We aimed to validate the paediatric logistic organ dysfunction (PELOD) score and estimate its validity when recorded daily (dPELOD).

METHODS

We did a prospective, observational, multicentre cohort study in seven multidisciplinary, tertiary-care paediatric intensive care units of university-affiliated hospitals (two French, three Canadian, and two Swiss). We included 1806 consecutive patients (median age 24 months; IQR 5-90). PELOD score includes six organ dysfunctions and 12 variables and was recorded daily. For each variable, the most abnormal value each day and during the whole stay were used in calculating the dPELOD and PELOD scores, respectively. Outcome was vital status at discharge. We used Hosmer-Lemeshow goodness-of-fit tests to evaluate calibration and areas under receiver operating characteristic curve (AUC) to estimate discrimination.

FINDINGS

370 (21%) patients had no organ dysfunction, 471 (26%) had one, 457 (25%) had two, and 508 (28%) had three or more. Case fatality rate was 6.4% (115 deaths). PELOD score was significantly higher in non-survivors (mean 31.0 [SE 1.2]) than survivors (9.4 [0.2]; p<0.0001). Calibration (p=0.54) and discrimination (AUC=0.91, SE=0.01) of PELOD and dPELOD (p> or =0.39; AUC> or =0.79) scores were good.

INTERPRETATION

PELOD and dPELOD scores are valid outcome measures of the severity of multiple organ dysfunction syndrome in paediatric intensive care units; their use should significantly reduce the sample size required to complete clinical trials in critically ill children.

Pediatric septic shock and multiple organ failure

In the last 5 years, the understanding of the epidemiology and pathogenesis of pediatric sepsis, septic shock, and multiple organ failure has expanded greatly. There has also been a substantial increase in the number of successful randomized trials in which success has been measured as reduction in mortality in adults, children, and newborns. This article discusses these advances, updating the 1997 article on septic shock written by the author and by Dr. Robert E. Cunnion and following the format of the 1997 article.

Multiple organ dysfunction syndrome in children

OBJECTIVE

Delineation of multiple organ dysfunction syndrome (MODS) is important because of its frequent occurrence in the pediatric intensive care unit and its association with high mortality. However, studies in children are scarce, all have been done in developed countries, and, unlike adult studies, some showed that sepsis is not related to mortality. The aim of this study was to learn about the epidemiology of MODS in our pediatric intensive care unit and to observe if sepsis is associated with mortality.

DESIGN

Prospective, observational study.

SETTING

A 16-bed pediatric intensive care unit.

PATIENTS

A total of 269 patients admitted to the pediatric intensive care unit during the study period from August 1996 to January 1997.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

There were 276 admissions (269 patients) during the study period. A total of 156 of them (56.5%) had MODS at some time during their pediatric intensive care unit stay, and 132 (84.6%) of the children had it at the time of admission. There were 71 deaths during the study period, and 65 of them (91.5%) had MODS. The organs less frequently involved were gastrointestinal and hepatic. In children with MODS, 87 had sepsis, and mortality in this group (51.7%) was greater than in those who did not present with sepsis (28.9%, p < .001). A Pediatric Risk of Mortality score of > or =15 and the presence of sepsis were associated with an increase in mortality risk (odds ratio, 2.8; 95% confidence interval, 1.36-5.75; and odds ratio, 2.33; 95% confidence interval, 1.18-4.59; respectively).

CONCLUSIONS

MODS in children usually occurs early, and sepsis increases mortality. Hepatic and gastrointestinal failures are infrequent, and as has been suggested, they could be excluded from the majority of MODS diagnoses.

Coagulation/fibrinolysis abnormality and vascular endothelial damage in the pathogenesis of thrombocytopenic multiple organ failure

OBJECTIVE

Until recently, attention has been directed to disseminated intravascular coagulation as a cause of multiple organ failure (MOF). On the other hand, it has now become clear that humoral mediators play important roles in the pathogenesis of MOF. Therefore, we performed the present study in patients with thrombocytopenic MOF to investigate the relationship between various humoral mediators and vascular endothelial damage reported to be triggered by such humoral mediators in the pathogenesis of MOF.

DESIGN

A retrospective clinical study.

SETTING

Intensive care unit of a university hospital.

PATIENTS

The study included 18 thrombocytopenic patients whose conditions progressed to septic MOF (MOF group) and 20 others who did not progress to MOF (non-MOF group). The MOF group and non-MOF group were also presented with infection and with platelet counts of <100,000/mm3.

MEASUREMENTS AND MAIN RESULTS

The MOF group had fibrinolysis abnormality, as indicated by increased plasminogen activator inhibitor-1 level. On the other hand, the MOF group had increased polymorphonuclear elastase and polymorphonuclear-mediated fibrinogen degradation product levels with consequent prolonged elevation of thrombomodulin. In addition, both polymorphonuclear elastase and polymorphonuclear-fibrinogen degradation products were significantly positively correlated with thrombomodulin in the MOF group, but no such positive correlation was observed between interleukin-6 or plasminogen activator inhibitor-1 and thrombomodulin. In the non-MOF group, on the other hand, thrombomodulin exhibited no significant positive correlation with polymorphonuclear elastase, polymorphonuclear-fibrinogen degradation products, interleukin-6, or plasminogen activator inhibitor-1.

CONCLUSIONS

Our study provided evidence that vascular endothelial damage was the primary cause of organ failures in patients with thrombocytopenic MOF and that humoral mediators played a major role in the development of vascular endothelial damage in such patients. These results suggest that it is important to treat thrombocytopenic MOF as a condition of vascular endothelial damage, with weight placed on countermeasures against disorders of humoral mediators.

Plasmapheresis and renal replacement therapy in children

The use of extracorporeal techniques for the treatment of pediatric diseases has expanded dramatically in the past decade. During this time, experience with both plasmapheresis and renal replacement therapy has become commonplace in ICUs and nephrology programs throughout the world. The indications for these therapies range through treatment of vasculitis, drug removal, support from inborn error metabolism, multiorgan system failure, primary renal disease, and sepsis. Because these therapies are somewhat intermingled based on the commonality of the need for vascular access, extracorporeal blood volumes, and bedside nursing support, and furthermore because the indications for these may overlap, these therapies are often used in tandem or parallel to support the child with illness.