Continuous arteriovenous hemofiltration attenuates polymorphonuclear leukocyte phagocytosis in porcine intra-abdominal sepsis

Correlation Between Serum Concentrations of Menaquinone-4 and Developmental Quotients in Children With Autism Spectrum Disorder

Objective: The vitamin K family has a wide range of effects in the body, including the central nervous system. Menaquinone-4 (MK-4), a form of vitamin K2, is converted from phylloquinone (PK), which is the main source of dietary vitamin K and is the main form of vitamin K in the brain. We conducted this study to investigate the serum concentration of MK-4 and the correlations between MK-4 and developmental quotients in children with autism spectrum disorder (ASD). Methods: We selected 731 children with ASD who were diagnosed for the first time. During the same period, 332 neurotypical children who underwent regular physical examinations in our outpatient department were selected as the TD group. We investigated the general situation of children, including gender and age. Children in ASD group were assessed for autistic symptoms and development quotients, including Autism Behavior Checklist (ABC), Childhood Autism Rating Scale (CARS), ADOS-2, and Griffiths Development Scales-Chinese Language Edition (GDS-C). Both groups of children were tested for serum menaquinone-4. We compared serum menaquinone-4 levels of ASD group and TD group. We then conducted a correlation analysis between the level of menaquinone-4 and the developmental quotient of children with ASD. Results: The results of this study indicate that the serum concentration of MK-4 in children with ASD is lower than that in children with typical development (t = -2.702, P = 0.007). The serum concentration of MK-4 is related to the developmental quotients of several subscales in ASD children, and this correlation is more obvious in males. Conclusion: we conclude that MK-4 is present in lower concentrations in children with ASD, which may affect cognition and developmental quotients. The role of MK-4 in ASD needs to be further explored.

Vitamin K and the nervous system: an overview of its actions

The role of vitamin K in the nervous system has been somewhat neglected compared with other physiological systems despite the fact that this nutrient was identified some 40 y ago as essential for the synthesis of sphingolipids. Present in high concentrations in brain cell membranes, sphingolipids are now known to possess important cell signaling functions in addition to their structural role. In the past 20 y, additional support for vitamin K functions in the nervous system has come from the discovery and characterization of vitamin K-dependent proteins that are now known to play key roles in the central and peripheral nervous systems. Notably, protein Gas6 has been shown to be actively involved in cell survival, chemotaxis, mitogenesis, and cell growth of neurons and glial cells. Although limited in number, studies focusing on the relationship between vitamin K nutritional status and behavior and cognition have also become available, pointing to diet and certain drug treatments (i.e., warfarin derivatives) as potential modulators of the action of vitamin K in the nervous system. This review presents an overview of the research that first identified vitamin K as an important nutrient for the nervous system and summarizes recent findings that support this notion.

Vitamin K, an emerging nutrient in brain function

Historically discovered for its role in blood coagulation, there is now convincing evidence that vitamin K has important actions in the nervous system. As a unique cofactor to the γ-glutamyl carboxylase enzyme, vitamin K contributes to the biological activation of proteins Gas6 and protein S, ligands for the receptor tyrosine kinases of the TAM family (Tyro3, Axl, and Mer). Functionally, Gas6 has been involved in a wide range of cellular processes that include cell growth, survival, and apoptosis. In brain, vitamin K also participates in the synthesis of sphingolipids, an important class of lipids present in high concentrations in brain cell membranes. In addition to their structural role, sphingolipids are now known to partake in important cellular events such as proliferation, differentiation, senescence and cell-cell interactions. In recent years, studies have linked alterations in sphingolipid metabolism to age-related cognitive decline and neurodegenerative diseases such as Alzheimer's disease (AD). Emerging data also point to unique actions of the K vitamer menaquinone-4 (MK-4) against oxidative stress and inflammation. Finally, there is now data to suggest that vitamin K has the potential to influence psychomotor behavior and cognition. This review presents an overview of what is known of the role of vitamin K in brain function.

Outcomes of hematopoietic stem cell transplant patients who received continuous renal replacement therapy in a pediatric oncology intensive care unit

OBJECTIVES

To assess the long-term benefits of continuous renal replacement therapy (CRRT) in this patient population and to analyze factors associated with survival. Hematopoietic stem cell transplantation is being utilized as curative therapy for a variety of disorders. However, organ dysfunction is commonly associated with this therapy. Continuous renal replacement therapy (CRRT) is increasingly being used in the treatment of this multiorgan dysfunction.

DESIGN

Retrospective cohort study.

SETTING

A free-standing, tertiary care, pediatric oncology hospital.

PATIENTS

Twenty-nine allogeneic hematopoietic stem cell transplantation patients who underwent 33 courses of CRRT in the intensive care unit between January 2003 and December 2007.

INTERVENTIONS

Cox proportional hazards regressions models were used to examine the relationship between demographic and clinical variables and length of survival.

MEASUREMENTS AND MAIN RESULTS

The median length of survival post CRRT initiation was 31 days; only one patient survived >6 mos. Factors associated with increased risk of death included: higher bilirubin and blood urea nitrogen levels before and at 48 hrs into CRRT, lower Pao2/Fio2 ratios at 48 hrs of CRRT, and higher C-reactive protein levels, as well as lower absolute neutrophil counts at CRRT end.

CONCLUSION

In this single-center study, CRRT was not associated with long-term survival in pediatric allogeneic hematopoietic stem cell transplantation patients. Clinical data exist, both before and during CRRT, that may be associated with length of survival. Lower C-reactive protein levels at CRRT end were associated with longer survival, suggesting that the ability to attenuate inflammation during CRRT may afford a survival advantage. These findings require confirmation in a prospective study.

Impact of continuous venovenous hemofiltration on organ failure during the early phase of severe sepsis: a randomized controlled trial

OBJECTIVE

The impact of continuous venovenous hemofiltration on sepsis-induced multiple organ failure severity is controversial. We sought to assess the effect of early application of hemofiltration on the degree of organ dysfunction and plasma cytokine levels in patients with severe sepsis or septic shock.

DESIGN

Prospective, randomized, open, multicenter study setting, 12 French intensive care units.

PATIENTS

A total of 80 patients were enrolled within 24 hours of development of the first organ failure related to a new septic insult.

INTERVENTIONS

Patients were randomized to group 1 (HF), who received hemofiltration (25 mL/kg/hr) for a 96-hour period, or group 2 (C) who were managed conventionally.

MEASUREMENTS AND MAIN RESULTS

The primary end point was the number, severity, and duration of organ failures during 14 days, as evaluated by the Sepsis-Related Organ Failure Assessment score, on an intention-to-treat analysis. Strict guidelines were provided to perform continuous hemofiltration under the same conditions and bearing the same objectives in all centers. Because of inclusion stagnation, the trial was discontinued after an interim analysis by which time 76 patients had been randomized. The number and severity of organ failures were significantly higher in the HF group (p < 0.05). No modifications in plasma cytokine levels could be detected.

CONCLUSION

These data suggest that early application of standard continuous venovenous hemofiltration is deleterious in severe sepsis and septic shock. This study does not rule out an effect of high-volume hemofiltration (>35 mL/kg/hr) on the course of sepsis.

Cost-effectiveness analysis of early veno-venous hemofiltration for severe acute pancreatitis in China

AIM: To determine the most cost-effective hemofiltration modality for early management of severe acute pancreatitis (SAP) in China.

METHODS: We carried out a search of Pub-Medline and Chinese Biomedical Disk database. Controlled clinical trials on Chinese population were included in the analysis. The four decision branches that were analyzed were: continuous or long-term veno-venous hemofiltration (CVVH/LVVH), short-term veno-venous hemofiltration (SVVH), SVVH plus peritoneal dialysis (PD), and non-hemofiltration control group. The effectiveness of the technique was determined by survival rate, complications prevention and surgery preservation. The total cost of hospitalization was also assessed.

RESULTS: The SVVH only technique was the least costly modality, $5809 (44 449 RMB), and was selected as the baseline treatment modality. SVVH only arm achieved the lowest C/E ratio in terms of overall survival, complications prevention and surgery preservation. In incremental cost-effectiveness analysis, the CVVH/LVVH only and the control arms were inferior to other techniques. Sensitivity analysis showed SVVH only and SVVH plus PD arms overlapped in C/survival ratio.

CONCLUSION: The role of early veno-venous hemofiltration as an alternative therapy for SAP remains controversial. However, we propose that early use of short-term high-volume veno-venous hemofiltration would have a beneficial impact on the management of SAP.

The impact of long-term haemofiltration (continuous veno-venous haemofiltration) on cell-mediated immunity during endotoxaemia

BACKGROUND

Increased survival with high-volume continuous veno-venous haemofiltration (CVVH) has been demonstrated in critically ill patients. This may be the result of intensified blood purification or an effect on the immune system. We hypothesized that CVVH modifies the cell-mediated immunity. We investigated the effect of high-volume CVVH for 24 h on the cell-mediated immunity following endotoxin infusion.

METHODS

Thirty pigs were divided into three groups. Ten pigs received 30 microg/kg of Escherichia coli endotoxin. These pigs were treated with CVVH (replacement 35 ml/kg/h) over the following 24 h. Ten pigs received the same bolus of endotoxin and ten pigs served as a control group. The adhesion molecules CD18, CD44 and CD62L and the ability to respond with an oxidative burst were measured. The number of neutrophils was counted in blood and lung tissue. The lymphoproliferative response and cytokines interleukin-6 and interleukin-10 were measured.

RESULTS

The infusion of endotoxin was followed by initial granulocytopenia and, later, granulocytosis, activation of CD18 and CD62L, and increased oxidative burst. The cytokine level was increased. CVVH had no effect on the adhesion molecules or cytokine level and did not reduce the number of granulocytes in the lung significantly. CVVH, however, reduced the oxidative burst activity of neutrophils after 2 h of treatment.

CONCLUSION

In the first few hours after endotoxaemia, high-volume CVVH reduced the oxidative burst activity of neutrophils. However, in the long term, CVVH was unable to modify the endotoxin-induced changes in cell-mediated immunity.

Hemofiltration in sepsis and systemic inflammatory response syndrome: the role of dosing and timing

INTRODUCTION

The benefit of hemofiltration (HF) as an adjunctive treatment of sepsis or the systemic inflammatory response syndrome (SIRS) in critically ill patients is a subject of severe debate. Firm conclusions on this subject are hampered by the heterogeneity in study populations and HF treatments, and the lack of adequately sized randomized controlled clinical trials. The aim of this review was to determine the importance of ultrafiltration dose and timing on the physiologic and clinical effects of HF in sepsis and SIRS. In addition, we discuss the issue of filter pore size.

METHODS

Literature search was done in Embase and PubMed database for animal and human studies.

RESULTS

Animal studies suggest beneficial effects of HF on hemodynamics; gas exchange; sepsis-induced immunoparalysis; histology of gut, lung, and kidney; and (short-term) survival. These effects were more prominent with "very high" ultrafiltrate rates (> or =100 mL/kg per hour) and early initiation of HF (ie, before or very early after the septic challenge). Three small randomized studies and 3 observational studies in patients with sepsis or SIRS show beneficial effects of short-term or pulse HF using very high ultrafiltrate rates and/or early initiation of HF on physiologic endpoints and survival. However, the studies were underpowered for survival. The first observations of high permeability HF (pore size, about 10 nm; in vitro cutoff, 100 kd) are promising, but so far, it has not been sufficiently examined to allow strong conclusions.

CONCLUSION

Human and animal studies suggest that early initiation and high ultrafiltrate volumes are determinants of the beneficial physiologic and clinical effect of HF in sepsis and SIRS. As yet, the evidence in humans is too low to recommend HF as an adjunctive therapy for critically ill patients with sepsis or SIRS. Regarding the many uncertainties about optimal volume (high or very high) and type of membrane, clinical studies should first focus on endpoints as recovery from organ failure and length of treatment before survival studies are started.

Effects of time interval for hemofiltration on the prognosis of severe acute pancreatitis

AIM: To evaluate the impact of time interval for hemofiltration (HF) on the prognosis of severe acute pancreatitis (SAP).

METHODS: Thirty-six consecutive patients with severe acute pancreatitis were included in the study. Atlanta classification system was applied for stratification. They were randomly divided into short veno-venous HF group, (SVVH, Group 1, 20 patients); and long veno-venous HF group (LVVH, Group 2, 16 patients). In group 1, SVVH was stopped when the abdominal signs disappeared, and heart rate and breath rate were less than 90 beats/min and 20 times/min, respectively. HF was stopped if SVVH was continued, and when heart rate and breath rate were more than 90 beats/min and 20 times/min again (Group 2). Except that the time interval for HF was different, other parameters for HF were the same. And conservative curing rate, survival rate, cost for hospital stay and length of hospital stay were observed.

RESULTS: Time interval for HF in Group 1 (3.81 ± 1.3 h) was shorter than that of in Group 2 (9.38 ± 2.9 hr), P < 0.01. Conservative curing rate (90%) in Group 1 was much higher than that in Group 2 (56.3%) (P < 0.05); but cost in Group 1 (RMB 56600 ± 56400 Yuan) was lower than that in Group 2 (RMB 137000 ± 105000 Yuan) (P < 0.05). And the survival rate (95%) in Group 1 was higher than that in Group 2 (81.3%) (P < 0.25); however, hospital stay in Group 1 (44.3 ± 41 d) was shorter than that in Group 2 (55.2 ± 39.5 d) (P < 0.2). So, the prognosis was not improved through the prolongation of time interval for HF, but side-effects were seen.

CONCLUSION: The prognosis was not further improved by LVVH in the treatment of SAP, with side-effects. Time interval for HF plays an important role in treatment of SAP in early stage. SVVH is thought to be superior to LVVH; and LVVH is superior to CVVH in early (72 h) treatment of SAP.

The use of extracorporeal techniques to remove humoral factors in sepsis

OBJECTIVE

To determine whether there is sufficient evidence of a benefit of hemofiltration or plasma filtration in sepsis.

DATA SOURCES

Medline search, search of references in articles found in Medline search, literature known to local experts.

STUDY SELECTION

Trials and reports where clinical outcome measures were included.

DATA EXTRACTION

Clinically relevant information was presented.

DATA SYNTHESIS

Studies were grouped according to hemofiltration or plasma filtration and within each of these groups into animal or human studies; then they were graded from case report, through case series, nonrandomized trials, and randomized trials.

CONCLUSION

There is a lack of randomized trials. The available studies show an absence of benefit for hemofiltration. Further studies are needed in plasma filtration.

Non-renal indications for continuous renal replacement therapy

While there is clear support for the use of continuous renal replacement therapy (CRRT) in critically ill acute renal failure patients, there are other illnesses without renal involvement where CRRT might be of value. These include sepsis and other inflammatory syndromes such as acute respiratory distress syndrome (ARDS) and cardiopulmonary bypass where removal of inflammatory mediators by hemofiltration is hypothesized to improve outcome. Adsorption appears to be the predominant mechanism of mediator elimination. However, the observed hemodynamic improvement can, at least partially, be attributed to a reduction of body temperature or to fluid removal, and the evidence for a clinically important removal of proinflammatory cytokines remains limited. Continuous and therefore smooth fluid removal may improve organ function in ARDS, after surgery with cardiopulmonary bypass, and in patients with refractory congestive heart failure. Continuous removal of endogenous toxins, eventually combined with intermittent hemodialysis, is probably beneficial in inborn errors of metabolism, severe lactic acidosis, or tumor lysis syndrome.