Hemoperfusion with polymyxin B immobilized fibers for urinary albumin excretion in septic patients with trauma

Blood Purification for Adult Patients With Severe Infection or Sepsis/Septic Shock: A Network Meta-Analysis of Randomized Controlled Trials

OBJECTIVES

This study aimed to conduct a comprehensive and updated systematic review with network meta-analysis (NMA) to assess the outcome benefits of various blood purification modalities for adult patients with severe infection or sepsis.

DATA SOURCES

We conducted a search of PubMed, MEDLINE, clinical trial registries, Cochrane Library, and Embase databases with no language restrictions.

STUDY SELECTION

Only randomized controlled trials (RCTs) were selected.

DATA EXTRACTION

The primary outcome was overall mortality. The secondary outcomes were the length of mechanical ventilation (MV) days and ICU stay, incidence of acute kidney injury (AKI), and kidney replacement therapy requirement.

DATA SYNTHESIS

We included a total of 60 RCTs with 4,595 participants, comparing 16 blood purification modalities with 17 interventions. Polymyxin-B hemoperfusion (relative risk [RR]: 0.70; 95% CI, 0.57-0.86) and plasma exchange (RR: 0.61; 95% CI, 0.42-0.91) were associated with low mortality (very low and low certainty of evidence, respectively). Because of the presence of high clinical heterogeneity and intransitivity, the potential benefit of polymyxin-B hemoperfusion remained inconclusive. The analysis of secondary outcomes was limited by the scarcity of available studies. HA330 with high-volume continuous venovenous hemofiltration (CVVH), HA330, and standard-volume CVVH were associated with shorter ICU stay. HA330 with high-volume CVVH, HA330, and standard-volume CVVH were beneficial in reducing MV days. None of the interventions showed a significant reduction in the incidence of AKI or the need for kidney replacement therapy.

CONCLUSIONS

Our NMA suggests that plasma exchange and polymyxin-B hemoperfusion may provide potential benefits for adult patients with severe infection or sepsis/septic shock when compared with standard care alone, but most comparisons were based on low or very low certainty evidence. The therapeutic effect of polymyxin-B hemoperfusion remains uncertain. Further RCTs are required to identify the specific patient population that may benefit from extracorporeal blood purification.

Effect of Extracorporeal Blood Purification on Mortality in Sepsis: A Meta-Analysis and Trial Sequential Analysis

OBJECTIVE

The objective of this study was to conduct a meta-analysis and trial sequential analysis (TSA) of published randomized controlled trials (RCTs) to determine whether mortality benefit exists for extracorporeal blood purification techniques in sepsis.

DATA SOURCES

A systematic search on MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials for RCTs was performed.

STUDY SELECTION

RCTs investigating the effect of extracorporeal blood purification device use on mortality among critically ill septic patients were selected.

DATA EXTRACTION

Mortality was assessed using Mantel-Haenszel models, and I2 was used for heterogeneity. Data are presented as odds ratios (OR); 95% confidence intervals (CIs); p values; I2. Using the control event mortality proportion, we performed a TSA and calculated the required information size using an anticipated intervention effect of a 14% relative reduction in mortality.

DATA SYNTHESIS

Thirty-nine RCTs were identified, with 2,729 patients. Fourteen studies used hemofiltration (n = 789), 17 used endotoxin adsorption devices (n = 1,363), 3 used nonspecific adsorption (n = 110), 2 were cytokine removal devices (n = 117), 2 used coupled plasma filtration adsorption (CPFA) (n = 207), 2 combined hemofiltration and perfusion (n = 40), and 1 used plasma exchange (n = 106). On conventional meta-analysis, hemofiltration (OR 0.56 [0.40-0.79]; p < 0.001; I2 = 0%), endotoxin removal devices (OR 0.40 [0.23-0.67], p < 0.001; I2 = 71%), and nonspecific adsorption devices (OR 0.32 [0.13-0.82]; p = 0.02; I2 = 23%) were associated with mortality benefit, but not cytokine removal (OR 0.99 [0.07-13.42], p = 0.99; I2 = 64%), CPFA (OR 0.50 [0.10-2.47]; p = 0.40; I2 = 64%), or combined hemofiltration and adsorption (OR 0.71 [0.13-3.79]; p = 0.69; I2 = 0%). TSA however revealed that based on the number of existing patients recruited for RCTs, neither hemofiltration (TSA-adjusted CI 0.29-1.10), endotoxin removal devices (CI 0.05-3.40), nor nonspecific adsorption devices (CI 0.01-14.31) were associated with mortality benefit.

CONCLUSION

There are inadequate data at present to conclude that the use of extracorporeal blood purification techniques in sepsis is beneficial. Further adequately powered RCTs are required to confirm any potential mortality benefit, which may be most evident in patients at greatest risk of death.

Effectiveness of polymyxin B-immobilized hemoperfusion against sepsis and septic shock: A systematic review and meta-analysis

PURPOSE

To evaluate the efficacy and safety of Polymyxin B-immobilized hemoperfusion (PMX-HP) against sepsis or septic shock.

METHODS

We searched databases (PubMed, EMBASE and Cochrane Library) to identify eligible randomized controlled trials (RCTs). The primary outcomes we included in this review were mortality at the longest follow-up available and serious adverse events associated with treatments. We used the Cochrane risk of bias assessment tool to evaluate risk of bias. Trial Sequential Analysis (TSA) was performed to assess the conclusion reached in our research.

RESULTS

Thirteen studies including 1163 patients were identified. Use of PMX-HP could reduce overall mortality [relative risk (RR) 0.68, 95% confidence interval (CI) 0.51-0.91, P = 0.01]. An interesting finding was that the mortality of patients in Acute Physiology and Chronic Health Evaluation (APACHE II) scores <25 group (RR 0.64, 95% CI 0.52-0.78, P < 0.0001) and sepsis group (RR 0.48, 95% CI 0.32-0.72, P = 0.0003) significantly decreased after PMX-HP treatment. The result also showed that PMX-HP could reduce endotoxin levels [Standardized mean difference (SMD) -1.53, 95% CI -2.92- -0.13, P = 0.03] and improve mean arterial pressure (SMD 1.07, 95% CI 0.14-2.01, P = 0.02). Serious adverse events between the PMX-HP group and standard therapy group were not significantly different (RR 2.16, 95% CI 0.97-4.80, I² = 0%, P = 0.06). However, TSA did not provide conclusive evidence and more high quality RCTs were required.

CONCLUSION

Using PMX-HP to treat patients with less severe sepsis can reduce overall mortality and is safe. Treatment efficacy may benefit from the reduction of endotoxin level and the improvement of hemodynamics. More high quality RCTs are required to further evaluate the clinical role of PMX-HP against severe sepsis or septic shock.

Blood Purification and Mortality in Sepsis and Septic Shock: A Systematic Review and Meta-analysis of Randomized Trials

BACKGROUND

Sepsis and septic shock are severe inflammatory conditions related to high morbidity and mortality. We performed a systematic review with meta-analysis of randomized trials to assess whether extracorporeal blood purification reduces mortality in this setting.

METHODS

Electronic databases were searched for pertinent studies up to January 2019. We included randomized controlled trials on the use of hemoperfusion, hemofiltration without a renal replacement purpose, and plasmapheresis as a blood purification technique in comparison to conventional therapy in adult patients with sepsis and septic shock. The primary outcome was mortality at the longest follow-up available. We calculated relative risks and 95% CIs. The grading of recommendations assessment, development and evaluation methodology for the certainty of evidence was used.

RESULTS

Thirty-seven trials with 2,499 patients were included in the meta-analysis. Hemoperfusion was associated with lower mortality compared to conventional therapy (relative risk = 0.88 [95% CI, 0.78 to 0.98], P = 0.02, very low certainty evidence). Low risk of bias trials on polymyxin B immobilized filter hemoperfusion showed no mortality difference versus control (relative risk = 1.14 [95% CI, 0.96 to 1.36], P = 0.12, moderate certainty evidence), while recent trials found an increased mortality (relative risk = 1.22 [95% CI, 1.03 to 1.45], P = 0.02, low certainty evidence); trials performed in the United States and Europe had no significant difference in mortality (relative risk = 1.13 [95% CI, 0.96 to 1.34], P = 0.15), while trials performed in Asia had a positive treatment effect (relative risk = 0.57 [95% CI, 0.47 to 0.69], P < 0.001). Hemofiltration (relative risk = 0.79 [95% CI, 0.63 to 1.00], P = 0.05, very low certainty evidence) and plasmapheresis (relative risk = 0.63 [95% CI, 0.42 to 0.96], P = 0.03, very low certainty evidence) were associated with a lower mortality.

CONCLUSIONS

Very low-quality randomized evidence demonstrates that the use of hemoperfusion, hemofiltration, or plasmapheresis may reduce mortality in sepsis or septic shock. Existing evidence of moderate quality and certainty does not provide any support for a difference in mortality using polymyxin B hemoperfusion. Further high-quality randomized trials are needed before systematic implementation of these therapies in clinical practice.

Polymyxin B-immobilized hemoperfusion and mortality in critically ill adult patients with sepsis/septic shock: a systematic review with meta-analysis and trial sequential analysis

PURPOSE

Polymyxin B-immobilized hemoperfusion (PMX-HP) is an adjuvant therapy for sepsis or septic shock that clears circulating endotoxin. Prior trials have shown that PMX-HP improves surrogate endpoints. We aimed to conduct an evidence synthesis to evaluate the efficacy and safety of PMX-HP in critically ill adult patients with sepsis or septic shock.

METHODS

We searched for randomized controlled trials (RCTs) in MEDLINE, EMBASE, the Cochrane Library, the Health Technology Assessment Database, CINAHL, "Igaku Chuo Zasshi", the National Institute of Health Clinical Trials Register, the World Health Organization International Clinical Trials Registry Platform, the University Hospital Medical Information Network Clinical Trials Registry, the reference lists of retrieved articles, and publications by manufacturers of PMX-HP. The primary outcomes were 28-day all-cause mortality, the number of patients with at least one serious adverse event, and organ dysfunction scores. The GRADE methodology for the certainty of evidence was used.

RESULTS

Six trials (857 participants; weighted mean age 62.5 years) proved eligible. Patient-oriented primary outcomes were assessed. The pooled risk ratio (RR) for 28-day mortality associated with PMX-HP was 1.03 [95% confidence interval (CI) 0.78-1.36; I ² = 25%; n = 797]. The pooled RR for adverse events was 2.17 (95% CI 0.68-6.94; I ² = 0%; n = 717). Organ dysfunction scores over 24-72 h after PMX-HP treatment did not change significantly (standardized mean difference - 0.26; 95% CI - 0.64 to 0.12; I ² = 78%; n = 797). The certainty of the body of evidence was judged as low for both benefit and harm using the GRADE methodology.

CONCLUSIONS

There is currently insufficient evidence to support the routine use of PMX-HP to treat patients with sepsis or septic shock.

REGISTRATION

PROSPERO International Prospective Register of Systematic Reviews (CRD42016038356).

Management and Novel Adjuncts of Necrotizing Soft Tissue Infections

Necrotizing soft tissue infections (NSTI) have been recognized for millennia and continue to impose considerable burden on both patient and society in terms of morbidity, death, and the allocation of resources. With improvements in the delivery of critical care, outcomes have improved, although disease-specific therapies are lacking. The basic principles of early diagnosis, of prompt and broad antimicrobial therapy, and of aggressive debridement have remained unchanged. Clearly novel and new therapeutics are needed to combat this persistently lethal disease. This review emphasizes the pillars of NSTI management and then summarizes the contemporary evidence supporting the incorporation of novel adjuncts to the pharmacologic and operative foundations of managing this disease.

Glycocalyx and sepsis-induced alterations in vascular permeability

Endothelial cells line the inner portion of the heart, blood vessels, and lymphatic vessels; a basal membrane of extracellular matrix lines the extraluminal side of endothelial cells. The apical side of endothelial cells is the site for the glycocalyx, which is a complex network of macromolecules, including cell-bound proteoglycans and sialoproteins. Sepsis-associated alterations of this structure may compromise endothelial permeability with associated interstitial fluid shift and generalized edema. Indeed, in sepsis, the glycocalyx acts as a target for inflammatory mediators and leukocytes, and its ubiquitous nature explains the damage of tissues that occurs distant from the original site of infection. Inflammatory-mediated injury to glycocalyx can be responsible for a number of specific clinical effects of sepsis, including acute kidney injury, respiratory failure, and hepatic dysfunction. Moreover, some markers of glycocalyx degradation, such as circulating levels of syndecan or selectins, may be used as markers of endothelial dysfunction and sepsis severity. Although a great deal of experimental evidence shows that alteration of glycocalyx is widely involved in endothelial damage caused by sepsis, therapeutic strategies aiming at preserving its integrity did not significantly improve the outcome of these patients.

Blood purification and mortality in sepsis: a meta-analysis of randomized trials

OBJECTIVES

Although blood purification improves outcomes in animal studies of sepsis, results of clinical trials have been mixed. We conducted a systematic review and meta-analysis of randomized trials to determine the association between various blood purification techniques and all-cause mortality in humans with sepsis.

DATA SOURCES

We searched for relevant studies in MEDLINE, EMBASE, and the Cochrane Library database from January 1966 to May 2012.

STUDY SELECTION

Inclusion required a diagnosis of sepsis and comparison of blood purification techniques including hemofiltration, hemoperfusion, plasma exchange, or hemodialysis with no blood purification (control group).

DATA EXTRACTION

Two authors independently selected studies and extracted data. Summary statistics, risk ratios, and CIs were calculated using random-effects modeling. Study quality was assessed using Jadad score, and publication bias was assessed using funnel plots and Egger's statistic.

DATA SYNTHESIS

Overall, blood purification decreased mortality compared with no blood purification (35.7% vs 50.1%; risk ratio, 0.69 [95% CI, 0.56-0.84]; p<0.001; 16 trials, n=827). However, these results were driven mainly by hemoperfusion (risk ratio, 0.63 [95% CI, 0.50-0.80]; p<0.001; 10 trials, n=557) and plasma exchange (risk ratio, 0.63 [95% CI, 0.42-0.96]; p=0.03; two trials, n=128). Pooling of all trials of blood purification for treatment of sepsis was no longer associated with lower mortality (risk ratio, 0.89 [95% CI, 0.71-1.13]; p=0.36; eight trials, n=457) after excluding trials using polymyxin B hemoperfusion.

CONCLUSIONS

Blood purification techniques including hemoperfusion, plasma exchange, and hemofiltration with hemoperfusion were associated with lower mortality in patients with sepsis. These results were mainly influenced by studies using polymyxin B hemoperfusion from Japan.

Extracorporeal therapies in sepsis

The treatment of sepsis is an ongoing challenge for clinicians; despite the wide choice of effective antibiotics to treat infection, sepsis remains the leading cause of morbidity and mortality for patients admitted to an intensive care unit. Dysregulation of the immune response is now recognized to be a key factor in multiple organ dysfunction, yet our therapy for inflammation remains ineffective. It has been advocated for more than a decade that cytokine reduction in blood compartment could lead to a reduction in mortality in sepsis. Over the years, multiple extracorporeal techniques have evolved, with the intent of influencing the circulating levels of inflammatory mediators like cytokines and chemokines, the complement system, as well as factors of the coagulation system. These include high-volume hemofiltration, use of high cutoff membranes, and systems based on adsorption, such as coupled plasma filtration adsorption and the polymyxin-B column. In addition, new experimental systems that utilize human phagocytic cells and immobilized antibodies for targeted immunomodulation have emerged. In the context of limited resources and growing expansion in the availability of technologies, a better understanding of these therapies is required before they can be properly integrated into standard clinical practice in the hope of influencing major clinical outcomes. In this article, we will provide a concise overview of selected extracorporeal modalities currently in clinical use and briefly introduce some new promising techniques for sepsis.

Direct hemoperfusion with polymyxin B immobilized fiber for abdominal sepsis in Europe

Since direct hemoperfusion with polymyxin B immobilized fiber (PMX-DHP) received its product certification for use in Europe in 1998, several prospective randomized controlled trials (RCTs) have been conducted in European countries. The first RCT, performed in six European academic medical centers in 2005, concluded that PMX-DHP is associated with improved hemodynamic status and cardiac function. Subsequently, a meta-analysis of PMX-DHP was presented in Italy in 2007. This systematic review found positive effects of PMX-DHP on mean arterial pressure and dopamine/ dobutamine use, PaO2/FiO2 ratio, endotoxin removal, and mortality. However, like most trials on extracorporeal therapies, none of the studies was double-blinded. The EUPHAS study, a multicenter RCT performed in ten Italian intensive care units in 2009, found that PMX-DHP improved 28-day survival, blood pressure, vasopressor requirement, and degree of organ failure. However, investigators in Belgium and Canada pointed out that there was no statistical difference in 28-day survival. Two more RCTs, the ABDO-MIX and EUPHRATES studies, the primary end points of which are 28-day mortality, were started in Europe and the United States at the end of 2010. We are hoping that these RCTs will resolve this issue.

Development of small-molecule endotoxin sequestering agents

Sepsis, otherwise referred to as "blood poisoning" is a serious clinical problem, the incidence of which continues to rise in the US and worldwide despite advances in antimicrobial chemotherapy. The primary trigger in Gram-negative sepsis is endotoxin, a lipopolysaccharide (LPS) constituent of the outer membrane of all Gram-negative bacteria. The structurally highly conserved glycolipid called lipid A is the active moiety of LPS. Lipid A is composed of a hydrophilic, bis-phosphorylated di-glucosamine backbone, and a hydrophobic polyacyl domain. The bis-anionic, amphiphilic nature of lipid A enables it to interact with a variety of cationic hydrophobic ligands, including polymyxin B, a toxic peptide antibiotic which binds to lipid A and neutralizes endotoxicity. Having determined the structural basis of the interaction of polymyxin B with lipid A, our long-term goal has been to rationally design non-peptidic, nontoxic, small-molecule LPS-sequestrants. Our efforts began with defining the central pharmacophore that determined LPS-recognition and -neutralization properties in small molecules, which led to the discovery of a novel lipopolyamine lead, DS-96. DS-96 is an effective LPS-neutralizer, rivaling polymyxin B in a panel of vitro assays, as well as in protecting animals against endotoxicosis. Structure-activity relationships in our effort to rationally design endotoxin sequestering agents, preclinical assessment of hits and leads, and approaches to overcoming issues with toxicity are described in this chapter.

Effectiveness of polymyxin B-immobilized fiber column in sepsis: a systematic review

INTRODUCTION

Severe sepsis and septic shock are common problems in the intensive care unit and carry a high mortality. Endotoxin, one of the principal components on the outer membrane of gram-negative bacteria, is considered important to their pathogenesis. Polymyxin B bound and immobilized to polystyrene fibers (PMX-F) is a medical device that aims to remove circulating endotoxin by adsorption, theoretically preventing the progression of the biological cascade of sepsis. We performed a systematic review to describe the effect in septic patients of direct hemoperfusion with PMX-F on outcomes of blood pressure, use of vasoactive drugs, oxygenation, and mortality reported in published studies.

METHODS

We searched PubMed, the Cochrane Collaboration Database, and bibliographies of retrieved articles and consulted with experts to identify relevant studies. Prospective and retrospective observational studies, pre- and post-intervention design, and randomized controlled trials were included. Three authors reviewed all citations. We identified a total of 28 publications - 9 randomized controlled trials, 7 non-randomized parallel studies, and 12 pre-post design studies - that reported at least one of the specified outcome measures (pooled sample size, 1,425 patients: 978 PMX-F and 447 conventional medical therapy).

RESULTS

Overall, mean arterial pressure (MAP) increased by 19 mm Hg (95% confidence interval [CI], 15 to 22 mm Hg; p < 0.001), representing a 26% mean increase in MAP (range, 14% to 42%), whereas dopamine/dobutamine dose decreased by 1.8 microg/kg per minute (95% CI, 0.4 to 3.3 microg/kg per minute; p = 0.01) after PMX-F. There was significant intertrial heterogeneity for these outcomes (p < 0.001), which became non-significant when analysis was stratified for baseline MAP. The mean arterial partial pressure of oxygen/fraction of inspired oxygen (PaO2/FiO2) ratio increased by 32 units (95% CI, 23 to 41 units; p < 0.001). PMX-F therapy was associated with significantly lower mortality risk (risk ratio, 0.53; 95% CI, 0.43 to 0.65). The trials assessed had suboptimal method quality.

CONCLUSION

Based on this critical review of the published literature, direct hemoperfusion with PMX-F appears to have favorable effects on MAP, dopamine use, PaO2/FiO2 ratio, and mortality. However, publication bias and lack of blinding need to be considered. These findings support the need for further rigorous study of this therapy.

Low-dose hydrocortisone during severe sepsis: effects on microalbuminuria

OBJECTIVE

The aim of this study was to investigate the effect of low-dose hydrocortisone on glomerular permeability measured by the microalbuminuria to creatinine ratio (MACR) and on other markers of sepsis in severe septic patients.

DESIGN

Randomized prospective study.

SETTING

University intensive care unit.

PATIENTS

The study involved 40 patients with severe sepsis randomized into the hydrocortisone group (n = 20) and the standard therapy group (n = 20).

INTERVENTIONS

The hydrocortisone group received standard therapy plus a continuous infusion of hydrocortisone for 6 days, whereas the standard therapy group received only standard therapy.

MEASUREMENTS AND MAIN RESULTS

MACR, serum C-reactive protein, and procalcitonin concentrations were recorded every day from the day before the steroid therapy (T(0)) until the 6 days after (T(1), T(2), T(3), T(4), T(5), and T(6)). Concentrations in the hydrocortisone group and the standard therapy group were compared using Mann-Whitney test at each time. We also compared with Wilcoxon signed rank test the values determined in each group at T(0) with those at each subsequent time. Median MACR decreased from T(0) to T(6) in both patient groups; however, values were significantly lower in the hydrocortisone group from T(3) through to T(6). Median serum C-reactive protein also decreased from T(0) in both patient groups, with significantly lower values in the hydrocortisone group from T(3) through to T(6). There were no significant differences in procalcitonin between groups compared with baseline values or at any individual time point.

CONCLUSIONS

Low-dose hydrocortisone seems to reduce MACR and serum C-reactive protein but not procalcitonin in patients with severe sepsis. Further studies are needed to confirm these results and to understand the underlying molecular mechanisms.

Effects of polymyxin B immobilized fiber on urinary N-acetyl-beta-glucosaminidase in patients with severe sepsis

Severe sepsis is known to cause multiple organ failure, including renal dysfunction. During sepsis, endotoxin targets the renal proximal tubular cells, the function of which can be evaluated on the basis of urinary N-acetyl-beta-glucosaminidase (NAG). We investigated whether urinary NAG activity is altered in patients with severe sepsis and whether treatment with polymyxin B immobilized fibers (PMX-F) affects this activity. Subjects of this study were 120 patients with severe sepsis and 60 healthy volunteers matched for age and gender. Patients were randomly assigned to one of two treatments: PMX-F treatment (n = 70) or conventional treatment (n = 50). The plasma endotoxin level was significantly reduced, from 34.6 +/- 10.2 to 6.8 +/- 2.4 pg/ml (p < 0.01) in patients treated with PMX-F, and the urinary NAG/creatinine ratio was reduced from 46.5 +/- 26.8 U/gm to 18.6 +/- 13.6 U/gm (p < 0.01). The plasma endotoxin level and urinary NAG/creatinine ratio were unchanged in patients who received conventional treatment. The increased urinary NAG/creatinine ratio in patients with severe sepsis may reflect proximal tubular dysfunction. PMX-F is effective in reducing proximal tubular dysfunction, in part owing to reduced plasma endotoxin levels.

Effect of polymyxin B-immobilized fiber on bone resorption in patients with sepsis

OBJECTIVE

To analyze the effects of polymyxin B-immobilized fiber (PMX-F) on bone resorption in septic patients.

DESIGN AND SETTING

Observational prospective study in intensive care units of a general hospital.

PATIENTS AND PARTICIPANTS

25 patients with severe sepsis and 20 healthy controls.

MEASUREMENTS AND RESULTS

Septic patients were randomly assigned to two groups: PMX-F treatment group (n=15) and conventional treatment group (n=10). Total pyridinium crosslink pyridinoline (PYD) and deoxypyridinoline (DPD) in urine were determined by modified high-performance liquid chromatography. Nitric oxide production was assessed by measuring the ratio of the nitric oxide breakdown products to urinary creatinine (NOx/Cr). Plasma endotoxin levels were determined by endospecy test. The blood albumin, ionized calcium, and parathyroid hormone were also measured. PMX-F treatment was performed twice separated by 24 h. Urinary NOx/Cr, PYD/Cr, and DPD/Cr were significantly increased in septic patients compared with those in healthy controls. Blood ionized calcium in septic patients was lower than in healthy controls, while parathyroid hormone levels in septic patients were higher than in healthy controls (P<0.01). PMX-F treatment reduced plasma endotoxin, urinary NOx/Cr, PYD/Cr, DPD/Cr, and serum parathyroid hormone levels and increased blood ionized calcium significantly; however, conventional treatment did not affect these levels.

CONCLUSIONS

Septic patients increased nitric oxide production and bone resorption, and PMX-F treatment is effective in reducing nitric oxide levels and bone resorption markers.

Effects of polymyxin B-immobilized fiber hemoperfusion on amino acid imbalance in septic encephalopathy

BACKGROUND

Septic encephalopathy is a common term denoting the signs of progressing central nervous system dysfunction in septic patients. Metabolic alterations including amino acid imbalance are involved in the pathogenesis of septic encephalopathy. The aim of the present study was to determine whether the ratio of branched-chain amino acids to aromatic amino acids is altered in patients with septic encephalopathy and whether polymyxin B-immobilized fiber (PMX-F) hemoperfusion affects this balance.

METHODS

16 septic patients with encephalopathy, 10 septic patients without encephalopathy, and 20 healthy controls were included in this study. Sepsis was diagnosed according to the ACCP/SCCM Consensus Conference criteria. Plasma endotoxin levels, interleukin-6 (IL-6) levels, and amino acid ratios were measured before and after PMX-F treatment.

RESULTS

Within 12 h of the onset of septic encephalopathy, plasma endotoxin and IL-6 levels were increased significantly in septic patients with encephalopathy in comparison to those in septic patients without encephalopathy (endotoxin, p < 0.05; IL-6, p < 0.01) and those in healthy controls (endotoxin; p < 0.001; IL-6, p < 0.001). The ratio of branched-chain amino acids to aromatic amino acids in septic patients with encephalopathy was decreased in comparison to the ratio in septic patients without encephalopathy (p < 0.05) and that in healthy controls (p < 0.01). PMX-F treatment reduced plasma endotoxin (p < 0.01) and IL-6 levels (p < 0.01) and increased the ratio of branched-chain amino acids to aromatic amino acids (p < 0.01).

CONCLUSION

The amino acid imbalance in patients with septic encephalopathy may be a marker for the severity of the septic syndrome, and PMX-F hemoperfusion is effective in ameliorating the increased plasma endotoxin and IL-6 levels and the amino acid imbalance in these patients.

Effects of LDL apheresis and vitamin E-modified membrane on carotid atherosclerosis in hemodialyzed patients with arteriosclerosis obliterans

BACKGROUND

Hemodialysis patients manifest accelerated atherosclerosis. Hemodialysis is associated with oxidative stress, which can be partially prevented with the use of a vitamin E-coated dialyzer. Adsorption of low-density lipoprotein (LDL) has been applied in the treatment of arteriosclerosis obliterans (ASO). The aim of the present study was to determine whether the vitamin E-coated dialyzer and/or LDL apheresis affects carotid atherosclerosis in hemodialysis patients with ASO.

METHODS

Thirty hemodialysis patients with ASO were divided into four treatment groups: treatment with conventional cellulose or synthetic membranes (group A, n = 12), treatment with vitamin E-coated membrane (group B, n = 7), treatment with conventional membrane and LDL apheresis (group C, n = 6), and treatment with vitamin E-coated membrane and LDL apheresis (group D, n = 5). Carotid artery intima-media thickness (IMT) and arterial stiffness assessed by pulse wave velocity (PWV), plasma C-reactive protein (CRP) and interleukin (IL)-6 were measured before and 10 weeks after treatment and compared between groups. All values were referred to measurements after LDL apheresis.

RESULTS

IMT and PWV, plasma CRP and IL-6 showed little change in group A throughout the experimental period. These decreased slightly from the baseline value in group B, but the change was not significant. In group C, IMT decreased from 1.12 +/- 0.24 to 1.02 +/- 0.18 mm (p < 0.05), and PWV decreased from 2,266 +/- 380 to 1,968 +/- 342 cm/s (p < 0.05). Plasma CRP and IL-6 concentrations also decreased significantly compared with baseline (p < 0.05). In group D, IMT decreased from 1.18 +/- 0.26 to 0.92 +/- 0.18 mm (p < 0.01), and PWV decreased from 2,284 +/- 390 to 1,786 +/- 284 cm/s (p < 0.01). Plasma CRP and IL-6 levels also decreased significantly compared with baseline (p < 0.01).

CONCLUSION

These data suggest that LDL apheresis and the vitamin E-coated membrane dialysis in combination may prevent further progression of atherosclerosis in hemodialysis patients with ASO.