Intraoperative direct hemoperfusion with a polymyxin-B immobilized fiber column for treatment of infective endocarditis

Effects of polymyxin B haemoperfusion on septic shock caused by Gram-positive bacteria

Polymyxin B haemoperfusion is commonly used to adsorb endotoxins in septic shock caused by Gram-negative bacterial infections. Polymyxin B haemoperfusion has been reported to improve hypotension in Gram-positive bacterial infections; however, its efficacy and mechanism in treating such cases are unclear. We hypothesised that polymyxin B haemoperfusion would be equally effective in improving haemodynamics during Gram-positive bacterial infections as in Gram-negative bacterial infections. We conducted a retrospective study that included patients with septic shock admitted to the intensive care unit. The patients were divided into two groups according to bacterial culture results: Gram-negative rod (GNR) and Gram-positive coccus (GPC). We calculated the vasoactive inotropic score (VIS) before (0 h) and 2, 6, 12 and 24 h after polymyxin B haemoperfusion therapy. Data were analysed using two-way analysis of variance and post hoc tests for the associations between infection type and treatment time. Overall, 157 patients with septic shock were enrolled in the study: 81 and 76 patients were treated or not treated with extracorporeal haemoperfusion therapy, respectively. Although there was no significant difference in the VIS in polymyxin B haemoperfusion between patients with GNR and GPC infections, there was a significant decrease in the VIS over time, even when GPC was the causative organism. In addition, the degree of reduction in the VIS was significantly different in both the GNR and GPC groups compared with that in the non-extracorporeally treated group. Thus, polymyxin B haemoperfusion for septic shock caused by GNR reduced the VIS and could be effective even in cases of GPC infection.

Use of Cytokine Filters During Cardiopulmonary Bypass: Systematic Review and Meta-Analysis

INTRODUCTION

Cardiac surgery involving cardiopulmonary bypass (CPB) activates an inflammatory response releasing cytokines that are associated with less favourable outcomes. This study aims to compare i) CPB during cardiac surgery (control) versus ii) CPB with haemoadsorption therapy; and assess the effect of adding this therapy in reducing the inflammatory cytokines burden.

METHODS

A systematic literature review with metanalysis was conducted regarding the main outcomes (operative mortality, ventilation duration, intensive care unit [ICU] and hospital stays) and day-1 inflammatory markers levels post-surgery. Fifteen (15) studies were included for final analysis (eight randomised controlled trials, seven observational studies) with no evidence of publication bias.

RESULTS

Subgroup analysis of non-elective surgeries across observational studies (emergency and infective endocarditis) significantly favoured cytokine filters in terms of 30-day mortality (OR 0.40, 95% CI 0.20, 0.83; p=0.01) and shorter ICU stay (MD -42.36, 95% CI -68.07, -16.65; p=0.001). At day-1 post-surgery, there was a significant difference favouring the cytokine filter group in c-reactive protein (CRP) (MD -0.71, 95% CI -0.84, -0.59; p<0.001) with no differences in white blood count (WBC), procalcitonin (PCT), tumour necrosis factor-alpha (TNF-α), IL-6, IL-8 and lactate. When comparing cytokine filters and control across all studies there was no significant difference in operative mortality, ventilation duration, hospital stay and ICU length of stay. Also, there were no statistical differences in randomised controlled trials (RCTs) using haemadsorption filters.

CONCLUSIONS

A significant reduction in 30-day mortality and ICU stay could be obtained by using haemadsorption therapy during non-elective cardiac surgery, especially emergency surgery and in patients with higher inflammatory burden such as infective endocarditis.

Potential survival benefit of polymyxin B hemoperfusion in patients with septic shock: a propensity-matched cohort study

BACKGROUND

The purpose of this study was to investigate whether polymyxin B hemoperfusion (PMX-HP) improves the survival of patients with septic shock.

METHODS

This was a retrospective, multicenter study conducted on patients treated during a 3-year period. We performed propensity-score analyses of the Japan Septic Disseminated Intravascular Coagulation (JSEPTIC DIC) study database. The study included data on 1723 patients with septic shock aged 16 years or older. Furthermore, we divided patients into to PMX-HP- and non-PMX-HP-treated groups. The primary endpoint was all-cause hospital mortality; secondary endpoints included intensive care unit (ICU) mortality and number of ICU-free days (ICUFDs) in the first 28 days.

RESULTS

Of 1,723 eligible patients, 522 had received PMX-HP. Propensity score matching created 262 matched pairs (i.e., 262 patients in each of the non-PMX-HP and PMX-HP groups). The proportion of all-cause hospital mortality was significantly lower in the PMX-HP group than in the non-PMX-HP group (32.8% vs. 41.2%; odds ratio (OR): 0.681; 95% confidence interval (CI): 0.470-0.987; P = 0.042). The number of ICUFD in the first 28 days was significantly higher in the PMX-HP group than in the non-PMX-HP group (18 (0-22) vs. 14 (0-22) days, respectively; P = 0.045). On the other hand, there was no significant difference in ICU mortality between the two groups (21.8% vs. 24.4%; OR: 0.844; CI: 0.548-1.300; P = 0.443).

CONCLUSIONS

Our results strongly suggest that PMX-HP reduces all-cause hospital mortality and length of ICU stay in patients with septic shock.

Immunomodulation in sepsis: the role of endotoxin removal by polymyxin B-immobilized cartridge

Severe sepsis results in high morbidity and mortality. Immunomodulation strategies could be an adjunctive therapy to treat sepsis. Endotoxin is a component of gram-negative bacteria and plays an important role in the pathogenesis of septic shock when it is recognized by immune cells. Removal of endotoxin could be an effective adjunctive approach to the management of sepsis. Devices to adsorb endotoxin or inflammatory cytokines have been designed as a strategy to treat severe sepsis, especially sepsis caused by gram-negative bacteria. Polymyxin B-immobilized cartridge has been successfully used to treat patients with sepsis of abdominal origin. Although this cartridge was conceived to adsorb endotoxin, several other immunological mechanisms have been elucidated, and this device has also yielded promising results in patients with nonseptic respiratory failure. In this paper, we summarize the immune modulation actions of Polymyxin B-immobilized cartridge to explore its potential usefulness beyond endotoxin elimination.

Removal of increased circulating CD4+CD25+Foxp3+ regulatory T cells in patients with septic shock using hemoperfusion with polymyxin B-immobilized fibers

BACKGROUND

Although sepsis-induced immunosuppression has long been considered to be a factor in the late mortality of patients with sepsis, little is known about regulatory T cell (Treg)-mediated immunosuppression and the effect of polymyxin B-immobilized fiber (PMX-F) on sepsis-induced immunosuppression. We sought to investigate the role of CD4(+)CD25(+)Foxp3(+) Tregs in septic patients, and to evaluate the effect of hemoperfusion with PMX-F on the recovery from immunosuppression owing to septic shock.

METHODS

Thirty-two septic patients who had an identified focus of infection in the abdominal cavity were enrolled in this study. Peripheral blood mononuclear cells in the septic patients were examined to evaluate the roles of Tregs and the serum cytokine levels. We also examined the effects of PMX-F therapy on CD4(+) T cells, especially Tregs and serum cytokine levels in patients with septic shock.

RESULTS

The percentage of Tregs in the CD4(+) T-cell population, and the serum IL-6 and IL-10 levels, were significantly higher among patients with septic shock compared with those without septic shock, and PMX-F therapy significantly decreased the number of Tregs, as well as the serum IL-6 and IL-10 levels. Furthermore, a significant increase in the number of CD4(+) T cells, a significant decrease in the percentage of Tregs in the CD4(+) T-cell population, and a significant decrease in the serum IL-6 and IL-10 levels 24 hours after PMX-F therapy were observed in septic shock survivors compared with nonsurvivors.

CONCLUSION

We found a major increase in the percentage of Tregs in peripheral blood circulating CD4(+) T cells from patients with septic shock, and observed that the removal of Tregs by hemoperfusion with PMX-F might represent a novel strategy for inducing recovery from the immunosuppression associated with sepsis.

New concepts in the pathogenesis, diagnosis and treatment of bacteremia and sepsis

Bacteremia and sepsis are major health concerns. Despite intensive research, there are only a limited number of successful treatment options, and it is difficult to see the forest for the trees when considering the pathogenesis of this condition. Studies in the last decade have shown that a major pathophysiologic event in sepsis is the progression from proinflammation to an immunosuppressive state. However, recent genome-based data indicate that sepsis-related inflammatory responses are highly variable, which calls in question the classic two-phase model of sepsis. Adequate and timely antimicrobial treatment is a cornerstone for survival in patients with bacteremia and sepsis. However, microbial resistance has emerged as an increasing challenge for clinicians and with an increasing number of resistant pathogens causing infections, selection of empiric antimicrobial treatment has become difficult. Treatment options currently under way are targeted to enhance immune responses, rebalance the regulation of the dysregulated immune system, remove endotoxin and block/inhibit apoptosis.