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

Sepsis in elderly patients: the role of neutrophils in pathophysiology and therapy

Sepsis is among the most important causes of mortality, particularly within the elderly population. Sepsis prevalence is on the rise due to different factors, including increasing average population age and the concomitant rise in the prevalence of frailty and chronic morbidities. Recent investigations have unveiled a "trimodal" trajectory for sepsis-related mortality, with the ultimate zenith occurring from 60 to 90 days until several years after the original insult. This prolonged temporal course ostensibly emanates from the sustained perturbation of immune responses, persevering beyond the phase of clinical convalescence. This phenomenon is particularly associated with the aging immune system, characterized by a broad dysregulation commonly known as "inflammaging." Inflammaging associates with a chronic low-grade activation of the innate immune system preventing an appropriate response to infective agents. Notably, during the initial phases of sepsis, neutrophils-essential in combating pathogens-may exhibit compromised activity. Paradoxically, an overly zealous neutrophilic reaction has been observed to underlie multi-organ dysfunction during the later stages of sepsis. Given this scenario, discovering treatments that can enhance neutrophil activity during the early phases of sepsis while curbing their overactivity in the later phases could prove beneficial in fighting pathogens and reducing the detrimental effects caused by an overactive immune system. This narrative review delves into the potential key role of neutrophils in the pathological process of sepsis, focusing on how the aging process impacts their functions, and highlighting possible targets for developing immune-modulatory therapies. Additionally, the review includes tables that outline the principal potential targets for immunomodulating agents.

Influence of therapeutic plasma exchange treatment on short-term mortality of critically ill adult patients with sepsis-induced organ dysfunction: a systematic review and meta-analysis

INTRODUCTION

The impact of therapeutic plasma exchange (TPE) on short-term mortality in adult patients with sepsis-induced organ dysfunction remains uncertain. The objective of the study is to assess the effect of adjunct TPE in this setting through a comprehensive literature review.

METHODS

The National Library of Medicine's Medline, Ovid (Embase), the Cochrane Library database and clinicaltrial.gov from January 01, 1966, until October 01, 2022, were searched for terms: therapeutic plasma exchange, plasmapheresis, sepsis, and septic shock. We reviewed, selected and extracted data from relevant randomized clinical trials (RCTs) and matched cohort studies (MCSs) comparing short-term mortality in critically ill adult septic patients treated with standard therapy versus those receiving adjunct TPE. Risk of bias was assessed in the RCTs using Cochrane Collaboration tool and in MCSs using ROBINS-I tool. Summary statistics, risk ratios (RRs), and confidence intervals (CIs) were calculated using random effects model.

RESULTS

This systematic review included 937 adult critically ill septic patients from five RCTs (n = 367) and fifteen MCSs (n = 570). Of these total, 543 received treatment with TPE in addition to standard care. The meta-analysis includes all five RCTs and only six MCSs (n = 627). The adjunct TPE treatment (n = 300) showed a significant reduction in short-term mortality (RR 0.59, 95% CI 0.47-0.74, I2 3%) compared to standard therapy alone (n = 327). The systematic review of all 20 trials revealed that adding TPE to the standard therapy of critically ill septic patients resulted in faster clinical and/or laboratory recovery.

CONCLUSIONS

Our comprehensive and up-to-date review demonstrates that adjunct TPE may provide potential survival benefits when compared to standard care for critically ill adult patients with sepsis-induced organ dysfunction. While results of this meta-analysis are encouraging, large well-designed randomized trials are required to identify the optimal patient population and TPE procedure characteristics prior to widespread adoption into practice.

Blood Purification in Patients with Sepsis Associated with Acute Kidney Injury: A Narrative Review

Sepsis leads to organ dysfunction. Acute kidney injury, a common type of organ dysfunction, is associated with a high mortality rate in patients with sepsis. Kidney replacement therapy can correct the metabolic, electrolyte, and fluid imbalances caused by acute kidney injury. While this therapy can improve outcomes, evidence of its beneficial effects is lacking. Herein, we review the indications for blood purification therapy, including kidney replacement therapy, and the current knowledge regarding acute kidney injury in terms of renal and non-renal indications. While renal indications have been well-documented, indications for blood purification therapy in sepsis (non-renal indications) remain controversial. Excessive inflammation is an important factor in the development of sepsis; blood purification therapy has been shown to reduce inflammatory mediators and improve hemodynamic instability. Given the pathophysiology of sepsis, blood purification therapy may decrease mortality rates in these patients. Further trials are needed in order to establish the effectiveness of blood purification therapy for sepsis.

An inquiry into the treatment of sepsis using plasma exchange therapy: A systematic review and meta-analysis

Sepsis is a potentially lethal condition that occurs when the body's response to infection damages tissue and organs. The production of inflammatory mediators typically assists in defending the body against infection; however, an overreaction to inflammation can cause coagulation problems, vascular endothelial damage, and organ hypoperfusion. Blood purification methods, such as plasmapheresis, can effectively remove inflammatory mediators from plasma. The purpose of this meta-analysis was to explore the efficacy of plasma exchange for sepsis treatment as noted in recent studies. The authors searched the Pubmed (Medline), Cochrane Central Register of Controlled Trials (The Cochrane Library), Embase (Ovid), and Scopus databases and included controlled clinical studies that compared plasmapheresis or plasma filtration with conventional treatment in patients with severe sepsis. The Newcastle-Ottawa Scale literature quality assessment tool was used to assess the risk of bias. The primary study outcome was all-cause mortality. The random effects model was adopted for conducting the meta-analysis. Among the 1013 records found, the study included 5 trials, all of which carried a low risk of bias. The use of plasmapheresis was associated with a longer stay in the intensive care unit (odds ratio [OR], 0.85, 95% confidence interval [CI], 0.39-1.32, heterogeneity [I2 ] = 0%), a significant reduction in all-cause mortality (OR, 0.54, 95% CI, 0.33-0.89, I2  = 70%), and reduced mortality (OR, 0.29, 95% CI, 0.13-0.67, I2  = 0%) in adults; the results for children differed from this (OR, 0.79, 95% CI, 0.36-1.72, I2  = 89%). Four trials reported no adverse events; one trial reported an adverse event related to plasma exchange, including an instance of hypotension in one patient. Plasmapheresis appeared to be an effective treatment for patients suffering from sepsis. A large number of additional randomised controlled trials are needed to confirm this finding.

Extracorporeal blood purification benefits in post-caesarean patient with severe acute respiratory distress syndrome due to miliary tuberculosis: a case report

BACKGROUND

Miliary tuberculosis is a life-threatening disease caused by the hematogenous spread of Mycobacterium tuberculosis. It is uncommon in pregnancy. Mortality rates for patients with miliary tuberculosis who require mechanical ventilation are high (60-70%).

CASE PRESENTATION

We reported a rare and challenging case, a 35-year-old Asian woman with 34 weeks of pregnancy, and miliary tuberculosis with acute respiratory distress syndrome and septic shock. The patient presented with severe acute respiratory distress syndrome, necessitating mechanical ventilation, vasopressor, and pregnancy termination with caesarean section. The patient underwent blood purification with continuous veno-venous hemofiltration using an oXiris filter for 24 hours. After continuous veno-venous hemofiltration, the patient's condition was greatly improved, and the patient was successfully extubated and was able to breathe spontaneously without vasopressor on the third day. High levels of interleukin-6, interleukin-10, procalcitonin, C-reactive protein, interferon-γ, and tumor necrosis factor-α were found postoperatively.

CONCLUSION

The bacterial infection of tuberculosis, acute respiratory distress syndrome, and the stress response from the caesarean section contributed to the high levels of cytokines, which correlated with the patient's severe inflammatory condition. The cytokine levels were greatly reduced after the blood purification procedure and this might be associated with the patient's clinical improvement. Extracorporeal blood purification could help to disrupt the vicious cycle of inflammation.

Clinical and Economic Evaluation of the Blood Purification with Selective Sorption Techniques in ICU Patients

The objective was to analyze the clinical and economic feasibility of using selective methods  of lipopolysaccharide (LPS) sorption  for sepsis treatment.

Materials and methods.  A clinical and economic model was used to assess the feasibility of using some technologies of selective lipopolysaccharide sorption. The model was developed in accordance with the current industry standard «Clinical and Economic Research» used in Russia. The target  population was patients of 18 years old and older with sepsis. The methodology involved the evaluation of available randomized clinical trials, as well as studies involving data from network meta-analyses and systematic  reviews of the use of the studied  technologies. The calculation of direct  medical and indirect non-medical  costs was made with an analysis of the impact on the budget  during  the first year and on the time horizon for five years.

Results. The value of direct  and indirect costs was determined when using sorption  devices based on Efferon LPS, Toraymyxin,  Alteco LPS Adsorber,  Toxipak  columns. It was shown that  among the therapeutic alternatives, the use of the Efferon LPS column had the least burden on the budget.

Conclusion. The  use of selective  lipopolysaccharide sorption  technologies in the  intensive  care program  for sepsis patients, although accompanied  by an increase  in direct  and indirect financial costs, leads to budget  savings in the medium  term. Improving  the mechanism  for compensating the costs of using this technology is a promising way to improve the outcomes of sepsis treatment.

The Techniques of Blood Purification in the Treatment of Sepsis and Other Hyperinflammatory Conditions

Even in the absence of strong indications deriving from clinical studies, the removal of mediators is increasingly used in septic shock and in other clinical conditions characterized by a hyperinflammatory response. Despite the different underlying mechanisms of action, they are collectively indicated as blood purification techniques. Their main categories include blood- and plasma processing procedures, which can run in a stand-alone mode or, more commonly, in association with a renal replacement treatment. The different techniques and principles of function, the clinical evidence derived from multiple clinical investigations, and the possible side effects are reviewed and discussed along with the persisting uncertainties about their precise role in the therapeutic armamentarium of these syndromes.

Rationale for sequential extracorporeal therapy (SET) in sepsis

Sepsis and septic shock remain drivers for morbidity and mortality in critical illness. The clinical picture of patients presenting with these syndromes evolves rapidly and may be characterised by: (a) microbial host invasion, (b) establishment of an infection focus, (c) opsonisation of bacterial products (e.g. lipopolysaccharide), (d) recognition of pathogens resulting in an immune response, (e) cellular and humoral effects of circulating pathogen and pathogen products, (f) immunodysregulation and endocrine effects of cytokines, (g) endothelial and organ damage, and (h) organ crosstalk and multiple organ dysfunction. Each step may be a potential target for a specific therapeutic approach. At various stages, extracorporeal therapies may target circulating molecules for removal. In sequence, we could consider: (a) pathogen removal from the circulation with affinity binders and cartridges (specific), (b) circulating endotoxin removal by haemoperfusion with polymyxin B adsorbers (specific), (c) cytokine removal by haemoperfusion with sorbent cartridges or adsorbing membranes (non-specific), (d) extracorporeal organ support with different techniques for respiratory and cardiac support (CO₂ removal or extracorporeal membrane oxygenation), and renal support (haemofiltration, haemodialysis, or ultrafiltration). The sequence of events and the use of different techniques at different points for specific targets will likely require trials with endpoints other than mortality. Instead, the primary objectives should be to achieve the desired action by using extracorporeal therapy at a specific point.

Potential survival benefit and early recovery from organ dysfunction with polymyxin B hemoperfusion: perspectives from a real-world big data analysis and the supporting mechanisms of action

Background

Endotoxin (ET) removal therapy with polymyxin B-immobilized fiber column hemoperfusion (PMX-HP) has been used for the treatment of septic shock. Some observational studies reported clinical benefits, particularly in specific subgroups of patients. However, larger randomized controlled trial results have been disappointing.

Main body

The four studies that revealed the survival benefit of PMX-HP were based on the Japanese Diagnosis Procedure Combination (DPC) national inpatient database (J-DPC study). Nevertheless, one J-DPC study and a randomized controlled trial (RCT) conducted in France evaluated PMX-HP in patients with abdominal septic shock and did not report a significant survival benefit. In both studies, the severity of illness was too low to find substantial significant differences in mortality. The results of the J-DPC studies further suggest that some subpopulations of patients could benefit from PMX-HP. Based on these results, this review revisited prior RCTs and other large-scale studies on PMX-HP. In addition, four J-DPC studies and one large-scale study reported a survival benefit with PMX-HP. A secondary analysis of the EUPHRATES trial, the most recent double-blinded RCT of PMX-HP conducted in North America, suggested a survival benefit in patients with high levels of endotoxemia. In the J-DPC studies and the EUPHRATES trial, ventilator-free days, vasoactive drug-free days, and renal replacement-free days were significantly improved in the PMX-HP groups. These findings suggest that PMX-HP can contribute to early recovery from organ dysfunction. The reduction of supportive care likely provides important health and economic benefits for managing patients with septic shock. Finally, the blood levels of mediators or biomarkers related to respiratory, cardiovascular, and renal dysfunction have been reported to be normalized with PMX-HP.

Conclusions

These results support the biological rationale for the improvement in organ dysfunction observed in the J-DPC studies and other large-scale studies, including the EUPHRATES trial. Real-world evidence from large data sets suggests an appropriate patient population that are likely to benefit from the utility of PMX-HP for septic shock.

Mortality and adverse events of hemoadsorption with CytoSorb® in critically ill patients: a systematic review and meta-analysis of randomized controlled trials

Background

The effects and safety of extracorporeal hemoadsorption with CytoSorb® in critically ill patients with inflammatory conditions are controversial.

Methods

We performed a systematic review with meta‐analysis and trial sequential analysis (TSA) of randomized‐controlled trials to assess the mortality and safety of CytoSorb® therapy in critically ill patients with inflammatory conditions. Electronic databases were searched up to April 2022. The primary outcome was mortality at longest follow‐up and secondary outcomes included various adverse event (AE) outcomes. Conflict of interest and funding of each trial were assessed. We calculated relative risk (RR) and 95% confidence interval (CI).

Results

Fourteen published (n = 764) and 4 unpublished (n = 111) trials were included. Eight trials were performed in medical ICU patients and 10 in complex cardiac surgery. Ten trials had significant industrial funding or an author conflict of interest. Hemoadsorption with CytoSorb® was associated with higher mortality at latest follow‐up (16 trials, n = 807, 120 of 402 [29.85%] patients in the CytoSorb® group vs. 98 of 405 [24.20%] patients in the control group, RR = 1.24 [95% CI, 1.04–1.49], p = .02, [TSA‐adjusted CI, 0.92–1.68]) and at 30‐days or in‐hospital (11 trials, n = 727; RR = 1.41 [95% CI, 1.06–1.88], p = .02, [TSA‐adjusted CI, 0.44–4.62]). Only one trial reported the definition of adverse event, while detailed results were reported in 3 trials; the risk of adverse events was not higher with CytoSorb®. Certainty of evidence ranged from low to very low.

Conclusion

Low certainty of evidence showed that the use of CytoSorb® might increase mortality in critically ill patients with inflammatory conditions. Adverse events were frequent but underreported and not systematically evaluated. Industrial funding and conflict of interest were common. Considerable uncertainty about the findings does not allow firm conclusions and suggests a need for high‐quality randomized trials to clarify mortality and adverse events related to CytoSorb®.

Editorial Comment

Hemoadsorption with CytoSorb® have been used in critically ill patients despite lack of high quality data from RCTs suggesting any patient‐important benefits. The findings from this systematic review and meta‐analysis suggests an increased risk of adverse events including mortality. With no apparent benefits and at the same time risk of harm, use of hemoadsorption with CytoSorb® in daily clinical practice cannot be recommended at this time.

Blood Purification Studies in the ICU: What Endpoints Should We Use?

The potential for treatment of the critically ill using blood purification techniques has been discussed for several decades. However, since the first attempts at applying extracorporeal techniques to patients with sepsis were described, there has been considerable hesitancy towards the widespread adoption of such methods, given the lack of mortality benefit observed and indeed the paucity of randomized controlled studies. However, this is not unique so far as studies on the critically ill are concerned where there is a dearth of studies providing a positive finding to influence clinical practice. Consequently, as well as targeted patient selection, it is perhaps time to consider endpoints other than mortality in studies on the critically ill, particularly in blood purification studies where, to-date, such heterogeneous groups of patients have been studied.

The Austrian ICU survey : A questionnaire-based evaluation of intensive care medicine in Austria

Background

While structures of intensive care medicine in Austria are well defined, data on organisational and medical practice in intensive care units (ICUs) have not been systematically evaluated.

Methods

In this explorative survey, organisational and medical details of ICUs in Austria were collected using an online questionnaire consisting of 147 questions.

Results

Out of 249 registered ICUs 73 (29.3%) responded, 60 were adult, 10 pediatric/neonatal ICUs and 19, 25 and 16 ICUs were located in level I, II and III hospitals, respectively. Of the respondents 89% reported that the ICU director was board-certified in intensive care medicine. Consultants were constantly present in 78% of ICUs during routine working hours and in 45% during nights and weekends. The nurse:bed ratio varied between 1:1 and 1:2 in 74% during day shifts and 60% during night shifts. Routine physiotherapist rounds were reported to take place daily except weekends in 67% of ICUs. Common monitoring techniques were reported to be in routine or occasional use in 85% and 83% of ICUs, respectively. The majority of ICUs provided daily visiting hours ranging between 2–12 h. Waiting rooms for relatives were available in 66% and an electronic documentation system in 66% of ICUs. Written protocols were available in 70% of ICUs.

Conclusion

The Austrian ICU survey suggests that ICUs in Austria are clearly structured, well-organized and well-equipped and have a high nurse:bed ratio. In view of the relatively low return rate we cannot exclude that a selection bias has led to overestimation of the survey findings.

Supplementary Information

The online version of this article (10.1007/s00508-021-02002-x) contains supplementary material, which is available to authorized users.

Blood purification in sepsis and systemic inflammation

PURPOSE OF REVIEW

Sepsis and septic shock are life-threatening diseases with high mortality. Although efforts have made to improve the survivals, the outcomes are still frustrating. Blood purification was thought to be a promising adjunctive therapy to regulate the excessive cytokine storm or to reduce the endotoxin activity caused by sepsis. Critically ill COVID-19 characterized with the similar disease to sepsis may also benefit from blood purification.

RECENT FINDINGS

The recent studies mainly focused on hemadsorption materials. The results of the clinical trials showed a tendency in decrease of cytokine levels and endotoxin activity and improvement in haemodynamics. However, the results were controversial. More evidence about blood purification in sepsis and COVID-19 are needed from currently ongoing trials and future well designed trials.

SUMMARY

The blood purification therapy demonstrated the tendency in decrease of cytokines and endotoxin activity in different degree according to the current studies. However, the effect on mortality and haemodynamics is still in controversy. Further well designed, large sample sized studies should focus on the timing of initiating blood purification, the appropriate indications and the optimal type of blood purification membrane or cartridge to provide more evidence for clinical practice.

Renal Replacement Techniques in Septic Shock

Sepsis is defined as a life-threatening organ dysfunction caused by a dysregulated host response to an infection; it carries a risk for mortality, considerably exceeding that of a mere infection. Sepsis is the leading cause for acute kidney injury (AKI) and the requirement for renal replacement therapy (RRT) in intensive care unit (ICU) patients. Almost every second critically ill patient with sepsis will develop AKI. In septic shock, the dysregulated host response to infectious pathogens leads to a cytokine storm with uncontrolled production and release of humoral proinflammatory mediators that evoke cellular toxicity and promote the development of organ dysfunction and increased mortality. In addition to treating AKI, RRT techniques can be employed for extracorporeal adsorption of inflammatory mediators using specifically developed adsorption membranes, hemoperfusion sorbent cartridges or columns; these techniques are intended to decrease the level and early deleterious effects of circulating proinflammatory cytokines and endotoxins during the first hours and days of septic shock treatment, in order to improve patient outcomes. Several methods and devices, such as high cut-off membranes, the Oxiris®-AN69 membrane, CytoSorb® and HA380 cytokine hemoadsorption, polymyxin B endotoxin adsorption, and plasmapheresis have been examined in small study series or are under evaluation as ways of improving patient outcomes in septic shock. However, to date, the data on actual outcome benefits have remained controversial, as discussed in this review.

Efficacy and safety of Shenfu injection in the treatment of sepsis: A protocol for systematic review and meta-analysis

BACKGROUND

Sepsis is a syndrome of infection-induced systemic inflammatory response. Conventional treatment combined with Shenfu injection (SFI) has been previously validated clinical effective in alleviating inflammatory response in patients with septic shock. However, evidence-based medical evidence is scant. Herein, we designed the protocol of a proposed study based on the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines, aiming to systematically evaluate the efficacy and safety of SFI in patients with sepsis.

METHODS

Eligible studies reporting the efficacy and safety of SFI in the treatment of sepsis published before August 2021 will be searched from online databases, including the PubMed, Web of Science, EMBASE, Ovid, the Cochrane Library, Wanfang Database, China National Knowledge Infrastructure, and China Biology Medicine Disc. The literature selection process will be reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines. After data extraction and methodological quality evaluation, Stata 12.0 software will be used to synthesize the data through fixed/random effects of meta-analysis models.

RESULTS

The results of this meta-analysis will be submitted to a peer-reviewed journal for publication.

CONCLUSION

This study will provide reliable evidence-based basis for the clinical application of SFI in the treatment of sepsis.

OSF REGISTRATION NUMBER

DOI 10.17605/OSF.IO/KCMDQ.