Leukaplasmapheresis in meningococcal septic shock

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.

Complement deficiency states and associated infections

A major function of the immune system is to protect the host from microbial infections. The complement system plays important roles in both the innate and the adaptive immune defense and also acts as a bridge between these arms of immunity. This is obvious from complement deficiencies which in varying degree, depending on which factor is missing, are associated with increased infection susceptibility and also increased risk for other, mainly autoimmune diseases. Genetically determined deficiencies are described for almost all complement proteins but the consequences show a wide variation. Here the genetic defects and molecular abnormalities in complement deficient persons, related clinically relevant infections and the options for prevention and therapy are reviewed. The roles of complement in host defense against common infections are also discussed.

Guidelines on the use of therapeutic apheresis in clinical practice--evidence-based approach from the Apheresis Applications Committee of the American Society for Apheresis

The American Society for Apheresis (ASFA) Apheresis Applications Committee is charged with a review and categorization of indications for therapeutic apheresis. Beginning with the 2007 ASFA Special Issue (fourth edition), the subcommittee has incorporated systematic review and evidence-based approach in the grading and categorization of indications. This Fifth ASFA Special Issue has further improved the process of using evidence-based medicine in the recommendations by refining the category definitions and by adding a grade of recommendation based on widely accepted GRADE system. The concept of a fact sheet was introduced in the Fourth edition and is only slightly modified in this current edition. The fact sheet succinctly summarizes the evidence for the use of therapeutic apheresis. The article consists of 59 fact sheets devoted to each disease entity currently categorized by the ASFA as category I through III. Category IV indications are also listed.

Plastic surgery management in pediatric meningococcal-induced purpura fulminans

Purpura fulminans associated with meningococcemia is a devastating disease in children. The tissue loss can be extensive and difficult to determine at the outset. The authors suggest a strategy to manage these wounds with the goal of preserving as much tissue and function as possible. At the present time, conservative therapy to the wounds appears to be the best course in the initial, critical phase, as long as no active local purulence is found. Debridement or amputation is performed when the nonviable tissue margins are delineated. Temporary coverage with allograft may be required; definitive coverage is accomplished when the local tissue perfusion has recovered. Future revisions are often necessary to improve these children's quality of life.

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.

Impaired fibrinolysis in the pathogenesis of dengue hemorrhagic fever

The mechanisms contributing to bleeding complications in dengue hemorrhagic fever were studied by investigating the pattern of activation of the coagulation and fibrinolytic systems in 50 children with severe dengue hemorrhagic fever. Thirteen patients (26%) died, and activation of coagulation was most pronounced in the deceased group. Fibrinolysis was also activated, but this activation was relatively weak compared with that of coagulation as a result of persistently high plasminogen activator inhibitor levels. Plasminogen activator inhibitor also prevented a switch from the procoagulant to the profibrinolytic state in lethal dengue hemorrhagic fever, which was further enhanced by an acquired protein C deficiency. The present study is the first to demonstrate such a mechanism in a viral infection. This imbalance between coagulation and fibrinolysis may be used as a prognostic marker, but it may also be a target for future therapeutic intervention.

The effects of leucodepletion in patients who develop the systemic inflammatory response syndrome following cardiopulmonary bypass

The development of the systemic inflammatory response syndrome (SIRS) is associated with increased morbidity and mortality. Numerous anticytokine trials have failed to demonstrate any outcome benefit and there has been little evidence of improvement in the prognosis of this condition over the past 20 years. This study examines the effect of using a white cell filter designed to remove polymorphonuclear cells (PMNs) in patients who developed SIRS 36 h after cardiopulmonary bypass (CPB). Twenty-four patients were randomized to receive either leucofiltration (LF) or control therapy (CT). The two groups were well matched at study entry in terms of age, severity of illness and length of time on CPB. LF patients received 60 min filtration periods using a venovenous extracorporeal circuit at a flow rate of 200 ml/min with the cycle repeated every 12 h while SIRS and other entry criteria were met. CT patients received standard therapy. LF patients received an average of 4.2 cycles (range 1-8) and, after 15 min filtration, the total leucocyte count had fallen from 16.2 +/- 5.3 to 10.4 +/- 3.3 x 10(9)/l and PMN from 14.4 +/- 5.2 to 8.3 +/- 4.2 x 10(9)/l. The mean platelet count changed from 127 +/- 87 to 117 +/- 82 x 10(9)/l. No adverse effects related to leucodepletion were observed. There was no difference between the groups in either mortality or length of stay at the intensive care unit or at hospital discharge. Organ function was assessed regularly during the study period and significant changes occurred only in respiratory and renal function. In the LF patients, respiratory function assessed by change in hypoxaemia index from baseline and renal function assessed by serum creatinine showed significant treatment effects compared to CT patients (p < 0.01, < 0.01 respectively); three CT patients, but no LF patients, received haemofiltration during the study period. Leucofiltration safely and effectively removes circulating PMNs from patients with SIRS following CPB. This may result in improved pulmonary and renal function in these patients. Further studies are required of the kinetics and phenotypic characteristics of PMN removal by leucofiltration and a larger multicentre study will be necessary to determine whether this novel therapy has a significant outcome benefit in critically ill patients with SIRS.

Do new strategies in meningococcemia produce better outcomes?

Meningococcal septic shock (MSS) has high mortality and morbidity rates. In addition to the traditional prompt antibiotics and respiratory and circulatory support, new treatment strategies have been proposed.

AGAINST THE INFLAMMATORY CASCADE

Immunotherapy, such as antiserum to Escherichia coli J5 and human antilipid A monoclonal antibodies/centoxin (HA-1A), did not significantly alter the mortality rate of MSS; we are awaiting the results of the bactericidal/permeability-increasing protein multicenter trial. Two series reported the effects of hemofiltration and hemodiafiltration in MSS, but the true benefits remain unknown.

TO TREAT HEMOSTATIC ABNORMALITIES

In MSS, heparin is still controversial and antithrombin concentrate use has been reported in only one child. Several case reports on protein C and recombinant tissue plasminogen activator have been published; the efficacy (improvement in shock and organ dysfunction and reduction in amputation rate) and safety (intracerebral hemorrhage with recombinant tissue plasminogen activator) of these treatments need further evaluation. Blood and plasma exchange appear to be safe and are supposed to reduce mortality, but it is difficult to draw firm conclusions from published studies. Finally, local application of medicinal leeches has been reported to improve purpuric lesions.

TO INDUCE VASODILATION

Prostacyclin, or epoprostenol, infusion, sodium nitroprussiate infusion, sympathetic blockade, and topical nitroglycerin have been reported to improve distal perfusion; however, these reports are all anecdotal.

OTHER STRATEGIES

Improvement in limb perfusion was achieved after hyperbaric oxygenation in patients with purpura fulminans caused by different pathogens. Most authors recommend monitoring of compartment pressures and performing fasciotomy as indicated. Finally, extracorporeal membrane oxygenation was recently proposed to support seven children with intractable MSS.

CONCLUSIONS

There is no proof that unconventional treatments have a significant impact on outcome in MSS; prospective multicenter trials are needed. At present, early recognition of meningococcal sepsis and appropriate treatment seem to be the optimal methods of improving outcome. Efforts to find an effective meningococcal vaccine must be continued.

Meningococcemia as a model for testing the hypothesis of antisepsis therapies

OBJECTIVE

To critically review the advantages and disadvantages of pediatric meningococcemia as a model for testing antisepsis therapies.

DATA SOURCES

Research and review articles on the pathogenesis and treatment of human meningococcemia, as well as editorial commentaries discussing the failure of clinical trials for adult sepsis or Systemic Inflammatory Response Syndrome. Data from these sources are presented in the context of the author's experience as principal investigator in a large, randomized trial on children with invasive meningococcal disease.

STUDY SELECTION AND DATA EXTRACTION

Studies were selected to include aspects of epidemiology, pathophysiology, outcome prediction, and therapeutic trials.

DATA SYNTHESIS

Compared with an adult sepsis population, meningococcemia is a single disease, diagnosed clinically with high reliability. Patients are previously healthy, without underlying medical or surgical conditions. In contrast to sepsis trials, nearly all patients with meningococcal disease receive effective antibiotics. Finally, meningococcemia most closely resembles animal models of endotoxin infusion, in which most antisepsis therapies have been highly effective. However, the meningococcal model carries major disadvantages, among them that meningococcemia is rare and rapidly progressive and patients are widely dispersed geographically. In addition, a wide range of experimental therapies is routinely provided in an attempt to preserve life or limbs.

CONCLUSIONS

Meningococcemia is an ideal model of a rapidly progressive bacterial infection associated with marked endotoxemia. Problems with the model can be overcome by extensive pretrial logistic planning, as well as close coordination and cooperation with national regulatory agencies.

Cellular origin and procoagulant properties of microparticles in meningococcal sepsis

Patients with meningococcal sepsis generally suffer from disseminated intravascular coagulation (DIC). The aim of this study was to address whether these patients have elevated numbers of circulating microparticles that contribute to the development of DIC. Plasma samples from 5 survivors, 2 nonsurvivors, and 5 healthy volunteers were analyzed for the presence of microparticles by flow cytometry. Ongoing coagulation activation in vivo was quantified by enzyme-linked immunosorbent assay of plasma prothrombin fragment F1 + 2, and procoagulant properties of microparticles in vitro were estimated by thrombin-generation assay. On admission, all patients had increased numbers of microparticles originating from platelets or granulocytes when compared with controls (P = .004 and P = .008, respectively). Patients had elevated levels of F1 + 2 (P = .004), and their microparticles supported thrombin generation more strongly in vitro (P = .003) than those of controls. Plasma from the patient with the most fulminant disease course and severe DIC contained microparticles that expressed both CD14 and tissue factor, and these microparticles demonstrated extreme thrombin generation in vitro. We conclude that patients with meningococcal sepsis have elevated numbers of circulating microparticles that are procoagulant. These findings may suggest a novel therapeutic approach to combat clinical conditions with excessive coagulation activation.

Recognition, treatment and complications of meningococcal disease

Meningococcal disease remains a major cause of death in young children. A decrease in mortality requires recognition and treatment of the disease at a number of stages in the illness. Life-threatening meningococcal disease usually presents as septicaemia rather than meningitis. The cardinal feature of meningococcal septicaemia is the purpuric rash. Many parents recognise the rash and seek medical advice because of it. When primary care physicians recognise the rash, the administration of parenteral penicillin may decrease mortality. However, antibacterials are not given promptly if there is no rash or if the disease presents in an atypical form. In hospital, antibacterial therapy with a third-generation cephalosporin should be given. Disease severity needs to be assessed by a valid method, such as the Glasgow Meningococcal Septicaemia Prognostic Score (GMSPS). This can identify those patients who need intensive care and/or might benefit from new therapies. The 2 life-threatening complications are septic shock and meningoencephalitis with raised intracranial pressure. Despite numerous case reports of success with potential new treatments, none has been proven safe and/or effective by controlled trials. Although it is tempting to focus on new treatments, the early recognition of severe meningococcal disease by parents, primary care physicians and junior hospital doctors is equally, if not more, important as a potential means of decreasing mortality.

Variation in plasminogen-activator-inhibitor-1 gene and risk of meningococcal septic shock

BACKGROUND

Some patients infected with Neisseria meningitidis develop septic shock accompanied by fibrin deposition and microthrombus formation in various organs, whereas others develop bacteraemia or meningitis without septic shock. We investigated whether genetic differences in the fibrinolytic system influence the development of meningococcal septic shock.

METHODS

We investigated 50 patients who survived meningococcal infection, and 131 controls from the same geographical region. Because we had no information on genotypes of patients who died, we also genotyped 183 first-degree relatives of a consecutive series of patients with meningococcal infection for the 4G/5G deletion/insertion polymorphism in the promoter region of the plasminogen-activator-inhibitor-1 gene (PAI-1). The 4G allele is associated with increased gene transcription in cell lines in vitro and with increased PAI-1 concentrations in carriers in vivo.

FINDINGS

The allele frequencies of 4G and 5G were similar between patients and controls. However, the 4G/4G genotype was present in only 9% of relatives of patients with meningitis compared with 36% of relatives of patients with septic shock. The 5G/5G genotype was more common among relatives of patients with meningitis (31 vs 11%, p=0.001). Patients whose relatives were carriers of the 4G/4G genotype had a six-fold higher risk of developing septic shock than meningitis (odds ratio 5.9 [95% CI 1.9-18.0]) compared with all other genotypes.

INTERPRETATION

Variation in the PAI-1 gene does not affect the probability of contracting meningococcal infection, but does influence the development of septic shock.

Effect of hemocarboperfusion on organ blood flow and survival in porcine endotoxic shock

OBJECTIVE

To evaluate the effects of hemocarboperfusion on hemodynamics, organ blood flow, and survival in endotoxin shock.

DESIGN

Prospective, placebo-controlled, animal trial.

SETTING

Research laboratory in a major university teaching hospital.

SUBJECTS

Pentobarbital-anesthetized pigs.

INTERVENTIONS

Twenty-eight pentobarbital-anesthetized pigs (18.5 to 22.3 kg) received 100 micrograms/kg of Escherichia coli endotoxin (lipopolysaccharide 0127) over 30 mins. Group 1 animals (n = 14) were controls and had blood diverted through an extracorporeal circuit without activated charcoal for 60 mins after lipopolysaccharide infusion. Group 2 animals (n = 14) underwent nonpulsatile hemocarboperfusion (activated charcoal SCN-1K).

MEASUREMENTS AND MAIN RESULTS

Mean arterial pressure, cardiac output, systemic vascular resistance, mean pulmonary arterial pressure, pulmonary vascular resistance, oxygen delivery, and regional blood flow (radiolabeled microsphere technique) were determined at baseline and every 30 mins for 150 mins. Results are presented as mean +/- SD. Parameters in the two groups were compared by two-way analysis of variance. A p < .05 was considered significant. The survival rate was ten (71%) of 14 animals in group 1 compared with 14 (100%) of 14 animals in group 2 (p < .05, Fisher's exact test). The mean cardiac output at the end of hemocarboperfusion was 1.6 +/- 0.6 L/min in group 1 compared with 3.0 +/- 0.9 L/min in group 2, and remained lower in group 1 animals throughout the experiment. Pulmonary arterial pressure and pulmonary vascular resistance were lower in the hemocarboperfusion-treated animals during and after hemocarboperfusion. Systemic vascular resistance increased by 70% after lipopolysaccharide infusion and returned to baseline values in the hemocarboperfusion group but remained increased in controls. Oxygen delivery was lower in group 1 at 90 and 150 mins (287 +/- 34 vs. 478 +/- 48 mL/min and 251 +/- 24 vs. 356 +/- 21 mL/min, respectively). Blood flow rates to the brain (38.5 +/- 7.5 vs. 27.1 +/- 5.4 mL/min/100 g), large intestine (26.6 +/- 1.1 vs. 17.7 +/- 2.5 mL/ min/100 g), and adrenal cortex (200 +/- 45 vs. 139 +/- 41 mL/min/100 g) were higher in the hemocarboperfusion group at the completion of carboperfusion but not at later time points.

CONCLUSION

These data suggest that hemocarboperfusion may be of value in the treatment of septic shock.

Blood filtration in children with severe sepsis: safe adjunctive therapy

OBJECTIVE

To review the safety and efficacy of haemofiltration and plasmafiltration in children with severe sepsis.

DESIGN

Retrospective case notes analysis.

SETTING

University Paediatric Intensive Care Unit.

PATIENTS

All children admitted to the intensive care unit between November 1985 and May 1992 with a primary diagnosis of severe sepsis who also received blood filtration therapy.

INTERVENTIONS

Continuous haemofiltration (HF) 18 patients; continuous haemofiltration and plasmafiltration (PF) 9 patients.

MEASUREMENTS AND RESULTS

27 children with sepsis-induced MOSF, median age 26.6 months (range 0.33-185), median weight 12 kg (range 2.5-58), mean PRISM score 19.4 (SD 8.6), mean number of organs failing 2.78 (SD 0.9) received filtration for a median duration of 36 hours (range 2-145). Eight (30%) survived (HF 5/18, PF 3/9). There was no significant difference in the demographic features between the HF group and the PF group and no difference in mortality. The two groups were pooled to assess the effect of commencement of filtration on clinical wellbeing. Arterial blood gases, electrolytes, full blood examination, ventilator settings and doses of inotropes were recorded immediately prior to commencement of filtration and 18 h after commencement. Serum anion gap and osmolality were calculated using conventional formulae. There were no significant changes in the level of cardiorespiratory support, or biochemical markers of severity following commencement of filtration. Platelet count fell 32% (p = 0.029) but no bleeding was encountered. No severe complications were observed during 1222 h of filtration. No bleeding or infection was observed at the site of cannulation. One child developed haemodynamic instability following commencement of plasmafiltration necessitating abandonment of the procedure.

CONCLUSION

Haemofiltration or plasmafiltration can be performed safely in children with severe sepsis but their effect on outcome remains unknown.