The role of plasmapheresis in severe acute disseminated encephalomyelitis with clinical findings of transverse myelitis

INTRODUCTION

Acute disseminated encephalomyelitis is a rare acute demyelinating disease of the central nervous system (CNS). The pathogenesis remains unclear but is suspected to be autoimmune. High doses of methylprednisolone (HDMP) are currently considered standard of treatment. Plasmapheresis (PE) is typically given in steroid refractory cases. There is currently limited evidence supporting its use in ADEM.

MATERIALS AND METHODS

We report a 16-year-old girl with ADEM who improved rapidly after initiating PE.

RESULTS

The patient presented with acute onset of multifocal CNS symptoms, including encephalopathy, requiring intensive care unit management. Despite HDMP administration, her clinical condition continued to deteriorate. PE was therefore initiated on the same day as HDMP. Her clinical condition improved significantly following the first session. She was extubated and discharged from the intensive care unit the following day.

CONCLUSION

HDMP combined with PE may be an effective first-line treatment in patients with fulminant ADEM.

Neurological complications of influenza vaccination: navigating the spectrum with a focus on acute disseminated encephalomyelitis (ADEM)

Introduction

Acute disseminated encephalomyelitis (ADEM) is a rare neurological disorder characterized by inflammation in the brain and spinal cord. This systematic review aims to investigate the potential association between ADEM and influenza vaccination by analyzing relevant case reports. ADEM is traditionally thought to be a monophasic condition, predominantly affecting children, often following viral illnesses or immunizations. Recent attention has focused on a possible link between ADEM and influenza vaccination, prompting the need for a thorough investigation.

Methods

The systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and the AMSTAR2 (A MeaSurement Tool to Assess systematic Reviews 2) guidelines. Electronic searches were conducted on PubMed, Cochrane Library, and clinicaltrials.gov databases, spanning up to August 2023. Inclusion criteria encompassed full-text articles in English, observational studies, case reports, and case series providing comprehensive details for confirming clinical diagnoses of ADEM following influenza vaccination. Data were extracted, including demographic information, vaccination details, clinical symptoms, diagnostic evaluations, treatment modalities, and outcomes. Quality assessment was performed using the Joanna Briggs Institute (JBI) Critical Appraisal tool.

Results

A total of 23 cases of ADEM following influenza vaccination were identified from 19 included articles. The mean age of affected individuals was 40.2 years (±25.7) with 60.8% being male. Common presenting symptoms included muscle weakness (52.1%), urinary abnormalities (30.4%), altered consciousness (26%), and sensory disturbances (26%). Neurological examination revealed findings such as extensor plantar reflex (positive Babinski sign) in 26%, hyperreflexia in 30.4%, and generalized hyporeflexia in 13% of the cases. Diagnostic evaluations involved MRI, showing multiple hyperintense lesions in cerebral hemispheres (43.4%), subcortex (60.8%), and spinal cord (39.1%). Cerebrospinal fluid analysis indicated elevated white blood cell count in 69.5% of cases, with lymphocytic pleocytosis in 52.1%. Oligoclonal bands were reported positively in 8.6% of cases. Treatment approaches varied, with intravenous methylprednisolone being the most common (39.1%). Out of the 23 cases, two (8.6%) patients had a fatal outcome, while the rest showed clinical improvement with complete or partial resolution of symptoms. Persisting symptoms included numbness in the lower extremities (8.6%) and impaired ability to walk after 10 months (4.3%).

Conclusion

While the association between ADEM and influenza vaccination is rare, healthcare professionals should remain vigilant and consider patients' vaccination history, particularly following an influenza immunization. This systematic review highlights the clinical manifestations, diagnostic tools, treatment approaches, and outcomes of ADEM cases post-influenza vaccination. Further research is essential to understand this association and improve clinical decision-making, ensuring the safety and efficacy of immunization programs.

Can early-onset acquired demyelinating syndrome (ADS) hide pediatric Behcet's disease? A case report

Behcet's disease (BD) is a rare vasculitis characterized by multisystemic inflammation. Central nervous system (CNS) involvement is rare and heterogeneous, particularly in the pediatric population. A diagnosis of neuro-Behcet could be highly challenging, especially if neurological manifestations precede other systemic features; however, its timely definition is crucial to prevent long-term sequelae. In this study, we describe the case of a girl who, at 13 months of age, presented with a first episode of encephalopathy compatible with acute disseminated encephalomyelitis, followed, after 6 months, by a neurological relapse characterized by ophthalmoparesis and gait ataxia, in association with new inflammatory lesions in the brain and spinal cord, suggesting a neuromyelitis optica spectrum disorder. The neurological manifestations were successfully treated with high-dose steroids and intravenous immunoglobulins. In the following months, the patient developed a multisystemic involvement suggestive of Behcet's disease, characterized by polyarthritis and uveitis, associated with HLA-B51 positivity. The challenge presented by this unique case required a multidisciplinary approach involving pediatric neurologists, neuro-radiologists, and pediatric rheumatologists, with all of these specialists creating awareness about early-onset acquired demyelinating syndromes (ADSs). Given the rarity of this presentation, we performed a review of the literature focusing on neurological manifestations in BD and differential diagnosis of patients with early-onset ADS.

Clinical Presentation and Outcomes of Acute Disseminated Encephalomyelitis in Adults Worldwide: Systematic Review and Meta-Analysis

Background

Acute disseminated encephalomyelitis (ADEM) is a rare demyelinating disorder that is often misdiagnosed. To improve early diagnosis, we performed a systematic review and meta-analysis of clinical features, outcomes for ADEM in adults.

Methods

The PubMed, Embase, Web of Science and Cochrane Library databases were searched for studies reporting the clinical features of adults with ADEM between January 1990 and May 2021. A random-effects meta-analysis model was used to pool data on clinical features and functional outcomes.

Results

Twelve studies examining 437 adults with ADEM met the inclusion criteria. Overall, the clinical features and diagnostic findings observed in more than two-thirds of the patients were white matter lesions [87.1%, 95% confidence interval (CI)=75-95.6], polyfocal onset (80.5%, 95% CI=50.5-98.9) and pyramidal signs (68.7%, 95% CI =40.0-91.9). The mortality rate was 7.8% (95% CI = 3.3–13.5), and the risk of residual deficits was 47.5% (95% CI = 31.8–63.4).

Conclusions

Adults with ADEM had worse outcomes than children. Clinicians should maintain high clinical suspicion for patients presenting with certain clinical features and diagnostic findings.

Rapidly progressive dementia in a nonagenarian with acute disseminated encephalomyelitis

We describe a case of rapidly progressive dementia (RPD) in a nonagenarian. Dementia was caused by an acute disseminated encephalomyelitis (ADEM). Although not frequently diagnosed in the very elderly acute disseminated encephalomyelitis should not be overlooked for it is a treatable condition. A recent infection followed by rapid cognitive deterioration and multifocal neurologic signs should raise the attention to curable autoimmune diseases. Although the cause of ADEM is still unclear, immune suppression is the mainstay of treatment. Most patients improve on high-dose glucocorticoids and eventually immune globulin treatment or plasma exchange if steroid-unresponsive.

Clinicoradiological and prognostic features of COVID-19-associated acute disseminated encephalomyelitis

INTRODUCTION

The Covid-19 pandemic has resulted in a spark in interest in the subject given the high exposure rate to viral antigens in the form of infections and vaccines. It is expected that acute disseminated encephalomyelitis (ADEM) cases see a rise in incidence during this period. Given the plethora of Covid-19-related central nervous system (CNS) involvement, it is important to be aware of the varied presentations of ADEM.

CASE REPORTS

In this paper, we report 3 cases of ADEM following Covid-19 infection. Patients presented with polyfocal neurological symptoms 6 to 18 days after respiratory symptoms onset. The diagnosis of Covid-19 was made based on nasal swab reverse transcriptase-polymerase chain reaction (RT-PCR) and chest computerized tomography (CT).

DISCUSSION

These cases illustrate both classic and atypical presentations requiring exclusion of a spectrum of CNS conditions to be able to retain the diagnosis of ADEM. Consequently, we stress the importance of context, clinical examination and MRI findings in the differentials. In addition, we discuss workup, and particularly, the indication of brain biopsy. Also, the paper discusses options in therapy and the prognosis. The prognosis of covid-associated ADEM is dependent on the extent of pathology intrinsic to ADEM and the intrication of the prognosis of Covid-19 infection.

CONCLUSION

The key message in these 3 cases is that clinicians should have a low threshold of suspicion of ADEM in the Covid-19 context, adopt appropriate workup strategies, and initiate adequate treatment for better outcomes.

Acute disseminated encephalomyelitis following endonasal resection of a craniopharyngioma: illustrative case

BACKGROUND

Acute disseminated encephalomyelitis (ADEM) is a rare, acquired demyelination syndrome that causes cognitive impairment and focal neurological deficits and may be fatal. The potentially reversible disease mainly affects children, often after vaccination or viral infection, but may be seen rarely in adults.

OBSERVATIONS

A 50-year-old woman presented with loss of visual acuity of the left eye. Magnetic resonance imaging (MRI) revealed an intra- and suprasellar mass, which was removed successfully. On postoperative day 1, MRI showed gross total resection of the lesion and no surgery-related complications. On postoperative day 2, the patient presented with a progressive left-sided hemiparesis, hemineglect, and decline of cognitive performance. MRI showed white matter edema in both hemispheres. Cerebrospinal fluid analysis revealed mixed pleocytosis (355/µL) without further evidence of infection. In synopsis of the findings, ADEM was diagnosed and treated with intravenous immunoglobulins. Shortly thereafter, the patient recovered, and no sensorimotor deficits were detected in the follow-up examination.

LESSONS

Pituitary gland pathologies are commonly treated by transsphenoidal surgery, with only minor risks for complications. A case of ADEM after craniopharyngioma resection has not been published before and should be considered in case of progressive neurological deterioration with multiple white matter lesions.

Acute onset anarthria in a 7-year-old patient as a presentation of acute disseminated encephalomyelitis: A rare clinical and radiological entity

Acute disseminated encephalomyelitis (ADEM), also called post-infectious encephalomyelitis, is defined as an immune-mediated inflammatory and demyelinating event that involves the central nervous system. It usually follows an infectious episode or an active immunization several weeks prior the disease onset. ADEM is typically presented with an encephalopathy associated to focal neurological signs. Cerebrospinal fluid analysis is usually nonspecific, showing signs of central nervous system inflammation with negative viral and bacterial cultures. The diagnosis is based on clinical and MRI findings. Patients with ADEM respond well to anti-inflammatory and immunosuppressive agents, with high-dose of intravenous steroids administered as first-line treatment. Herein, we present the case of a 7-year-old male patient diagnosed of acute disseminated encephalomyelitis most likely secondary to a viral upper respiratory tract infection. It is a unique case, as the inaugurating sign is an acute onset anarthria. The patient responded favorably to the first-line therapy with an almost full recovery within the first week of treatment.

SARS-CoV-2-associated acute disseminated encephalomyelitis: a systematic review of the literature

The literature on cases of acute disseminated encephalomyelitis (ADEM) associated with SARS-CoV-2 infection has been rapidly increasing. However, the specific clinical features of ADEM associated with SARS-CoV-2 (SARS-CoV-2-ADEM) have not been previously evaluated. We screened all articles resulting from a search of PubMed and Web of Science databases looking for reports of ADEM published between December 01, 2019, and June 5, 2021. Of the 48 ADEM cases identified from 37 studies, 34 (71%) had ADEM while 14 (29%) were of AHLE. RT-PCR for SARS-CoV-2 was positive in 83% (n = 19) of patients. 26 patients (54%) were male, and 18 patients (38%) were female, with a male to female sex ratio of 1.4:1; median age was 44 (1.4–71) years. 9 patients (19%, 9/48) were children. Of the 9 children patients, their median age was 9 years (range 1.4–13 years), 6 patients (67%) were female, and 2 patients (22%) were male, with a female to male sex ratio of 3:1.39 patients (81%) was performed CSF analysis. PCR for SARS-CoV-2 tested positive in 3 patients (14%, 3/22) on CSF sample. 31 (64%) of patients had a poor outcome on discharge from hospital. Five (10%) patients died in hospital. Compared to classic ADEM, SARS-CoV-2-ADEM have a more longer duration between the onset of the antecedent infective symptoms and the start of ADEM symptoms, the older age distribution of the patients, relatively poor outcome, a lower full recovery rate, a more frequently brain lesions involved the periventricular white matter and corpus callosum, and less frequently affected the deep gray matter. Taken together, the present comprehensive review reveals that although rare, ADEM can be associated with SARS-CoV-2 infection. SARS-CoV-2-ADEM seems to share most features of classic ADEM, with moderate discrepancies from the classical ADEM.

Fulminant inflammatory demyelination presenting as stroke-in-evolution in an elderly subject

BACKGROUND

Fulminant inflammatory demyelination is a possible presentation of inflammatory demyelinating disorders, thus representing a potential stroke mimic especially in younger patients.

AIMS OF THE STUDY

To describe clinical and diagnostic pitfalls in a case of fulminant inflammatory demyelination presenting with stroke-like symptoms in an elderly patient.

METHODS

Case report and case-based review of the literature.

RESULTS

A 67-year-old woman, who accessed the emergency room as suspect stroke for hyperacute onset of rapidly worsening speech impairment and drowsiness, was later diagnosed with a huge brain inflammatory demyelination. Clinical, laboratory, and neuroimaging tests did not allow to put a more specific diagnosis. Due to the rapidly deteriorating course, she received immunosuppression with benefit.

CONCLUSION

This report is meant to highlight the diagnostic challenges connected with fulminant inflammatory demyelination, which sometime can resemble a stroke-in evolution and appear clinically unfitting for inclusion in any specific pathological entities within the broad-spectrum of inflammatory demyelinating disorders.

Acute myelitis and ChAdOx1 nCoV-19 vaccine: Casual or causal association?

A 44-year-old previously healthy woman developed acute myelitis in close temporal relationship with ChAdOx1 nCoV-19 vaccine first-dose administration. The neurological involvement was mainly sensory with neuroimaging showing two mono-metameric lesions involving the posterior and lateral cord at dorsal level. Significant improvement was promptly recorded with high-dose intravenous steroids, with complete recovery within one month.

The strict temporal relationship between vaccination and myelitis, together with the absence of clues pointing to alternative diagnoses, might suggest a conceivable role for anti-SARS-CoV-2 vaccine as immunological trigger, although a causal relationship has yet to be established and our preliminary observation suggests caution.

Pseudotumoral Demyelinating Lesions: A Presentation of Acute Disseminated Encephalomyelitis

Pseudotumoral forms of demyelination are related to central nervous system demyelinating disorders, usually considered to be an atypical presentation of multiple sclerosis including its different varieties such as Balo's, Schilder's, and Marburg diseases. These lesions could also be seen in myelin oligodendrocyte glycoprotein antibody-associated demyelination, acute disseminated encephalomyelitis (ADEM), and neuromyelitis optica spectrum disorder. The pseudotumoral aspect may be mistakenly considered as an abscess or a cancerous tumor, in which case, patients could endure unnecessary possibly harmful brain biopsy and have a delay in their disease diagnostics and management. Once latter differential diagnosis is discarded, pseudotumoral demyelination prompts uncertainties concerning the nature of the underlying demyelinating condition as prognosis and management differ from multiple sclerosis to other syndromes, especially whether a chronic treatment is needed or not. In this case report, we present a 35-year-old male patient hospitalized in the department of neurology for a rapidly progressive onset of encephalopathy and polyfocal neurological deficits, with pseudotumoral lesions shown on brain MRI. On further investigations, ADEM was the more likely diagnosis that could fit the patient's clinical and radiological presentation. Thence, he was put on high dose of intravenous corticosteroids, with a followed good recovery within the first week of the treatment.

Update on Acute Disseminated Encephalomyelitis in Children and Adolescents

Acute disseminated encephalomyelitis (ADEM) is an immune-mediated, inflammatory demyelinating disease of the central nervous system (CNS) that usually affects children and young adults after an infection or vaccination. The presence of several conditions mimicking ADEM, added to the lack of specific biomarkers, makes diagnosis potentially hard. Prompt diagnosis is necessary to start adequate treatment to improve the clinical course and long-term outcome. Because of its heterogeneity in both clinical presentation and course, challenges remain in establishing the most appropriate therapeutic approach in each patient. The aim of this review is to provide an update on management of this disease with a focus on acute treatment and to give suggestions for future research. We showed that there are currently no guidelines that help clinicians manage ADEM and therapeutic decisions are often made on a case-by-case basis. Further studies are necessary to identify clinical, laboratory, and instrumental criteria that could be correlated with outcomes and guide clinicians in choosing when and what treatment should be given in each case.

Acute Disseminated Encephalomyelitis: Current Perspectives

Acute disseminated encephalomyelitis (ADEM) is an immune-mediated central nervous system (CNS) disorder, characterized by polyfocal symptoms, encephalopathy and typical magnetic resonance imaging (MRI) findings, that especially affects young children. Advances in understanding CNS neuroimmune disorders as well as the association of myelin oligodendrocyte glycoprotein antibody (MOG-Ab) with both monophasic and recurrent forms of ADEM have led to new insights into its definition, management and outcome. In this review, we aim to provide an update based on current epidemiologic, clinical, radiological and immunopathological aspects and clinical outcome of ADEM.

Decompressive craniectomy as a lifesaving intervention for acute disseminated encephalomyelitis (ADEM)

Acute disseminated encephalomyelitis (ADEM), is an immune-mediated demyelinating disease of the central nervous system that commonly affects children and young adults of both sexes. Hyperacute variants of ADEM represent 2% of cases and are associated with rapid progression of symptoms, malignant brain edema, and high mortality rates. We report a case of a young woman presenting with a hyperacute storming course of few days who was managed with pulse steroid therapy and emergency craniectomy with an excellent outcome. We believe that our patient's acute clinical deterioration and findings on neuroimaging warranted prompt neurosurgery. Although treatment with immunomodulatory medications was commenced, the severity of her condition indicated that only surgical intervention was likely to be lifesaving. We recommend immediate neurosurgical consultation to consider prompt decompressive craniectomy in hyperacute variants with significant brain swelling. Multidisciplinary care including neurologist, neuroradiologist, neurosurgeon, neuropathologist, and neurointensivist is the only way to achieve success and improve survival in patients presenting with hyperacute ADEM.

Antibody-negative autoimmune encephalitis as a complication of long-term immune-suppression for liver transplantation

Autoimmune encephalitis is a rare spectrum of disease that can be a complication of chronic immunosuppression. Diagnosis often requires the presence of antineuronal antibodies, but many causative antibodies have not yet been identified. Antibody-negative autoimmune encephalitis (AbNAE) is especially difficult to diagnose and must rely largely on exclusion of other causes. In chronically immune-suppressed transplant recipients, the differential is broad, likely resulting in underdiagnosis and worse outcomes. Here, we present a 58-year-old liver transplant recipient taking tacrolimus for prevention of chronic rejection who presented with 5 days of confusion, lethargy and lightheadedness. He was diagnosed with AbNAE after an extensive workup and recovered fully after high-dose corticosteroids. Our case highlights the importance of recognising the association between chronic immunosuppression and autoimmune encephalitis. Autoimmune encephalitis, even in the absence of characterised antibodies, should be considered when transplant recipients present with central neurologic symptoms.

Acute Disseminated Encephalomyelitis

Acute disseminated encephalomyelitis (ADEM) is an autoimmune demyelinating disease of central nervous system (CNS). ADEM is most commonly seen in children, although adults can also be affected. The disease typically starts with an abrupt onset within day to weeks after a viral infection or immunization. Presenting features include an acute encephalopathy with multifocal neurologic signs and fever. ADEM generally has a monophasic course, although recurrent ADEM has also been described and is defined as multiphasic ADEM. MRI shows widespread lesions located in both brain and spinal cord. An involvement of basal ganglia and thalami has also been described. Analysis of cerebrospinal fluid (CSF) may reveal mild lymphocytic pleocytosis and increased proteins, whereas oligoclonal bands are usually negative. In the absence of specific biologic markers, ADEM remains a diagnosis of exclusion and it is still based on clinical manifestations, imaging, and laboratory features. Therapy is based on steroid administration and the prognosis is usually favorable.

Guidelines on the Use of Therapeutic Apheresis in Clinical Practice - Evidence-Based Approach from the Writing Committee of the American Society for Apheresis: The Eighth Special Issue

The American Society for Apheresis (ASFA) Journal of Clinical Apheresis (JCA) Special Issue Writing Committee is charged with reviewing, updating and categorizing indications for the evidence-based use of therapeutic apheresis (TA) in human disease. Since the 2007 JCA Special Issue (Fourth Edition), the committee has incorporated systematic review and evidence-based approaches in the grading and categorization of apheresis indications. This Eighth Edition of the JCA Special Issue continues to maintain this methodology and rigor in order to make recommendations on the use of apheresis in a wide variety of diseases/conditions. The JCA Eighth Edition, like its predecessor, continues to apply the category and grading system definitions in fact sheets. The general layout and concept of a fact sheet that was introduced in the Fourth Edition, has largely been maintained in this edition. Each fact sheet succinctly summarizes the evidence for the use of TA in a specific disease entity or medical condition. The Eighth Edition comprises 84 fact sheets for relevant diseases and medical conditions, with 157 graded and categorized indications and/or TA modalities. The Eighth Edition of the JCA Special Issue seeks to continue to serve as a key resource that guides the utilization of TA in the treatment of human disease.

[Clinical characteristics and diagnosis of disseminated encephalomyelitis in adults]

AIM

To analyze clinical, neuroimaging and laboratory characteristics of acute disseminated encephalomyelitis (ODEM) in adults with an analysis of the frequency of diagnostic errors at the initial examination stage.

MATERIAL AND METHODS

The study included 23 patients hospitalized with a diagnosis of ODEM. The analysis of clinical characteristics, MRI results and cerebrospinal fluid (CSF) was performed. The diagnosis of the disease in each case was specified after a full examination and dynamic observation.

RESULTS

The diagnosis of ODEM was confirmed only in 16 cases. In 6 cases, the final diagnosis of multiple sclerosis (MS) was made, and one case of Susak syndrome, primary CNS lymphoma and levamisole-associated multifocal inflammatory leukoencephalopathy was also detected. It has been shown that ODEM in adults is characterized by the acute development of multifocal brain lesions in combination with clinical manifestations of encephalopathy, which in half of cases is preceded by an infectious disease. There were no specific clinical, neuroimaging and laboratory features, which could allow differentiation of ODEM from onset of MS.

CONCLUSION

To make a correct diagnosis in the first episode of acute multifocal brain lesion, a dynamic observation, including repeated MRI, is needed. The development of specific biomarkers may be of great importance for the early differential diagnosis of demyelinating diseases.

Diagnosis and Treatment of NMO Spectrum Disorder and MOG-Encephalomyelitis

Neuromyelitis optica spectrum disorders (NMOSD) are autoantibody mediated chronic inflammatory diseases. Serum antibodies (Abs) against the aquaporin-4 water channel lead to recurrent attacks of optic neuritis, myelitis and/or brainstem syndromes. In some patients with symptoms of NMOSD, no AQP4-Abs but Abs against myelin-oligodendrocyte-glycoprotein (MOG) are detectable. These clinical syndromes are now frequently referred to as "MOG-encephalomyelitis" (MOG-EM). Here we give an overview on current recommendations concerning diagnosis of NMOSD and MOG-EM. These include antibody and further laboratory testing, MR imaging and optical coherence tomography. We discuss therapeutic options of acute attacks as well as longterm immunosuppressive treatment, including azathioprine, rituximab, and immunoglobulins.

Acute Disseminated Encephalomyelitis

Acute disseminated encephalomyelitis (ADEM) is an inflammatory demyelinating syndrome with encephalopathy. ADEM typically affects young children, is often postinfectious, and is typically monophasic. MRI neuroimaging, which shows new lesions with poorly demarcated borders, but not old and established lesions, is essential to diagnosis. Autoantibodies against myelin oligodendrocyte glycoprotein (MOG) are found in ∼40% of ADEM patients, and these patients have different clinical and neuroimaging features to seronegative patients. Treatment in the acute phase is typically with high-dose corticosteroids and intravenous immunoglobulin or plasma exchange for refractory patients. Outcome is usually good, but residual cognitive, inattentive, and executive issues are likely underestimated. In patients who have a relapse, biomarkers and imaging should help differentiate multiphasic ADEM, neuromyelitis optica spectrum disorder, anti-MOG antibody–associated relapsing demyelination, and multiple sclerosis.

Plasmapheresis and other extracorporeal filtration techniques in critical patients

Plasmapheresis is an extracorporeal technique that eliminates macromolecules involved in pathological processes from plasma. A review is made of the technical aspects, main indications in critical care and potential complications of plasmapheresis, as well as of other extracorporeal filtration techniques such as endotoxin-removal columns and other devices designed to eliminate cytokines or modulate the inflammatory immune response in critical patients.