Therapeutic regulation of complement activation in extracorporeal circuits and intravascular treatments with special reference to the alternative pathway amplification loop.

A number of clinical treatment modalities involve contact between blood and biomaterials: these include extracorporeal circuits such as hemodialysis, cardiopulmonary bypass, plasmapheresis, and intravascular treatments. Common side effects arising from these treatments are caused by activation of the cascade systems of the blood. Many of these side effects are mediated via the complement system, including thromboinflammatory reactions and rejection of implants. Depending on the composition of the materials, complement activation is triggered via all the activation pathways but is by far mostly driven by the alternative pathway amplification loop. On biomaterial surfaces the alternative pathway amplification is totally unregulated and leads under optimal conditions to deposition of complement fragments, mostly C3b, on the surface leading to a total masking of the underlying surface. In this review, we discuss the mechanism of the complement activation, clinical consequences of the activation, and potential strategies for therapeutic regulation of the activation, using hemodialysis as demonstrator.

The efficacy of intermittent hemodialysis in severe bromovalerylurea poisoning.

Bromvalerylurea (BVU) is a sedative-hypnotic drug with a high risk of acute poisoning. In the present case, hemodialysis (HD) was introduced in a patient with severe BVU poisoning who later demonstrated respiratory arrest, and then HD clearances (CLHD) were assessed in detail. A 20-year-old female was transported to the emergency department by ambulance, an estimated two to four hours after orally ingesting 144 tablets of Utto® (12,000 mg BVU) in a suicide attempt. The patient was comatose on arrival. After intratracheal intubation, 50 g of activated charcoal was administered through nasogastric tube. She was then transferred to the intensive care unit. Ten hours after arrival at the hospital, her light reflex, contralateral light reflex, corneal reflex, and spontaneous respiration disappeared, resulting in an introduction of HD 16 h after arrival. Eighteen hours after arrival, her light reflex, contralateral light reflex, and corneal reflexes had recovered. Twenty-one hours after arrival, her consciousness level improved and the patient was weaned from HD. During HD treatment, blood samples were collected pre-HD and post-HD every hour. Serum BVU concentrations were determined using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The median CLHD was 133.61 mL/min, and the systemic clearance (CLSYS) was 117.77 mL/min. Higher CLHD of BVUs over CLSYS suggests that HD may play an important role in the treatment of severe BVU poisoning.

Poisoning by abnormally high blood phenobarbital concentration treated with extracorporeal therapy.

Phenobarbital poisoning, which may cause circulatory collapse as well as respiratory arrest in severe cases, has one of the highest mortality rates among acute drug poisonings. A 58-year-old man arrived at the emergency room in a deep coma (Glasgow Coma Scale E1V1M1) after taking an unknown dose of phenobarbital which had been prescribed for his cat's seizures. Venous blood gas analysis revealed hypercapnia (PvCO2: 113.0 mmHg) and a blood phenobarbital concentration of 197.3 µg/mL. Shortly after his arrival, respiratory arrest and circulatory collapse occurred. Mechanical ventilation after intubation, intravenous noradrenaline infusion, and multiple-dose activated charcoal through a nasogastric tube was started. Six hours after arrival, blood phenobarbital concentration was abnormally elevated to 356.8 µg/mL with circulatory collapse requiring an increased dose of intravenous noradrenaline infusion (up to 0.13 µg/kg/min). Continuous renal replacement therapy including high flow continuous hemodialysis was performed until hospital day 5, during which blood phenobarbital concentration decreased to 96.2 µg/mL on hospital day 4, resulting in a sufficient resumption of spontaneous breathing and full improvement of circulatory collapse. A search of the literature revealed that the peak phenobarbital concentration in the present case exceeded those of fatal cases, as well as those of survivors of acute phenobarbital poisoning. However, the patient was successfully treated with continuous renal replacement therapy. Among modalities of extracorporeal treatment, continuous renal replacement therapy could be considered if a patient's circulation is unstable.

Microbead-based extracorporeal immuno-affinity virus capture: a feasibility study to address the SARS-CoV-2 pandemic.

In this paper, we report on the utilization of micro-technology based tools to fight viral infections. Inspired by various hemoperfusion and immune-affinity capture systems, a blood virus depletion device has been developed that offers highly efficient capture and removal of the targeted virus from the circulation, thus decreasing virus load. Single-domain antibodies against the Wuhan (VHH-72) virus strain produced by recombinant DNA technology were immobilized on the surface of glass micro-beads, which were then utilized as stationary phase. For feasibility testing, the virus suspension was flown through the prototype immune-affinity device that captured the viruses and the filtered media left the column. The feasibility test of the proposed technology was performed in a Biosafety Level 4 classified laboratory using the Wuhan SARS-CoV-2 strain. The laboratory scale device actually captured 120,000 virus particles from the culture media circulation proving the feasibility of the suggested technology. This performance has an estimated capture ability of 15 million virus particles by using the therapeutic size column design, representing three times over-engineering with the assumption of 5 million genomic virus copies in an average viremic patient. Our results suggested that this new therapeutic virus capture device could significantly lower virus load thus preventing the development of more severe COVID-19 cases and consequently reducing mortality rate.

Optimal vascular access to hemodialysis, or what modern medicine offers us.

Hemodialysis is a life-saving method for patients with acute and chronic kidney failure. This treatment requires sufficiently large and safe vascular access. Ensuring optimal vascular access is therefore a prerequisite and an integral part of the care of these patients. In addition to commonly known vascular approaches such as non-tunnelized or tunneled hemodialysis catheters and AV fistulas, less well-known methods are also available, such as a translumbar or directly surgically inserted hemodialysis catheter into the right atrium. However, these alternative approaches are the only, life-saving alternative for some patients. The ambition of this review article is to offer a comprehensive view of the available options for vascular access, the algorithm for its selection and solutions to the most common complications in clinical practice.

Interim analysis of the COSA (COVID-19 patients treated with the Seraph® 100 Microbind® Affinity filter) registry.

BACKGROUND: The Seraph® 100 Microbind® Affinity Blood Filter is a haemoperfusion device that is licensed for the reduction of pathogens, including several viruses, in the blood. It received Emergency Use Authorization for the treatment of severe coronavirus disease 2019 (COVID-19) by the Food and Drug Administration (FDA). Several studies have shown that the blood viral load of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) correlates with adverse outcomes and removal of the nucleocapsid of the SARS-CoV-2 virus by the Seraph® 100 has been recently demonstrated. The aim of this registry was to evaluate the safety and efficacy of Seraph® 100 treatment for COVID-19 patients. METHODS: Twelve hospitals from six countries representing two continents documented patient and treatment characteristics as well as outcome parameters without reimbursement. Additionally, mortality and safety results of the device were reported. A total of 102 treatment sessions in 82 patients were documented in the registry. Four patients were excluded from mortality analysis due to incomplete outcome data, which were available in the other 78 patients. RESULTS: Overall, a 30-day mortality rate of 46.2% in the 78 patients with complete follow-up was reported. The median treatment time was 5.00 h (4.00-13.42) and 43.1% of the treatments were performed as haemoperfusion only. Adverse events of the Seraph® 100 treatment were reported in 8.8% of the 102 treatments and represented the premature end of treatment due to circuit failure. Patients who died were treated later in their intensive care unit (ICU) stay and onset of COVID symptoms. They also had higher ferritin levels. Multivariate Cox regression revealed that delayed Seraph® 100 treatment after ICU admission (>60 h), as well as bacterial superinfection, were associated with mortality. While average predicted mortality rate according to Sequential Organ Failure Assessment (SOFA) score in ICU patients was 56.7%, the observed mortality was 50.7%. In non-ICU patients, Coronavirus Clinical Characterisation Consortium (4C) score average predicted a mortality rate of 38.0%, while the observed mortality rate was 11.1%. CONCLUSIONS: The treatment of COVID-19 patients with Seraph® 100 is well tolerated and the circuit failure rate was lower than previously reported for kidney replacement therapy (KRT) in COVID-19 patients. Mortality correlated with late initiation of Seraph treatment after ICU admission and bacterial superinfection. Compared with predicted mortality according to 4C and SOFA scores, mortality of Seraph® 100-treated patients reported in the registry was lower.

Clinical and biochemical endpoints and predictors of response to plasma exchange in septic shock: results from a randomized controlled trial.

BACKGROUND: Recently, a randomized controlled trial (RCT) demonstrated rapid but individually variable hemodynamic improvement with therapeutic plasma exchange (TPE) in patients with septic shock. Prediction of clinical efficacy in specific sepsis treatments is fundamental for individualized sepsis therapy. METHODS: In the original RCT, patients with septic shock of < 24 h duration and norepinephrine (NE) requirement ≥ 0.4 µg/kg/min received standard of care (SOC) or SOC + one single TPE. Here, we report all clinical and biological endpoints of this study. Multivariate mixed-effects modeling of NE reduction was performed to investigate characteristics that could be associated with clinical response to TPE. RESULTS: A continuous effect of TPE on the reduction in NE doses over the initial 24 h was observed (SOC group: estimated NE dose reduction of 0.005 µg/kg/min per hour; TPE group: 0.018 µg/kg/min per hour, p = 0.004). Similarly, under TPE, serum lactate levels, continuously decreased over the initial 24 h in the TPE group, whereas lactate levels increased under SOC (p = 0.001). A reduction in biomarkers and disease mediators (such as PCT (p = 0.037), vWF:Ag (p < 0.001), Angpt-2 (p = 0.009), sTie-2 (p = 0.005)) along with a repletion of exhausted protective factors (such as AT-III (p = 0.026), Protein C (p = 0.012), ADAMTS-13 (p = 0.008)) could be observed in the TPE but not in the SOC group. In a multivariate mixed effects model, increasing baseline lactate levels led to greater NE dose reduction effects with TPE as opposed to SOC (p = 0.004). CONCLUSIONS: Adjunctive TPE is associated with the removal of injurious mediators and repletion of consumed protective factors altogether leading to preserved hemodynamic stabilization in refractory septic shock. We identified that baseline lactate concentration as a potential response predictor might guide future designing of large RCTs that will further evaluate TPE with regard to hard endpoints. Trial registration Retrospectively registered 18th January 2020 at clinicaltrials.gov (Identifier: NCT04231994 ).

Acute kidney injury requiring renal replacement therapy due to Clostridioides difficile infection in a 15-year-old boy

Acute gastroenteritis is commonly seen in pediatric clinical practice. It is a largely self-limited disease with a benign course. We present a case of teenager with gastroenteritis resulting in severe acute kidney injury. The decline in glomerular filtration was so significant that renal replacement therapy had to be initiated. We had to continue in intermitent hemodialysis for seven days until sufficient improvement in renal function. Clostridioides difficile was identified as a cause of vomiting, bloody diarrhea and subsequent dehydration. To our knowledge, this is the first reported case of C. difficile-associated diarrhea accompanied by acute kidney injury requiring renal replacement therapy in a child.

Partial resection of native and prosthetic arteriovenous fistula as a treatment of late infections complications - series of case reports.

INTRODUCTION: Infection of arteriovenous fistula (AV) used for hemodialysis (HD) is associated with massive bleeding, sepsis development, formation of metastatic infectious foci, and a high risk of AV loss. Urgent management of an infected AV is crucial for successful treatment and AV salvage. CASE REPORTS: We present the use of partial resection as a successful method of dealing with late AV infection in two cases. In case 1, the resection was performed due to an infection of the native arteriovenous fistula (AVF) with two defects above the drainage vein aneurysms. In case 2, partial resection and replacement of the prosthetic arteriovenous fistula (AVG) were done due to an infection of HD puncture site. The AVs remained patent in both cases, with no further signs of infection postoperatively and, most importantly, without the need to use a temporary HD catheter. CONCLUSION: The establishment of a new AV is limited by the quality of the venous and arterial systems. All surgical, interventional and non-surgical means should be used to safely maintain the created AV patent. Provided that the requirements of an early indication are met, partial resection of the AV is the method of choice for AV infections and allows us to avoid using a permanent dialysis catheter in our patients.

Comparison of the EXtracorporeal TReatments In Poisoning (EXTRIP) and Paris criteria for neurotoxicity in lithium poisoned patients.

AIMS: Two guidelines for haemodialysis in lithium poisoning, one from the Extracorporeal TReatments in Poisoning (EXTRIP) workgroup and a single centre retrospective one (Paris) differ. We compared outcomes in lithium poisoning based on these criteria with a primary outcome of worsening neurological symptoms in patients for whom EXTRIP and Paris criteria were discordant. METHODS: Poison centre data were queried for lithium poisoned patients for whom haemodialysis was either recommended or performed. Patients were categorized according to EXTRIP and Paris criteria and excluded if the peak lithium concentration was <1.2 mmol/L or if neurological follow-up was unavailable. Comparative analyses were only performed when both criteria could be assessed. RESULTS: In total, 219 patients were analysed. Paris criteria were met in 70 and EXTRIP criteria in 178. Forty two patients were excluded because Paris criteria could not be evaluated. When Paris and EXTRIP both supported haemodialysis, 50/57 (88%) of patients who received haemodialysis improved, as did all 3 who did not receive haemodialysis. When Paris and EXTRIP did not support haemodialysis, all nondialysed patients did well. Among the 86 patients for whom EXTRIP supported haemodialysis but Paris did not, 4/19 (21%) patients not dialysed deteriorated (P = .02; odds ratio = 8.7, 95% confidence interval = 1.5-51.8), 1 of whom died. All 8 patients for whom Paris criteria supported haemodialysis but EXTRIP did not were dialysed and improved. CONCLUSIONS: When the EXTRIP and Paris criteria are discordant, EXTRIP criteria outperforms the Paris criteria at identifying potentially ill patients who might benefit from haemodialysis.

Effect of Therapeutic Plasma Exchange on Immunoglobulin Deficiency in Early and Severe Septic Shock.

BACKGROUND: Deficiency of immunoglobulins of the classes IgG, IgG1, IgA and IgM is associated with severity of disease and mortality in sepsis and septic shock. Therapeutic plasma exchange (TPE) with fresh frozen plasma (FFP) has recently gained attention as an adjunctive therapeutic option in early septic shock. We hypothesized that TPE might modulate immunoglobulin deficiencies besides sole elimination of circulating injurious molecules. METHODS: We conducted a prospective single center study with TPE in 33 patients with early septic shock (onset < 12 h) requiring high doses of norepinephrine (NE > 0.4µg/kg/min). Clinical and biochemical data, including measurement of immunoglobulin subgroups IgG, IgG1, IgM and IgA were obtained before and after TPE. The following immunoglobulin cut-off values were used to analyze subgroups with low immunoglobulin concentrations at baseline (IgG ≤ 6.5, IgG1 ≤ 3, IgM ≤ 1.5 and IgA ≤ 0.35 g/L). RESULTS: At inclusion, median (IQR) SOFA score was 18 (15-20) and NE dose was 0.8 (0.6-1.2) µg/kg/min. The majority of patients demonstrated profound reductions in immunoglobulins levels of all classes. Globally, immunoglobulin levels were not significantly changed after a single TPE session. However, in patients with low baseline immunoglobulin levels a significant increase in all classes was observed (IgG 1.92 (0.96-3) g/L (+41%), IgG1 2.1 (1.46-2.32) g/L (+96%), IgA 0.44 (0.12-0.62) g/L (59%) and IgM 0.18 (0.14-0.34) g/L (+55%), p < 0.001 for comparison to patients above cut-off). CONCLUSIONS: The majority of early and severe septic shock patients had reduced immunoglobulin levels and a single TPE could attenuate immunoglobulin deficiencies of all classes. The clinical relevance of this observation has to be investigated in a proper designed trial.

Medium Cut-Off Membrane Can Be a New Treatment Tool in Amanita phalloides Poisoning.

Mushroom poisoning is a common health problem that can be seen seasonally and geographically. Most mushroom poisoning requiring treatment worldwide is due to Amanita phalloides. Although liver failure and kidney injury are frequent, poisoning can also lead to more serious clinical situations, such as shock, pancreatitis, encephalopathic coma, cardiac failure, disseminated intravascular coagulation, and multiple organ dysfunction syndrome, and may cause death. In addition, when standard treatment approaches fail, extracorporeal treatment methods are often used. We report 2 cases in which hemodialysis with medium cut-off membrane was performed. We observed an improvement in liver and kidney function in both of our cases. The first case recovered, but the second case proved fatal owing to Acinetobacter sepsis, despite an improvement in renal function. Medium cut-off membrane hemodialysis may be an alternative option in the treatment of Amanita phalloides poisoning.

Effect of therapeutic plasma exchange on endothelial activation and coagulation-related parameters in septic shock.

BACKGROUND: A dysbalanced coagulation system is part of the pathological host response to infection in sepsis. Activation of pro-coagulant pathways and attenuation of anti-coagulant activity ultimately lead to microvascular stasis and consequent organ failure. No treatment approaches specifically targeting this axis are available. We explored the effects of therapeutic plasma exchange (TPE) on microvascular coagulation dysbalance in septic shock. METHODS: We conducted a prospective single-center study enrolling 31 patients with early septic shock (onset < 12 h) requiring high doses of norepinephrine (NE > 0.4 µg/kg/min). Clinical and biochemical data, including measurement of protein C; a disintegrin and metalloprotease with a thrombospondin type 1 motif, member 13 (ADAMTS13); and von Willebrand factor antigen (vWF:Ag), were obtained before and after TPE against fresh frozen plasma. RESULTS: Antithrombotic acting proteins such as antithrombin-III (ATIII) and protein C were markedly reduced in septic patients, but their activity increased after TPE (ATIII, 51% (41-61) vs. 63% (48-70), p = 0.029; protein C, 47% (38-60) vs. 62% (54-69), p = 0.029). Median ADAMTS13 activity was increased by TPE from 27 (21-42) % before to 47 (38-62) % after TPE (p < 0.001). In contrast, vWF:Ag was elevated and could be reduced by TPE (353 (206-492) IU/dL vs. 170 (117-232) IU/dL, p < 0.001). Regression analysis yielded a correlation between ADAMTS13 activity and platelet count (p = 0.001, R2 = 0.316). CONCLUSIONS: Septic shock was associated with activation of pro-coagulant pathways and simultaneous depletion of anti-coagulant factors. TPE partially attenuated this dysbalance by removing pro- and by replacing anti-coagulant factors. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03065751. Retrospectively registered on 28 February 2017.

Extracorporeal treatment of metforminassociated lactic acidosis in clinical practice: a retrospective cohort study.

PURPOSE: To assess whether extracorporeal treatment (ECTR) improves outcome of patients with metformin-associated lactic acidosis (MALA) and to evaluate the clinical applicability of the Extracorporeal Treatments in Poisoning Workgroup (EXTRIP) criteria for starting ECTR in metformin poisoning. METHODS: Patients with metformin serum concentrations above 2 mg/l who were admitted in the Deventer Teaching Hospital between January 2000 and July 2019 and complied with the definition of MALA (pH < 7.35 and lactate concentration > 5 mmol/l) were included. Mortality and clinical parameters of patients treated with ECTR or not were compared. In addition, treatment of MALA in clinical practice was verified against the criteria of EXTRIP. RESULTS: Forty-two patients were included. Lactate (13.8 versus 10.5 mmol/l, p = 0.01), creatinine (575 versus 254 umol/l, p < 0.01)), metformin (29.4 versus 8.6 mg/l, p < 0.01) concentrations, and vasopressor requirement (72% versus 23%, p < 0.01) were significantly higher in the ECTR-group. Blood pH (7.05 versus 7.19, p = 0.03) and bicarbonate (6 versus 11 mmol/l, p < 0.01) were significantly lower. Mortality, length of hospital stay, and mechanical ventilation requirement were not statistically different. In 83% of patients, treatment of MALA was in accordance with the EXTRIP criteria. CONCLUSIONS: Although there was no statistical benefit in mortality shown from ECTR, ECTR might be lifesaving in MALA, considering the ECTR-group was significantly sicker than the non-ECTR-group. The majority of patients were treated in line with the EXTRIP criteria. Severity of lactic acidosis and renal impairment were the main indications for initiating ECTR.

Extracorporeal removal techniques in toxicology: part 1.

Supporting clearance of a toxic substance by an extracorporeal removal technique is one of the advanced treatment methods applied in poisoned patient management. General indications stem from toxicokinetics of the poison while individual indications are determined by poisoning severity. The first part of this review deals in detail with particular options of extracorporeal treatment in toxicology and also with its specific application when treating lithium and salicylates poisoning or dabigatran overdose. The aim of this review is to facilitate the clinicians and nephrologists decision making whether to indicate this invasive procedure, to communicate and summarize the existing recommendations and to highlight the most important ways of how to treat poisoning by specific toxic substances.

Extracorporeal removal techniques in toxicology: part 2.

The second part of the review deals in detail with the diagnostics and treatment of toxic alcohols poisoning and management and indication of extracorporeal removal techniques in intoxication with other drugs, theophylline, valproic acid, metformin and metformin associated lactic acidosis, respectively. The extracorporeal treatment enhances the clearance of the toxin and corrects patients metabolic disturbances as well. It is necessary to use this treatment in severe intoxications. Indication of this invasive procedure falls within clinicians and nephrologists competence being advised by a toxicologist. This review could help make fast decisions.

Early therapeutic plasma exchange in septic shock: a prospective open-label nonrandomized pilot study focusing on safety, hemodynamics, vascular barrier function, and biologic markers.

BACKGROUND: Given the pathophysiological key role of the host response to an infection rather than the infection per se, an ideal therapeutic strategy would also target this response. This study was designed to demonstrate safety and feasibility of early therapeutic plasma exchange (TPE) in severely ill individuals with septic shock. METHODS: This was a prospective single center, open-label, nonrandomized pilot study enrolling 20 patients with early septic shock (onset < 12 h) requiring high doses of norepinephrine (NE; > 0.4 µg/kg/min) out of 231 screened septic patients. Clinical and biochemical data were obtained before and after TPE. Plasma samples were taken for ex-vivo stimulation of human umbilical vein endothelial cells (HUVECs) to analyze barrier function (immunocytochemistry and transendothelial electrical resistance (TER)). Cytokines were measured by cytometric bead array (CBA) and enzyme-linked immunosorbent assays (ELISAs). An immediate response was defined as > 20% NE reduction from baseline to the end of TPE. RESULTS: TPE was well tolerated without the occurrence of any adverse events and was associated with a rapid reduction in NE (0.82 (0.61-1.17) vs. 0.56 (0.41-0.78) µg/kg/min, p = 0.002) to maintain mean arterial pressure (MAP) above 65 mmHg. The observed 28-day mortality was 65%. Key proinflammatory cytokines and permeability factors (e.g., interleukin (IL)-6, IL-1b, and angiopoietin-2) were significantly reduced after TPE, while the protective antipermeability factor angiopoietin-1 was not changed. Ex-vivo stimulation of HUVECs with plasma obtained before TPE induced substantial cellular hyperpermeability, which was completely abolished with plasma obtained after TPE. CONCLUSIONS: Inclusion of early septic shock patients with high doses of vasopressors was feasible and TPE was safe. Rapid hemodynamic improvement and favorable changes in the cytokine profile in patients with septic shock were observed. It has yet to be determined whether early TPE also improves outcomes in this patient cohort. An appropriately powered multicenter randomized controlled trial is desirable. TRIAL REGISTRATION: Clinicaltrials.gov, NCT03065751 . Retrospectively registered on 28 February 2017.

Extracorporeal Treatment in the Management of Acute Poisoning: What an Intensivist Should Know?

Extracorporeal treatment (ECTR) represents a treatment modality promoting removal of endogenous or exogenous poisons and supporting or temporarily replacing a vital organ. This article aims to provide a brief overview of the technical aspects and the potential indications and limitations of the different ECTRs, highlighting the important characteristics of poison amenable to ECTR and the most appropriate prescriptions used in the setting of acute poisoning. The various principles that govern poison elimination by ECTR (diffusion, convection, adsorption, and centrifugation) and how components of the ECTR can be adjusted to maximize clearance have also being discussed.

Lithium Poisoning.

Lithium is a commonly prescribed treatment for bipolar affective disorder. However, treatment is complicated by lithium's narrow therapeutic index and the influence of kidney function, both of which increase the risk of toxicity. Therefore, careful attention to dosing, monitoring, and titration is required. The cause of lithium poisoning influences treatment and 3 patterns are described: acute, acute-on-chronic, and chronic. Chronic poisoning is the most common etiology, is usually unintentional, and results from lithium intake exceeding elimination. This is most commonly due to impaired kidney function caused by volume depletion from lithium-induced nephrogenic diabetes insipidus or intercurrent illnesses and is also drug-induced. Lithium poisoning can affect multiple organs; however, the primary site of toxicity is the central nervous system and clinical manifestations vary from asymptomatic supratherapeutic drug concentrations to clinical toxicity such as confusion, ataxia, or seizures. Lithium poisoning has a low mortality rate; however, chronic lithium poisoning can require a prolonged hospital length of stay from impaired mobility and cognition and associated nosocomial complications. Persistent neurological deficits, in particular cerebellar, are described and the incidence and risk factors for its development are poorly understood, but it appears to be uncommon in uncomplicated acute poisoning. Lithium is readily dialyzable, and rationale support extracorporeal treatments to reduce the risk or the duration of toxicity in high-risk exposures. There is disagreement in the literature regarding factors that define patients most likely to benefit from treatments that enhance lithium elimination, including specific plasma lithium concentration thresholds. In the case of extracorporeal treatments, there are observational data in its favor, without evidence from randomized controlled trials (none have been performed), which may lead to conservative practices and potentially unnecessary interventions in some circumstances. More data are required to define the risk-benefit of extracorporeal treatments and their use (modality, duration) in the management of lithium poisoning.

Extracorporeal Treatment in Phenytoin Poisoning: Systematic Review and Recommendations from the EXTRIP (Extracorporeal Treatments in Poisoning) Workgroup.

The Extracorporeal Treatments in Poisoning (EXTRIP) Workgroup conducted a systematic literature review using a standardized process to develop evidence-based recommendations on the use of extracorporeal treatment (ECTR) in patients with phenytoin poisoning. The authors reviewed all articles, extracted data, summarized findings, and proposed structured voting statements following a predetermined format. A 2-round modified Delphi method was used to reach a consensus on voting statements, and the RAND/UCLA Appropriateness Method was used to quantify disagreement. 51 articles met the inclusion criteria. Only case reports, case series, and pharmacokinetic studies were identified, yielding a very low quality of evidence. Clinical data from 31 patients and toxicokinetic grading from 46 patients were abstracted. The workgroup concluded that phenytoin is moderately dialyzable (level of evidence = C) despite its high protein binding and made the following recommendations. ECTR would be reasonable in select cases of severe phenytoin poisoning (neutral recommendation, 3D). ECTR is suggested if prolonged coma is present or expected (graded 2D) and it would be reasonable if prolonged incapacitating ataxia is present or expected (graded 3D). If ECTR is used, it should be discontinued when clinical improvement is apparent (graded 1D). The preferred ECTR modality in phenytoin poisoning is intermittent hemodialysis (graded 1D), but hemoperfusion is an acceptable alternative if hemodialysis is not available (graded 1D). In summary, phenytoin appears to be amenable to extracorporeal removal. However, because of the low incidence of irreversible tissue injury or death related to phenytoin poisoning and the relatively limited effect of ECTR on phenytoin removal, the workgroup proposed the use of ECTR only in very select patients with severe phenytoin poisoning.