The role of continuous renal replacement therapy in the treatment of poisoning

Chlorfenapyr poisoning: mechanisms, clinical presentations, and treatment strategies

BACKGROUND

Chlorfenapyr is used to kill insects that are resistant to organophosphorus insecticides. Chlorfenapyr poisoning has a high mortality rate and is difficult to treat. This article aims to review the mechanisms, clinical presentations, and treatment strategies for chlorfenapyr poisoning.

DATA RESOURCES

We conducted a review of the literature using PubMed, Web of Science, and SpringerLink from their beginnings to the end of October 2023. The inclusion criteria were systematic reviews, clinical guidelines, retrospective studies, and case reports on chlorfenapyr poisoning that focused on its mechanisms, clinical presentations, and treatment strategies. The references in the included studies were also examined to identify additional sources.

RESULTS

We included 57 studies in this review. Chlorfenapyr can be degraded into tralopyril, which is more toxic and reduces energy production by inhibiting the conversion of adenosine diphosphate to adenosine triphosphate. High fever and altered mental status are characteristic clinical presentations of chlorfenapyr poisoning. Once it occurs, respiratory failure occurs immediately, ultimately leading to cardiac arrest and death. Chlorfenapyr poisoning is difficult to treat, and there is no specific antidote.

CONCLUSION

Chlorfenapyr is a new pyrrole pesticide. Although it has been identified as a moderately toxic pesticide by the World Health Organization (WHO), the mortality rate of poisoned patients is extremely high. There is no specific antidote for chlorfenapyr poisoning. Therefore, based on the literature review, future efforts to explore rapid and effective detoxification methods, reconstitute intracellular oxidative phosphorylation couplings, identify early biomarkers of chlorfenapyr poisoning, and block the conversion of chlorfenapyr to tralopyril may be helpful for emergency physicians in the diagnosis and treatment of this disease.

Management of acute carbamazepine poisoning: A narrative review

Standard management protocols are lacking and specific antidotes are unavailable for acute carbamazepine (CBZ) poisoning. The objective of this review is to provide currently available information on acute CBZ poisoning, including its management, by describing and summarizing various therapeutic methods for its treatment according to previously published studies. Several treatment methods for CBZ poisoning will be briefly introduced, their advantages and disadvantages will be analyzed and compared, and suggestions for the clinical treatment of CBZ poisoning will be provided. A literature search was performed in various English and Chinese databases. In addition, the reference lists of identified articles were screened for additional relevant studies, including non-indexed reports. Non-peer-reviewed sources were also included. In the present review, 154 articles met the inclusion criteria including case reports, case series, descriptive cohorts, pharmacokinetic studies, and in vitro studies. Data on 67 patients, including 4 fatalities, were reviewed. Based on the summary of cases reported in the included articles, the cure rate of CBZ poisoning after symptomatic treatment was 82% and the efficiency of hemoperfusion was 58.2%. Based on the literature review, CBZ is moderately dialyzable and the recommendation for CBZ poisoning is supportive management and gastric lavage. In severe cases, extracorporeal treatment is recommended, with hemodialysis as the first choice.

Lithium poisoning and renal replacement therapy: pathophysiology and current clinical recommendations

Lithium intoxication is still an undefined and underestimated disease, especially those cases requiring extracorporeal treatment. Lithium is a monovalent cation with small molecular mass of 7 Da that has been regularly and successfully used since 1950 in the treatment of mania and bipolar disorders. However, its careless assumption can lead to a wide spectrum of cardiovascular, central nervous system and kidney diseases in case of acute, acute on chronic and chronic intoxications. In fact, lithium serum range is strict between 0.6 and 1.3 mmol/L, with a mild lithium toxicity observed at the steady-state of 1.5-2.5 mEq/L, moderate toxicity when lithium reaches 2.5-3.5 mEq/L, and severe intoxication with observed serum levels > 3.5 mEq/L. Its favorable biochemical profile allows the complete filtration and partial reabsorption in the kidney due to the similarity to sodium and also the complete removal by renal replacement therapy, that should be considered in specific poisoning conditions. In this narrative and updated review we discussed a clinical case of lithium intoxication, the different pattern of diseases attributable to excessive lithium load and the current indications for extracorporeal treatment.

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.

Acute abrin poisoning treated with continuous renal replacement therapy and hemoperfusion successfully: A case report

RATIONALE

Abrin is a highly toxic protein obtained from the seeds of Abrus precatorius, but poisoning due to ingestion of A precatorius is extremely rare in China.

PATIENT CONCERNS

A 16-year-old girl, perfectly healthy before, was admitted to the department of gastroenterology owing to intentional ingestion of 10 crushed A precatorius seeds, with multiple episodes of somnolent and anxious mental status, vomiting, abdominal pain, diarrhea, hematochezia, and hematuria.

DIAGNOSIS

Acute abrin poisoning.

INTERVENTIONS

We immediately took effective measures including gastric lavage, purgation, gastric acid suppression by proton pump inhibitor (PPI), liver protection, hemostasis, blood volume and electrolytes resuscitation, continuous renal replacement therapy (CRRT), and hemoperfusion (HP).

OUTCOMES

Her unwell mental status was improved to the point at which she became conscious and relaxed. The symptoms of vomiting, abdominal pain, diarrhea, hematochezia, and hematuria disappeared gradually. The girl eventually made an excellent recovery with no complications at her 3-month follow-up.

LESSONS

The combination of CRRT and HP is an efficient measure in the treatment of abrin poisoning for which there is no specific antidote. This is the first reported case of an abrin poisoning patient successfully treated by CRRT plus HP. Our experience will be useful to other physicians in managing patients of acute abrin poisoning in the future.

Acute Pancreatitis and Rhabdomyolysis with Acute Kidney Injury following Multiple Wasp Stings

Multiple wasp stings can induce multiple organ dysfunction by toxic reactions. However, acute pancreatitis is a rare manifestation in wasp sting injury. A 74-year-old woman visited the emergency department by anaphylactic shock because of multiple wasp stings. Acute kidney injury, rhabdomyolysis, hepatotoxicity, and coagulopathy were developed next day. Serum amylase and lipase were elevated and an abdominal computed tomography revealed an acute pancreatitis. Urine output was recovered after 16 days of oliguria (below 500 ml/day). Her kidney, liver, and pancreas injury gradually improved after sessions of renal replacement therapy.

Use of continuous renal replacement therapy in salicylate toxicity: A case report and review of the literature

OBJECTIVE

To report a case of salicylate toxicity treated with continuous venovenous hemodiafiltration (CVVHDF) and review the literature regarding the use of continuous renal replacement therapy (CRRT) for salicylate toxicity.

CASE

A 16-year-old male presented after ingesting 1901 mg/kg of enteric coated aspirin. Salicylate level was 92 mg/dl 4 h after ingestion. Sequele included seizure, acute kidney injury, pulmonary edema, and prolonged QTc. He received 5.5 h of hemodialysis followed by CVVHDF to continue to augment clearance. His aspirin level fell to 37.4 mg/dl after HD and then to 11.3 mg/dl after nearly 10 h of CVVHDF.

DISCUSSION

Cited reasons for the use of CRRT for salicylate toxicity primarily have been hypotension or desire for ongoing augmentation of salicylate clearance in the setting of multiorgan toxicity. CVVHDF may have a role in severe salicylate toxicity to enhance ongoing clearance after an initial round of HD in order to prevent significant rebound.

Acute interstitial nephritis, toxic hepatitis and toxic myocarditis following multiple Asian giant hornet stings in Shaanxi Province, China

OBJECTIVES

During July to October 2013, the Asian giant hornet has killed 42 and injured 1,675 people in the southern part of Shaanxi Province, China. This study investigated this unusual and frequent public health event.

METHODS

During the 3 months, 103 patients with severe Asian hornet stings were hospitalized in our hospital. Clinical data were collected using a standardized data collection form which included sex, age, length of hospital stay and medical recorder.

RESULTS

After physical examination and laboratory investigation, 25.2, 46.6 and 44.7 % of the patients were found with varying degrees of acute interstitial nephritis, acute toxic hepatitis and acute toxic myocarditis, respectively. After timely and appropriate treatment including removal of the stings and the use of intravenous methylprednisolone and antihistamines, the kidney function, liver function and heart function of 99 patients recovered within 1 month, while four patients died.

CONCLUSIONS

This study provided a good opportunity for recognizing the effect of Asian giant hornet stings and evaluating this serious public health event.

Developments in extracorporeal therapy for the poisoned patient

The modern use of extracorporeal therapies to treat poisoning and drug overdoses dates back to the early 20th century and has evolved along with their use as treatment for acute kidney injury or as maintenance therapy in advanced kidney disease. As our understanding of drug pharmacokinetics and membrane materials has increased, the technologies of extracorporeal therapy and their applications have become more sophisticated. Despite that, there is little robust evidence to guide clinicians on the optimal use of extracorporeal therapy in treating poisoning beyond case reports and series. New efforts are underway to remedy that: the Extracorporeal Treatments in Poisoning Workgroup (EXTRIP) is an international effort on the part of nephrologists, pharmacists and toxicologists to review the available data and formulate evidence-based guidelines on how to use extracorporeal techniques to treat poisoning and improve patient outcomes. Meanwhile, new techniques and membranes are under development. This review will summarize those key scientific and technologic developments, the efforts to optimize their use and new directions in research.

A case of methyl ethyl ketone peroxide poisoning and a review of complications and their management

Methyl Ethyl Ketone Peroxide (MEKP) is a highly toxic clear liquid used as a solvent. It is a strong oxidizing agent and a corrosive. Acute and chronic toxicity can occur as an occupational hazard. Ingestion is associated with corrosive burns leading to stricture formation, inhalational pneumonitis, acidosis, liver failure and renal failure. In this paper we present a case of a young patient who intentionally ingested MEKP. The patient developed multiple complications including proximal intestinal obstruction, acidosis and acute kidney injury. He was managed conservatively and recovered after a prolonged hospital stay. He had multiple inflammatory strictures on esophageal endoscopy, which improved over 3–6 moths.

Acute self-induced poisoning with sodium ferrocyanide and methanol treated with plasmapheresis and continuous renal replacement therapy successfully: a case report

Self-induced poisoning with chemicals is one of the most commonly used suicide methods. Suicide attempts using massive pure sodium ferrocyanide and methanol are rare. This article discusses the management of acute intentional self-poisoning using sodium ferrocyanide and methanol. We present a case of acute self-induced poisoning using sodium ferrocyanide and methanol admitted to our hospital 2 hours after ingestion. He was deeply unconscious and unresponsive to painful stimuli. The laboratory findings showed acute kidney injury and severe metabolic acidosis. We took effective measures including endotracheal intubation and mechanical ventilation to ensure the vital signs were stable. Subsequently, we treated the patient using gastric lavage, bicarbonate, ethanol, plasmapheresis (plasma exchange), and continuous renal replacement therapy (CRRT) successfully. He gradually recovered from poisoning and was discharged without abnormalities on the 6th day. Follow-up for 3 months revealed no sequelae. Blood purification including plasmapheresis and CRRT is an effective method to scavenge toxicants from the body for acute self-poisoning with sodium ferrocyanide and methanol. Treatment strategies in the management of poisoning, multiple factors including the removal efficiency of toxin, the protection of vital organs, and the maintenance of homeostasis must be considered.

Extracorporeal Treatment for Lithium Poisoning: Systematic Review and Recommendations from the EXTRIP Workgroup

The Extracorporeal Treatments in Poisoning Workgroup was created to provide evidence-based recommendations on the use of extracorporeal treatments in poisoning. Here, the EXTRIP workgroup presents its recommendations for lithium poisoning. After a systematic literature search, clinical and toxicokinetic data were extracted and summarized following a predetermined format. The entire workgroup voted through a two-round modified Delphi method to reach a consensus on voting statements. A RAND/UCLA Appropriateness Method was used to quantify disagreement, and anonymous votes were compiled and discussed in person. A second vote was conducted to determine the final workgroup recommendations. In total, 166 articles met inclusion criteria, which were mostly case reports, yielding a very low quality of evidence for all recommendations. A total of 418 patients were reviewed, 228 of which allowed extraction of patient-level data. The workgroup concluded that lithium is dialyzable (Level of evidence=A) and made the following recommendations: Extracorporeal treatment is recommended in severe lithium poisoning (1D). Extracorporeal treatment is recommended if kidney function is impaired and the [Li(+)] is >4.0 mEq/L, or in the presence of a decreased level of consciousness, seizures, or life-threatening dysrhythmias irrespective of the [Li(+)] (1D). Extracorporeal treatment is suggested if the [Li(+)] is >5.0 mEq/L, significant confusion is present, or the expected time to reduce the [Li(+)] to <1.0 mEq/L is >36 hours (2D). Extracorporeal treatment should be continued until clinical improvement is apparent or [Li(+)] is <1.0 mEq/L (1D). Extracorporeal treatments should be continued for a minimum of 6 hours if the [Li(+)] is not readily measurable (1D). Hemodialysis is the preferred extracorporeal treatment (1D), but continuous RRT is an acceptable alternative (1D). The workgroup supported the use of extracorporeal treatment in severe lithium poisoning. Clinical decisions on when to use extracorporeal treatment should take into account the [Li(+)], kidney function, pattern of lithium toxicity, patient's clinical status, and availability of extracorporeal treatments.

[Hemolytic anemia due to naphthalene poisoning]

INTRODUCTION

Naphthalene ingestion is a rare cause of hemolysis.

CASE REPORT

We report a 33-year-old woman, originating from the Comoros, hospitalized for intense fatigue associated with delirium, fever and jaundice, three days after ritual ingestion of naphthalene. Biochemical parameters showed marked hemolysis. Outcome was favorable after red cells transfusion and hydratation with intravenous fluids.

CONCLUSION

Diagnostic work-up of unexplained hemolysis should include the search for toxic exposition. Naphthalene poisoning can present with diagnostic challenge for physicians.

A stepwise approach for the management of poisoning with extracorporeal treatments

The use of an extracorporeal treatment (ECTR) in a poisoned patient may be life-saving in a limited number of scenarios. The decision-processes surrounding the use of ECTR in poisoning is complex: most nephrologists are not trained to assess a poisoned patient while clinical toxicologists rarely prescribe ECTRs. Deciding on which ECTR is most appropriate for a poison requires a good understanding of the poison's physicochemical and pharmacokinetic properties. Further, a detailed understanding of the capabilities and limitations of the different ECTRs can be useful to select the most appropriate ECTR for a given clinical situation. This manuscript provides a stepwise approach to assess the usefulness of ECTRs in poisoning.

Available extracorporeal treatments for poisoning: overview and limitations

Poisoning is a significant public health problem. In severe cases, extracorporeal treatments (ECTRs) may be required to prevent or reverse major toxicity. Available ECTRs include intermittent hemodialysis, sustained low-efficiency dialysis, intermittent hemofiltration and hemodiafiltration, continuous renal replacement therapy, hemoperfusion, therapeutic plasma exchange, exchange transfusion, peritoneal dialysis, albumin dialysis, cerebrospinal fluid exchange, and extracorporeal life support. The aim of this article was to provide an overview of the technical aspects, as well as the potential indications and limitations of the different ECTRs used for poisoned patients.

Clinical features of severe wasp sting patients with dominantly toxic reaction: analysis of 1091 cases

Background

Massive wasp stings have been greatly underestimated and have not been systematically studied. The aim of this study was to identify the clinical features and treatment strategies of severe wasp stings.

Methods and Findings

A multicenter retrospective study was undertaken in 35 hospitals and medical centers including 12 tertiary care hospitals and 23 secondary care hospitals in the Hubei Province, China. The detailed clinical data of 1091 hospitalized wasp sting patients were investigated. Over three-fourths (76.9%) of the cases had 10 or more stings and the in-hospital mortality of patients was 5.1%. Forty-eight patients died of organ injury following toxic reactions to the stings, whereas six died from anaphylactic shock. The in-hospital mortality in patients with >10 stings was higher than that of ≤10 stings (5.2% vs. 1.0%, p = 0.02). Acute kidney injury (AKI) was seen in 21.0% patients and most patients required blood purification therapy. Rhabdomyolysis was seen in 24.1% patients, hemolysis in 19.2% patients, liver injury in 30.1% patients, and coagulopathy in 22.5% patients. Regression analysis revealed that high creatinine level, shock, oliguria, and anemia were risk factors for death. Blood purification therapy was beneficial for patients with ≥20 stings and delayed hospital admission of patients (≥4 hours after sting).

Conclusions

In China, most patients with multiple wasp stings presented with toxic reactions and multiple organ dysfunction caused by the venom rather than an anaphylactic reaction. AKI is the prominent clinical manifestation of wasp stings with toxic reaction. High creatinine levels, shock, oliguria, and anemia were risk factors for death.

Lithium and venlafaxine poisoning — a case report

In treatment of manic-depressive conditions long-term lithium therapy may be combined with an effective and relatively safe antidepressant venlafaxine. Combined overdose may increase the risk of early toxicity of both drugs and of delayed lithium intoxication, responding to symptomatic and renal replacement therapy. We present a patient with combined lithium and venlafaxine self-poisoning with nothing but delayed signs of lithium intoxication with the emphasis on early and late treatment. 41-year old woman attempted suicide by large amount of lithium and venlafaxine. On admission she was asymptomatic, but with increased serum lithium over 5mmol/L. After gastric lavage, active charcoal and laxative administration she was receiving IV fluids. After a delay of 63 hours she deteriorated acutely by disorientation, confusion, fasciculation and tremor and was readmitted to Intensive care unit. In spite serum lithium decreased to 2mmol/L clinical signs were attributed to delayed lithium intoxication. After symptomatic and renal replacement therapy the patient’s condition improved after few days. We conclude that decontamination procedures are effective in particular for venlafaxine poisoning. If increased serum lithium levels are noted renal replacement therapy may be started even in asymptomatic patients as delayed lithium intoxication is most likely after few days.

Higher requirements of dialysis in severe lithium intoxication

Severe lithium poisoning is a frequent condition in the intoxicated intensive care unit population. Dialysis is the treatment of choice, but no clinical markers predicting higher requirement for dialysis have been identified to date. We analyze the characteristics of lithium overdose patients needing dialysis to improve lithium clearance, and identify the ones associated with higher dialysis requirement. This is an observational, retrospective study of 14 patients with lithium poisoning admitted from 2004 to 2009. Median age was 41.8 ± 16.1 years. Poisonings were acute in 7.1%, acute-on-chronic in 64.28%, and chronic in 28.5% of cases. Comparing clinical and biochemical data in patients requiring more than one dialysis session with those requiring only one session, the univariate analysis showed differences at admission in creatinine clearance (40.5 ± 23 vs. 73.3 ± 24.9 mL/min, P = 0.025), white blood cells (17,528 ± 3,530 vs. 11,580 ± 3360 cells/L, P = 0.007), and blood sodium concentration (134.8 ± 5.9 vs. 141.8 ± 8.4 mmol/L, P=0.035). We measured the degree of association between the number of sessions and the variables with partial correlations. High lithium levels (P = 0.006, r = 0.69), low creatinine clearance (P = 0.04, r = -0.55), and low blood sodium concentration (P = 0.024, r = -0.59) were associated with a greater number of dialysis sessions. The correlation remained significant for blood sodium concentration (P = 0.016, r = -0.67) after adjustment for creatinine clearance and initial lithium levels. Presence on admission of low creatinine clearance, low blood sodium concentration, and/or high lithium levels correlated with a higher number of dialysis sessions in severe lithium poisoning. These factors, especially low blood sodium concentration, are associated with higher dialysis requirements in severe lithium intoxication.

Nonrenal indications for continuous renal replacement therapy: A report from the Prospective Pediatric Continuous Renal Replacement Therapy Registry Group

OBJECTIVE

Continuous renal replacement therapy is the most often implemented dialysis modality in the pediatric intensive care unit setting for patients with acute kidney injury. However, it also has a role in the management of patients with nonrenal indications such as clearance of drugs and intermediates of disordered cellular metabolism.

MEASUREMENTS AND METHODS

Using data from the multicenter Prospective Pediatric Continuous Renal Replacement Therapy Registry, we report a cohort of pediatric patients receiving continuous renal replacement therapy for nonrenal indications. Nonrenal indications were obtained from the combination of "other" category for continuous renal replacement therapy initiation and patient diagnosis (both primary and secondary). This cohort was further divided into three subgroups: inborn errors of metabolism, drug toxicity, and tumor lysis syndrome.

RESULTS

From 2000 to 2005, a total of 50 continuous renal replacement therapy events with nonrenal indications for therapy were included in the Prospective Pediatric Continuous Renal Replacement Therapy Registry. Indication-specific survival of the subgroups was 62% (inborn errors of metabolism), 82% (tumor lysis syndrome), and 95% (drug toxicity). The median small solute dose delivered among the subgroups ranged from 2125 to 8213 mL/1.73 m/hr, with 54%-59% receiving solely diffusion-based clearance as continuous venovenous hemodialysis. No association was established between survival and dose delivered, modality of continuous renal replacement therapy, or use of intermittent hemodialysis prior to continuous renal replacement therapy.

CONCLUSIONS

Pediatric patients requiring continuous renal replacement therapy for nonrenal indications are a distinct cohort within the population receiving renal replacement therapy with little published experience of outcomes for this group. Survival within this cohort varies by indication for continuous renal replacement therapy and is not associated with continuous renal replacement therapy modality. Additionally, survival is not associated with small solute doses delivered within a cohort receiving >2000 mL/1.73 m/hr. Our data suggest metabolic control is established rapidly in pediatric patients and that acute detoxification may be provided with continuous renal replacement therapy for both the initial and maintenance phases of treatment using either convection or diffusion at appropriate doses.

Management of toxic ingestions with the use of renal replacement therapy

Although rare, renal replacement therapy (RRT) for the treatment of the metabolic, respiratory and hemodynamic complications of intoxications may be required. Understanding the natural clearance of the medications along with their volume of distribution, protein binding and molecular weight will help in understanding the benefit of commencing RRT. This information will aid in choosing the optimal forms of RRT in an urgent setting. Overdose of common pediatric medications are discussed with suggestions on the type of RRT within this educational review.

Extracorporeal removal of drugs and toxins

Renal replacement therapies (RRT) are increasingly used for the treatment of acute and chronic kidney diseases as well as intoxications and accidental drug overdoses. These therapies offer a mechanism for the removal of toxic substances from the patient's blood and supplement the standard detoxification protocols. If instituted early, RRT can have a significant effect on the course of the toxicity; however, this process is not selective for the removal of only harmful products and can also result in the clearance of medications intended for therapeutic use.

[Acid-base disturbances in intensive-care patients]

BACKGROUND

Acid-base disturbances may cause a variety of symptoms, multi-organ failure and compromised immune defense. The aim of this paper is to provide an overview of acid-base disturbances in intensive-care patients.

MATERIAL AND METHOD

The article is based on a non-systematic search in Pub Med, a textbook on intensive care and the authors' clinical experience.

RESULTS

The Henderson-Hasselbalch equation describes acid-base status by changes in pCO2 and bicarbonate. Changes in pCO2 reflect the respiratory and bicarbonate the metabolic status. Standard base excess describes the metabolic part more exactly. Anion gap is calculated as a supplement. The Stewart method, describes acid-base status through three independent variables (pCO2, weak acids and strong ion difference [SID]) that regulate the dependent variables pH and bicarbonate concentration.

INTERPRETATION

The Henderson-Hasselbalch equation and standard base excess do not consider which acids or bases that are involved, The anion gap may disclose unmeasured anions and distinguish hyperchloremic acidosis from other types of metabolic acidosis, but the calculation is associated with uncertainty. The Stewart method describes the involved ions, but complicated equations makes it unsuitable in clinical practice. A combination of standard base excess and anion gap corrected for albumin levels provide a good description of acid-base status.

Extracorporeal Removal Techniques for the Poisoned Patient: A Review for the Intensivist

The kidney is able to rapidly eliminate many water-soluble xenobiotics (exogenous chemicals). However, in the face of extraordinary serum concentrations of these xenobiotics or renal dysfunction, alternative elimination techniques often become necessary. Extracorporeal removal (ECR) techniques are used to increase the clearance of xenobiotics. These techniques include hemodialysis (HD), charcoal hemoperfusion (HP), and modalities grouped under the heading of continuous renal replacement therapy (CRRT): continuous venovenous hemofiltration (CVVH) and continuous venovenous hemodiafiltration (CVVHDF). Extracorporeal removal is limited to patients with significant or potentially significant clinical poisoning because the resources required to perform ECR are great. Therefore, most patients who are treated with these techniques are being cared for in intensive care units (ICUs). Our goal in this review is to discuss the properties that make xenobiotics amenable to removal by ECR and the advantages and disadvantages of the individual techniques. We discuss xenobiotics that constitute clear indications for ECR, including the toxic alcohols, salicylates, and lithium. We review the use of CRRT, a modality for which clear indications for treatment of poisonings are currently lacking.

Continuous renal replacement therapy for patients with acute kidney injury caused by melamine-related urolithiasis

BACKGROUND

In 2008 there was an epidemic of renal disease affecting infants after consumption of melamine-tainted milk products. Most of the infected children were asymptomatic or with mild symptoms, and a few suffered from acute obstructive kidney injury secondary to melamine-contained renal stones (8 of 15,577 children screened at our hospital for urolithiasis). This study was intended to retrospectively review the management of acute kidney injury using continuous renal replacement therapy (CRRT) in the 8 children with acute kidney injury.

METHODS

The 8 infants with acute kidney injury caused by melamine-related urolithiasis were referred to the pediatric intensive care unit at the hospital in late 2008. CRRT was given to treat their kidney injuries. Medical records of the infants were reviewed for demographic features, diagnosis, CRRT treatment, and outcomes.

RESULTS

Before CRRT, hypertension was found in 6 of the 8 children. Varying degrees of oliguria, anuria, elevated levels of blood urea nitrogen (BUN) (13.11-35.6 mmol/L) and creatinine (Cr) (238.8-773.7 mumol/L) were observed in these patients. After CRRT, the levels of BUN, Cr and electrolytes decreased. Urine output and edema were improved clinically.

CONCLUSION

CRRT can rapidly improve renal function, avoiding such surgical interventions as lithotripsy, percutaneous nephrolithotomy, and ureteroscopy. It is an efficient modality to treat acute kidney injury caused by melamine-related urolithiasis.

Dialysis in the poisoned patient

Patients who ingest toxic substances may require extracorporeal removal of the poisons or their toxic metabolites if native renal clearance is not sufficient because of acute kidney injury, acuity of symptoms, or burden of toxin. Here, a case is presented, and the literature on renal replacement therapy in the event of acute intoxication is reviewed. Extracorporeal therapy efficacy is examined in terms of the characteristics of the toxin (molecular size, charge, protein, or lipid binding); the patient (body habitus and volume of distribution); and the process (membrane effects on extraction ratios and sieving, role of blood, and dialysate flow rates). The choice of extracorporeal therapy and hemodialysis prescriptions for specific poisonings are discussed.

Accidental methanol ingestion: case report

Background

The incidence of methanol (CH₃OH) intoxication differs enormously from country to country. Methanol intoxication is extremely rare in the Dutch population. Even a low dose can already be potentially lethal. Patients are conventionally treated with hemodialysis. Therefore we'd like to present a report of a foreign sailor in Rotterdam who accidentally caused himself severe methanol intoxication, with a maximum measured concentration of 4.4 g/L.

Case presentation

The patient presented with hemodynamic instability and severe metabolic acidosis with pH 6.69. The anion gap was 39 mmol/L and the osmol gap 73 mosmol/kg. Treatment with ethanol and continuous venovenous hemodiafiltration (CVVH-DF) was initiated. Despite the hemodynamic instability it is was possible to achieve rapid correction of pH and methanol concentration with CVVH-DF while maintaining a stable and therapeutic ethanol serum concentration. Despite hemodynamic and acid-base improvement, our patient developed massive cerebral edema leading to brain death. Permission for organ donation was unfortunately not ascertained.

Conclusions

We conclude that in a hemodynamic instable situation high methanol concentrations and methanol-induced derangements of homeostasis are safely and effectively treated with CVVH-DF and that severe cerebral edema is another possible cause of death rather than the classical bleeding in the putamen area.

Case Report: An Unusual Presentation of Ethylene Glycol Poisoning

A 42-year-old man presented to the intensive care unit with respiratory and renal failure, nine days after admission to hospital with acute renal failure and a raised anion-gap acidosis. He went on to develop an acute, painful ascending motor and sensory neuropathy. Ethylene glycol toxicity was diagnosed on the basis of nerve conduction tests, a renal biopsy showing oxalate crystals, and retrospective analysis of admission blood tests. The case reviews diagnosis and treatment of ethylene glycol toxicity. It also raises the ethical dilemmas faced by staff treating patients who deny ingestion in the face of the evidence.

Sustained low-efficiency dialysis (SLED) for acute lithium intoxication

Acute lithium intoxication may cause serious neurologic and cardiac manifestations, up to the patient's death. Owing to its low molecular weight, relatively small volume of distribution close to that of total body water, and its negligible protein binding, lithium can be efficiently removed by any extracorporeal modality of renal replacement therapy (RRT). However, the shift from the intracellular to the extracellular compartment, with the inherent rebound phenomenon after the end of RRT, might limit the efficacy of the conventional, short-lasting haemodialysis. There have been no published studies up to now concerning the use of sustained low-efficiency dialysis (SLED) in lithium intoxication. This report describes a woman with a voluntary acute lithium ingestion of 40 tablets of lithium carbonate (8.12 mEq lithium each). The lithium concentration increased up to 4.18 mEq/l about 24 h after admission, notwithstanding treatment with intravenous crystalloids and gastric lavage. She developed mental status changes, oliguria, hypotension and bradycardia. We started SLED (8 h) with a blood flow of 200 ml/min and countercurrent dialysate flow of 300 ml/min. Lithium serum levels decreased by 86% during treatment, and the patient fully awoke recovering a normal mental status within the first 4 h of treatment. SLED was completed safely within the prescribed time. After the end of treatment, the rebound of lithium concentration was unremarkable. Renal function fully recovered, and the patient was transferred into a psychiatric facility 3 days after admission.

Toxicology in the critical care unit

Toxicologic conditions are encountered in critically ill patients due to intentional or unintentional misuse of or exposure to therapeutic or illicit drugs. Additionally, toxicities related to medical interventions may develop in hospitalized patients. This review focuses on recent developments in the field of critical care toxicology. Early interventions to decrease absorption or enhance elimination of toxins have limited value. Specific interventions to manage toxicities due to analgesics, sedative-hypnotics, antidepressants, antipsychotics, cardiovascular agents, alcohols, carbon monoxide, and cholinergic agents are reviewed. Hospital-acquired toxicities due to methemoglobinemia, propylene glycol, and propofol should be recognized and treated. The clinician is continually required to incorporate clinical judgment along with available scientific data and clinical evidence to determine the best therapy for toxicologic conditions.

Metabolic acidosis in the critically ill: part 2. Causes and treatment

The correct identification of the cause, and ideally the individual acid, responsible for metabolic acidosis in the critically ill ensures rational management. In Part 2 of this review, we examine the elevated (corrected) anion gap acidoses (lactic, ketones, uraemic and toxin ingestion) and contrast them with nonelevated conditions (bicarbonate wasting, renal tubular acidoses and iatrogenic hyperchloraemia) using readily available base excess and anion gap techniques. The potentially erroneous interpretation of elevated lactate signifying cell ischaemia is highlighted. We provide diagnostic and therapeutic guidance when faced with a high anion gap acidosis, for example pyroglutamate, in the common clinical scenario 'I can't identify the acid--but I know it's there'. The evidence that metabolic acidosis affects outcomes and thus warrants correction is considered and we provide management guidance including extracorporeal removal and fomepizole therapy.