Prediction the prognosis of the poisoned patients undergoing hemodialysis using machine learning algorithms

BACKGROUND

Hemodialysis is a life-saving treatment used to eliminate toxins and metabolites from the body during poisoning. Despite its effectiveness, there needs to be more research on this method precisely, with most studies focusing on specific poisoning. This study aims to bridge the existing knowledge gap by developing a machine-learning prediction model for forecasting the prognosis of the poisoned patient undergoing hemodialysis.

METHODS

Using a registry database from 2016 to 2022, this study conducted a retrospective cohort study at Loghman Hakim Hospital. First, the relief feature selection algorithm was used to identify the most important variables influencing the prognosis of poisoned patients undergoing hemodialysis. Second, four machine learning algorithms, including extreme gradient boosting (XGBoost), histgradient boosting (HGB), k-nearest neighbors (KNN), and adaptive boosting (AdaBoost), were trained to construct predictive models for predicting the prognosis of poisoned patients undergoing hemodialysis. Finally, the performance of paired feature selection and machine learning (ML) algorithm were evaluated to select the best models using five evaluation metrics including accuracy, sensitivity, specificity the area under the curve (AUC), and f1-score.

RESULT

The study comprised 980 patients in total. The experimental results showed that ten variables had a significant influence on prognosis outcomes including age, intubation, acidity (PH), previous medical history, bicarbonate (HCO3), Glasgow coma scale (GCS), intensive care unit (ICU) admission, acute kidney injury, and potassium. Out of the four models evaluated, the HGB classifier stood out with superior results on the test dataset. It achieved an impressive mean classification accuracy of 94.8%, a mean specificity of 93.5 a mean sensitivity of 94%, a mean F-score of 89.2%, and a mean receiver operating characteristic (ROC) of 92%.

CONCLUSION

ML-based predictive models can predict the prognosis of poisoned patients undergoing hemodialysis with high performance. The developed ML models demonstrate valuable potential for providing frontline clinicians with data-driven, evidence-based tools to guide time-sensitive prognosis evaluations and care decisions for poisoned patients in need of hemodialysis. Further large-scale multi-center studies are warranted to validate the efficacy of these models across diverse populations.

Development and qualification of clinical grade decellularized and cryopreserved human esophagi

Tissue engineering is a promising alternative to current full thickness circumferential esophageal replacement methods. The aim of our study was to develop a clinical grade Decellularized Human Esophagus (DHE) for future clinical applications. After decontamination, human esophagi from deceased donors were placed in a bioreactor and decellularized with sodium dodecyl sulfate (SDS) and ethylendiaminetetraacetic acid (EDTA) for 3 days. The esophagi were then rinsed in sterile water and SDS was eliminated by filtration on an activated charcoal cartridge for 3 days. DNA was removed by a 3-hour incubation with DNase. A cryopreservation protocol was evaluated at the end of the process to create a DHE cryobank. The decellularization was efficient as no cells and nuclei were observed in the DHE. Sterility of the esophagi was obtained at the end of the process. The general structure of the DHE was preserved according to immunohistochemical and scanning electron microscopy images. SDS was efficiently removed, confirmed by a colorimetric dosage, lack of cytotoxicity on Balb/3T3 cells and mesenchymal stromal cell long term culture. Furthermore, DHE did not induce lymphocyte proliferation in-vitro. The cryopreservation protocol was safe and did not affect the tissue, preserving the biomechanical properties of the DHE. Our decellularization protocol allowed to develop the first clinical grade human decellularized and cryopreserved esophagus.

Hemodialysis treatment for poisoning patients in the emergency department

INTRODUCTION

We aimed to evaluate the hemodialysis (HD) use in adult patients after acute poisoning in the emergency department.

METHODS

The study was performed as a retrospective observational cohort study. We analyzed hospital electronic data system and patient files.

RESULTS

A total of 55 patients were included in the study. Among the 10 toxins exposed, the most common were methanol and metformin. The most common indications for HD treatment were: 67.3% (n = 37) for toxin elimination, 20% (n = 11) for treatment-resistant metabolic acidosis, hemodynamic disorder. The most common complication (50.9%) in all patients was central nervous system depression. Ten patients died from ingestion of methanol, one of aluminum phosphide, and one of opioid-sympathomimetic-hallucinogen agents.

CONCLUSION

HD is the most commonly used extracorporeal treatment method in the treatment of poisoning patients. HD should be considered without any delay in treating poisoned patients if there is no response to conventional treatments.

Severe Carbamazepine Toxicity Treated with Continuous Venovenous Hemofiltration at Palestine Medical Complex: Two Case Reports

Carbamazepine intoxication is not uncommon and accounts for many cases of poisoning among anticonvulsive medications users. Since there is no specific antidote for carbamazepine overdose, management is limited to gastric decontamination and supportive therapy. With its high protein binding, the role of extracorporeal elimination in carbamazepine intoxication is still questionable. Here two cases of severe carbamazepine intoxication are presented; the cases were brought to the emergency department after the ingestion of 12,000 mg of controlled release carbamazepine for the first case, and unknown amounts of the same drug for the second case. Both cases were presented with altered mental status, convulsion, and high serum carbamazepine levels of more than 20 mcg/mL. They were intubated and treated with continuous venovenous hemofiltration, after which carbamazepine levels declined significantly along with subsequent clinical improvement and complete neurological recovery. Both cases were discharged home for further psychiatric care.

Dialysis and Extracorporeal Therapies for Enhanced Elimination of Toxic Ingestions and Poisoning

Poisoning and toxic ingestions cause significant morbidity and mortality worldwide. Extracorporeal therapies such as dialysis, haemoperfusion and plasma exchange are selectively applied to patients with severe intoxications unresponsive to standard interventions and can be lifesaving. Extracorporeal therapies are a complex but fundamental aspect of the practice of nephrology. Without high-quality evidence to guide implementation, an understanding of toxicokinetics and the physiochemical principles of the enhanced elimination techniques is especially important. This review provides a comphrensive, user-friendly outline of the application of extracorporeal therapy in the poisoned patient.

Extracorporeal blood purification in acutely intoxicated veterinary patients: A multicenter retrospective study (2011-2018): 54 cases

OBJECTIVE

To investigate the clinical outcome and complications associated with extracorporeal blood purification (EBP) using either hemodialysis (HD), hemodialysis and hemoperfusion (HD + HP), or therapeutic plasma exchange (TPE) for the management of acute toxin ingestion in small animals.

DESIGN

Retrospective, multicenter study from January 2011 to July 2018.

SETTING

One university teaching hospital and one private specialty hospital.

ANIMALS

Fifty-one dogs and 3 cats with a history of acute toxin exposure that could lead to severe morbidity and mortality, managed with different EBP techniques.

MAIN RESULTS

Nonsteroidal anti-inflammatory drugs (38/54, 52%), baclofen (8/54, 15%), and ethylene glycol (7/54, 13%) were the most common toxicities treated with EBP. Membrane-based TPE was used most commonly (22/54, 40.7%), followed by HD (17/54, 31.5%) and then HD + HP (15/54, 27.8%). There was an 83.3% (45/54) overall survival, with 88.9% (8/9) of nonsurvivors having clinical signs prior to therapy. One third (18/54) of the patients never developed clinical signs of toxicity. Treatment complications occurred in 44.4% (24/54) of the animals, although only 18.5% (10/54) of these complications, such as mild hypotension, thrombocytopenia secondary to the HP cartridge, facial swelling after plasma transfusion for TPE, bleeding from catheter size secondary to heparinization, or clotting of the system, could be attributed to the EBP treatment. None of the nonsurvivors died because of EBP complications.

CONCLUSIONS

Early initiation of EBP therapy might be considered as an alternative route of decontamination in severe acute toxicities with high potential for significant morbidity and mortality. The survival rate in small animals undergoing EBP is high despite exposure to potential lethal doses of toxins, and survival appears to be more likely if clinical signs of toxicity are not present at the time of EBP. Continued research is warranted with randomized controlled clinical trials to further evaluate the clinical efficacy and benefit of EBP.

Extracorporeal membrane oxygenation use in poisoning: a narrative review with clinical recommendations

CONTEXT

Poisoning may lead to respiratory failure, shock, cardiac arrest, or death. Extracorporeal membrane oxygenation (ECMO) may be used to provide circulatory support, termed venoarterial (VA) ECMO; or respiratory support termed venovenous (VV) ECMO. The clinical utility of ECMO in poisoned patients remains unclear and guidelines on its use in this setting are lacking.

OBJECTIVES

To perform a literature search and narrative review on the use of ECMO in poisonings. Additionally, to provide recommendations on the use of ECMO in poisonings from physicians with expertise in ECMO, medical toxicology, critical care, and emergency medicine.

METHODS

A literature search in Ovid MEDLINE from 1946 to October 14, 2020, was performed to identify relevant articles with a strategy utilizing both MeSH terms and adjacency searching that encompassed both extracorporeal life support/ECMO/Membrane Oxygenation concepts and chemically-induced disorders/toxicity/poisoning concepts, which identified 318 unique records. Twelve additional manuscripts were identified by the authors for a total of 330 articles for screening, of which 156 were included for this report.

NARRATIVE LITERATURE REVIEW

The use of ECMO in poisoned patients is significantly increasing over time. Available retrospective data suggest that patients receiving VA ECMO for refractory shock or cardiac arrest due to poisoning have lower mortality as compared to those who receive VA ECMO for non-poisoning-related indications. Poisoned patients treated with ECMO have reduced mortality as compared to those treated without ECMO with similar severity of illness and after adjusted analyses, regardless of the type of ingestion. This is especially evident for poisoned patients with refractory cardiac arrest placed on VA ECMO (termed extracorporeal cardiopulmonary resuscitation [ECPR]).

INDICATIONS

We suggest VA ECMO be considered for poisoned patients with refractory cardiogenic shock (continued shock with myocardial dysfunction despite fluid resuscitation, vasoactive support, and indicated toxicologic therapies such as glucagon, intravenous lipid emulsion, hyperinsulinemia euglycemia therapy, or others), and strongly considered for patients with cardiac arrest in institutions which are structured to deliver effective ECPR. VV ECMO should be considered in poisoned patients with ARDS or severe respiratory failure according to traditional indications for ECMO in this setting.

CONTRAINDICATIONS

Patients with pre-existing comorbidities with low expected survival or recovery. Relative contraindications vary based on each center's experience but often include: severe brain injury; advanced age; unrepaired aortic dissection or severe aortic regurgitation in VA ECMO; irreversible organ injury; contraindication to systemic anticoagulation, such as severe hemorrhage.

CONCLUSIONS

ECMO may provide hemodynamic or respiratory support to poisoned patients while they recover from the toxic exposure and metabolize or eliminate the toxic agent. Available literature suggests a potential benefit for ECMO use in selected poisoned patients with refractory shock, cardiac arrest, or respiratory failure. Future studies may help to further our understanding of the use and complications of ECMO in poisoned patients.

[Acute intoxications in the intensive care unit: A 10-year analysis]

BACKGROUND

Acute intoxications play a special role in preclinical emergency medicine, in the emergency department, and in intensive care. This study characterizes cases of acute intoxications from an intensive care perspective.

OBJECTIVES

All cases of acute intoxications admitted to the intensive care units at the University Hospital Hamburg-Eppendorf between 01 January 2007 and 30 June 2017 were retrospectively analyzed.

RESULTS

During the study period, 587 patients with acute intoxications were admitted to the university hospital's intensive care units. Median age was 45 years (interquartile range [IQR] 31 years); 83.1% of patients were younger than 70 years. The most common cause of intoxication in the younger patients was a suicide attempt (55.1%), while in older patients it was an iatrogenic event (47.5%). Cases involving intoxications with psychotropic medication (48.7%), alcohol (32.9%), analgesics (23.3%), and drugs (17.0%) were most frequent. In 50.6% of cases, intoxication was due to more than one substance. Intoxication-specific therapy was performed in 40.0% of cases and intensive care therapy in 42.4% of cases. The median length of intensive care unit stay was 2 days (IQR 3). Hospital mortality was 5.5%. In older patients (≥ 70 years) compared with younger patients, the need for intensive care treatment (56.6% vs. 39.5% of cases, p = 0.002), the length of intensive care unit stay (3 days [IQR 5] vs. 2 days [IQR 3], p = 0.0004) and in-hospital mortality (17.2% vs. 3.1%, p < 0.001) were significantly higher.

CONCLUSIONS

Acute intoxications are part of the spectrum of disorders treated in the intensive care unit. In older patients, iatrogenic causes are frequently found, which is associated with an increased risk of death.

Extracorporeal Therapies in the Emergency Room and Intensive Care Unit

Extracorporeal treatments create opportunity for removing disease causing solutes within blood. Intoxications, renal failure, and immune-mediated diseases may be managed with these treatments, often providing new hope for patients with severe or refractory disease. Understanding solute pharmacokinetics and the limitations of each type of extracorporeal technique can allow for the selection of the optimal treatment modality.

Charcoal Hemoperfusion for Methotrexate Toxicity: A Safe and Effective Life-Rescue Alternative When Glucarpidase Is Not Available

Background: High dose methotrexate (HDMTX) is used for the treatment of pediatric hemato-oncological diseases. HDMTX can induce acute kidney injury in cases of delayed elimination. The use of leucovorin remains the most effective rescue action. Further treatment options are of difficult access in the rare cases where leucovorin fails to prevent renal failure from occurring. Glucarpidase is an effective treatment in cases of methotrexate (MTX) delayed elimination, but cost is high and availability is limited. Charcoal hemoperfusion (CHP) is a very efficient procedure to remove protein-bound drugs, promoting fast MTX elimination, but is rarely considered as a treatment option. Methods: We present three pediatric cases with prolonged exposure to MTX after HDMTX and delayed elimination in which hemoperfusion was performed as rescue treatment for methotrexate intoxication. Results: Charcoal hemoperfusion was performed with positive results and no complications as bridging until glucarpidase was available in two cases and in one case where two doses of glucarpidase led to insufficient reduction of MTX levels. Conclusions: CHP can be considered as a rescue treatment option in MTX intoxication, since it is an effective and safe extracorporeal method for removing MTX, in cases where rescue with leucovorin is insufficient and glucarpidase is not available or while waiting for delivery.

The Crashing Toxicology Patient

This article examines, using an organ-systems based approach, rapid diagnosis, resuscitation, and critical care management of the crashing poisoned patient in the emergency department. The topics discussed in this article include seizures and status epilepticus, respiratory failure, cardiovascular collapse and mechanical circulatory support, antidotes and drug-specific therapies, acute liver failure, and extracorporeal toxin removal.

Treatment of ibuprofen intoxication with charcoal haemoperfusion in two dogs

Case history: Two dogs presented separately to the Small Animal Hospital, University of Florida (Gainsville, FL, USA) for ingestion of ibuprofen. The first dog ingested 561.8 mg/kg ibuprofen in addition to paracetamol and caffeine and vomited prior to admission. This patient also received fluid therapy for 8 hours prior to charcoal haemoperfusion. The second dog ingested 500 mg/kg of ibuprofen and the owners induced vomiting with hydrogen peroxide prior to presentation. Due to the severity of clinical signs, both patients were treated with charcoal haemoperfusion.Clinical findings: The concentrations of ibuprofen in the blood of the dogs prior to treatment were 478 and 301 mg/L. During the treatment ibuprofen concentrations were reduced by 95.8% and 45.5%, respectively, with no treatment side effects and minimal clinical signs after treatment.Diagnosis: Toxicity due to ingestion of ibuprofen toxicity that was successfully treated with charcoal haemoperfusion.Clinical relevance: In the cases described here minimal benefit was seen after 3 hours of treatment using one haemoperfusion cartridge. This is in contrast to a previously published report in which dogs were treated for 6 hours with two charcoal haemoperfusion cartridges. This suggests that one cartridge may be sufficient. The amount of ibuprofen ingested was not a reliable predictor of the concentration in blood at the initiation of treatment. Charcoal haemoperfusion is an effective means of reducing plasma concentrations of ibuprofen, however, its use may be limited by its cost and availability.

Initial Management of Poisoned Patient

How to cite this article: Chandran J, Krishna B. Initial Management of Poisoned Patient. Indian J Crit Care Med 2019;23(Suppl 4):S234-S240.

Extracorporeal treatment in children with acute severe poisoning

Acute poisoning in children is a clinical emergency. Prompt and effective treatment is critical for life-threatening poisoning. Extracorporeal treatment (ECTR) is a practical option for enhancing the elimination of poisons.We conducted a retrospective observational study on 338 children with severe acute poisoning who received ECTR during hospitalization from January 2010 to December 2017. The poisonous substances, utilization of ECTR, adverse reactions to ECTR, and outcomes were recorded.The top 3 poisoning categories, in order of frequency, were found to be pesticides (57.99%), biotoxins (25.15%), and pharmaceuticals (14.20%). Paraquat (35.21%), an organic heterocyclic herbicide with high toxicity to humans, was the most common toxic substance. The main modalities of ECTR use were hemoperfusion (50.59%) and therapeutic plasma exchange (42.60%), followed by continuous renal replacement therapy (4.44%) and hemodialysis (1.18%). There were also 4 patients (1.18%) with a combination of ECTR performed. Adverse events of ECTR included errhysis and hematomas around the catheter exit site, oral cavity bleeding, allergic reactions, hypothermia, hypotension, and blood coagulation. The adverse reactions were mostly mild to moderate and were manageable. During the study period, there were 295 patients (87.28%) who were cured, 9 (2.66%) who experienced some improvement, and 34 (10.06%) who died.ECTR modalities were found to be clinically effective approaches to the treatment of poisoning by pesticides, biotoxins, and pharmaceuticals, indicating they are important modalities in toxicology and treatment, and are well tolerated by children.

Use of charcoal hemoperfusion and hemodialysis in the treatment of methotrexate toxicosis in a dog

OBJECTIVE

To describe the successful use of charcoal hemoperfusion (HP) and hemodialysis (HD) in a dog in the treatment of methotrexate (MTX) toxicosis.

CASE SUMMARY

An American Pit Bull Terrier accidentally ingested 56.8 mg/m² of MTX. The patient's initial serum MTX concentration was 0.11 μmol/L. At this dosage, myelosuppression and gastrointestinal epithelial necrosis have been reported. Charcoal HP and HD in series were used to enhance elimination of MTX. Serial serum samples were obtained during the session at 0, 30, 60, 90, 120, 150, and 180 minutes and 12 hours after the session. These were later analyzed for MTX concentrations. Clearance of MTX was 73% and extraction ratio was 63% within the first 30 minutes of HP/HD. A 3-hour session eliminated all detectable traces of MTX. The dog tolerated the session well and did not develop any clinical signs of MTX toxicosis.

NEW OR UNIQUE INFORMATION PROVIDED

HP and HD together were highly effective in enhancing elimination of MTX from this patient. The prompt use of extracorporeal techniques decreased toxic concentrations of MTX to safer values, which prevented myelosuppression and gastrointestinal injury. HP and HD in conjunction or in place of traditional therapy may be a viable option for the treatment of acute toxic exposures to MTX.

Continuous venovenous hemofiltration in the management of paraquat poisoning: A meta-analysis of randomized controlled trials

BACKGROUND

Paraquat (PQ) poisoning is a widespread occurrence, especially in underdeveloped areas. The treatment of PQ poisoning has always been difficult, and there is currently no definite effective treatment. Continuous venovenous hemofiltration (CVVH) treatment for PQ poisoning has been widely used in clinical practice; however, its effect remains uncertain. Accordingly, the purpose of this meta-analysis was to evaluate the efficacy of CVVH in the treatment of PQ poisoning.

METHODS

We searched for relevant trials using PubMed, Embase, the Cochrane Library, and 3 Chinese databases, the Chinese BioMedical Literature Database, National Knowledge Infrastructure Database, and Wanfang Database. We included all qualified randomized controlled trials (RCTs) of CVVH treatment for patients with PQ poisoning. The primary outcome was mortality, while the secondary outcomes included the survival time and constituent ratios of death due to respiratory failure and circulatory failure.

RESULTS

Three RCTs involving 290 patients were included. The mortality rates of the intervention and control groups were 57.9% and 61.0%, respectively. Pooled analysis demonstrated no significant difference in mortality between the CVVH treatment and control groups (risk ratio [RR] 0.94, 95% confidence interval [CI]: 0.78-1.15, P = .56), with a low level of heterogeneity (X = 1.75, I = 0%). However, the CVVH group was associated with a longer survival time compared to the control group (weighted mean difference 1.73, 95% CI: 0.56-2.90, P = .004). Respiratory failure as the cause of death was more common in the CVVH group, as compared with the control group (RR 1.66, 95% CI: 1.24-2.23, P = .0008), whereas patients in the control group were more likely to die from circulatory failure than in the CVVH group (RR 0.56, 95% CI: 0.40-0.81, P = .002).

CONCLUSION

Although CVVH treatment might not noticeably reduce mortality for patients with PQ poisoning, it can prolong the survival time of the patients and improve the stability of the circulatory system, thereby enabling further treatment.

[Suicide attempt by means of phenobarbital overdose. Effective treatment with continuous veno-venous hemodialysis]

A 68-year-old woman tried to commit suicide using phenobarbital, which was initially prescribed for her dog that suffered from seizures. At admission she was unconscious and ventilated. Five days of intensive care therapy did not improve her state of consciousness. Subsequent continuous veno-venous hemodialysis accelerated the elimination of phenobarbital compared to endogenous elimination by a factor of five. The patient survived without sequelae. Detailed history taking and well-timed indication for dialysis were crucial.

Intentional drug poisoning care in a physician-manned emergency medical service

OBJECTIVES

Severely poisoned patients can benefit from intensive and specific treatments. Emergency medical services (EMS) may therefore play a crucial role by matching prehospital care and hospital referral to the severity of poisoned patients. Our aim was to investigate EMS accuracy in this condition.

METHODS

A 3-year retrospective study was conducted in a university hospital. Emergency telephone calls about adult patients with intentional drug poisoning (IDP) were included. In daily practice, an emergency physician answers such telephone calls and dispatches either first responders or a mobile intensive care unit (MICU). According to on-scene evaluation, patients are referred to the emergency department (ED) or to an intensive care unit (ICU). We therefore calculated global EMS accuracy according to patients' actual medical needs. We further evaluated the performance of dispatch and hospital referral decision. We also performed a regression analysis to identify factors of inappropriate dispatch.

RESULTS

A total of 2,227 patients were studied. Median age was 41 years old (range 30-49) and 63% were women. Dispatch was appropriate for 1,937 (87%) patients. Sensitivity and specificity of dispatch decision were 0.43 and 0.93, respectively. Decision of patients' referral to an appropriate hospital facility had a sensitivity of 0.67 and a specificity of 0.98. Toxicological data, age, and Glasgow coma scale were significantly associated with inappropriate EMS decisions.

CONCLUSIONS

A physician-operated EMS is an accurate system to provide prehospital care to IDP patients. However, dispatch physicians should pay attention, especially to toxicological anamnesis, to anticipate proper patient care.

Phenytoin removal by continuous venovenous hemofiltration

OBJECTIVE

To describe 2 cases of clinically significant phenytoin removal during continuous venovenous hemofiltration (CVVH) and review the relevant literature regarding phenytoin removal by renal replacement modalities.

CASE SUMMARY

A 64-year-old female with chronic kidney disease and cirrhosis was admitted to the intensive care unit (ICU) with a traumatic subdural hematoma and seizures. The patient received a loading dose of intravenous phenytoin 1000 mg, followed by maintenance intravenous administration of phenytoin 100 mg and levetiracetam 250 mg every 12 hours. CVVH was initiated for acidosis. A 63-year-old male was admitted to the ICU after cardiac surgery complicated by hypotension. CVVH was initiated for fluid overload, and phenytoin was initiated 3 days later for seizures. A loading dose of intravenous phenytoin 2700 mg was administered, followed by maintenance dosing of intravenous phenytoin 150 mg every 8 hours. Concentrations of unbound phenytoin in serum and CVVH effluent samples were measured during concomitant treatment in each patient. In both patients, serum and effluent concentrations of unbound phenytoin fell steadily while they were on CVVH. Clearance of phenytoin by CVVH was calculated, as was the daily removal of phenytoin, as a percentage of total daily phenytoin dosage during each sampling period. Phenytoin clearance by CVVH ranged from 11 to 13 mL/min in these patients.

DISCUSSION

The clearance of phenytoin with CVVH in these 2 patients was much higher than the renal clearance of phenytoin reported in healthy volunteers with normal renal function. Previous case reports have demonstrated that only small, clinically insignificant amounts of phenytoin are removed by hemodialysis, and the only published report of phenytoin removal by continuous renal replacement therapy used hemofiltration rates much lower than those used in the 2 cases described here.

CONCLUSIONS

These cases demonstrate that a substantial amount-approximately 30%-of total daily phenytoin dose may be removed by CVVH, and patients may require higher than expected empiric doses. Phenytoin concentrations should be closely monitored in critically ill patients receiving CVVH.

Principles and operational parameters to optimize poison removal with extracorporeal treatments

A role for nephrologists in the management of a poisoned patient involves evaluating the indications for, and methods of, enhancing the elimination of a poison. Nephrologists are familiar with the various extracorporeal treatments (ECTRs) used in the management of impaired kidney function, and their respective advantages and disadvantages. However, these same skills and knowledge may not always be considered, or applicable, when prescribing ECTR for the treatment of a poisoned patient. Maximizing solute elimination is a key aim of such treatments, perhaps more so than in the treatment of uremia, because ECTR has the potential to reverse clinical toxicity and shorten the duration of poisoning. This manuscript reviews 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. Data supporting these recommendations will be presented, whenever available.

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.

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.

Renal failure: emergency evaluation and management

Patients with altered renal function are frequently encountered in the emergency department (ED) and emergency physicians often play an important role in the evaluation and management of renal disease. Early recognition, diagnosis, prevention of further iatrogenic injury, and management of renal disease have important implications for long-term morbidity and mortality. This article reviews basic renal physiology, discusses the differential diagnosis and approach to therapy, as well as strategies to prevent further renal injury, for adult patients who present to the ED with renal injury or failure.

Clinical features and treatment in patients with acute 2,4-dinitrophenol poisoning

OBJECTIVE

To report clinical features and treatment of 16 cases of acute 2,4-dinitrophenol poisoning.

METHODS

A total of 16 patients suffering from acute poisoning due to non-oral exposure to 2,4-dinitrophenol were sent to our hospital. Two died within 3 h after admission, while the other 14 responded to supportive treatment and hemoperfusion. Clinical features and treatment of the patients were retrospectively analyzed and presented.

RESULTS

Fourteen patients recovered and were discharged after four to six weeks of treatment. No obvious poisoning sequelae were found in the three-month follow-up.

CONCLUSIONS

Non-oral exposure to 2,4-dinitrophenol is toxic. Hemoperfusion and glucocorticoid treatments may be efficient measures to prevent mortality, but this requires further study.

Have advances in extracorporeal removal techniques changed the indications for their use in poisonings?

During the past 25 years, numerous changes have taken place in the use of hemodialysis as a therapeutic modality. Advances in technologies and a progression in our collective understanding of the pharmacokinetics of certain xenobiotics have resulted in alterations in the indications, effectiveness, and safety of hemodialysis. However, these changes have not necessarily been reflected in the current published data regarding treatment of intoxications. Reported clearance rates often reflect what was achievable in the 1970s and 1980s, and more recent reports are frequently lacking. Our goal in this review is to summarize the changes in hemodialysis and in other extracorporeal removal technologies and highlight the effects of these changes on the current indications for hemodialysis of the poisoned patient. Changes in dialysis performance that are reviewed in this article include the use of high-efficiency and high-flux dialysis membranes, improved hemodynamic stability because of ultrafiltration control, and the use of bicarbonate as a source of base. We review the indications for hemodialysis for removal of specific toxins, including vancomycin, methotrexate, carbamazepine, and valproic acid.