Extracorporeal management of poisonings

Extracorporeal methods have been an integral part in the management of poisonings. The elimination of a drug or toxin by extracorporeal techniques (ECT) is governed by the properties of the toxin and the chosen extracorporeal therapy. The various ECT include hemodialysis, hemoperfusion, hemofiltration, continuous renal replacement therapy and peritoneal dialysis, all of which have been used some time or another for the management of poisonings. This review highlights the concepts forming the basis for selecting one modality over the others.     

Adjuncts and alternatives to oxime therapy in organophosphate poisoning--is there evidence of benefit in human poisoning? A review

Organophosphate poisoning is common in developing countries. The morbidity and mortality with organophosphate poisoning is relatively high despite the use of atropine as specific antidotal therapy and oximes to reactivate acetylcholinesterase. Several adjunct and alternative therapies have been explored in animal and human studies. We reviewed the literature to ascertain if there was evidence of benefit of such therapies. Adjunct and alternative therapies included treatments to reduce poison absorption by topical application of creams, enhance toxin elimination by haemoperfusion or bioremediation and neutralise the poison by scavenging free organophosphate with cholinesterase-rich human plasma. In addition, magnesium, clonidine, diazepam, N-acetyl cysteine and adenosine receptor agonists have also been used to counteract poison effects. Detailed assessment was limited by the paucity of trials on adjunct/alternative therapies. The limited evidence from the review process suggested potential benefit from the use of human plasma infusion, early initiation of haemoperfusion and intravenous magnesium, in addition to standard therapy with atropine and pralidoxime. There appeared to be no additional benefit with alkalinisation or use of glycopyrrolate instead of atropine in human trials. Diazepam administration has been advocated by military authorities if symptoms developed following exposure to organophosphate. Bioremediation, clonidine, N-acetyl cysteine and adenosine receptor agonists have been evaluated only in animal models. The impact of adjunct and alternate therapies on outcomes in human poisoning needs to be further explored before implementation as standard treatment.     

Extracorporeal Treatment for Tricyclic Antidepressant Poisoning: Recommendations from the EXTRIP Workgroup

The Extracorporeal Treatments In Poisoning (EXTRIP) workgroup was formed to provide recommendations on the use of extracorporeal treatments (ECTR) in poisoning. Here, the workgroup presents its results for tricyclic antidepressants (TCAs). After an extensive literature search, using a predefined methodology, the subgroup responsible for this poison reviewed the articles, extracted the data, summarized findings, and proposed structured voting statements following a predetermined format. A two‐round modified Delphi method was chosen to reach a consensus on voting statements and RAND/UCLA Appropriateness Method to quantify disagreement. Blinded votes were compiled, returned, and discussed in person at a meeting. A second vote determined the final recommendations. Seventy‐seven articles met inclusion criteria. Only case reports, case series, and one poor‐quality observational study were identified yielding a very low quality of evidence for all recommendations. Data on 108 patients, including 12 fatalities, were abstracted. The workgroup concluded that TCAs are not dialyzable and made the following recommendation: ECTR is not recommended in severe TCA poisoning (1D). The workgroup considers that poisoned patients with TCAs are not likely to have a clinical benefit from extracorporeal removal and recommends it NOT to be used in TCA poisoning.     

ACCIDENTAL STRYCHNINE POISONING: A Case Report

The management of acute strychnine poisoning in a child is described.Convulsions of typical character occurred with full spinal tetanusfollowed by respiratory arrest. Aims of management were controlof convulsions, maintenance of a clear airway, with adequaterespiratory exchange, and elimination of poison from the stomach.Sufficient thiopentone sodium was given rectally to suppressthe convulsions without undue circulatory or respiratory depression.The danger of exchanging strychnine for barbiturate poisoningis stressed. Passage of a cuffed endotracheal tube prior togastric lavage is recommended. The possible use of specificmuscle relaxant drugs and long-term care are briefly considered.     

Three controversial issues in extracorporeal toxin removal

The optimal method of extracorporeal removal of many toxic compounds is often a matter of debate. Due to the lack of well‐designed studies, we are often left with circumstantial evidence, and we must exercise our best clinical judgment as to whether extracorporeal drug removal is beneficial and if so, by what method. It is clear, however, that rapidity in toxin removal is beneficial. We present three issues dealing with extracorporeal removal of toxins for which there is no definitive answer but which may arise in clinical practice. The first is whether continuous renal replacement therapy (CRRT) is better at removing dialyzable toxins than classic hemodialysis. The second is whether charcoal hemoperfusion is at all useful in treating paraquat poisoning. Finally, is any modality of extracorporeal treatment useful in the treatment of amatoxin poisoning? After a thorough literature review, it is evident that definitive answers are not strikingly apparent. However, extracorporeal treatment in the latter two instances may have potential benefit and may be the only hope for patient survival. Due to the urgent nature of treatment for poisoning, as well as the somewhat obscure nature of these issues, there may never be well‐designed evidence‐based studies to help guide us. In the meantime, we must continue to use less than ideal evidence and our own experience in dealing with these controversial issues to guide our decision‐making process.     

Kohle, Koks und Klapperschlangen

Background

Since ancient times poisoning has been treated medicinally. Clinical toxicology, in the narrow sense of the term, developed from the foundation of specialized medical treatment units for poisoning and the formation of the first poison information centers in the second half of the twentieth century. Historically, the first poison information centers were often localized at pediatric clinics or departments of internal medicine. It became increasingly more obvious that this pooling of competences made sense.

Aim

This article gives a general introduction in clinical toxicology and presents the functions and key activities of emergency poison centers.

Material and methods

The organisation and work of a poisons centre is demonstrated on the basis of the Poisons Information Center (GIZ) North annual report for 2011. In a short summary the basic principles of clinical toxicology are elucidated: the primary removal of poisons by gastric lavage and administration of activated charcoal, secondary removal of poisons by enhanced elimination using hemodialysis, hemoperfusion, multi-dose activated charcoal and molecular adsorbent recirculating systems (MARS) and the indications for administration of specific antidotes or antivenins (antisera against poisoning by poisonous animals).

Results

Gastric lavage is indicated within 1 h after ingestion of a potentially life-threatening dose of a poison. In cases of poisoning with substances which penetrate the central nervous system (CNS) gastric lavage should be performed only after endotracheal intubation due to the risk of aspiration. The basic management of poisoned patients by emergency medicine personnel out of hospital and on the way to hospital is presented. The Bremen list, a compilation of the five antidotes, atropine, 4-dimethylaminophenol (4-DMAP), tolonium chloride, naloxone and activated charcoal for out of hospital treatment by emergency doctors is presented.

Conclusion

In all, even questionable cases of poisoning consultation at emergency poison centers is recommended. An extensive list of all German speaking poison information centers is available on the homepage of GIZ-Nord (http://www.giz-nord.de).     

Use of hemodialysis and hemoperfusion in poisoned patients

Extracorporeal removal techniques such as hemodialysis, charcoal hemoperfusion, and peritoneal dialysis have been used to remove toxins from the body. To define trends in the use of these techniques for toxin removal, we analyzed the 19,351 cases requiring extracorporeal removal reported to U.S. poison centers from 1985-2005. The number of such patients who received hemodialysis, excluding those with other medical indications, (normalized per million calls) increased from 231 to 707 whereas hemoperfusion decreased from 53 to 12 in the years 1985-2005. Peritoneal dialysis decreased from 2.2 in 1985 to 1.6 in 1991. The most common toxins removed by hemodialysis were lithium and ethylene glycol. There were more dialysis treatments for poisonings with valproate and acetaminophen in 2001-2005 than for methanol and theophylline, although hemodialysis for acetaminophen removal is generally not recommended. Theophylline was the most common toxin removed by hemoperfusion from 1985-2000, but carbamazepine became the most frequent toxin for removal during 2001-2005. Our study shows that the profile of toxins and the type of extracorporeal technique used to remove the toxins have changed over the years.     

Why are we Still Dialyzing Overdoses to Tricyclic Antidepressants? A subanalysis of the NPDS database

A recent analysis of the American Association of Poison Control Centers database, showed that poisonings from toxins not usually considered amenable to extracorporeal purification (“non‐classic toxins” such as ethanol and tricyclic antidepressants) continue to be reported. This publication investigates factors that may explain these findings. Our results suggest that: 1) the relatively high absolute number of ECTR performed for non‐classic toxins may simply reflect the large number of exposures to these toxins, 2) poisoning from another toxin may have been the reason for ECTR initiation in some exposures to non‐classic toxins, 3) poisoning from non‐classic toxins may receive ECTR for purposes other than toxin removal, and 4) the decisional threshold to initiate ECTR may be lower for non‐classic toxins because of heightened toxicity.     

Comparison of patients hemodialyzed for lithium poisoning and those for whom dialysis was recommended by PCC but not done: what lesson can we learn?

AIMS: To compare patients for whom hemodialysis was done for lithium poisoning and those for whom it was recommended by the poison control centre (PCC) but not done and to evaluate the effect of withholding hemodialysis on outcomes. METHODS: All lithium overdoses brought to the attention of the PCC were prospectively followed from January 1 to December 31, 1996. Patients for whom hemodialysis was done were compared with those for whom it was recommended but not done in terms of clinical presentation, lithium elimination half-life, need for transfer to another centre for hemodialysis, and outcome (death, or sequel or recovery). RESULTS: A total of 205 cases of lithium overdoses were collected including 110 with levels higher than 1.5 mmol/l. There were 12 acute lithium overdoses; no patients required hemodialysis and there were no sequel or deaths. There were 174 acute on chronic overdoses; hemodialysis was recommended in 9 patients but only 6 underwent hemodialysis; one patient died during hemodialysis but no other had sequel. There were 19 chronic poisonings; hemodialysis was recommended in 9 patients but only 2 had hemodialysis, a third patient underwent hemodialysis despite it not being recommended; one patient died without hemodialysis and one other had sequel after hemodialysis. No difference were observed between the groups for age, sex, type of poisoning (acute on chronic/chronic), levels (initial/peak/6 hours/extrapolated at 30 hours), time of presentation post-ingestion, presence of co-ingestants, symptoms and signs, Hansen and Amdisen grade, initial creatinine, time of recommendation to perform hemodialysis (daytime or nighttime), need to transfer patients to another centre to perform hemodialysis, and outcome. Patients with acute on chronic poisoning that were not hemodialyzed had longer elimination half-life than those for whom hemodialysis was done even before hemodialysis was performed: 50.1 +/- 13.6 h (n = 3) versus 12.9 +/-12.1 (n = 3) (p = 0.007), respectively. CONCLUSION: No difference was observed between patients for whom hemodialysis was done and those for whom it was recommended by PCC but not done. Despite the death of one patient clearly associated with voluntary withholding hemodialysis, sequel was not seen in that group. The indications for hemodialysis in lithium poisoning should be reconsidered to include only the more severe cases.     

Variability in the Management of Lithium Poisoning

Three patterns of lithium poisoning are recognized: acute, acute‐on‐chronic, and chronic. Intravenous fluids with or without an extracorporeal treatment are the mainstay of treatment; their respective roles may differ depending on the mode of poisoning being treated. Recommendations for treatment selection are available but these are based on a small number of observational studies and their uptake by clinicians is not known. Clinician decision‐making in the treatment of four cases of lithium poisoning was assessed at a recent clinical toxicology meeting using an audience response system. Variability in treatment decisions was evident in addition to discordance with published recommendations. Participants did not consistently indicate that hemodialysis was the first‐line treatment, instead opting for a conservative approach, and continuous modalities were viewed favorably; this is in contrast to recommendations in some references. The development of multidisciplinary consensus guidelines may improve the management of patients with lithium poisoning but prospective randomized controlled trials are required to more clearly define the role of extracorporeal treatments.     

Acute Liver Failure due to Amanita phalloides Poisoning: Therapeutic Approach and Outcome

Introduction

Amanita phalloides poisoning is a potentially fatal cause of acute liver failure. The aim of this study was to analyze the impact of initial patients' characteristics and different treatment modalities on the outcome of patients with liver failure caused by Amanita poisoning.

Role of level-1 trauma and critical care centers in treatment of acute poisoning

In the summer of 1998, the so-called Wakayama currty poisoning case occurred, and subsequently additional murders took place in which the accusred used sodium aziede and thallium to posison their victims. When the poison victims were admitted to hospital, food poisoning was mistakenly diagnosed. Due to serious concerns that such misdiagnoses might recur, the Japanese Ministry of Health and Welfare equipped 10 level-1 trauma and critical care centers and 66 critical care centers nationwide with high-performance liquid chromotographs, ion chromatographs, gas chromatographs, fluorescence X-ray analyzers, and high-frequency plasma mass spectrometers. This equipment will allow the detection of most types of industial and other chemicals as well as most therapeutic drugs. This report describes the current status of poison analysis systems and the role of level-1 trauma and critical care centers in cases of poisoning.     

50例急性有机磷农药中毒患者的抢救与护理体会

目的 探讨急性有机磷农药中毒患者的急救与护理经验.方法 回顾性分析50例急性有机磷农药中毒的临床资料.结果 本组患者除1例因服毒剂量大,且就诊时间>30 min,中毒程度深而抢救无效死亡,其余患者均治愈出院,抢救成功率98%.结论 严密的病情观察,积极有效的护理,是有机磷农药中毒患者抢救成功的关键.     

有机磷中毒病人人工气道洗涤排痰法的探讨

为有效清除有机磷中毒呼吸衰竭病人呼吸道分泌物 ,保持呼吸道通畅 ,对 32例有机磷中毒呼吸衰竭病人进行常规人工气道湿化法 (注入 0 .9%氯化钠注射液 5 m l湿化气道 ) ,经评估 ,排痰效果差 ,改用人工气道洗涤法 (即在人工气道内注入 0 .9%氯化钠注射液 15 ml)。结果 ,两种方法排痰效果比较 ,差异有极显著性意义 (P<0 .0 0 1) ,洗涤法明显优于湿化法。提示洗涤法能有效稀释痰液 ,利于分泌物排出 ,防止气道阻塞 ,对控制感染及改善通气有重要意义     

Carbon monoxide poisoning.

Carbon monoxide is a common domestic and industrial poison which may be lethal. Survivors can develop permanent neuropsychiatric disability. The mechanisms of toxicity are poorly understood and the traditional criteria used to determine the severity of the poisoning have low predictability. Oxygen is the recommended antidote to carbon monoxide, but it appears that oxygen under hyperbaric conditions repeated either daily or as indicated by the patient's condition may be required to provide an effective dose. A reliable marker of the severity of carbon monoxide poisoning is urgently needed so that trials of alternative regimens can proceed.     

Epidemiology of poisonings in the Bloemfontein area, 1980-1985

An epidemiological study of human poisoning in the Bloemfontein area over a recent 6-year period was performed. Deliberate and accidental poisonings were studied relative to: (i) age of poisoned persons; (ii) sex of poisoned persons; (iii) type of poison involved; and (iv) the time the poisoning occurred. The study also included the number of patients admitted to hospital after poisoning. The incidences of some agents involved were compared with those in two previous studies done in the same area.