Continuing controversy on gut decontamination

Current Controversies in Gastrointestinal Decontamination

Most poisonings reported to American poison control centers occur in the home. The most common route of exposure is ingestion, which is responsible for most fatalities. The goal of gastrointestinal decontamination is to prevent absorption of the toxin. Trends in treating poisoned patients have changed over the past few decades in light of a move toward practicing evidence-based medicine. Efficacy and clinical outcome have come into question and have led to position papers published recently regarding syrup of ipecac, gastric lavage, activated charcoal, and whole-bowel irrigation. These different methods of decontamination and the scientific data supporting each one will be reviewed, and the current controversies surrounding each will be discussed.

Parenteral emulsions and liposomes to treat drug overdose

Drug overdoses from both pharmaceutical and recreational drugs are a major public health concern. Although some overdoses may be treated with specific antidotes, the most common treatment involves providing supportive care to allow the body to metabolize and excrete the toxicant. In many cases, supportive care is limiting, ineffective, and expensive. There is a clear medical need to improve the effectiveness of detoxification, in particular by developing more specific therapies or antidotes for these overdoses. Intravenous lipid emulsions (ILEs) have been investigated as a potential treatment for overdoses of local anesthetics and other hydrophobic drugs. While ILE therapy has been successful in several cases, its use beyond local anesthetic systemic toxicity is controversial and its mechanism of detoxification remains a subject of debate. ILEs were not originally developed to treat overdose, but clarifying the mechanisms of detoxification observed with ILE may allow us to design more effective future treatments. Liposomes are highly biocompatible and versatile formulations, thus it was a natural step to explore their use for drug overdose therapy as well. Several researchers have designed liposomes using a variety of approaches including surface charge, pH gradients, and inclusion of enzymes in the liposome core to optimize the formulations for detoxification of a specific drug or toxicant. The in vitro results for drug sequestration by liposomes are very promising and animal trials have in some cases shown comparable performance to ILE at reduced lipid dosing. This narrative review summarizes the current status and advances in the use of emulsions and liposomes for detoxification and also suggests several areas in which studies are needed for developing future therapies.

Fatal Cleistanthus collinus toxicity: a case report and review of literature

Cleistanthus collinus is an extremely toxic plant poison. We report a case of suicidal ingestion of boiled water decoction of C. collinus where the patient presented with abdominal pain and giddiness. There was persistent metabolic acidosis and fluctuation in the level of serum potassium. The ECG changes indicated a probable myocardial injury with conduction abnormality. At autopsy, the viscera were found to be congested. The toxins were detected in the viscera and blood by TLC and HPLC. Cleistanthin A and B, collinusin, and diphyllin are the principal toxic constituents of the plant. Consumption of a boiled decoction of leaves is highly toxic and, medical management of patients is mainly supportive because the molecular mechanisms of toxin action are unknown. In the recent years, C. collinus has created a considerable amount of interest because of its complex metabolites and their cytotoxic activities. Through this study, the authors have tried to highlight different properties pertaining to C. collinus.

Epidemiology of Cleistanthus collinus (oduvan) poisoning: clinical features and risk factors for mortality

Cleistanthus collinus (local name: oduvan) poisoning is a common suicidal poisoning method used in rural southern India. There are few studies on this issue and they have small sample sizes. This study examines the epidemiology of oduvan poisoning in a large sample, highlighting socio-demographic and clinical profile, complications, and risk factors for mortality. This study is a retrospective case series of 127 oduvan intentionally poisoned patients presenting at a tertiary care teaching hospital between the years 1990-1999. Descriptive statistics, cumulative case fatality rates and time to death from ingestion of poison were calculated. Cox regression adjusting for left truncation was used to investigate the effects of covariates on death. Patients' average (sd) age was 29.1 (10.9), 62% were female, 76% were married and 49% were housewives. The cumulative case fatality rate was 30%. The median time to death after oduvan ingestion was 3 days. Common signs and symptoms included hypokalaemia, vomiting, hyponatraemia, altered sensorium, bradycardia and abnormal ECG. There was a 58% risk reduction (95% CI: 29-75) in death with each 1 mmol/l increase in plasma potassium level. Patient's age was associated with an increased risk of death and the estimated hazard ratio for an increase of 10 years in age was 1.56 (95% CI: 1.18-2.07). Use of boiled oduvan extract was associated with an increased mortality (HR: 2.71, 95% CI: 1.17-6.32) compared to ingesting fresh leaves. Risk factors for oduvan poisoning mortality were hypokalaemia, older age, mode of consumption and an elevated risk for death with presence of chronic disease. When consumed as a boiled extract, oduvan is more lethal. We recommend close monitoring, correction of plasma potassium and appropriate supportive measures.

Gastrointestinal decontamination of the poisoned patient

Gastrointestinal decontamination has been a historically accepted modality in the emergency management of oral intoxicants. Theoretically, gastric and whole-bowel emptying procedures hinder absorption, remove toxic substances, prevent clinical deterioration, and hasten recovery. This article presents a current overview of gastrointestinal decontamination. It challenges the accepted precepts of gut decontamination and assesses the utility of syrup of ipecac-induced emesis, orogastric lavage, single-dose-activated charcoal, cathartics, and whole-bowel irrigation.

Multiple-dose activated charcoal in acute self-poisoning: a randomised controlled trial

BACKGROUND

The case-fatality for intentional self-poisoning in the rural developing world is 10-50-fold higher than that in industrialised countries, mostly because of the use of highly toxic pesticides and plants. We therefore aimed to assess whether routine treatment with multiple-dose activated charcoal, to interrupt enterovascular or enterohepatic circulations, offers benefit compared with no charcoal in such an environment.

METHODS

We did an open-label, parallel group, randomised, controlled trial of six 50 g doses of activated charcoal at 4-h intervals versus no charcoal versus one 50 g dose of activated charcoal in three Sri Lankan hospitals. 4632 patients were randomised to receive no charcoal (n=1554), one dose of charcoal (n=1545), or six doses of charcoal (n=1533); outcomes were available for 4629 patients. 2338 (51%) individuals had ingested pesticides, whereas 1647 (36%) had ingested yellow oleander (Thevetia peruviana) seeds. Mortality was the primary outcome measure. Analysis was by intention to treat. The trial is registered with controlled-trials.com as ISRCTN02920054.

FINDINGS

Mortality did not differ between the groups. 97 (6.3%) of 1531 participants in the multiple-dose group died, compared with 105 (6.8%) of 1554 in the no charcoal group (adjusted odds ratio 0.96, 95% CI 0.70-1.33). No differences were noted for patients who took particular poisons, were severely ill on admission, or who presented early.

INTERPRETATION

We cannot recommend the routine use of multiple-dose activated charcoal in rural Asia Pacific; although further studies of early charcoal administration might be useful, effective affordable treatments are urgently needed.

The hazards of gastric lavage for intentional self-poisoning in a resource poor location

OBJECTIVE

The 10-20% case fatality found with self-poisoning in the developing world differs markedly from the 0.5% found in the West. This may explain in part why the recent movement away from the use of gastric lavage in the West has not been followed in the developing world. After noting probable harm from gastric lavage in Sri Lanka, we performed an observational study to determine how lavage is routinely performed and the frequency of complications.

CASE SERIES

Fourteen consecutive gastric lavages were observed in four hospitals. Lavage was given to patients unable or unwilling to undergo forced emesis, regardless of whether they gave consent or the time elapsed since ingestion. It was also given to patients who had taken non-lethal ingestions. The airway was rarely protected in patients with reduced consciousness, large volumes of fluid were given for each cycle (200 to more than 1000 ml), and monitoring was not used. Serious complications likely to be due to the lavage were observed, including cardiac arrest and probable aspiration of fluid. Health care workers perceived lavage as being highly effective and often life-saving; there was peer and relative pressure to perform lavage in self-poisoned patients.

CONCLUSIONS

Gastric lavage as performed for highly toxic poisons in a resource-poor location is hazardous. In the absence of evidence for patient benefit from lavage, (and in agreement with some local guidelines), we believe that lavage should be considered for few patients - in those who have recently taken a potentially fatal dose of a poison, and who either give their verbal consent for the procedure or are sedated and intubated. Ideally, a randomized controlled trial should be performed to determine the balance of risks and benefits of safely performed gastric lavage in this patient population.

The hospital management of fatal self-poisoning in industrialized countries: an opportunity for suicide prevention?

Suicide by self-poisoning is a prevalent cause of death worldwide. A substantial proportion of individuals who poison themselves come into contact with medical services before they die. Our focus in the current study was the medical management of drug self-poisoning in industrialized countries and its possible contribution to suicide prevention. We reviewed the literature to determine the proportion of self-poisoning suicides who reach hospital alive, the sociodemographic and clinical characteristics of in-hospital overdose deaths, the in-hospital management this group of patients receives, and whether there are specific aspects of pre-hospital care and in-hospital management that have the potential to improve survival. Between 11% and 28% of individuals who died following deliberate ingestion of drugs reached hospital alive. The substances which were most frequently implicated in death were paracetamol (acetaminophen) and paracetamol compounds, tricyclic antidepressants, and benzodiazepines. Most patients received fairly intensive treatment, yet death may have been preventable in a small proportion of cases. Only one intervention (the administration of acetylcysteine) was shown to reduce mortality and this was in a highly selected group of patients (those who had ingested paracetamol and developed fulminant hepatic failure). It is possible that other interventions such as better airway management, the prompt administration of activated charcoal, and improved pre-hospital care may improve outcomes but their potential contribution to suicide prevention needs to be investigated in future studies.

Single‐Dose Activated Charcoal‐Backup and Reassess

Single-dose activated charcoal (SDAC) is frequently administered to poisoned patients. The assumption is that toxin absorption is prevented and that toxicity (as defined by morbidity and mortality) of the poisoning is decreased. Yet there is no evidence that SDAC improves outcome. Risks of this procedure have not been determined. The reported adverse events following SDAC administration are reviewed and risk:benefit ratio for this procedure is discussed.

Eficacia y seguridad de la descontaminación digestiva en la intoxicación medicamentosa aguda

BACKGROUND AND OBJECTIVE

Gut decontamination (GD) may be used as a treatment for acute therapeutic drug overdose (ATDO) to reduce the absorption of the drug and thereby avoid the presence or worsening of signs and symptoms of intoxication. The objective of this study was to assess the efficacy and safety of GD in ATDO patients.

PATIENTS AND METHOD

A 4-month prospective observational study was designed to include all patients admitted to the emergency department due to an ATDO. On admission, epidemiological data, vital signs and physical examination results were all recorded and a blood sample was taken for toxicological analysis. An algorithm was used to determine the GD method to be applied. A clinical reassessment was made at 3-6 hours and a further sample was taken for toxicological analysis. Patients were followed until hospital discharge, with all possible adverse events due to GD being recorded.

RESULTS

Ninety-four patients were included. GD was indicated in 60 patients (63.8%): 3.3% received ipecacuana syrup, 8.3% gastric lavage, 21.6% gastric lavage followed by activated charcoal and 71.6% oral activated charcoal alone. The clinical state worsened in 19.1% of patients, usually on the basis of a diminished consciousness. Adverse events attributable to GD were observed in 8.3% of patients. A toxicological analysis was made in 50 patients and in 42% of them, drug concentrations were higher at 3 or 6 hours than on admission. An analysis of the method of decontamination used showed that the procedure recommended by the algorithm was applied in 70 patients (group A) while in the remaining 24 (group B) another decontamination technique was used. Clinical deterioration was seen in 14.3% of patients in group A and 33.3% in group B (p = 0.041). There was a favourable evolution of the analytic curve in 63.9% patients in group A and 42.9% in group B (p = NS); severe adverse events attributable to GD were suffered by 2.4% patients in group A and 11.1% in group B (p = NS).

CONCLUSIONS

The efficacy and safety of GD in ATDO increases in patients in whom the decision-making algorithm is applied. However, this does not prevent clinical deterioration or continued drug absorption in all cases and may be accompanied by adverse events.

Does gastric lavage really push poisons beyond the pylorus? A systematic review of the evidence

Classically, treatment of acute self-poisoning involves resuscitation and supportive care, followed by gastric emptying, administration of activated charcoal, and use of specific antidotes. Recently, however, the practice of gastric emptying has fallen out of favor in the West because physicians have recognized its complications and the lack of evidence for clinical benefit from its practice. Authoritative position statements have stated that forced emesis should not be used and that gastric lavage should be used in restricted settings. One commonly cited complication of gastric lavage is propulsion of poison beyond the pyloric sphincter into the small bowel. We have carried out a systematic search for studies addressing this issue and found only 2. The first, a randomized controlled trial of patients presenting to an emergency department, reported propulsion of poison into the small bowel and has been widely cited as showing evidence for such a complication. However, analysis of the data presented in this article shows no significant difference in the number of radio-opaque marker pellets present in the small bowel after gastric lavage, ipecac-induced forced emesis, or no intervention. The second, an observational study using human volunteers, showed significantly less poison in the small bowel after gastric lavage than after no intervention. In conclusion, it seems that no published data support the statement that gastric lavage forces poison into the small bowel.

Efficacy of superactivated charcoal administered late (3 hours) after acetaminophen overdose

The purpose of this study was to investigate the effect of superactivated charcoal (SAC) given late after a drug overdose. Acetaminophen was chosen as our overdose drug because it has relatively few side effects, serum levels are easily attainable and measurable, and it is generally a common drug overdose. Forty-six healthy adult volunteers participated in this randomized, controlled study. Acetaminophen was administered the morning after an overnight fast. Thirteen participants received 2000 mg acetaminophen and the remaining 33 received 3000 mg. After 3 hours, half of the participants (22 of 46) received 75 g of SAC (Requa, Greenwich, CT) orally as a slurry in 8 oz of apple juice. Serum acetaminophen levels were measured at 4 and 7 hours after the initial acetaminophen administration. There were significantly lower uncorrected and corrected acetaminophen levels in the SAC group compared with the control group at both 4 and 7 hours after ingesting acetaminophen. This randomized human experimental design trial demonstrates some detoxification benefit in administering superactivated charcoal 3 hours after an overdose.

Activated charcoal: the untold story

Introduction. To identify the prevalence and appropriateness of prescribing activated charcoal in the management of acute poisoning and to document patient compliance with treatment.Methods. A prospective study was conducted, between October 1998 and September 1999, on patients attending our accident and emergency department, with a history of overdose. Overdoses were classified as potentially toxic or non-toxic according to the history and/or information received from the National Poisons Information Service.Results. Two hundred and seventy five patients presented following overdose; 17% within one hour, 102 were prescribed charcoal (37.1%) but of these, 40 (39%) refused it, and of the 62 patients (61%) who accepted charcoal only 15 (24.2%) took all that was prescribed. Patients were 5.4 times more likely to take charcoal if they had taken a potentially toxic overdose. Of those who presented within one hour and were judged to have taken a potentially toxic overdose, only three patients took the full-prescribed amount.Conclusion. We report a substantially greater proportion of patients (39%) refusing charcoal than previously reported (9.9%). The widespread availability of TOXBASE Copyright should help redress this discrepancy.

Assessment and management of acute poisoning by petroleum products

Petroleum products are highly complex chemical mixtures consisting predominantly of hydrocarbons. Their composition varies with source and intended use of the product. Virtually all are blended products that come into contact with man in a wide range of circumstances. Their toxicity for man is generally low and the use of additives rarely affects the toxicity of the final product. Because products are blended to meet performance, and not chemical specifications, their composition varies significantly. Management of toxicity benefits from simplified guidelines that consider the product by its type. Management in most cases is symptomatic, but the doctor needs to be aware of the potential for development of sequelae such as aspiration pneumonia and central nervous system (CNS) depression. Local and systemic effects of exposure to hydrocarbons are reviewed, as are immediate assessment and recommended management of acute exposure to petroleum products. Because of the large scope of this subject, this paper limits itself to acute toxicity of petroleum products encountered inthe public domain. It does not address topics such as chronic toxicity, solvent abuse, petrochemicals, or pesticides.

The first line of response for people who self-poison: exploring the options for gut decontamination

The trend for increasing numbers of self-poisoning incidents has been noted and a variety of policy initiatives have been launched. Nurses, particularly in emergency room environments occupy a pivotal place in the chain of response to such acts. Any such response needs to be firmly rooted in evidence-based practice yet the initial management of self-poisoning often involves a consideration of procedures, the application of which can vary enormously. This paper offers some contextual information prior to a critical perspective of management modes, namely emesis, lavage, the use of activated charcoal and whole bowel irrigation. A comparison of the relative advantages and disadvantages of each mode precedes suggestions for nursing practice.

Rheumatoid Arthritis: Pathophysiology

This article reviews the incidence, etiology, and pathophysiology of rheumatoid arthritis (RA), along with signs and symptoms, laboratory, and other diagnostic parameters of the disease. Criteria utilized for defining RA are discussed. While the primary cause is unknown, theories implicate genetic, hormonal, viral, bacterial, autoimmune, atmospheric, and environmental factors. Recent studies focus on the role of immune complexes, endothelial cells, and antibodies in the disease process.

Effect of activated charcoal alone or given after gastric lavage in reducing the absorption of diazepam, ibuprofen and citalopram

AIMS

The efficacy of activated charcoal alone, and gastric lavage followed by charcoal in reducing the absorption of diazepam, ibuprofen and citalopram was studied in healthy volunteers.

METHODS

In a randomized cross-over study with three phases, nine healthy volunteers were administered single oral doses of 5 mg diazepam, 400 mg ibuprofen and 20 mg citalopram, taken simultaneously after an overnight fast. Thirty minutes later, the subjects were assigned to one of the following treatments: 200 ml water (control), 25 g activated charcoal as a suspension in 200 ml water or gastric lavage followed by 25 g charcoal in suspension given through the lavage tube. Plasma concentrations of diazepam, ibuprofen and citalopram were determined up to 10 h.

RESULTS

The AUC(0,10 h) of diazepam was reduced by 27% (P<0.05) by both charcoal alone and charcoal combined with lavage. The increase in plasma diazepam concentration from 0.5 h onwards was prevented by both interventions (P</=0.05), whereas the Cmax of diazepam was not significantly affected by either treatment. The AUC(0, 10 h) of ibuprofen was reduced by 49% (P<0.05) after the combination treatment and by 30% (P<0.05) after charcoal alone, but there was no significant difference between these two treatments. Both charcoal alone and the combination treatment were equally effective in preventing the increase in plasma ibuprofen from 0.5 h onwards (P<0.01). The Cmax of ibuprofen was reduced by 45% (P<0.05) and by 21% (P=NS), respectively. The AUC(0,10 h) of citalopram was reduced by 51% (P<0.05) after both charcoal alone and charcoal combined with lavage, and the Cmax by 52% (P<0.05) and 54% (P<0.05), respectively. The increase in plasma citalopram concentration from 0.5 h onwards was reduced by about 50% (P<0.01) by both interventions.

CONCLUSIONS

Activated charcoal alone and charcoal combined with lavage showed similar efficacy in preventing the absorption of diazepam, ibuprofen and citalopram. These results suggest that gastric lavage needs not be routinely performed before administration of charcoal.

Drugs used in acquaintance rape

OBJECTIVE

To describe gamma-hydroxybutyrate (GHB), flunitrazepam, and ketamine and their purported uses to facilitate acquaintance rape. Patient presentation characteristics, treatment regimens, processes to detect the presence of the medications by toxicology screening, and methods to avoid exposure are discussed.

DATA SOURCES

MEDLINE search from 1985 to 1998; additional references found within the articles; information obtained from the Internet.

STUDY SELECTION

Clinical trials, reviews, and press releases concerning the use of GHB, flunitrazepam, and ketamine to facilitate acquaintance rape. Trials and reviews describing clinical effects, adverse effects, pharmacokinetics/pharmacodynamics, and usage trends were evaluated. Literature judged to be pertinent by the author was included in the discussion. DATA EXTRACTION/DATA SYNTHESIS: Reports of the use of GHB, flunitrazepam, and ketamine in acquaintance rape appear in the medical literature and lay press. Many health care professionals may not be familiar with these medications, and information about caring for patients under their influence is limited. Victims lose their ability to ward off attackers, develop amnesia, and are unreliable witnesses. Because symptoms caused by these agents mimic those of alcohol, not all victims are screened for their presence. Legislative efforts to further limit the use of or access to GHB, flunitrazepam, and ketamine have been initiated at the state and federal levels. Pharmacists should know the symptoms of exposure to the three agents; they should understand treatment regimens, methods to detect the presence of these and other drugs that may have been used in a sexual assault, and techniques individuals can use to avoid becoming victims of drug-assisted acquaintance rape.

CONCLUSION

Because of their extensive drug knowledge and frequent access to patients, pharmacists are uniquely positioned to educate patients and other health care professionals about the dangers of acquaintance rape drugs and methods to reduce their risk of becoming victims.

Epidemic of self-poisoning with seeds of the yellow oleander tree (Thevetia peruviana) in northern Sri Lanka

Deliberate self-harm is an important problem in the developing world. Ingestion of yellow oleander seeds (Thevetia peruviana) has recently become a popular method of self-harm in northern Sri Lanka -- there are now thousands of cases each year. These seeds contain cardiac glycosides that cause vomiting, dizziness, and cardiac dysrhythmias such as conduction block affecting the sinus and AV nodes. This paper reports a study of the condition's mortality and morbidity conducted in 1995 in Anuradhapura General Hospital, a secondary referral centre serving 750 000 people in Sri Lanka's north central province. 415 cases were admitted to the hospital during 11 months; 61% were women and 46% were less than 21 years old. A prospective study of 79 patients showed that 6% died soon after admission. 43% presented with marked cardiac dysrhythmias which necessitated ther transfer to the coronary care unit in Colombo for prophylactic temporary cardiac pacing. The reasons for the acts of self-harm were often relatively trivial, particularly in children; most denied that they wished to die. Unfortunately, the case fatality rate for oleander poisoning in Sri Lanka is at least 10%. This epidemic is not only causing many unnecessary deaths, it is also putting immense stress on the already stretched Sri Lankan health services. There is an urgent need for an intervention which could be used in rural hospitals, thus preventing the hazardous and expensive emergency transfer of patients to the capital.

Prospective single blinded randomised controlled trial of two orally administered activated charcoal preparations

OBJECTIVES

To compare two activated charcoal preparations (Carbomix and Actidose-Aqua) in terms of amount ingested and incidence of vomiting after ingestion.

METHODS

Single blinded prospective randomised controlled trial.

RESULTS

The mean amount of charcoal ingested was Carbomix 26.5 g, Actidose-Aqua 19.5 g. The mean difference was 7 g (95% confidence interval (CI) 1.5 to 12.4 g). The incidence of vomiting was for the Carbomix 6% and the Actidose-Aqua 8%. The mean difference in vomiting was 2% (95% CI -0.8 to 4.8)

CONCLUSIONS

Carbomix administration results in an increased amount of activated charcoal ingested after oral administration. Rates of vomiting after activated charcoal administration were low when compared with previously reported rates.