Journal of toxicology. Clinical toxicology最新文献

Ingestion of industrial-strength hydrogen peroxide is rare. Fatal outcomes have been reported with solutions of 35%. We report a six-year-old boy who unintentionally ingested an unknown quantity of hydrogen peroxide with a concentration of 60%. Upon admission to our Pediatric Intensive Care Unit he was intubated and received ventilatory assistance for 48h. Upper gastrointestinal endoscopy was performed soon after admission and laparoscopy was performed 24h later. Recovery was satisfactory, and the patient was discharged on day 18 with no evidence of pathological sequelae.

Background: Although it is a commonly held belief that the ingestion of drugs with an anticholinergic action would prolong the duration of time after drug ingestion for effective gastrointestinal decontamination, data are lacking to support this belief. The purpose of this study is to determine whether activated charcoal is more effective in the presence of concurrent anticholinergic activity.

Methods: A three-limbed randomized crossover study in 10 healthy volunteers was completed to determine the ability of a 50 g dose of activated charcoal to reduce the bioavailability of a simulated overdose of acetaminophen (12 x 325 mg tablets) in the presence and absence of a concurrently present anticholinergic drug, atropine (0.01 mg/kg I. M. administered 15 min prior to the acetaminophen ingestion).

Results: After the acetaminophen ingestion, median Cmax occurred at 1 h for all three exposures but was lower in the atropine-treated study arm (31+/-19 mg/L) than in the control or charcoal alone intervention arms (49+/-13 and 51+/-16 mg/L, respectively) (P<0.05). Compared to the control area under the serum concentration vs. time curve, a single dose of activated charcoal 1 h after drug ingestion reduced acetaminophen bioavailability by 20% (95% CI 4-36%) and by 47% (95% CI 35-59%) in the presence of atropine (P<0.05 atropine plus charcoal vs. charcoal alone).

Conclusions: Our data support the belief that activated charcoal is more effective in the presence of anticholinergic activity. Additional study is required to determine whether in patients with anticholinergic drug overdose, activated charcoal is effective at times beyond the recommendation for overdoses of drugs without this pharmacodynamic effect.

Objectives: To systematically review and summarize studies on the accuracy of ECG and tricyclic antidepressant (TCA) concentration as prognostic indicators of the risk of seizures, ventricular arrhythmia (VA) or death in patients with TCA overdose.

Methods: Articles were identified with MedLine and Cochrane register of controlled clinical trials searches and review of medical toxicology textbooks. Quality of the included studies was assessed. Pooled estimates of sensitivity, specificity, likelihood ratios and Summary Receiver Operating Characteristics (SROC) curves were generated.

Results: A total of 18 studies were included in the analysis. The pooled sensitivity (Se) and specificity (Sp) of the QRS for predicting seizures were 0.69 [95% CI 0.57-0.78] and 0.69 [95% CI 0.58-0.78] as compared to 0.75 [95% CI 0.61-0.85] and 0.72 [95% CI 0.61-0.81] for the TCA concentration. The Se and Sp of the QRS to predict VA were 0.79 [95% CI 0.58-0.91] and 0.46 [95% CI 0.35-0.59] compared to 0.78 [95% CI 0.56-0.90] and 0.57 [95% CI 0.46-0.67] for the TCA concentration. The Se and Sp of the QRS to predict death were 0.81 [95% CI 0.54-0.94] and 0.62 [95% CI 0.55-0.68] compared to 0.76 [95% CI 0.49-0.91] and 0.60 [95% CI 0.47-0.72] for the TCA concentration. Very few studies evaluated the accuracy of QTc, T 40 ms axis and the R/S ratio.

Conclusions: Overall, the studies suggested that the ECG and TCA concentration have similar but relatively poor performance for predicting complications, such as seizures, VA or death, associated with TCA overdose.

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.

Background: When Poisons Information, or Poisons Control Centers (PCC) give directive advice in response to general public calls it is usually assumed that the advice will be followed, but it is difficult to measure the actual compliance of callers to a PCC. Epidemiological data regarding the incidence of poisoning incidents (Toxicovigilance) often utilizes reports of calls to a PCC.

Methods: Retrospective review of advice given to all callers to the New Zealand National Poisons Centre (NZNPC) from a defined area for the calendar year 2001. Callers to the NZNPC telephone hotlines who were advised to attend or not to attend the hospital Emergency Department (ED) were subsequently matched with actual ED visits.

Results: The compliance rate for those advised to attend the ED was 76.1%, whereas those advised not to attend had a compliance rate of 98.7%. The overall compliance rate was 94.1%. Of the patients presenting to the ED with a potential poisoning, only 10.2% were referred by the PCC. The callers referred by PCC and direct ED visitors appeared to differ in some respects.

Conclusions: Compliance with PCC telephone advice is similar to the compliance rates in many other health interventions. Comparisons between populations calling a PCC and those self-presenting to an ED show that PCC data may not reflect the true burden of poisoning to health care systems.

Background: Approximately 35% of patients acutely poisoned with organophosphates (OP) in developing countries like Sri Lanka require intensive care and mechanical ventilation. However, death rates remain high.

Objective: To study the outcomes and predictors of mortality in patients with acute OP poisoning requiring intensive therapy at a regional center in Sri Lanka over a period of 40 months.

Methods: Retrospective analysis of all intensive care records of patients with acute OP poisoning admitted to the Intensive Care Unit (ICU) between March 1998 and July 2001.

Results: During the study period, 126 subjects were admitted to the ICU with acute OP poisoning. Records of 10 patients were lost and those of 37 were incomplete and hence were excluded. All the remaining 71 patients (59 male) had required endotracheal intubation and mechanical ventilation for a period of four (median) days (range 1-27) in addition to gastric lavage and standard therapy with atropine and oximes and adequate hydration. Of these 71 patients, 36 (28 male) had died. Life table analysis demonstrated a steep decline in the cumulative survival to 67% during the first three days. Systolic blood pressure of < 100 mmHg and FiO2 of >40% to maintain a SpO2 of >92% within the first 24 h were recognized as poor prognostic indicators among mechanically ventilated patients.

Conclusion: Mortality following OP poisoning remains high despite adequate respiratory support, intensive care, and specific therapy with atropine and oximes. One-third of the subjects needing mechanical ventilation and reaching intensive care units die within the first 72 h of poisoning. Systolic blood pressure of less than 100 mmHg and the necessity of a FiO2>40% to maintain adequate oxygenation are predictors of poor outcome in patients mechanically ventilated in the ICU.

Resorcinol (1,3 benzenediol; m-dihydroxybenzene: resorcin) is a pharmaceutical agent used topically in dermatological treatments such as acne and related skin conditions. It could also be used in combination with the other acne treatment agents such as sulphur. It could be very hazardous if taken orally and there are limited reports on its toxic effects in human. The present work aimed to report a resorcinol poisoning case in which resorcinol was taken accidentally by a woman at 30 weeks of pregnancy. The major clinical findings were unconsciousness, drowsiness, and respiratory failure that required mechanical ventilation along with tonic-clonic seizures and hypothermia. In addition, the laboratory findings were leucocytosis, high bilirubin levels, severe metabolic acidosis, and green-colored urine. The fetus was considered dead 24 h after delivery; however, mother's prognosis was well with supportive management. It could be concluded that the basic approach to the patient with resorcinol poisoning should include the initial stabilization of immediate life-threatening problems and elimination of the toxin. This is the first report on resorcinol poisoning in pregnant women, indicating its major clinical and laboratory findings.

Concretion formation is a documented complication of large iron ingestions. The generally accepted treatment is supportive care, whole bowel irrigation, and intravenous deferoxamine for systemic toxicity. Laparotomy and gastrotomy have also been used in patients with a high iron burden and bezoar formation. Though experiments suggest that iron is poorly absorbed in the colon, there are no case reports of iron overdose without systemic toxicity, despite a retained colonic bezoar. We report the case of a 16-month-old who presented to an Emergency Department 19 h after an iron ingestion. Initial laboratory studies revealed an anion gap of 14 mEq/L, and a 20 h serum iron concentration of 429 mcg/dL. An abdominal radiograph revealed multiple pills throughout the stomach and small bowel; whole bowel irrigation was initiated. Deferoxamine was administered at 10 mg/kg/h and then stopped when the serum iron level reached 27 mcg/dL, 36 h later. At this time, the abdominal radiograph showed an iron bezoar remaining in the ascending colon despite a clear rectal effluent from whole bowel irrigation. Despite whole bowel irrigation over the next 36 h, the iron bezoar was not removed and actually migrated proximally in the colon. Treatment was stopped on the third day and a normal diet was instituted with prompt passage of the bezoar.

Whole bowel irrigation (WBI) should not be used routinely in the management of the poisoned patient. Although some volunteer studies have shown substantial decreases in the bioavailability of ingested drugs, no controlled clinical trials have been performed and there is no conclusive evidence that WBI improves the outcome of the poisoned patient. Based on volunteer studies, WBI should be considered for potentially toxic ingestions of sustained-release or enteric-coated drugs particularly for those patients presenting greater than two hours after drug ingestion. WBI should be considered for patients who have ingested substantial amounts of iron as the morbidity is high and there is a lack of other options for gastrointestinal decontamination. The use of WBI for the removal of ingested packets of illicit drugs is also a potential indication. WBI is contraindicated in patients with bowel obstruction, perforation, ileus, and in patients with hemodynamic instability or compromised unprotected airways. WBI should be used cautiously in debilitated patients or in patients with medical conditions that may be further compromised by its use. The concurrent administration of activated charcoal and WBI may decrease the effectiveness of the charcoal. The clinical relevance of this interaction is uncertain. A review of the literature since the preparation of the 1997 Whole Bowel Irrigation Position Statement revealed no new evidence that would require a revision of the conclusions of the Statement.

Objective: The aim of the our study was to investigate the role of adenosine receptors on cardiovascular toxicity induced by amitriptyline, a tricyclic antidepressant agent. Therefore, the hypothesis of this study was that adenosine receptor antagonists would improve and/or prevent amitriptyline-induced hypotension and conduction abnormalities in an anesthetized rat model of amitriptyline intoxication.

Methods: Two separate experimental protocols were performed. Amitriptyline intoxication was induced by the infusion of amitriptyline 0.94 mg/kg/min until 40-45% reduction of mean arterial pressure (MAP). Sodium cromoglycate (10 mg/kg) was injected i.v. to inhibit the A3 receptor-mediated activation of mast cells. In protocol 1, after amitriptyline infusion, while control animals (n=8) were given dextrose solution, treatment groups received a selective adenosine A1 antagonist DPCPX (8-cyclopentyl-1,3-Dipropylxanthine, 20 microg/kg/min, n=8) or a selective A2a antagonist CSC (8-(3-chlorostyryl) caffeine, 24 microg/kg/min, n=8) for 60 minutes. In protocol 2, after the sodium cromoglycate, while control group of rats (n=8) recevied a dextrose solution, treatment groups of rats were administered DPCPX (20 microg/kg/min, n=8) or CSC (24 microg/kg/min, n=8) infusion to block adenosine A1 and A2a receptors for 20 minutes before amitriptyline infusion. After pretreatment with adenosine antagonists, all rats were given a dose of 0.94 mg/kg/min of amitriptyline infusion during 60 minutes. Outcome measures were mean arterial pressure (MAP), heart rate (HR), QRS duration and survival rate.

Results: In protocol 1, amitriptyline infusion significantly reduced MAP and prolonged QRS within 15 minutes. HR was not changed significantly during the experiments. While dextrose did not improve MAP and QRS prolongation, DPCPX or CSC administration developed a significant improvement in MAP compared to the dextrose group within 10 min (88.5 +/- 2.8%, 75.6 +/- 4.7% and 50.1 +/- 14.7%, p<0.01, p<0.05, respectively). Both DPCPX and CSC decreased QRS prolongation (p<0.05) and increased median survival time significantly (log-rank test, p<0.00001). In protocol 2, pretreatment with DPCPX or CSC prevented the reduction in MAP due to amitriptyline toxicity compared to rats administered dextrose infusion (99.5 +/- 2.6%, 102.4 +/- 2.6%, 81.8 +/- 5.4, p<0.01 at 30 min; 98.0 +/- 2.9%, 93.5 +/- 6.0%, 64.9 +/- 4.7, p<0.001, p<0.01 at 40 min, respectively). Pretreatment with DPCPX or CSC also prevented the QRS prolongation (p<0.05) and increased median survival time significantly (log-rank test, p<0.0001).

Conclusion: Adenosine antagonists were found to be effective in improving hypotension, QRS prolongation and survival time in our rat model of amitriptyline toxicity. Additionally, amitriptyline-induced cardiotoxicity was abolished by pretreatment with adenosine receptor antagonists. These results s