Do poison center triage guidelines affect healthcare facility referrals?

BACKGROUND: The purpose of this study was to determine the extent to which poison center triage guidelines influence healthcare facility referral rates for acute, unintentional acetaminophen-only poisoning and acute, unintentional adult formulation iron poisoning. METHODS: Managers of US poison centers were interviewed by telephone to determine their center's triage threshold value (mg/kg) for acute iron and acute acetaminophen poisoning in 1997. Triage threshold values and healthcare facility referral rates were fit to a univariate logistic regression model for acetaminophen and iron using maximum likelihood estimation. RESULTS: Triage threshold values ranged from 120-201 mg/kg (acetaminophen) and 16-61 mg/kg (iron). Referral rates ranged from 3.1% to 24% (acetaminophen) and 3.7% to 46.7% (iron). There was a statistically significant inverse relationship between the triage value and the referral rate for acetaminophen (p < 0.001) and iron (p = 0.0013). The model explained 31.7% of the referral variation for acetaminophen but only 4.1% of the variation for iron. CONCLUSION: There is great variability in poison center triage values and referral rates for iron and acetaminophen poisoning. Guidelines can account for a meaningful proportion of referral variation. Their influence appears to be substance dependent. These data suggest that efforts to determine and utilize the highest, safe, triage threshold value could substantially decrease healthcare costs for poisonings as long as patient medical outcomes are not compromised.

Out-of-hospital and interhospital management of crotaline snakebite.

Despite insufficient data for the development of evidence-based guidelines for the out-of-hospital treatment of crotaline snake envenomation, practical concerns dictate a rational approach based on existing information. Out-of-hospital care should focus on stabilization and rapid transport of the victim to a health care facility with the capability of antivenom administration. However, the out-of-hospital interval provides for the evaluation and management of the patients with snakebite. Out-of-hospital providers must be familiar with common first-aid techniques and be aware of their potential complications. Proven measures to slow systemic absorption are limited but should include immobilization of the bitten extremity in a neutral position in every case, and the patient should maintain strict bed rest. Constriction bands or pressure wraps placed on the wound at the scene and without vascular compromise should be left in place until arrival at a health care facility. Placement of a constriction band or pressure wrap (to delay systemic absorption of venom) can be considered for prolonged transport times or when the patient's condition is deteriorating. A suction device, if applied and functioning, should be left in place. Vital signs should be closely monitored to assess for hypotension as a sign of systemic toxicity. The extent of local swelling should be documented, and information regarding extent and progression of the envenomation syndrome should be relayed to the receiving hospital to expedite antivenom administration, if indicated. During interhospital transport of patients who have received or continue to receive antivenom, the patient should be monitored for allergic reactions to treatment and treated appropriately. Routine stocking of the existing horse serum antivenom product on ambulances is not recommended because of the extended length of time required to prepare the infusion and potential allergic complications. Antivenoms with improved side effect profiles may be better suited to use in the out-of-hospital setting in well-defined cases.

Acute elevation of blood lead levels within hours of ingestion of large quantities of lead shot.

BACKGROUND: Ingestion of elemental lead foreign bodies is felt to have a low risk of clinically significant lead absorption unless gastrointestinal pathology and/or prolonged transit time are present. We present a case of ingestion of a large quantity of small diameter lead shot accompanied by rapid elevation of blood lead levels. CASE REPORT: A 5 1/2-year-old previously healthy girl was found eating the pellets from an ankle weight. She vomited and complained of abdominal pain. In the emergency department, she had no complaints and normal vital signs. An abdominal X-ray showed thousands of small, round, metallic density objects in the stomach. Her white blood cell count was 14,700/mm3, and the hemoglobin, mean corpuscular volume, free erythrocyte protoporphyrin, zinc protoporphyrin, biochemistry panel 21, and urinalysis were normal. She had no prior lead level for comparison. Whole-bowel irrigation was begun and she passed over 11 stools with pellets as well as other foreign bodies (erasers, bead, etc.) in the first 24 hours. Pellets were still seen on X-ray the following day so she received a high-fiber diet and bisacodyl tablets 10 mg/d. On hospital day 2, her admission blood lead (drawn 13 hours after ingestion) was reported as 57 microg/dL (2.7 microm/L) and chelation was begun with oral 2,3-dimercaptosuccinic acid 10 mg/kg 3x/d for 5 days, then 2x/d for 14 days. Her peak measured lead level was 79 microg/dL approximately 36 hours after ingestion. She excreted 2,273 microg lead in the urine during her first 24 hours of chelation. Her blood lead dropped to 14.3 microg/dL by the end of chelation. She did not develop any apparent signs of lead poisoning. CONCLUSION: Acute elevations of blood lead concentrations may occur rapidly after ingestion of multiple small elemental lead objects.

Does transportation by ambulance decrease time to gastrointestinal decontamination after overdose?

STUDY OBJECTIVE: Because the ability of gastrointestinal decontamination to alter drug absorption varies inversely with time, we compared the time from arrival in the emergency department to gastrointestinal decontamination (gastric lavage or activated charcoal) for patients transported by ambulance with patients transported by other means after overdose. METHODS: A retrospective chart review was conducted in an academic university ED with an annual volume of 56,000 visits. Consecutive cases of oral overdose treated by gastrointestinal decontamination between December 1, 1995, and May 31, 1996, were identified from International Classification of Diseases, ninth revision, billing codes. ED charts were reviewed to determine the patient's age, sex, mode of transportation, disposition, and time interval to gastrointestinal decontamination with either gastric lavage or activated charcoal. RESULTS: Two hundred eighty-one patient visits were identified. Complete data were available for 173 visits. Six patients were excluded because the diagnosis of overdose was not made on presentation, leaving 167 cases for analysis. The median age for all patients was 27 years; 95 (57%) were female. Overdose patients were transported by ambulance in 105 (67%) cases. Admission rates were similar for patients transported by ambulance and those who arrived by other means. The median interval from arrival to any gastrointestinal decontamination (lavage or charcoal) for patients transported by ambulance was shorter than patients who arrived by other means at 55 and 73 minutes, respectively (95% confidence interval for difference 2.5 to 30.5 minutes, P =.03). Subgroup analysis showed this difference was largely the result of gastric lavage. CONCLUSION: Overdose patients transported by ambulance have a shorter time interval from ED arrival to gastrointestinal decontamination than patients arriving by other means. This difference was largely related to more rapid gastric lavage.

Transdermal kinetics of a mercurous chloride beauty cream: an in vitro human skin analysis.

BACKGROUND: Crema de Belleza-Manning is a popular mercurous chloride-containing beauty cream used to smooth and lighten the complexion and treat acne. Hundreds of people in the Southwestern US border states have been identified with elevated (>20 microg/L) urine mercury levels believed to be secondary to using this cream. The kinetic characteristics of percutaneous mercury absorption are incompletely defined. The objective of this study was to determine the transdermal kinetics of two formulations of mercurous chloride from a beauty cream in an in vitro human skin model. METHODS: A proprietary formulation and an aqueous formulation of the beauty cream were studied using modified Franz diffusion cells. Mercury content in the skin samples and the underlying diffusion buffer was determined using atomic absorption spectrophotometry. RESULTS: A rapid initial increase in mercury content both in the skin and the buffer was noted for both formulations. Mercury concentrations in the aqueous samples were significantly (p < 0.05) higher in both the skin and the diffusion buffer compared to parallel samples containing glycerol. CONCLUSIONS: Mercury was readily absorbed through the skin in this in vitro human skin model. The aqueous preparation had a markedly increased rate and extent of mercury absorption relative to the proprietary formulation.

Butoxyethanol ingestion with prolonged hyperchloremic metabolic acidosis treated with ethanol therapy.

BACKGROUND: Severe toxic ingestions of butoxyethanol (CAS No. 111-76-2) are rare despite the prevalence of this glycol ether in products such as glass and surface cleaners. Manifestations of acute butoxyethanol toxicity include metabolic acidosis, hemolysis, hepatorenal dysfunction, and coma, but vary widely in reported cases. Furthermore, the optimal therapeutic approach is not yet established. Much of the toxicity of butoxyethanol has been ascribed to its aldehyde and acid metabolites which are similar to those produced by oxidative metabolism of methanol and ethylene glycol. Although the roles of alcohol dehydrogenase inhibition with ethanol or fomepizole and hemodialysis are clear in the case of toxic ingestions of methanol and ethylene glycol, they remain poorly defined for butoxyethanol poisoning. CASE REPORT: We report the case of a 51-year-old female who ingested up to 8 ounces of Sanford Expo White Board Cleaner (butoxyethanol and isopropanol). She developed prolonged hyperchloremic metabolic acidosis and mental status depression and was treated with ethanol therapy but not hemodialysis. This patient recovered without apparent sequelae. The kinetics of butoxyethanol metabolism in this case are described and the potential therapeutic options are discussed.

Toxicology cart for stocking sufficient supplies of poisoning antidotes.

Within a three-month period, the University of New Mexico Health Sciences Center (UNMHSC) encountered three toxicological emergencies in which antidotes were either unavailable or inadequately stocked. Patient A was a patient with ethylene glycol intoxication. The emergency department (ED) physician ordered a 10% ethanol infusion. The pharmacy staff was unable to locate the commercially available solution and had to compound the infusion, resulting in a delay in administration of the antidote. Patient B was a patient at an outside hospital with organophosphate exposure whose transfer to our ED was requested by the other hospital. The pharmacy staff was unable to locate the pralidoxime needed to treat this patient; therefore; the patient was not transferred. It was later discovered that the pralidoxime had been stored in a location inconsistent with the storage policy for this medication. Patient C was a patient with severe rattlesnake envenomation. The pharmacy staff could locate only half of the antivenin needed to treat this patient. In each of these three cases, it was necessary to compound the required medication or to obtain it from other local facilities. These cases underscore the need for pharmacies to stock adequate amounts of poisoning antidotes in one immediately accessible location. A similar problem with understocking of poisoning antidotes exists throughout the United States.

Elemental mercury in the appendix: an unusual complication of a Mexican-American folk remedy.

BACKGROUND: Ingestion of small amounts of elemental mercury is generally thought to be harmless. However, in 4 previously reported cases, ingested mercury became sequestered in the appendix, causing appendicitis in one. We present a case in which elemental mercury was administered as a Mexican-American folk remedy for abdominal pain and became sequestered in the appendix. CASE REPORT: A 10-year-old Hispanic male presented with 3 days of right-sided abdominal pain, diarrhea, fever, and malaise. On admission, his temperature was 41.5 degrees C and he had right abdominal tenderness. Urinalysis showed 3 WBCs, 9 RBCs, occasional bacteria, and 1+ protein. An abdominal CT scan suggested right focal pyelonephritis, but also showed multiple intraabdominal metallic densities. On further questioning, the family admitted giving him elemental mercury as a remedy for "empacho." He was treated with intravenous ampicillin/sulbactam and gentamicin for a focal pyelonephritis. Because of mercury remaining in the gastrointestinal tract, activated charcoal and sorbitol were given. By hospital day 3, mercury filled the appendix as shown by abdominal radiograph. He was placed in the left lateral decubitus position overnight, and by the next morning, the mercury partially emptied from the appendix. By hospital day 8, his symptoms had resolved and mercury was no longer seen in the appendix. There were only minimal increases in urine mercury levels (18 mg/L). At 5-month follow-up, he has remained asymptomatic.

Antacid-induced hypermagnesemia in a patient with normal renal function and bowel obstruction.

OBJECTIVE: To report a case of severe hypermagnesemia caused by magnesium hydroxide in a woman with normal renal function. CASE SUMMARY: A 42-year-old Hispanic woman with schizophrenia and bipolar affective disorder was transported from jail to the emergency department with confusion, abdominal pain, vomiting, and constipation. She had been treated in jail with magnesium hydroxide, ordered as milk of magnesia 30 mL po each night and Maalox 30 mL po three times daily. Additional medications included lithium carbonate 300 mg po three times daily, chlorpromazine 150 mg po three times daily, benztropine mesylate 1 mg po twice daily, and docusate sodium 100 mg po each morning. Her temperature was 35.1 degrees C, blood pressure 108/58 mm Hg, heart rate 112 beats/min, and respiratory rate 24 breaths/min. She would respond only briefly to voice or painful stimuli. Her abdomen was distended and diffusely tender. Laboratory tests included serum magnesium concentration 9.1 mEq/L (normal 1.3-2), blood urea nitrogen 16 mg/dL (8-22), creatinine 0.9 mg/dL (0.5-1.1), calcium 3.9 mEq/L (4.2-5.2), and lithium 1.0 mEq/L. A laparotomy was performed, and an adhesive band from a previous oophorectomy was found to be compressing the sigmoid colon. Hypermagnesemia, hypothermia, and hypotension continued in the intensive care unit. Despite successful treatment of the hypermagnesemia with calcium, intravenous fluids, and furosemide, the patient's cardiac rhythm degenerated into fatal, pulseless electrical activity on postoperative day 2. DISCUSSION: This case of severe hypermagnesemia from magnesium hydroxide ingestion illustrates many of the risk factors for hypermagnesemia in patients with normal renal function. People using magnesium-containing medications for relief of gastrointestinal distress may be at increased risk for hypermagnesemia. A brief review of magnesium physiology, clinical effects, and treatment is provided. Frequent use of the laboratory to identify hypermagnesemia is encouraged because it is often a clinically unexpected finding and responds well to early treatment.

Vitreous humor cocaine and metabolite concentrations: do postmortem specimens reflect blood levels at the time of death?

The interpretation of postmortem cocaine concentrations is made in an attempt to estimate drug concentrations present at the time of death and thus infer not only drug presence but drug toxicity. Previous data suggest that changes in postmortem blood cocaine concentrations over time are not predictable and interpretation of cocaine levels should be done with caution. However, these data come from autopsy case series where vital information, such as blood cocaine concentration at the time of death, dose and time since last use, and postmortem interval is often not known. The purpose of this study was to characterize postmortem changes in cocaine and metabolite concentrations relative to premortem concentrations over time at two anatomic sites: peripheral blood and vitreous humor, in a controlled, large animal model. Juvenile swine were given cocaine HCl 10 mg/kg as an IV bolus which resulted in seizures and wide complex tachycardia. Five minutes after cocaine administration, animals were euthanized. At time of death and eight hours postmortem, femoral venous blood and vitreous humor (VH) samples were obtained for quantitation of cocaine, benzoyl ecgonine (BE), and ecgonine methyl ester (EME) by GC/MS. There were no significant increases over time in mean femoral vein concentrations of cocaine or BE. However, a large interanimal variability in direction and magnitude of concentration changes was seen. Mean EME concentrations at the femoral site increased significantly over 8 hours (P < 0.03). Mean VH cocaine concentrations at time of death were significantly lower than corresponding blood concentrations (P < 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

Methamphetamine toxicity prevented by activated charcoal in a mouse model.

STUDY OBJECTIVE: To determine the effectiveness of activated charcoal in preventing toxicity from oral methamphetamine HCI. DESIGN: Randomized, prospective, nonblinded, controlled animal study. SETTING: Animal care facility. PARTICIPANTS: CD-1 male mice. INTERVENTIONS: Mice were given 100 mg/kg methamphetamine HCI (lethal dose 60) in water by oral gavage. Within 1 minute of methamphetamine administration, mice received either 1 g/kg activated charcoal or an equivalent volume of water as control. MEASUREMENTS AND MAIN RESULTS: Mice were observed for time to onset of symptoms (piloerection, agitation, and tremor) and mortality at 1, 24, and 48 hours. Activated charcoal delayed onset of symptoms (5.53 +/- 1.25 minutes versus 4.27 +/- 1.22 minutes, P < .002) and decreased mortality compared to controls at 1 hour (1 of 20 versus 10 of 20, P < .003) and 24 hours (five of 20 versus 12 of 20, P < .05). There was no difference between groups in mortality at 48 hours. CONCLUSION: A single dose of activated charcoal given after oral methamphetamine delayed onset of toxicity and decreased early mortality in mice. There was no effect on overall mortality.

Acute zinc chloride ingestion in a child: local and systemic effects.

A 16-month-old boy ingested liquid zinc chloride/ammonium chloride soldering flux. He developed severe local burns, metabolic acidosis, hepatic damage, hyperamylasemia, lethargy, and hypertension. Peak measured plasma zinc was 1,199 micrograms/dL. Because of persistent signs of systemic toxicity, he was chelated with dimercaprol (BAL) and EDTA. Although clinical improvement was noted coincident with the initiation of chelation, there was no apparent increase in urinary zinc excretion. Scarring in the gastric antrum necessitated an antrectomy. The child recovered without other apparent complications.

The preadministration of activated charcoal and aspirin absorption.

There is little information describing the effects of activated charcoal preadministration on drug absorption. This study was undertaken to determine the effect of activated charcoal preadministration at two different times on aspirin absorption. Fifteen volunteer subjects completed three study phases: 1) 975 mg aspirin alone, 2) 975 mg aspirin 30 min after 10 g activated charcoal, and 3) 975 mg aspirin 60 min after 10 g activated charcoal. Urine was collected for 48 h after the initiation of each study phase, and total aspirin recovery determined by HPLC. The aspirin recovery was 88.8% +/- 4.5% for the control phase, and 84.8% +/- 9.4% (Phase 1) and 85.8% +/- 12.6% (Phase 2) for the activated charcoal treatments (p > 0.05). These results suggest that activated charcoal administered 30 and 60 min prior to drug ingestion has little effect on drug absorption. Further studies of the effect of charcoal preadministration on the absorption of other drugs may provide useful information regarding factors important in determining activated charcoal efficacy.

Activated charcoal and acetylcysteine absorption: issues in interpreting pharmacokinetic data.

Studies determining the effects of activated charcoal on drug absorption frequently use area under the plasma drug concentration versus time curve or drug and metabolite recovery in the urine as endpoints. The considerations in using these endpoints is presented using studies that have evaluated the effects of activated charcoal on acetylcysteine absorption. Acetylcysteine's pharmacokinetics, quantitation of plasma concentrations, and the lack of an identifiable pharmacokinetic-pharmacodynamic relationship all contribute to the difficulties in determining whether activated charcoal inhibits the oral absorption of acetylcysteine, or alters acetylcysteine's efficacy in treating acetaminophen overdoses. The results of these studies should be interpreted cautiously, with consideration of internal and external study validity.