Marsha Ford

2012 Annual Report of the American Association of Poison Control Centers’ National Poison Data System (NPDS): 30th Annual Report

Abstract Background: This is the 30th Annual Report of the American Association of Poison Control Centers’ (AAPCC) National Poison Data System (NPDS). As of July 1, 2012, 57 of the nations poison centers (PCs) uploaded case data automatically to NPDS. The upload interval was 7.58 [6.30, 11.22] (median [25%, 75%]) min, creating a near real-time national exposure and information database and surveillance system. Methodology: We analyzed the case data tabulating specific indices from NPDS. The methodology was similar to that of previous years. Where changes were introduced, the differences are identified. Poison center cases with medical outcomes of death were evaluated by a team of 34 medical and clinical toxicologist reviewers using an ordinal scale of 1–6 to assess the Relative Contribution to Fatality (RCF) of the exposure to the death. Results: In 2012, 3,373,025 closed encounters were logged by NPDS: 2,275,141 human exposures, 66,440 animal exposures, 1,025,547 information calls, 5,679 human confirmed nonexposures, and 218 animal confirmed nonexposures. Total encounters showed a 6.9% decline from 2011, while healthcare facility (HCF) exposure calls increased by 1.2%. All information calls decreased by 14.8% and HCF information calls decreased by 1.7%, medication identification requests (Drug ID) decreased by 22.0%, and human exposures reported to US PCs decreased by 2.5%. Human exposures with less serious outcomes have decreased by 3.7% per year since 2008, while those with more serious outcomes (moderate, major, or death) have increased by 4.6% per year since 2000. The top five substance classes most frequently involved in all human exposures were analgesics (11.6%), cosmetics/personal care products (7.9%), household cleaning substances (7.2%), sedatives/hypnotics/antipsychotics (6.1%), and foreign bodies/toys/miscellaneous (4.1%). Analgesic exposures as a class increased the most rapidly (8,780 calls/year) over the last 12 years. The top five most common exposures in children aged 5 years or less were cosmetics/ personal care products (13.9%), analgesics (9.9%), household cleaning substances (9.7%), foreign bodies/toys/ miscellaneous (7.0%), and topical preparations (6.3%). Drug identification requests comprised 54.4% of all information calls. NPDS documented 2,937 human exposures resulting in death with 2,576 human fatalities judged related (RCF of 1-Undoubtedly responsible, 2-Probably responsible, or 3-Contributory). Conclusions: These data support the continued value of PC expertise and need for specialized medical toxicology information to manage the more severe exposures, despite a decrease in calls involving less severe exposures. Unintentional and intentional exposures continue to be a significant cause of morbidity and mortality in the US. The near real-time, always current status of NPDS represents a national public health resource to collect and monitor US exposure cases and information calls. The continuing mission of NPDS is to provide a nationwide infrastructure for public health surveillance for all types of exposures, public health event identification, resilience response, and situational awareness tracking. NPDS is a model system for the nation and global public health.

2013 Annual Report of the American Association of Poison Control Centers’ National Poison Data System (NPDS): 31st Annual Report

ABSTRACT Background: This is the 31st Annual Report of the American Association of Poison Control Centers’ (AAPCC) National Poison Data System (NPDS). As of January 1, 2013, 57 of the nations poison centers (PCs) uploaded case data automatically to NPDS. The upload interval was 8.08 [7.10, 11.63] (median [25%, 75%]) minutes, creating a near real-time national exposure and information database and surveillance system. Methodology: We analyzed the case data tabulating specific indices from NPDS. The methodology was similar to that of previous years. Where changes were introduced, the differences are identified. Poison center (PC) cases with medical outcomes of death were evaluated by a team of 38 medical and clinical toxicologist reviewers using an ordinal scale of 1–6 to assess the Relative Contribution to Fatality (RCF) of the exposure to the death. Results: In 2013, 3,060,122 closed encounters were logged by NPDS: 2,188,013 human exposures, 59,496 animal exposures, 806,347 information calls, 6,116 human-confirmed nonexposures, and 150 animal-confirmed nonexposures. Total encounters showed a 9.3% decline from 2012, while health care facility human exposure calls were essentially flat, decreasing by 0.1%.All information calls decreased 21.4% and health care facility (HCF) information calls decreased 8.5%, medication identification requests (drug ID) decreased 26.8%, and human exposures reported to US PCs decreased 3.8%. Human exposures with less serious outcomes have decreased 3.7% per year since 2008 while those with more serious outcomes (moderate, major or death) have increased by 4.7% per year since 2000. The top five substance classes most frequently involved in all human exposures were analgesics (11.5%), cosmetics/personal care products (7.7%), household cleaning substances (7.6%), sedatives/hypnotics/antipsychotics (5.9%), and antidepressants (4.2%). Sedative/hypnotics/antipsychotics exposures as a class increased most rapidly (2,559 calls/year) over the last 13 years for cases showing more serious outcomes. The top five most common exposures in children of 5 years or less were cosmetics/personal care products (13.8%), household cleaning substances (10.4%), analgesics (9.8%), foreign bodies/toys/miscellaneous (6.9%), and topical preparations (6.1%). Drug identification requests comprised 50.7% of all information calls. NPDS documented 2,477 human exposures resulting in death with 2,113 human fatalities judged related (RCF of 1, undoubtedly responsible; 2, probably responsible; or 3, contributory). Conclusions: These data support the continued value of PC expertise and need for specialized medical toxicology information to manage the more severe exposures, despite a decrease in calls involving less severe exposures. Unintentional and intentional exposures continue to be a significant cause of morbidity and mortality in the United States. The near real-time, always current status of NPDS represents a national public health resource to collect and monitor US exposure cases and information calls. The continuing mission of NPDS is to provide a nationwide infrastructure for public health surveillance for all types of exposures, public health event identification, resilience response and situational awareness tracking. NPDS is a model system for the nation and global public health.

Insulin-glucose as adjunctive therapy for severe calcium channel antagonist poisoning.

CASE REPORT This case series documents the clinical courses of 4 patients after verapamil overdose and 1 patient after amlodipine-atenolol overdose. All subjects had hypodynamic circulatory shock (hypotension, bradycardia, and acidosis) that was not adequately responsive to conventional treatment. After initiation of insulin-dextrose infusion, the hemodynamic status of all 5 patients stabilized and all patients survived. Plasma drug concentrations are reported for all cases and verapamil levels were extremely high in 2 patients (3710 ng/mL and 3980 ng/mL). However, because patients were not treated according to a standard protocol, each patient received variable other supportive measures and inotropic agents, and the infusion rates of insulin were variable among patients. This report provides preliminary evidence toward a larger trial of insulin-dextrose to treat hypodynamic shock from calcium channel blocker overdose.

Glycolate Kinetics and Hemodialysis Clearance in Ethylene Glycol Poisoning

OBJECTIVE Toxic manifestations following ethylene glycol exposure are due to accumulation of metabolites, particularly glycolate. We characterized glycolate elimination kinetics and dialysis properties in a series of ethylene glycol poisonings. METHODS Patients who ingested ethylene glycol and received fomepizole (4-methylpyrazole; 4-MP) +/- hemodialysis were prospectively evaluated. Serial blood samples for ethylene glycol, glycolate, pH, and bicarbonate were drawn to determine glycolate elimination rate, t1/2, and correlations between initial glycolate and initial markers of acidosis. Dialyzer inlet and outlet samples were obtained to measure hemodialysis glycolate clearance. Plasma ethylene glycol and glycolate were determined by gas chromatography. RESULTS Ten patients, mean age 49 years (range 28-73 years), presented a mean of 10.5 hours (range 3.5-21.5 hours) after ethylene glycol ingestion. Mean initial ethylene glycol was 18.5 mmol/L (range 0.8-62.2 mmol/L) (115 mg/dL; range 5-386 mg/dL) and glycolate was 17.0 mmol/L (range 10.0-23.7 mmol/L). Nine of 10 underwent hemodialysis. Nonhemodialysis (n = 4) elimination rate was 1.08 +/- 0.67 mmol/L/h (mean +/- SD) and t1/2 was 626 +/- 474 minutes. Elimination t1/2 during hemodialysis (n = 8) was 155 +/- 42 minutes. Hemodialysis clearance (n = 5) was 170 +/- 23 mL/min with flow rates 250-400 mL/min. Pearson correlation coefficients were: anion gap vs glycolate r2 = 0.65 (p = 0.005), bicarbonate vs glycolate r2 = 0.10 (NS) and pH vs glycolate r2 = 0.06 (NS). CONCLUSION Glycolate has a slow elimination rate and long half-life. Hemodialysis effectively clears glycolate. An increased anion gap correlates with the presence of glycolate. Hemodialysis is projected as useful for ethylene glycol-poisoned patients with anion gap acidosis and low ethylene glycol blood levels.

Formate Kinetics in Methanol Poisoning

Objective: We sought to describe the kinetics, dialysis clearance, and laboratory markers of formate (FA), the toxic metabolite of methanol (meOH). Methods: Data were obtained from a prospective, multicenter study of fomepizole±dialysis for methanol poisoning. Inclusion criteria confirmed methanol exposure or suspicion of exposure plus either acidemia or abnormal osmolar gap. Dialysis indications were [meOH]>50 mg/dL, pH<7.1, refractory acidosis, or visual toxicity. Serial plasma formate, methanol, pH, and electrolyte measurements were made. Formate was determined by gas chromatography. Endogenous and dialysis elimination half-lives were calculated as t1/2=0.693/Ke, with Ke (elimination constant) derived from the slope of log (FA) vs. time. Half-lives were compared with an unpaired Students t-test. Dialysis clearance was calculated using the Fick Principle. Pearson correlation analysis compared initial formate with initial pH, serum bicarbonate, and anion gap. Results: Eleven patients were treated in the study. Eight had detectable formate with mean [FA] of 15.1 mmol/L (range 0.5–34.8). Endogenous elimination half-life was 205±90 minutes. Elimination half-life during dialysis (n=5) was 150±37 minutes, which was not different (t=0.22; NS). The overall dialysis formate clearance rate was 223±25 mL/min. Correlation coefficients were: pH vs. formate r2=0.93; bicarbonate vs. formate r2=0.81; and anion gap vs. formate r2=0.76 (all p<0.05). Conclusions: Although dialysis clears formate, it did not significantly enhance endogenous elimination in our series of patients. Low pH, low bicarbonate, and elevated anion gap correlate independently with formate presence.

Ethylene Glycol Ingestion Resulting in Brainstem and Midbrain Dysfunction

Introduction: Ethylene glycol toxicity has produced central nervous system abnormalities including coma, cerebral edema, and cranial nerve dysfunction. Case Report: A 26-year-old male developed widespread brainstem and midbrain dysfunction with corresponding cranial computed tomography findings after ingesting ethylene glycol. The computed tomography scan which was obtained 3 days after ethylene glycol ingestion showed low density areas in the basal ganglia, thalami, midbrain, and upper pons. The neurologic findings in our patient reflected dysfunction of all the areas of hypodensity on the cranial computed tomography scan. A magnetic resonance imaging of the brain obtained 24 days after ingestion revealed bilateral putamen necrosis. The patients neurologic sequelae resolved over the following 4 months.

Severe puff adder (Bitis arietans) envenomation with coagulopathy

Background: The puff adder (Bitis arietans) is a highly toxic venomous snake that is responsible for a large proportion of the venomous snakebites in sub-Saharan Africa, where it is indigenous. Puff adder bites in North America result from snakes in captivity. Although thrombolytic enzymes are present in puff adder venom, significant coagulopathy has not been previously reported with a confirmed puff adder envenomation. Results: We report a serious puff adder envenomation to the finger, characterized by severe swelling, local tissue necrosis, hypotension, thrombocytopenia, severe coagulopathy, and hemorrhage. Fifteen vials of South Africa polyvalent antivenom were administered, beginning 4.5 hours post-envenomation, with step-wise improvement in hematological abnormalities. Other treatments included vasopressors, ventilatory support, leeches, transfusion, and eventual digit amputation. After a prolonged hospital course, the patient had a good outcome. Conclusions: Puff adder envenomation causes tissue necrosis, hypotension, coagulopathy, thrombocytopenia, and spontaneous bleeding. Severe coagulopathy may occur. Physicians treating severe cases should be prepared to administer at least 15 vials of antivenom if needed.

Acute intravaginal misoprostol toxicity with fetal demise

We report a case of an overdose with fetal demise from the intravaginal administration of misoprostol. A 25-yr-old gravid female self-administered 6000 micrograms misoprostol intravaginally and 600 micrograms orally. She rapidly developed shaking chills, abdominal and extremity cramping, emesis, and confusion. Hyperthermia and hypotension developed within 3.5 h after drug administration, with a temperature of 41.4 degrees C (106 degrees F). Ultrasound at 3.5 h after drug administration showed no fetal movement or heart motion. A nonviable fetus was delivered by emergent cesarean section. Treatment of the mother was supportive and included intravaginal decontamination and endotracheal intubation with neuroparalytic therapy to control agitation and hyperthermia. Recovery was complete within 15 h of drug administration.

Ingestion of an Unknown Alcohol

Abstract [Trummel J, Ford M, Austin P: Ingestion of an unknown alcohol. Ann Emerg Med March 1996;27:368-374.]

Classification tree methods for development of decision rules for botulism and cyanide poisoning

IntroductionIdentification of predictors of potential mass poisonings may increase the speed and accuracy with which patients are recognized, potentially reducing the number ultimately exposed and the degree to which they are affected. This analysis used a decision-tree method to sort such potential predictors.MethodsData from the Toxic Exposure Surveillance System were used to select cyanide and botulism cases from 1993 to 2005 for analysis. Cases of other poisonings from a single poison center were used as controls. After duplication was omitted and removal of cases from the control sample was completed, there remained 1,122 cyanide cases, 262 botulism cases, and 70,804 controls available for both analyses. Classification trees for each poisoning type were constructed, using 131 standardized clinical effects. These decision rules were compared with the current case surveillance definitions of one active poison center and the American Association of Poison Control Centers (AAPCC).ResultsThe botulism analysis produced a 4-item decision rule with Sensitivity (Se) of 68% and Specificity (Sp) of 90%. Use of the single poison center and AAPCC definitions produced Se of 19.5% and 16.8%, and Sp of 99.5% and 83.2%, respectively. The cyanide analysis produced a 9-item decision rule with Se of 74% and Sp of 77%. The single poison center and AAPCC case definitions produced Se of 10.2% and 8.6%, and Sp of 99.8% and 99.8%, respectively.ConclusionsThese results suggest the possibility of improved poisoning case surveillance sensitivity using classification trees. This method produced substantially higher sensitivities, but not specificities, for both cyanide and botulism. Despite limitations, these results show the potential of a classification-tree approach in the detection of poisoning events.