Richard F Clark

Publications of Richard F Clark

• Toxicology and Overdose of Atypical Antipsychotics.

  Authors: Alicia B Minns, Richard F Clark

  The Journal of emergency medicine. 05/2012;

  BACKGROUND: Second-generation antipsychotic medications, or "atypical antipsychotics," are now first-line therapy in the treatment of schizophrenia and other psychotic disorders, and are additionallyBACKGROUND: Second-generation antipsychotic medications, or "atypical antipsychotics," are now first-line therapy in the treatment of schizophrenia and other psychotic disorders, and are additionally being used in a wide array of other psychiatric and non-psychiatric conditions in both adults and children. Overdose is frequently reported to poison control centers. OBJECTIVES: We review the toxicology and general management of poisonings involving the atypical antipsychotic medications. DISCUSSION: The most serious toxicity involves the cardiovascular system and the central nervous system. All typical and atypical antipsychotics cause sedation, which is pronounced in overdose. The most common cardiovascular effects that occur after atypical antipsychotic overdose are tachycardia, mild hypotension, and prolongation of the QTc interval. Other clinical syndromes in overdose include neuroleptic malignant syndrome (NMS) and antimuscarinic delirium. Seizures may be observed. No antidotes exist for these poisonings, but they most often do well with supportive care. CONCLUSION: Antipsychotic overdose produces a gamut of manifestations that affect multiple organ systems. Treatment is primarily supportive. Specific therapies for NMS, hypotension, and seizures are discussed.

• Flumazenil Administration in Poisoned Pediatric Patients.

  Authors: Allyson A Kreshak, Christian A Tomaszewski, Richard F Clark, F Lee Cantrell

  Pediatric emergency care. 04/2012;

  OBJECTIVE: The goal of this retrospective cohort study of pediatric patients exposed to flumazenil was to identify the frequency of seizures. METHODS: Included patient were those aged 12 years orOBJECTIVE: The goal of this retrospective cohort study of pediatric patients exposed to flumazenil was to identify the frequency of seizures. METHODS: Included patient were those aged 12 years or younger who received flumazenil, who had evidence of clinical poisoning as defined by an altered mental status, and who were reported to the California Poison Control System for the period 1999 to 2008. Data variables were age, sex, seizure, death, acute exposure to a benzodiazepine, drugs of exposure, long-term use of benzodiazepines, history of a seizure disorder, mental status before flumazenil administration, and poison center recommendation of flumazenil (yes/no). RESULTS: Eighty-three patients were included. Forty-eight (58%) of this subset were female. Median age was 2 years (range, 3 months-12 years). Seventy (84%) patients were younger than 5 years. Of the 83 patients, 68 (82%) were allegedly exposed to a benzodiazepine; whereas, 12 (15%) had been allegedly exposed to a proconvulsant drug. No flumazenil-related seizures occurred (0% with 95% confidence interval, 0%-4%). The California Poison Control System recommended flumazenil use in 60 (72%) of the 83 cases, and 48 of these had been allegedly exposed to a benzodiazepine. CONCLUSIONS: No flumazenil-associated seizures occurred among allegedly benzodiazepine- and non-benzodiazepine-poisoned pediatric patients aged 12 years or younger.

• Energy Drink Use and Adverse Effects Among Emergency Department Patients.

  Authors: Sean Patrick Nordt, Gary M Vilke, Richard F Clark, F Lee Cantrell, Theodore C Chan, Melissa Galinato, Vincent Nguyen, Edward M Castillo

  Journal of community health. 02/2012;

  Energy drink usage is common and contains caffeine or other stimulants. We evaluated demographics, prevalence, reasons and adverse effects with consuming energy beverages. Cross-sectional study of aEnergy drink usage is common and contains caffeine or other stimulants. We evaluated demographics, prevalence, reasons and adverse effects with consuming energy beverages. Cross-sectional study of a convenience sample of patients recruited from two San Diego Emergency Departments from January to December 2009. One-thousand-two-hundred-ninety-eight subjects participated of which 52.6% were male. Ethnicity: Caucasian 48.3%, African American 17%, Hispanic 18%, Other 16.7%. Age ranges: 18-29 years (38.4%), 30-54 years (49.6%) and greater than 55 years (12%). Reasons for use: 57% to "increase energy", 9.5% for studying/work projects, 2.4% while prolonged driving, improve sports performance 2%, with ethanol 6.3%, "other" reasons 22.1%. Adverse reactions reported by 33.5% (429) patients. Two-hundred-eighty report feeling "shaky/jittery", insomnia 136, palpitations 150, gastrointestinal upset 82, headache 68, chest pain 39, and seizures in 6. Eighty-five patients reported co-ingestion with illicit "stimulants" including cocaine and methamphetamine. We identified one-third of patients reported at least one adverse effect. Whilst most were not severe, a small number were serious e.g., seizures. In addition, some report purposely ingesting with illicit drugs.

• Psychiatric implications of adolescent methamphetamine exposures.

  Authors: Jonathan D Auten, Michael J Matteucci, Micah J Gaspary, Daniel J Combs, Richard F Clark

  Pediatric emergency care. 12/2011; 28(1):26-9.

  Methamphetamine abuse has reached epidemic proportions during the last decade. Abuse among adolescents is linked to increased rates of depression and suicidal ideation. Sources suggest that there isMethamphetamine abuse has reached epidemic proportions during the last decade. Abuse among adolescents is linked to increased rates of depression and suicidal ideation. Sources suggest that there is an increase rate of suicide attempts in the methamphetamine-abusing adolescent patient population. Our study seeks to examine adolescent methamphetamine exposures reported to the California Poison Control System during the past decade of suicidal ideation and suicide attempts in comparison to rates reported by population-based surveys. The records of the California Poison Control System were searched for methamphetamine exposures from 2000 to 2009. All charts of patients identified between the ages of 11 and 18 years were reviewed and abstracted. The records of 293 youth between the ages of 11 and 18 years were identified and assigned levels of severity according to parameters set by the National Poison Data System Medical Outcome Criteria of the American Association of Poison Control Centers. Charts were categorized as follows: 11 as major, 52 as moderate, and 75 as minor. The remainder of the charts were not evaluated because of no effect (n = 13) or unable to follow (n = 142). In this cohort, more females were reported than males (57%). The most common presenting symptom in this patient population was agitation (39%). The most common events were suicidal ideation (31%) and suicide attempts (21%). In this data set, adolescent methamphetamine exposures were associated with increased rates of suicidal ideation and suicide attempts that are disproportionate to population-based surveys during the same period.

• Examination of adverse events following black widow antivenom use in California.

  Authors: Sean Patrick Nordt, Richard F Clark, Angie Lee, Kacie Berk, F Lee Cantrell

  Clinical toxicology (Philadelphia, Pa.). 12/2011; 50(1):70-3.

  Following widow spider (Latrodectus sp.) envenomation, local pain, erythema, abdominal pain, rigidity, hypertension, and diaphoresis can be seen. While an effective specific antivenom (AV) isFollowing widow spider (Latrodectus sp.) envenomation, local pain, erythema, abdominal pain, rigidity, hypertension, and diaphoresis can be seen. While an effective specific antivenom (AV) is available, its use is limited due to concern of possible severe allergic reaction. We performed the current study to determine rate of adverse effects and the efficacy of AV in patients treated for widow spider envenomation. Observational case series of the California Poison Control System electronic database from January 1999 to December 2009. All cases of widow spider envenomation treated with AV were included. Age, gender, signs, and symptoms, adjunctive therapy, number of vials of AV given, and adverse reaction to AV were recorded. Descriptive statistical methods were used. Ninety-six patients received AV, mean age 26 years (0.12-74 years), 76% male. Following widow spider envenomation generalized pain was reported in 91%, erythema at site in 57%, hypertension (≥ 140/90 mmHg) in 43%, muscle rigidity/cramping in 43%, abdominal pain in 41%, tachycardia (≥ 100 bpm) in 23% and diaphoresis in 21%. No patient required more than one vial of AV. One patient developed urticaria to AV halfway through infusion which was immediately discontinued. Another patient developed generalized flushing following completion of infusion but had no other effects. Two other patients reported myalgia and paresthesia. There were no deaths in any patients receiving AV. There was no shortness of breath or respiratory distress, no hypotension or chest pain following AV administration. All patients reported pain relief with AV and did not require additional AV doses. Our results suggest that Black Widow Spider Antivenin® (Merck) administration is relatively safe with mild to moderate adverse effects seen in only a small percentage of patients. There were no deaths, or severe allergic reactions identified. The retrospective use of poison control system data is a limitation of our study. Further prospective studies are needed to validate our findings and elucidate the full safety profile on this antivenom.

• Comparison of three aspirin formulations in human volunteers.

  Authors: Sean Patrick Nordt, Richard F Clark, Edward M Castillo, David A Guss

  The western journal of emergency medicine. 11/2011; 12(4):381-5.

  The treatment of acute coronary syndrome (ACS) includes the administration of aspirin. Current guidelines recommend chewing aspirin tablets to increase absorption. While this is intuitive, there areThe treatment of acute coronary syndrome (ACS) includes the administration of aspirin. Current guidelines recommend chewing aspirin tablets to increase absorption. While this is intuitive, there are scant data supporting this recommendation. The purpose of this study is to assess which of 3 different aspirin formulations is most rapidly absorbed after ingestion. A prospective, open-label, 3-way crossover volunteer study at a tertiary university medical center with human subjects 18 years or older. Fasted subjects were randomly assigned to receive aspirin 1,950 mg as (1) solid aspirin tablets swallowed whole, (2) solid aspirin tablet chewed then swallowed, or (3) a chewable aspirin formulation chewed and swallowed. Serum salicylate measurements were obtained over a period of 180 minutes. Pharmacokinetic parameters were determined. Thirteen males and 1 female completed all 3 arms of study. Peak serum salicylate concentrations were seen at 180 minutes in all groups. Mean peaks were 10.4, 11.3, and 12.2 mg/dL in groups 1, 2, and 3, respectively. Mean area under the time concentration was 1,153, 1,401, and 1,743 mg-min/dL in groups 1, 2, and 3, respectively. No measurable salicylate concentrations were seen in 6 subjects in group 1 at 60 minutes as compared to 1 subject in group 2. All subjects in group 3 had measurable levels at 45 minutes. There were no adverse effects in any of the subjects during the study period. Our data demonstrate that the chewable aspirin formulation achieved the most rapid rate of absorption. In addition, the chewable formulation absorption was more complete than the other formulations at 180 minutes. These data suggest that in the treatment of ACS, a chewable aspirin formulation may be preferable to solid tablet aspirin, either chewed or swallowed.

• Severe hypermagnesemia after enteral administration of Epsom salts.

  Authors: Sean Patrick Nordt, Jenny Chen, Richard F Clark

  American journal of health-system pharmacy : AJHP : official journal of the American Society of Health-System Pharmacists. 08/2011; 68(15):1384-5.

• Mass sociogenic illness initially reported as carbon monoxide poisoning.

  Authors: Sean Patrick Nordt, Alicia Minns, Shaun Carstairs, Allyson Kreshak, Colleen Campbell, Christian Tomaszweski, Stephen R Hayden, Richard F Clark, Alfred Joshua, Binh T Ly

  The Journal of emergency medicine. 06/2011; 42(2):159-61.

  Mass sociogenic illness (MSI) is a rare occurrence involving a constellation of physical signs and symptoms in a group of individuals that are exhibited subconsciously and have no correspondingMass sociogenic illness (MSI) is a rare occurrence involving a constellation of physical signs and symptoms in a group of individuals that are exhibited subconsciously and have no corresponding organic etiology. To describe an outbreak of MSI initially attributed to carbon monoxide (CO) poisoning. While attending a church service, one child fainted, followed by another. This led to multiple individuals reporting a constellation of symptoms. A total of 22 individuals presented to emergency departments (EDs) with neurologic, gastrointestinal, and respiratory complaints. The onset of symptoms followed evacuation in most of these patients. Prehospital personnel obtained carboxyhemoglobin (COHb) levels with a portable oximeter device, identifying levels up to 19% in 6 patients; 17 were taken to a tertiary hospital with a hyperbaric oxygen chamber, and the other 5 to a local ED. All other attendees were asymptomatic. Within the 15-min transport time, all patients were asymptomatic and had normal physical examinations. The mean age of patients was 13 years; 7 were male and 10 were female. Venous blood gas identified normal COHb levels in all patients. Pulse oximetry in the ED was normal. Another handheld oximeter device in the ED found normal COHb and methemoglobin levels. Varying complaints with onset after removal from the church suggest MSI. The hazardous materials team reproduced the scenario and no toxic gases were detected. Escalation of symptoms and an increased number of persons being affected along with increasing ambulance presence are common in MSI. We suspect that field oximeter readings were either aberrant from an inexperienced operator or were false-positive COHb readings. Clinicians should consider MSI after mass outbreaks of illness, particularly with rapid onset, rapid resolution of symptoms, and normal physical examinations and laboratory analyses. However, the diagnosis of MSI should be entertained only after potential toxicologic etiologies have been excluded.

• Ultrasound visualization of ingested tablets: a pilot study.

  Authors: Sean Patrick Nordt, Colleen Campbell, Anthony Medak, Christian Tomaszweski, Richard F Clark

  Pharmacotherapy. 03/2011; 31(3):273-6.

  To evaluate the ability of ultrasonography as a radiographic technique to visualize ingested tablets in the human stomach. Prospective, ultrasonographer-blinded, pilot study. Tertiary care medicalTo evaluate the ability of ultrasonography as a radiographic technique to visualize ingested tablets in the human stomach. Prospective, ultrasonographer-blinded, pilot study. Tertiary care medical center. Fifteen healthy adults (12 male, 3 female; mean age 35.5 yrs). After fasting for at least 12 hours, subjects were randomized to either ingest a total of 10 tablets (four acetaminophen, four ibuprofen, and two multivitamin tablets) with 500 ml of water or to drink 500 ml of water alone (control group). Nine subjects were randomized to the group taking the tablets and six to the control group. Within 30 minutes after ingesting the tablets with water or the water alone, each subject underwent ultrasonography 2 times by two respective blinded ultrasonographers (emergency department physicians who were experienced with the ultrasound technique). Each performed the radiographic technique in isolation of the other ultrasonographer so as not to influence each other's interpretation. They recorded whether or not they thought tablets were visible. One ultrasonographer was correct for 14 (93%) of the 15 subjects, but the other ultrasonographer was correct for only 6 subjects (40%). Interobserver agreement was assessed, with no agreement found between the two ultrasonographers (Cohen κ coefficient -0.25 [95% confidence interval -0.7-0.2]). The ultrasonographers also found six false positives (no drugs present in the stomach but incorrectly identified as present by the ultrasonographer) and four false negatives (tablets present in the stomach but not identified by the ultrasonographer). Our results do not support the application of ultrasonography to determine the presence or absence of tablets in an individual's stomach after an acute poisonings. We did show that, similar to other radiologic techniques (e.g., projection radiography), the absence of tablet visualization does not exclude their presence. However, the ultrasonographers also found several false positives. Thus, further studies are needed with larger numbers of both subjects and ultrasonographers to elucidate the potential benefit of ultrasonography in individuals who experience acute poisoning.

• The treatment of black widow spider envenomation with antivenin latrodectus mactans: a case series.

  Authors: Steven R Offerman, G Patrick Daubert, Richard F Clark

  The Permanente journal. 01/2011; 15(3):76-81.

  Black widow spiders (Latrodectus mactans) are found throughout the US. Though bites are relatively uncommon, they pose a significant health problem with over 2500 reported to American poison controlBlack widow spiders (Latrodectus mactans) are found throughout the US. Though bites are relatively uncommon, they pose a significant health problem with over 2500 reported to American poison control centers annually. Black widow spider bites cause a characteristic envenomation syndrome consisting of severe pain, muscle cramping, abdominal pain, and back pain. The significant pain associated with envenomation is often refractory to traditional analgesics. Antivenom (Antivenin Latrodectus mactans) is available and effective, but is often withheld because of a fear of acute hypersensitivity reactions. We report four cases of symptomatic black widow spider envenomation. One of the reported cases was managed without antivenom, and, in contrast, three were treated successfully with Antivenin Latrodectus mactans. We believe that these cases demonstrate safe and effective use of black widow antivenom. This article presents the rationale for use of antivenom in these cases, and a nonsystematic review of the pertinent literature.

• Transient vision loss in a patient with metformin-associated lactic acidosis.

  Authors: Allyson A Kreshak, Richard F Clark

  The American journal of emergency medicine. 11/2010; 28(9):1059.e5-7.

• Electrocardiogram and echocardiogram findings in runners completing a half marathon.

  Authors: Alicia B Minns, Cameron McFarland, Monet Strachan, Wendy Austin, Edward Castillo, Ori Ben-Yehuda, Richard F Clark

  The American journal of emergency medicine. 10/2010; 29(9):1182-7.

  The purpose of this study was to prospectively evaluate electrocardiograms (ECGs) before and after running a half marathon to characterize the changes that occur after exertion. Echocardiograms wereThe purpose of this study was to prospectively evaluate electrocardiograms (ECGs) before and after running a half marathon to characterize the changes that occur after exertion. Echocardiograms were also done postrace on selected runners. Volunteer runners older than 18 years completed a questionnaire detailing demographic and medical history. Prerace ECGs were performed at a prerace symposium and postrace ECGs were performed within 15 minutes of the participants' completion of the race. Echocardiograms were performed on a random sampling of runners who were judged to have abnormal or changed postrace ECGs. Eighty-seven runners were enrolled and completed the study. There were 46 males (53%) and 41 females (47%). Fifty-four (62%) runners had changes noted in their ECGs. The most common changes noted were atrial enlargement (37 runners). Other abnormalities seen on the ECGs included new conduction abnormalities, new Q waves, nonspecific ST/T-wave changes, and resolution of previous abnormalities that were seen on initial ECG. There was no statistically significant difference between runners with ECG changes and runners without ECG changes when comparing sex, age, previous marathon experience, exercise, history of exercise-induced chest pain, medical history, and family history of heart disease. Twenty runners with changed or abnormal postrace ECGs had postrace echocardiograms, and 8 were abnormal. Of the abnormal echocardiograms, 2 runners had normal but changed postrace ECGs and 4 runners had abnormalities that were inconsistent with what was seen on ECG. Our study suggests that ECG abnormalities and changes can occur in distance runners, but their significance is unclear.

• "Caustic cocktail": closed-circuit diving apparatus contamination leading to corrosive injury.

  Authors: Alicia B Minns, Shaun D Carstairs, Richard F Clark

  The American journal of emergency medicine. 09/2010; 28(7):843.e3-5.

• Recurrent coagulopathy and thrombocytopenia in children treated with crotalidae polyvalent immune fab: a case series.

  Authors: Alexander D Miller, Michael C Young, Megan C DeMott, Binh T Ly, Richard F Clark

  Pediatric emergency care. 08/2010; 26(8):576-82.

  Recurrent signs and symptoms after initial treatment and control of coagulopathy and thrombocytopenia after American pit viper (crotaline) envenomations have been previously described in patientsRecurrent signs and symptoms after initial treatment and control of coagulopathy and thrombocytopenia after American pit viper (crotaline) envenomations have been previously described in patients treated with Crotalidae polyvalent immune Fab antivenom (FabAV). The significance and necessity of treatment of these recurrent abnormalities are uncertain. Our goal was to further characterize recurrent coagulopathy or thrombocytopenia in pediatric patients. All cases presenting to our Toxicology Consult Service, which covers 6 hospitals in a metropolitan area, from May 2007 to April 2008 with recurrent coagulopathy after initial control with FabAV were included and retrospectively reviewed. Four cases of pediatric patients are presented who presented with recurrent coagulopathy and/or thrombocytopenia after initial control with FabAV. The patients were all treated with delayed administration of FabAV with variable results. Blood products administered without concurrent FabAV were of limited use. The laboratory abnormalities took up to 18 days to resolve in one case. One patient developed hemodynamically significant spontaneous bleeding. The cases presented here suggest administration of FabAV may correct delayed coagulopathy associated with crotaline envenomations. The first 3 cases illustrate that in the face of severe derangements in laboratory values, most envenomated patients treated with FabAV do not develop significant bleeding. These cases may respond to additional antivenom alone. However, case 4 illustrates that hemodynamically significant spontaneous bleeding can occur. Until more data are available, readministration of FabAV is a reasonable first-line therapy for delayed coagulopathy associated with crotaline envenomations.

• Isoniazid-induced status epilepticus in a pediatric patient after inadequate pyridoxine therapy.

  Authors: Alicia B Minns, Nazli Ghafouri, Richard F Clark

  Pediatric emergency care. 05/2010; 26(5):380-1.

  Isoniazid (INH) is an effective treatment for tuberculosis and among the most common causes of drug-induced seizures in the United States. Isoniazid intoxication produces a characteristic clinicalIsoniazid (INH) is an effective treatment for tuberculosis and among the most common causes of drug-induced seizures in the United States. Isoniazid intoxication produces a characteristic clinical syndrome including seizures, metabolic acidosis, and, in severe cases, respiratory depression and coma. A 10-month-old male infant was presented after being found with his father's INH. The patient was brought to a local hospital where he had a witnessed generalized seizure and was given 650 mg pyridoxine intravenously, which was based on a 70 mg/kg recommendation. Five hours after the time of ingestion, the patient developed recurrent generalized seizures. He was given diazepam and then loaded with phenobarbital 20 mg/kg, while awaiting more pyridoxine from the pharmacy. He received an additional 2 g pyridoxine for a suspected ingestion of approximately 2.7 g INH (290 mg/kg total dose), and his seizures subsequently resolved. Treatment of INH toxicity must address correction of gamma-aminobutyric acid deficiency with pyridoxine replacement and management of life-threatening events. For poisonings in which the amount of INH ingested is known, pyridoxine is dosed on a gram-for-gram basis. Several reference textbooks recommend pyridoxine dosing in children to be 70 mg/kg. This was the justification for the initial pyridoxine dose administered in our case. However, after review of the referenced literature, the rationale supporting this recommendation remains unclear. Benzodiazepines should also be given with pyridoxine as they have been shown to have a synergistic effect in terminating seizures in animal models. As soon as possible after INH overdose is suspected or diagnosed, pyridoxine should be administered in a dose approximately equal to the estimated amount of INH ingested regardless of the age of the patient.

• Worsening Gait Abnormalities in a 12-Year-Old Child.

  Authors: Arash Soroudi, Richard F Clark

  The Journal of emergency medicine. 04/2010;

• A retrospective review of supratherapeutic modafinil exposures.

  Authors: Shaun D Carstairs, Andrew Urquhart, Justin Hoffman, Richard F Clark, F Lee Cantrell

  Journal of medical toxicology : official journal of the American College of Medical Toxicology. 04/2010; 6(3):307-10.

  Modafinil is a non-amphetamine wakefulness-promoting agent used for the treatment of various sleep disorders characterized by excessive daytime sleepiness. There is little information in the medicalModafinil is a non-amphetamine wakefulness-promoting agent used for the treatment of various sleep disorders characterized by excessive daytime sleepiness. There is little information in the medical literature with respect to supratherapeutic doses of this medication. We performed a retrospective review of the California Poison Control System database for all cases of single-substance ingestion of modafinil with follow-up to a known outcome for the time period 1998-2008. Data collected included age, gender, dose ingested, clinical effects, and medical outcome. There were a total of 87 patients, 53 (61%) of which were female. Patient ages ranged from 1.25 to 72 years with a mean of 30 years; 17 (20%) patients were aged 6 years or less. Thirty-three (38%) were intentional overdoses. Most commonly reported effects were tachycardia (n=23), agitation (n=14), anxiety (n=11), headache (n=8), hypertension (n=6), dystonia/tremor (n=6), and dizziness (n=5). Forty-nine patients (56%) were managed at home, and 38 (44%) were managed in a healthcare setting. Therapies administered included activated charcoal (n=8), benzodiazepines (n=7), antihistamines (n=2), intravenous fluids (n=2), haloperidol (n=2), and beta-blockers (n=1). Effects were classified as none (n=22), minor (n=54), and moderate (n=11). No major effects and no deaths occurred. Effects of modafinil overdose appear to be mild in most cases, with tachycardia and CNS symptoms predominating. Clinically significant effects requiring treatment occurred in a small number of patients.

• The poison pen: bedside diagnosis of urinary diquat.

  Authors: Rais Vohra, Anthony Salazar, F L Cantrell, Ravindra Fernando, Richard F Clark

  Journal of medical toxicology : official journal of the American College of Medical Toxicology. 03/2010; 6(1):35-6.

  Diquat is a bipyridyl herbicide with nephrotoxic effects. This in vitro study demonstrates a colorimetric test for detection of diquat in human urine. Urine specimens using ten concentrations ofDiquat is a bipyridyl herbicide with nephrotoxic effects. This in vitro study demonstrates a colorimetric test for detection of diquat in human urine. Urine specimens using ten concentrations of diquat herbicide solution and controls for urine and glyphosate were prepared. A two-step assay (addition of bicarbonate followed by sodium dithionite) was performed, with a resulting color change of the original solution for each specimen. Color change intensity was noted immediately and after 30 min, by gross visual inspection. A green color with concentration-dependent intensity was detected in all specimens, in which concentrations of diquat solution ranged from 0.73 to 730 mg/L. This colorimetric effect disappeared after 30 min. The sodium bicarbonate/dithionite test may be useful as a qualitative bedside technique for the detection of urinary diquat in the appropriate clinical setting.

• Death due to acute salicylate intoxication despite dialysis.

  Authors: Alicia B Minns, F Lee Cantrell, Richard F Clark

  The Journal of emergency medicine. 03/2010; 40(5):515-7.

  Salicylate poisoning is a common problem with appreciable morbidity and mortality. We present a case of a patient with a large aspirin ingestion who expired despite aggressive hemodialysis (HD). ASalicylate poisoning is a common problem with appreciable morbidity and mortality. We present a case of a patient with a large aspirin ingestion who expired despite aggressive hemodialysis (HD). A 35-year-old man arrived at the Emergency Department 7.5 h after ingesting 400 tablets of 325-mg aspirin. He was afebrile, the respiratory rate (RR) was 30 breaths/min, heart rate (HR) 120 beats/min, blood pressure (BP) 125/76 mm Hg, and oxygen saturation 99% on room air. His salicylate concentration was 89.6 mg/dL. His initial arterial blood gas: pH 7.48, pCO(2) 21 mm Hg, PaO(2) 97 mm Hg, and bicarbonate 15.8 mmol/L. His initial serum chemistry panel was normal. He received activated charcoal and intravenous hydration with sodium bicarbonate. Two hours after arrival, salicylate concentration was 91.6 mg/dL. The patient became agitated and HD was initiated; 22 h after presentation, repeat salicylate concentration was 88.4 mg/dL and his creatinine was 3.9 mg/dL. A second run of HD was performed. After this, his temperature had risen to 39.06°C (102.3°F), BP 122/64 mm Hg, HR 168 beats/min, RR 43 breaths/min, and oxygen saturation 95% (2 L nasal cannula). His confusion increased, and he died 40 h after his ingestion. HD is widely advocated in managing severe salicylate intoxications, however, no consensus exists for the duration and best mode of therapy. Patients with severe salicylate poisonings may require extended durations of HD to effectively mitigate toxicity. Additional study is warranted to determine optimal therapy in severe salicylate intoxications.

• Guanfacine overdose resulting in initial hypertension and subsequent delayed, persistent orthostatic hypotension.

  Authors: Alicia B Minns, Richard F Clark, Aaron Schneir

  Clinical toxicology (Philadelphia, Pa.). 02/2010; 48(2):146-8.

  Guanfacine is an alpha(2)-adrenoreceptor agonist used for the treatment of attention-deficit hyperactivity disorder and tic disorders. Few reports exist regarding overdose with guanfacine. AGuanfacine is an alpha(2)-adrenoreceptor agonist used for the treatment of attention-deficit hyperactivity disorder and tic disorders. Few reports exist regarding overdose with guanfacine. A 16-year-old female with Tourette's syndrome presented with diaphoresis, dry mouth, and hypertension 8 h after ingesting 25 mg of guanfacine. These symptoms improved and her blood pressure (BP) normalized over 2 h. Thirty hours following ingestion, she experienced near syncope and returned to the emergency department. She was noted to have orthostatic hypotension and a prolonged QTc interval of 593 ms on electrocardiogram. With only fluid support, she was asymptomatic by 60 h postingestion and her QTc interval had improved to 511 ms. This experience suggests a much delayed onset of symptoms may occur and that the QTc interval may be prolonged, necessitating a longer period of monitoring in a patient presenting with an overdose.