Biomedical subjects

Wendy Klein-Schwartz

Publications and source records attributed to Wendy Klein-Schwartz.

22 records · Page 2Linked to original sources

PubMed2002

Electrocardiographic changes associated with beta-blocker toxicity.

STUDY OBJECTIVE: We sought to characterize the ECG changes associated with symptomatic beta-blocker overdose. METHODS: The study population consisted of a prospective cohort of patients reporting to 2 regional poison centers with beta-blocker overdose. Each patient received an ECG on presentation and a structured follow-up. The inclusion criteria for symptomatic overdose included heart rate of less than 60 beats/min or systolic blood pressure of less than 90 mm Hg; symptoms consistent with decreased end-organ perfusion; therapeutic intervention with cardioactive medication; and corroboration by 2 of the authors that this was a clear-cut case of symptomatic beta-blocker overdose with cardiovascular toxicity. Exclusion criteria included cardioactive coingestants, age younger than 6 years, and no available ECG. RESULTS: Of 167 patients, 13 were determined to have symptomatic exposures. First-degree heart block (>200 ms) was the most common ECG finding (10/12) and also had the greatest likelihood ratio (5.31) when comparing those with symptomatic exposures with those with asymptomatic exposures. Comparing the asymptomatic with the symptomatic groups, the mean PR interval was 167 ms (95% confidence interval [CI] 162 to 171 ms) versus 216 ms (95% CI 193 to 238 ms), the mean QRS interval was 89 ms (95% CI 87 to 91 ms) versus 112 ms (95% CI 92 to 132 ms), the mean QTc interval was 422 ms (95% CI 417 to 428) versus 462 ms (95% CI 434 to 490 ms), and the mean heart rate was 72 beats/min (95% CI 69 to 74 beats/min) versus 66 beats/min (95% CI 59 to 73 beats/min). Two cases of symptomatic acebutolol exposure appeared unique by demonstrating disproportionate prolongation of the QTc interval, an RaVR height of 3 mm or greater, and associated ventricular tachydysrhythmia. CONCLUSION: The majority of clinically significant beta-blocker intoxications demonstrate negative dromotropic effects on ECG. Several ECG differences in acebutolol intoxication might reflect unique pathophysiologic processes relative to other beta-blockers.

Acebutolol↗

PubMed2002

Acute, unintentional pediatric brodifacoum ingestions.

BACKGROUND: Brodifacoum is the major rodenticide used in the United States today. It is similar to warfarin but has more potent and prolonged effects. Large overdoses and chronic intoxication have been associated with significant coagulopathies and death. Currently, the management of acute unintentional ingestions by young children is controversial. METHODS: American Association of Poison Control Centers (AAPCC) data from 1993 to 1996 were retrospectively searched for acute, unintentional brodifacoum exposures without coingestions followed-up to a known outcome in children aged 6 years and younger. The cases were analyzed by management site, symptoms, therapy, and outcome. Cases coded as having clinical or laboratory evidence of coagulopathy were further evaluated for severity. RESULTS: Our study reviewed 10,762 cases that involved single, acute, unintentional ingestions of brodifacoum. All of the patients were followed-up to a known outcome as defined by AAPCC data collection standards. In this cohort, there were no deaths or major effects reported. Although 67 patients reported evidence of coagulopathy, no major effects or deaths were reported. Minor and moderate effects were reported in 38 and 54 children, respectively. Management occurred outside of a healthcare facility in 5404 (50.2 %) cases. Approximately half of all the children received some form of gastrointestinal decontamination. Decontamination had no effect on the distribution of outcomes. Adverse effects from decontamination therapy were reported in 42 patients. CONCLUSION: Acute pediatric ingestions of brodifacoum rarely caused clinical effects and were not associated with life-threatening symptoms or death in young children. It seems reasonable that acute unintentional ingestions of small quantities of brodifacoum by young children can be adequately managed with home observation and parent education.

4-Hydroxycoumarins↗

PubMed2002

Abuse and toxicity of methylphenidate.

The therapeutic use of methylphenidate for the management of attention-deficit hyperactivity disorder in children is increasing. As therapeutic use increases, the risk increases of unintentional overdoses, medication errors, and intentional overdoses caused by abuse, misuse, or suicide gestures and attempts. Side effects during therapy, which include nervousness, headache, insomnia, anorexia, and tachycardia, increase linearly with dose. Clinical manifestations of overdoses include agitation, hallucinations, psychosis, lethargy, seizures, tachycardia, dysrhythmias, hypertension, and hyperthermia. Methylphenidate tablets can be abused orally, or they can be crushed and the powder injected or snorted. Despite its abuse potential, there is disagreement regarding the extent to which methylphenidate is being diverted from legitimate use to abuse in preteens and adolescents.

Adolescent↗

PubMed2002

Epidemiology and toxicity of pediatric guanfacine exposures.

OBJECTIVE: To examine the epidemiology and toxicity of guanfacine exposures in children and adolescents reported to poison control centers. METHODS: Guanfacine exposures reported to the American Association of Poison Control Centers Toxic Exposure Surveillance System from 1993 to 1999 in children and adolescents <19 years of age were analyzed. RESULTS: There were 870 cases that met the inclusion criteria: 478 (54.9%) were children <6 years old, 304 (34.9%) were 6-12 years old, and 88 (10.1%) were adolescents 13-18 years old. The number of cases increased eight-fold over the 7-year period, with the largest increase in children <13 years of age. Analysis showed 29.7% of exposures were managed on site (non-healthcare facility) and 68.3% were managed in a healthcare facility. There were no symptoms in 546 (62.8%) children. In 324 symptomatic children, the most common symptoms were drowsiness/lethargy (76.8%), bradycardia (30.0%), and hypotension (25.8%). The majority of cases were acute (77.5%), 182 (20.9%) were acute-on-chronic, and 14 (1.6%) were chronic. Children aged 6-12 years represented the majority of the acute-on-chronic and chronic exposures with (n = 118). Overall, there were 195 (22.4%) exposures coded as minor, 121 (13.9%) as moderate, and 8 (0.9%) as major effects. CONCLUSIONS: These data demonstrated a trend of increasing numbers of guanfacine exposures annually. Although the majority of children experienced minimal or no toxicity, serious toxicity can occur.

Adolescent↗