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Greene Shepherd

Publications and source records attributed to Greene Shepherd.

At least 19 recordsLinked to original sources
PubMed2006

Treatment of poisoning caused by beta-adrenergic and calcium-channel blockers.

PURPOSE: The toxic effects and treatment of beta-adrenergic blocker and calcium-channel blocker (CCB) overdose are reviewed. SUMMARY: Overdoses with cardiovascular drugs are associated with significant morbidity and mortality. Beta-blockers and CCBs represent the most important classes of cardiovascular drugs. In overdose, beta-blockers and CCBs have similar presentation and treatment overlaps and are often refractory to standard resuscitation measures. The common feature of beta-blocker toxicity is excessive blockade of the beta-receptors resulting in bradycardia and hypotension. Poisoning by CCBs is characterized by cardiovascular toxicity with hypotension and conduction disturbances, including sinus bradycardia and varying degrees of atrioventricular block. Therapies include beta-agonists, glucagon, and phosphodiesterase inhibitors. However, in beta-blocker poisoning where symptomatic bradycardia and hypotension are present, high-dose glucagon is considered the first-line antidote. Traditionally, antidotes for CCB overdose have included calcium, glucagon, adrenergic drugs, and amrinone. For cases of CCB poisoning where cardiotoxicity is evident, first-line therapy is a combination of calcium and epinephrine; high-dose insulin with supplemental dextrose and potassium therapy (HDIDK) is reserved for refractory cases. Health-system pharmacists should be aware that when these drugs are used as antidotes, higher than normal dosing is needed. CONCLUSION: Poisoning by beta-blockers or CCBs usually produces hypotension and bradycardia, which may be refractory to standard resuscitation measures. For cases of beta-blocker poisoning where symptomatic bradycardia and hypotension are present, high-dose glucagon is considered the first-line antidote. For cases of CCB poisoning where cardiotoxicity is evident, a combination of calcium and epinephrine should be used initially, reserving HDIDK for refractory cases.

Adrenergic beta-Agonists↗
PubMed2006

Systemic toxicity after an ocular exposure to xylazine hydrochloride.

There are limited reports of human overdose with the animal tranquilizer, xylazine hydrochloride. The reported effects include hypotension, bradycardia, and respiratory depression. Ocular exposures to xylazine have not been previously reported. A 38-year-old man arrived in the Emergency Department, reporting the accidental irrigation of both eyes with approximately 8 mL of xylazine (100 mg/mL) 30 min before arrival. The patient was asymptomatic. The eyes were copiously irrigated with isotonic crystalloid. Two hours after the exposure, the patient developed sinus bradycardia (40-50 beats/min), hypotension (90/60 mm Hg), and a decreased level of consciousness. The patient was admitted for observation, during which the bradycardia and hypotension were noted to persist. He remained otherwise asymptomatic. The symptoms resolved without intervention, other than i.v. fluids, approximately 25 h after the exposure. The patient was discharged home. This case demonstrates that ocular exposure to xylazine can cause systemic central nervous system and cardiovascular effects.

Accidents, Occupational↗
PubMed2005

High-dose insulin therapy for calcium-channel blocker overdose.

OBJECTIVE: To evaluate the evidence for using high-dose insulin therapy with supplemental dextrose and potassium in calcium-channel blocker (CCB) overdose. DATA SOURCES: Evidence of efficacy for high-dose insulin therapy with supplemental dextrose and potassium was sought by performing a search of MEDLINE and Toxline between 1966 and July 2004 using combinations of the terms calcium-channel blocker, overdose, poisoning, antidote, and insulin. Abstracts from the North American Congress of Clinical Toxicology for the years 1996-2003 were also reviewed. STUDY SELECTION AND DATA EXTRACTION: Identified articles, including animal studies, case reports, and case series, were evaluated for this review. No clinical trials were available. DATA SYNTHESIS: Animal models of CCB overdose demonstrate that high-dose insulin with supplemental dextrose and potassium was a more effective therapy than calcium, glucagon, or catecholamines. High-dose insulin appears to enhance cardiac carbohydrate metabolism and has direct inotropic effects. Published clinical experience is limited to 13 case reports where insulin was used after other therapies were failing; 12 of these patients survived. High-dose insulin therapy was beneficial for CCB-induced hypotension, hyperglycemia, and metabolic acidosis. Bradycardia and heart block resolved in some patients, but persisted in others. CONCLUSIONS: Based on animal data and limited human experience, as well as the inadequacies of available alternatives for patients with significant poisoning, high-dose insulin therapy warrants further study and judicious use in patients with life-threatening CCB poisoning.

Adolescent↗
PubMed2005

Adverse effects associated with extra doses of bupropion.

STUDY OBJECTIVE: To determine the frequency of adverse effects, clinical outcomes, and possible dose-response relationships associated with inadvertent extra doses of bupropion. DESIGN: Retrospective review. DATA SOURCE: Toxic Exposure Surveillance System of the American Association of Poison Control Centers. SUBJECTS: Four hundred seventy-six patients who inadvertently took extra doses of bupropion. MEASUREMENTS AND MAIN RESULTS: Cases in the surveillance database were evaluated based on documented doses, treatment sites, symptoms, and clinical outcomes by using standard data-field definitions. Over a 4-year period from 2000-2003, more women than men unintentionally took extra doses of bupropion (354 [74.4%] vs 122 [25.6%]). Ingested doses ranged from 75-1500 mg with a median and mode of 300 mg. Of the 476 patients, only 127 (26.7%) had to be evaluated in an emergency department. Seizures were reported in four patients (0.8%), and one developed status epilepticus. Other prominent adverse effects were agitation (39 patients [8.2%]), dizziness (35 [7.4%]), tremor (34 [7.1%]), nausea and/or vomiting (32 [6.7%]), drowsiness (29 [6.1%]), tachycardia (26 [5.5%]), and hallucination (2 [0.4%]). Clinical outcomes were no effect (293 patients [61.6%]), minor effect (132 [27.7%]), moderate effect (49 [10.3%]), or major effect (2 [0.4%]). Overall, 183 patients (38.4%) had at least one adverse effect. Doses were higher in patients with adverse effects than in those with no effect (p = 0.045). Doses were slightly higher in those with moderate or major outcomes than in others, but the difference was not significant (p = 0.083). CONCLUSION: Adverse effects were common with extra doses of bupropion, and clinically significant effects occurred in approximately 10% of patients. Seizures were present twice as often as reported with therapeutic dosing. Extra doses of bupropion appear to increase the risk of adverse effects. Patients should be educated about these risks to minimize them.

Adolescent↗
PubMed2004

Pharmacokinetics and safety of epinephrine use in liposuction.

Patients are routinely exposed to high-dose epinephrine infiltration during large-volume liposuction. Because of the serious cardiovascular side-effect profile of catecholamine overdose, the authors examined the safety of larger-volume liposuction by assessing epinephrine pharmacokinetics. Five female volunteers with American Society of Anesthesiologists physical status of I or II, aged 29 to 40 years and weighing 75.9 to 95 kg, underwent liposuction. The wetting solution contained 7.3 mg (SEM, 0.7 mg) of epinephrine, corresponding to 0.09 mg/kg (0.04 mg/kg). Total plasma epinephrine and norepinephrine concentrations were assessed by high-performance liquid chromatography. Approximate exogenous epinephrine absorption was calculated after correction for estimated endogenous epinephrine production. Pharmacokinetic assessments were performed using standard equations. The total plasma epinephrine peak occurred at the final intraoperative reading (5 hours after induction) and was 323 pg/ml (24.8 pg/ml), three to four times maximum baseline resting levels. The norepinephrine level was slightly elevated throughout the study period, with a reversal of the normal epinephrine/norepinephrine ratio (<0.5:1) demonstrated intraoperatively (>5:1). Estimated time to peak exogenous epinephrine level ranged from 1 to 4 hours from the start of infiltration. Area under the plasma concentration versus time curve was approximately 2089 to 2610 pg x hour/ml. Peak exogenous epinephrine concentration was estimated to be 286 to 335 pg/ml. Clearance was 764,508 ml/hour and volume of distribution was 0.4 liter/kg (0.006 liter/kg). Total absorbed epinephrine was estimated, 1.8 mg to 2.2 mg, equivalent to 25 to 32 percent of the infiltrated dose. The reversal of the normal epinephrine/norepinephrine ratio and the fact that norepinephrine levels were within normal range implied that the majority of plasma epinephrine measured was exogenously infiltrated and not endogenously synthesized. On the basis of these observations, pharmacokinetic analyses were performed. Although unequivocal toxic epinephrine levels were not demonstrated, epinephrine peaks were three to four times the maximum observed in normal resting patients. Peak levels were comparable to those observed during major physiologic stresses, such as exercising to exhaustion, open abdominal surgery, or cross-clamping the aorta during surgical repair. Furthermore, epinephrine has been associated with myocardial infarction, arrhythmias, and fatal asystole in susceptible patients at these levels. Patients should be carefully screened for clinical evidence of hemodynamic and cardiac pathology before larger-volume liposuction is undertaken, as it may result in unnecessary high risk for patients who have preexisting cardiovascular disorders. Healthy American Society of Anesthesiologists physical status I or II patients should have sufficient cardiac reserve to tolerate these catecholamine levels.

Adult↗
PubMed2004

Delayed salicylate toxicity at 35 hours without early manifestations following a single salicylate ingestion.

OBJECTIVE: To report a case of delayed toxicity following a single ingestion of aspirin, where the initial concentrations were nearly undetectable and the patient was completely asymptomatic for the first 35 hours. CASE SUMMARY: A 14-year-old white female was evaluated after a single ingestion of 120 tablets of aspirin 81 mg/tablet hours before arrival to the emergency department. She denied nausea, abdominal pain, tinnitus, or shortness of breath. She received one dose of activated charcoal. The first salicylate concentration (4 h after ingestion) was 1 mg/dL. At 35 hours, the patient became symptomatic (dizziness, tinnitus, epigastric discomfort). Her salicylate concentration at that time was 46 mg/dL. A second dose of activated charcoal was administered, and intravenous bicarbonate with potassium was started as a continuous infusion for 30 hours. DISCUSSION: While delayed salicylate toxicity is well reported in the literature, no report was found regarding concentrations increasing to toxicity 35 hours after ingestion. The delayed aspirin absorption may be due to salicylate-induced pylorospasm or the formation of pharmacobezoars. CONCLUSIONS: In cases with known salicylate ingestion, it is important to follow salicylate concentrations every 4 hours until they are steadily decreasing according to a 4-hour half-life and the patient shows no symptoms of salicylate intoxication.

Adolescent↗
PubMed2004

Unintentional intravenous infusion of Golytely in a 4-year-old girl.

OBJECTIVE: To report an accidental intravenous infusion of Golytely (polyethylene glycol and electrolyte solution; PEG-ELS) in a pediatric patient that did not result in systemic toxicity. CASE SUMMARY: A 4-year-old Hispanic girl presented to the emergency department after ingestion of approximately 24 tablets of 6-mercaptopurine (6-MP) 2 hours earlier. She vomited twice after receiving syrup of ipecac at home. Upon arrival, her vital signs were temperature 36.2 degrees C, heart rate 102 beats/min, respiratory rate 42 breaths/min, and blood pressure 115/67 mm Hg. Her physical examination was normal. The patient received activated charcoal 1 g/kg. Golytely administered through a nasogastric tube was ordered. Upon reevaluation, it was noted that the patient had received 391 mL of Golytely intravenously. The infusion was immediately stopped. There was no evidence of acidosis, renal failure, or ethylene glycol toxicity. She was admitted for observation and was discharged 36 hours later. DISCUSSION: As of April 29, 2004, accidental intravenous infusion of PEG-ELS has not been previously reported. Potential toxicity from Golytely is mainly related to the molecular weight of PEG in the formulation. PEG can theoretically be degraded to ethylene glycol. It is thus important to monitor acid-base status, renal function, and pulmonary function in these patients. CONCLUSIONS: When administered correctly, an infusion of PEG-ELS by nasogastric tube is a safe gastrointestinal decontamination technique used in toxicology; PEG-ELS is not indicated for intravenous administration. Protocols need to be implemented in the workplace to minimize errors in the delivery of treatment to patients. Fortunately, this patient did not have any toxicity from the intravenous infusion of Golytely.

Child, Preschool↗
PubMed2004

Intentional bupropion overdoses.

Bupropion is an antidepressant that has recently seen increased usage in smoking cessation. This increased usage, along with its potential for causing seizures, has renewed interest among clinicians about the effects of this drug. The purpose of this study is to describe the clinical course of intentional bupropion overdoses in adults and adolescents. This study is a retrospective review of intentional bupropion overdoses reported to regional poison centers over a 2-year period. Our review included 385 cases. Women accounted for 63% of cases and ages ranged from 12 to 57 years. Significant clinical effects were noted in 26% of cases. Seizures were reported in 11% of patients. Seizures occurred within 6 h in most patients. Other prominent effects included tachycardia, agitation, and hallucinations. In conclusion, after a bupropion overdose, patients frequently display agitation, tachycardia, hallucinations and seizures. Seizures commonly occur within 6 h of the ingestion. However, seizures may occur beyond this time frame, particularly if persistent tachycardia, agitation, or hallucinations are noted.

Adolescent↗
PubMed2004

Iron bezoar retained in colon despite 3 days of whole bowel irrigation.

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.

Antidotes↗
PubMed2004

Pharmacokinetics and safety of lidocaine and monoethylglycinexylidide in liposuction: a microdialysis study.

High doses of lidocaine are administered to patients undergoing liposuction. Monoethylglycinexylidide, the active metabolite of lidocaine, is 80 to 90 percent as potent as lidocaine, and its relative toxicity is approximately that of lidocaine. Monoethylglycinexylidide has not previously been measured in studies on lidocaine in liposuction. The aims of this study were to characterize systemic exposure to lidocaine and monoethylglycinexylidide and to measure lidocaine and monoethylglycinexylidide levels within the tissues. Five female volunteers between the ages of 29 and 40 years underwent liposuction. Lidocaine (1577 to 2143 mg, corresponding to 19.9 to 27.6 mg/kg) was infiltrated during the procedure. Levels of lidocaine and monoethylglycinexylidide in blood and lipoaspirate were assessed perioperatively. Tissue lidocaine and monoethylglycinexylidide levels were measured postoperatively using a microdialysis technique in vivo. The peak (maximal) concentration of lidocaine plus monoethylglycinexylidide was 2.2 to 2.7 microg/ml. Time to peak lidocaine plus monoethylglycinexylidide was 8 to 28 hours after infiltration began. Absorbed lidocaine was estimated to be 911 to 1596 mg; therefore, 45 to 93 percent (mean, 64 percent) of the infiltrated dose was ultimately absorbed. Lipoaspirate analysis showed that 9.1 to 10.8 percent (mean, 9.7 percent) of the infiltrated dose was removed during the procedure. Tissue lidocaine levels below 5 microg/ml were demonstrated from 4 to 8 hours postoperatively. The peak lidocaine plus monoethylglycinexylidide concentration was within safe limits in this group of subjects. Time to peak lidocaine plus monoethylglycinexylidide signifies a delayed peak and therefore a longer period of potential lidocaine toxicity than was originally thought. Microdialysis results demonstrated that tissue lidocaine levels may be subtherapeutic within 4 to 8 hours of the procedure. Investigation into factors controlling the resorption of lidocaine during liposuction is warranted in an effort to improve the duration of effect. Furthermore, considering the active metabolite monoethylglycinexylidide, longitudinal studies are necessary to determine whether improving the side effect profile of lidocaine by reducing the dose administered during liposuction may be possible without decreasing the perioperative analgesic effect.

Adipose Tissue↗
PubMed2004

Cyanide poisoning and its treatment.

Cyanide is both widely available and easily accessible throughout the world. Although the compound is not frequently encountered, it has been used as a poison and contaminant in the past and is a potential terrorist agent. Cyanide has the ability to cause significant social disruption and demands special attention to public health preparedness. It can be obtained from a variety of sources, including industrial, medical, and even common household products. Another frequently encountered source of cyanide exposure is residential fires. Exposure to high concentrations of the chemical can result in death within seconds to minutes. Long-term effects from cyanide exposure can cause significant morbidity. The only treatment for cyanide toxicity approved for use in the United States is a kit consisting of amyl nitrite, sodium nitrite, and sodium thiosulfate. Future research aims to find a faster-acting, more effective, and better tolerated treatment for cyanide toxicity.

Antidotes↗
PubMed2004

Language preferences among callers to a regional Poison Center.

Providing service to non-English speaking populations is a common challenge facing Poison Centers (PC). Previous studies have identified that people who do not speak functional English are unlikely to call a PC. We developed a survey to determine the language preferences of poison center callers and to identify if we were failing to offer services in languages other than English to callers who felt they needed them. We surveyed 322 parents during routine callbacks about language spoken at home, first and second languages, country of birth, and satisfaction with language used by the PC. We found that 93% primarily spoke English, 5% spoke English and Spanish, and 5% spoke other languages at home in a region where approximately 10% of the population speak English poorly. The majority of respondents were born in the US and were comfortable using English when using the PC. There were 6 cases where callers would have preferred using a different language. Our study supports data suggesting that poison centers are underutilized by people that are recent immigrants and speak English poorly. Awareness programs and educational efforts should be directed toward this sub-population.

Communication Barriers↗
PubMed2004

Can textbook covers be used to increase poison center utilization?

An education program was implemented at a regional poison center to increase use of a new nationwide 800 number (800/222-1222) in counties in our region that had low rates of utilization. We identified 10 counties with the lowest utilization rates and provided textbook covers to the elementary and secondary schools in these areas. The covers contained the poison help logo and information about what to do if a poisoning occurs. Changes in utilization rate for these counties were compared to similar counties over the course of a year. Utilization rates increased in both sets of counties over the study period, but there was no significant difference (p = 0.84) between the 2 groups. Use of textbook covers to increase awareness and utilization made little impact beyond our normal efforts and was not cost-effective.

Child↗
PubMed2003

Serotonin syndrome with elevated paroxetine concentrations.

OBJECTIVE: To describe a case of serotonin syndrome due to paroxetine and ethanol. CASE SUMMARY: A 57-year-old white man was brought to the emergency department one day after ingesting paroxetine 3600 mg and a pint of hard liquor. He denied the use of any other drug or herbal products and regular use of alcohol. Upon arrival to the hospital, vital signs were blood pressure 188/103 mm Hg, heart rate 114 beats/min, respiratory rate 28 breaths/min, temperature 36.8 degrees C, and O2 saturation 96% on room air. Findings on physical examination included dilated pupils, facial flushing, diaphoresis, shivering, myoclonic jerks, tremors, and hyperreflexia. A tentative diagnosis of serotonin syndrome was made. Initially, cyproheptadine 8 mg was administered orally with no observable effect. An additional 12 mg was given in 3 doses over 24 hours. Symptoms abated slowly over the next 6 days, during which a thorough evaluation failed to reveal any other potential causes for the patient's condition. Serum paroxetine concentrations at 27.5 and 40 hours after ingestion were 1800 and 1600 ng/mL, respectively (normal 20-200 ng/mL). DISCUSSION: Serotonin syndrome is rarely reported in patients taking only one serotonergic medication. Although serum paroxetine concentrations have not been shown to correlate with efficacy or toxicity, our patient's serum paroxetine concentration was 9 times the upper end of the therapeutic range. Cyproheptadine, which has been suggested as a therapy, did not appear beneficial in this patient. Use of the Naranjo probability scale indicated a probable relationship between the serotonin syndrome and the overdose of paroxetine taken by this patient. CONCLUSIONS: More studies are needed to better assess the role of cyproheptadine and other serotonin antagonists in the management of the serotonin syndrome. Regardless of the use of cyproheptadine or other agents, attention should be paid to fluid status, decontamination, and management of hyperthermia, agitation, and seizures.

Drug Overdose↗
PubMed2003

Evaluation of the time frame for home ipecac syrup use when not kept in the home.

INTRODUCTION: The home administration of ipecac syrup remains a recommendation in some guidelines for the management of specific pediatric poisonings. A common challenge for poison specialists is how to approach the situation when ipecac syrup is indicated but not kept in the home. This study examines whether or not ipecac syrup can be administered and produce timely emesis in this situation. METHODS: Over a 6-month period, a prospective observational study was undertaken to determine if ipecac syrup can be administered in a timely manner when it is indicated but not available in the home. Cases where ipecac syrup was indicated but not kept in the home were included if parents stated that they could obtain ipecac within 15 minutes. Timely administration and the onset of emesis were defined as < 30 min and < 60 min, respectively. RESULTS: During our study 14,603 human exposures were evaluated; ipecac syrup was recommended by a poison specialist in 75 cases, and 25 of these were included in our study. Ages ranged from 1 to 6 years. The mean time to administration of ipecac from exposure time was 40 min (SD +/- 14 min). Administration of ipecac syrup occurred in < 30 min in 20% of the cases. The mean time to first emesis from exposure was 58 min (SD +/- 13). Initial emesis occurred in < 60 min in 36% of the cases. CONCLUSIONS: Ipecac syrup was rarely recommended by our center and was frequently unavailable when it was recommended. Ipecac syrup often could not be administered in a timely manner because it was not kept in the home. Parents of pediatric patients who have a significant ingestion should not be referred to purchase ipecac syrup.

Child↗
PubMed2003

The LSARS-II: Lethality of Suicide Attempt Rating Scale-Updated.

The concept of lethality is essential to the assessment of suicide risk; yet operational definitions of lethality for purposes of its measurement have been loose and varied. A number of scaling measures have been published in the literature, with no relative consensus on the best of these. In addition, only a few of these scales have published data on their psychometric properties. Of these, we argue that the best is the Lethality of Suicide Attempt Rating Scale (LSARS; Smith, Conroy, & Ehler, 1984). Presented here is a significantly revised and redesigned listing of drugs and chemicals and lethal ranges of ingestion (in caps, tabs, or ounces) by body weight to update that scale.

Dose-Response Relationship, Drug↗
PubMed2003

Opisthotonic posturing with neuromuscular irritability attributable to 4-aminopyridine ingestion by a healthy pediatric patient.

INTRODUCTION: 4-Aminopyridine (4-AP) is a potassium channel blocker used to increase muscle strength in the treatment of demyelinating diseases such as multiple sclerosis. We describe a case of ingestion by an 8-month-old child that resulted in severe but transient symptoms. CASE REPORT: An 8-month-old boy was found with greenish saliva, and a capsule with green 4-AP powder was missing. On arrival to an emergency department, he was jittery, tachycardic, and tachypneic. Activated charcoal, a cathartic, and midazolam (0.5 mg/kg) were administered before transfer to a tertiary pediatric hospital. On arrival, the infant remained tachycardic and tachypneic. His eyes deviated upward and he was noted to have 3+ deep tendon reflexes bilaterally. He was administered 0.9% normal saline (20 mL/kg) for a wide pulse pressure with low diastolic blood pressure. The patient developed dramatic opisthotonic posturing and vermiform tongue fasciculations. The symptoms responded well to repeated intravenous doses of benzodiazepines. In this case, we used 2 doses of lorazepam (0.05 mg/kg each). During opisthotonic posturing, an electroencephalogram performed in the intensive care unit revealed no evidence of seizure activity. Within 20 hours after admission, the patient became asymptomatic. CONCLUSION: This case is, to our knowledge, the first documented pediatric 4-AP ingestion. Clinical signs and symptoms are described as well as the response to therapy with benzodiazepines. The electroencephalogram performed while the patient was symptomatic was negative for seizures.

4-Aminopyridine↗