Michael Shannon

Lead exposure in children: Prevention, detection, and management

Fatal lead encephalopathy has disappeared and blood lead concentrations have decreased in US children, but approximately 25% still live in housing with deteriorated lead-based paint and are at risk of lead exposure with resulting cognitive impairment and other sequelae. Evidence continues to accrue that commonly encountered blood lead concentrations, even those less than 10 μg/dL, may impair cognition, and there is no threshold yet identified for this effect. Most US children are at sufficient risk that they should have their blood lead concentration measured at least once. There is now evidence-based guidance available for managing children with increased lead exposure. Housing stabilization and repair can interrupt exposure in most cases. The focus in childhood lead-poisoning policy, however, should shift from case identification and management to primary prevention, with a goal of safe housing for all children.

Intravenous magnesium therapy for moderate to severe pediatric asthma : Results of a randomized, placebo-controlled trial

OBJECTIVE To evaluate the efficacy of intravenous magnesium (IVMg) therapy for moderate to severe asthma exacerbations in pediatric patients. DESIGN Randomized, double-blind, placebo-controlled, clinical trial. SETTING Urban pediatric emergency department. PARTICIPANTS Thirty-one patients aged 6 to 18 years who were being treated for an acute asthma exacerbation with peak expiratory flow rate (PEFR) less than 60% of the predicted value after receiving three beta 2-adrenergic nebulizer treatments. INTERVENTIONS Magnesium sulfate infusion, 25 mg/kg (maximum, 2 gm), or equivolume saline solution for 20 minutes. MEASUREMENTS AND RESULTS Vital signs, O2 saturation by pulse oximetry, PEFR, forced vital capacity, forced expiratory volume at 1 second, and physical examination were serially recorded for 110 minutes, with serum magnesium concentrations measured before and after the 20-minute infusion. At 50 minutes the magnesium group had a significantly greater percentage of improvement from baseline in forced expiratory volume at 1 second (34% vs -1%; p = 0.05); this improvement was sustained and even greater at 110 minutes (75% vs 5%; p = 0.01). Results were similar for PEFR at 80 through 110 minutes (59% vs 20% at 110 minutes; p = 0.05) and for forced vital capacity (55% vs 8% at 80 minutes; p = 0.05). There were no significant intergroup differences in blood pressure at any point. Patients who received intravenous magnesium infusions were more likely to be discharged home from the emergency department than those who received placebo (4/15 vs 0/16; p = 0.03). CONCLUSIONS Children treated with intravenous magnesium infusions for moderate to severe asthma had significantly greater improvement in short-term pulmonary function without any significant alteration in blood pressure, suggesting a role for this agent as an adjunct in the treatment of such patients.

Adverse Drug Events in the Outpatient Setting: An 11-Year National Analysis

Adverse drug events (ADEs) are a common complication of medical care resulting in high morbidity and medical expenditure. Population level estimates of outpatient ADEs are limited. Our objective was to provide national estimates and characterizations of outpatient ADEs and determine risk factors associated with these events.

Ultraviolet light: A hazard to children

BACKGROUND Sunlight is subdivided into visible light, ranging from 400 nm (violet) to 700 nm (red); longer infrared, “above red” or .700 nm, also called heat; and shorter ultraviolet radiation (UVR), “below violet” or ,400 nm. UVR is further subdivided into UV-A (320–400 nm), also called black (invisible) light; UV-B (290–320 nm), which is more skin-penetrating; and UV-C (,290 nm). UV-B constitutes ,0.5% of sunlight reaching the earth’s surface, but is responsible for most of the acute and chronic sunrelated damage to normal skin.1 Most UVR is absorbed by stratospheric ozone. UV-B has greater intensity in summer than in winter, at midday than in morning or late afternoon, in places closer to the equator, and at high altitudes. Sand, snow, concrete, and water can reflect up to 85% of sunlight, thus intensifying exposure.1

Treatment of Calcium-Channel–Blocker Intoxication with Insulin Infusion

To the Editor: Overdose of calcium-channel blockers remains an important cause of fatal poisoning.1 Conventional therapy, consisting of intravenous fluids, calcium, dopamine, dobutamine, norepineph...

Safety and efficacy of flumazenil in the reversal of benzodiazepine-induced conscious sedation

Abstract Objective: To determine the safety and efficacy of flumazenil when given for reversal of benzodiazepine-induced conscious sedation in children. Design: Multicenter study conducted in emergency departments and pediatric endoscopy, bronchoscopy, or oncology suites. Patients: One hundred seven children (median age, 6 years; range, 1 to 17 years) who received intravenous benzodiazepine for an invasive procedure. Interventions: Flumazenil was given in increments of 0.01 mg/kg (0.2 mg maximum) at 1-minute intervals to a maximum total dose of 0.05 mg/kg (1.0 mg maximum). Measurements: Clinical efficacy was assessed by the Clinical Global Impression Scale and Observer’s Assessment of Alertness/Sedation Scale. The OAA/S, vital signs, lead II electrocardiogram, and clinical assessments were recorded at 0, 10, 30, 60, 90, and 120 minutes after flumazenil was given. Results: All children received midazolam (mean total dose, 0.18 mg/kg) for sedation. One hundred (96%) patients achieved a complete or partial response to flumazenil by 10 minutes after its administration, on the basis of their CGIS scores (the mean dose of flumazenil administered at the time of the first complete response was 0.017 ± 0.010 mg/kg). Seventy-one of 93 (76%) patients with a baseline OAA/S score ≤ 3 (1 = deep sleep, 5 = alert) experienced an increase of ≥ 2 points at 10 minutes after flumazenil administration, and 81 of 93 (87%) had a score of 4 or 5 after flumazenil administration. Seven patients, all within the 1- to 5-year age range, experienced resedation after initially responding to flumazenil. Thirty-seven of 107 patients (35%) experienced a total of 56 adverse events, most of which were considered to be unrelated to flumazenil administration. The most frequently occurring adverse events were abnormal crying, dizziness, nausea, fever, and headache. There were no clinically significant changes in vital signs or ECG tracings. No adverse events resulted in premature termination of drug administration. Conclusions: Flumazenil promptly and effectively reverses the central nervous system depressant effects of midazolam in children undergoing conscious sedation, with no significant adverse effects. Because of the potential for resedation, children who receive flumazenil should be monitored for 1 to 2 hours after its administration. (J Pediatr 1997;131:582-6)

Management of calcium channel antagonist overdose

Calcium channel antagonists are used primarily for the treatment of hypertension and tachyarrhythmias. Overdose of calcium channel antagonists can be lethal. Calcium channel antagonists act at the L-type calcium channels primarily in cardiac and vascular smooth muscle preventing calcium influx into cells with resultant decreases in vascular tone and cardiac inotropy and chronotropy. The L-type calcium channel is a complex structure and is thus affected by a large number of structurally diverse antagonists. In the setting of overdose, patients may experience vasodilatation and bradycardia leading to a shock state. Patients may also be hyperglycaemic and acidotic due to the blockade of L-type calcium channels in the pancreatic islet cells that affect insulin secretion. Aggressive therapy is warranted in the setting of toxicity. Gut decontamination with charcoal, or whole bowel irrigation or multiple-dose charcoal in the setting of extended-release products is indicated. Specific antidotes include calcium salts, glucagon and insulin. Calcium salts may be given in bolus doses or may be employed as a continuous infusion. Care should be exercised to avoid the administration of calcium in the setting of concomitant digoxin toxicity. Insulin administration has been used effectively to increase cardiac inotropy and survival. The likely mechanism involves a shift to carbohydrate metabolism in the setting of decreased availability of carbohydrates due to decreased insulin secretion secondary to blockade of calcium channels in pancreatic islet cells. Glucose should be administered as well to maintain euglycaemia. Supportive care including the use of phosphodiesterase inhibitors, adrenergic agents, cardiac pacing, balloon pump or extracorporeal bypass is frequently indicated if antidotal therapy is not effective. Careful evaluation of asymptomatic patients, including and electrocardiogram and a period of observation, is indicated. Patients ingesting a nonsustained-release product should be observed in a monitored setting for 12 hours, while those who ingest a sustained-release preparation should be observed for no less than 24 hours. Charcoal should be given to the asymptomatic patient with a history of calcium channel antagonist overdose.

Recurrence and Outcomes of Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis in Children

OBJECTIVES: To report clinical course, etiology, management, and long-term outcomes of children suffering from Stevens-Johnson syndrome (SJS) or toxic epidermal necrolysis (TEN). METHODS: We conducted a study of all pediatric patients with SJS or TEN admitted between 2000 and 2007 to the Hospital for Sick Children and Childrens Hospital Boston, and particular attention was paid to clinical manifestations, etiology, mortality, and long-term outcomes. RESULTS: We identified 55 cases of SJS (n = 47), TEN (n = 5), or SJS/TEN overlap syndrome (n = 3). Drugs were identified as the most likely etiologic agent in 29 children (53%); antiepileptic drugs were the most common agents (n = 16), followed by sulfonamide antibiotics (n = 7) and chemotherapy drugs (n = 2). Acute Mycoplasma pneumoniae infection was confirmed in 12 children (22%), and herpes simplex virus was confirmed in 5 children (9%). Treatment regimens differed significantly between participating sites and included systemic antimicrobial agents (67%), systemic corticosteroids (40%), and antiviral drugs (31%). Intravenous immunoglobulin was administered to 21 children (38%), of whom 8 received concomitant systemic corticosteroids. Ten children (18%) had recurrence of SJS up to 7 years after the index episode, and 3 experienced multiple recurrences. Twenty-six children (47%) suffered long-term sequelae that mostly involved the skin and eyes. CONCLUSIONS: Mortality rate in children was lower than that reported in adults, but half of affected children suffered long-term complications. The recurrence rate of SJS was high (1 in 5), which suggests vulnerability and potential genetic predisposition. In the absence of standardized management guidelines for these conditions, treatment regimens differed significantly between participating institutions.

Association between iron deficiency and low-level lead poisoning in an urban primary care clinic.

OBJECTIVES The purpose of this study was to examine the association between iron deficiency and low-level lead poisoning. METHODS Data were collected in an urban primary care clinic from 3650 children aged 9 to 48 months. Iron deficiency was defined as a red cell mean corpuscular volume (MCV) of less than 70 fL and a red cell distribution width (RDW) of more than 14.5 in children younger than 2 years, and an MCV of less than 73 fL and RDW of more than 14.5 in those 2 years or older. RESULTS After adjustment for age, hemoglobin concentration, and insurance status, the odds ratios for iron deficiency predicting blood lead levels greater than or equal to 5 micrograms/dL and greater than or equal to 10 micrograms/dL were 1.63 (95% confidence interval [CI] = 1.29, 2.04) and 1.44 (95% CI = 1.004, 2.05). CONCLUSIONS Iron deficiency is significantly associated with low-level lead poisoning in children aged 9 to 48 months.

Association of Race/Ethnicity with Emergency Department Wait Times

Objective. To determine whether wait times for children treated in emergency departments (EDs) nationally are associated with patient race/ethnicity. Methods. Data were obtained from the National Hospital Ambulatory Medical Care Survey, which collects information on patient visits to EDs throughout the United States. We examined data for patients ≤15 years of age who presented to EDs during the 4-year period of 1997–2000. Sample weights were applied to the identified patient records to yield national estimates. For the purposes of this study, race/ethnicity was analyzed for 3 major groups, ie, non-Hispanic white (NHW), non-Hispanic black (NHB), and Hispanic white (HW). Results. During the 4-year study period, 20633 patient visits were surveyed, representing a national sample of 92.9 million children ≤15 years of age. The race/ethnicity distribution included 9019 NHW children (59.5%), 3910 NHB children (23.9%), and 2991 HW children (16.6%). The wait time for all groups was 43.6 ± 1.7 minutes (mean ± SEM). There were significant unadjusted intergroup differences in wait times (38.5 ± 1.6 minutes, 48.7 ± 0.5 minutes, and 54.5 ± 0.1 minutes for NHW, NHB, and HW children, respectively). Visit immediacy (triage status), when reported, was categorized as <15 minutes for 2203 children (17.1%), 15 to 60 minutes for 5324 (41.4%), 1 to 2 hours for 3010 (25.1%), and >2 to 24 hours for 1910 (16.4%). There were significant unadjusted differences in triage status according to race, with 14.6% of NHW patients being placed in the >2-hour immediacy range, compared with 18.8% of NHB patients and 20.0% of HW patients. In a linear regression analysis with logarithmically transformed wait time as a dependent variable and with adjustment for potential confounders, including hospital location, geographic region, and payer status, both NHB and HW patients waited longer than NHW patients, although the results were statistically significant only for HW patients. Conclusions. These nationally representative data suggest that children who come to EDs have wait times that vary according to race/ethnicity. There are several potential explanations for this observation, including discrimination, cultural incompetence, language barriers, and other social factors. These data and similar data from the National Hospital Ambulatory Medical Care Survey are useful in identifying nonclinical influences on the delivery of pediatric emergency care.