Behavior of Endotracheal Tube Cuff Pressure During a Routine Control Maneuver With Different Manometers.

BACKGROUND: The main functions of the endotracheal tube (ETT) cuff are to prevent aspiration and to allow pressurization of the respiratory system. For this purpose, it is essential to maintain adequate pressure inside the cuff, thus reducing the risks for the patient. It is regularly checked using a manometer and is considered the best alternative. The objective of this study was to evaluate the cuff pressure behavior of different ETTs during the simulation of an inflation maneuver using different manometers. METHODS: A bench study was performed. Four brands of 8-mm internal diameter single lumen with a Murphy eye ETT with cuff and 3 different brands of manometers were used. In addition, a pulmonary mechanics monitor was connected to the inside of the cuff through the body of the distal end of the ETT. RESULTS: A total of 528 measurements were made on the 4 ETTs. During the complete procedure (connection and disconnection), there was a significant pressure drop of 7 ± 1.4 cm H2O from the initial pressure (Pinitial) (P < .001), of which 6 ± 1.4 cm H2O was lost during connection (difference between Pinitial and Pconnection). The Preconnection value was 19.1 ± 1.6 cm H2O, showing a significant total pressure drop of 11 ± 1.6 cm H2O (difference between Pinitial and Preconnection) (P < .001). The Pfinal mean was 29.6 ± 1.3 cm H2O. Significant differences were found between manometers according to the time of measurement. A similar phenomenon was evidenced when analyzing different ETTs. CONCLUSIONS: Significant pressure changes occur secondary to ETT cuff measurement, which has important implications for patient safety.

Deep immunophenotyping reveals biomarkers of multisystemic inflammatory syndrome in children in a Latin American cohort.

BACKGROUND: Multisystemic inflammatory syndrome in children (MIS-C) is a life-threatening disease that occurs 2-5 weeks after severe acute respiratory syndrome coronavirus 2 exposure and is characterized by severe multisystemic inflammation. Early recognition of MIS-C is key to prognosis; therefore, establishing clinical and laboratory biomarkers that predict complications is urgently needed. OBJECTIVE: We characterized the immune response and clinical features of patients with acute MIS-C and determined biomarkers of disease in a cohort of 42 Latin American patients. METHODS: Immune characterization was performed using flow cytometry from peripheral mononuclear cells and severe acute respiratory syndrome coronavirus 2-specific humoral and cellular response was performed using flow cytometry, enzyme-linked immunospot, enzyme-linked immunosorbent assay, and neutralizing antibody assays. RESULTS: MIS-C is characterized by robust T-cell activation and cytokine storm. We uncovered that while C-X-C motif chemokine ligand (CXCL) 9, IL-10, CXCL8, CXCL10, IL-6, and IL-18 are significantly elevated in patients with shock, while CCL5 was increased in milder disease. Monocyte dysregulation was specifically associated with KD-like MIS-C. Interestingly, MIS-C patients show a natural killer cell degranulation defect that is persistent after 6 months of disease presentation, suggesting it could underlie disease susceptibility. Most MIS-C had gastrointestinal involvement, and higher levels of neopterin were identified in their stools, potentially representing a biomarker of intestinal inflammation in MIS-C. Severe acute respiratory syndrome coronavirus 2-specific cellular response and neutralizing antibodies were identifiable in convalescent MIS-C patients, suggesting sustained immunity. CONCLUSION: Clinical characterization and comprehensive immunophenotyping of Chilean MIS-C cohort provide valuable insights in understanding immune dysregulation in MIS-C and identify relevant biomarkers of disease that could be used to predict severity and organ involvement.

Cardiac abnormalities determined by tissue Doppler imaging and arrhythmias in adolescents with anorexia nervosa.

BACKGROUND: Anorexia nervosa has a prevalence of 0.5-3% in adolescents, placing this population at increased risk of cardiac anomalies including arrhythmias, pericardial effusion, and myocardial dysfunction. Our objective is to describe cardiovascular anomalies observed by tissue Doppler imaging in patients with anorexia nervosa. METHODS: We retrospectively reviewed electrocardiogram, Holter, and echocardiography findings in 28 patients diagnosed with anorexia nervosa. RESULTS: Electrocardiogram was abnormal in 71% of patients with sinus bradycardia observed in 57%. Holter confirmed sinus bradycardia without significant pauses. Prolonged QTc, low voltage, and ectopic beats were each seen in 14% of patients. Wenckebach atrioventricular block was observed in one patient. Supraventricular or ventricular tachycardia was not observed. Echocardiography showed structurally normal heart in all patients. Pericardial effusion was seen in 7.1% of patients and left ventricular mass was decreased in 10.7%. Mean ejection fraction was 0.73 and mean fractional shortening was 38.4%. Tissue Doppler imaging revealed systolic or diastolic dysfunction in four patients with e', a', and s' velocities in the lateral and septal basal segments more than two standard deviations below the mean. Two patients had decreased left ventricular mass but no significant difference in disease duration from the group. Basal segment velocities below one standard deviation were also observed in an additional seven patients. CONCLUSION: A trend for decreased tissue Doppler imaging velocities was seen in 25.0% of patients, while significant systolic and diastolic dysfunction was seen in 14.3% of patients, associated with a significant reduction in left ventricular mass and independent of disease duration.

Hematologic parameters and biomarkers predictors of severity in Multisystem Inflammatory Syndrome in children associated with SARS-CoV-2. / Parámetros hematológicos y biomarcadores predictores de gravedad en Síndrome Inflamatorio Pediátrico Multisistémico asociado a SARS-CoV-2.

INTRODUCTION: The multisystem inflammatory syndrome in children associated with SARS-CoV-2 (MIS-C) is cha racterized by a hyperinflammatory state resulting from a cytokine storm, evidenced by alterations in laboratory blood testing and acute-phase proteins. OBJECTIVE: to describe the clinical and labora tory characteristics of patients hospitalized due to MIS-C and identify predictive markers of severity. PATIENTS AND METHOD: Retrospective study of 32 patients. The group was divided into critical and non-critical according to clinical presentation and therapy used. Clinical and laboratory aspects were studied, including complete blood count, coagulation tests, and biomarkers. RESULTS: 18/32 were males, with a median age of 6.8 years. The most frequent manifestations were cardiovascular (84.3%), digestive (84%), and mucocutaneous (59%). The group of critical patients included 15 patients, 12 were males with a median age of 8.9 years, and the non-critical group included 17 patients, 6 were males with a median age of 5.4 years. The laboratory parameters at the admission in the global group showed increased C-reactive protein, D-dimer, leukocytes, neutrophils, ferritin, and fibrinogen. In contrast, albumin and blood sodium levels were decreased. At admission, the critical group was cha racterized by presenting thrombocytopenia, hypoalbuminemia, prolonged prothrombin time, and elevated ferritin. At the time of deterioration, there was an intensification of thrombocytopenia, in creased C-reactive protein together with increased neutrophils level. CONCLUSION: The blood count, C-reactive protein, and albuminemia at admission proved to be significantly important in the identi fication of patients at risk of clinical deterioration.

[Recommendations for the suspected diagnosis and management of Multisystemic Inflammatory Syndrome (MIS-C) in the context of a SARS-CoV-2 pandemic. April 2021]. / Recomendaciones para la sospecha diagnóstica y manejo del Síndrome Inflamatorio Multisistémico (SIM-COVID-19) en contexto pandemia SARS-CoV-2. Abril 2021.

Multisystem inflammatory syndrome temporally associated with COVID-19 (MIS-C) is a post-infectious complication described in children and adolescents with previous exposure to SARS-CoV-2. Because of its potential to evolve to severe disease -including cardiovascular impairment and multiple organ failure it requires a prompt diagnosis and appropriate management, including intensive care for most cases. These guidelines compile recent information from scientific literature, from our local clinical experiences during the past pandemic year, and have been discussed by experts. The recommendations provided are meant to help the clinical work of health teams attending the pediatric population.

Recomendaciones para la sospecha diagnóstica y manejo del Síndrome Inflamatorio Multisistémico (SIM-COVID-19) en contexto pandemia SARS-CoV-2. Abril 2021 / Recommendations for the suspected diagnosis and management of Multisystemic Inflammatory Syndrome (MIS-C) in the context of a SARS-CoV-2 pandemic. April 2021

Resumen El síndrome inflamatorio multisistémico asociado a COVID-19 (SIM-COVID-19) es una complicación post-infecciosa descrita en niños y adolescentes con antecedente de exposición a SARS-CoV-2. Su potencial de evolución clínica grave, con compromiso hemodinámico y de falla de múltiples órganos lo convierten en una identidad que requiere de sospecha temprana, rápido diagnóstico y manejo adecuado, incluyendo terapia intensiva en la mayoría de los casos. Las siguientes recomendaciones recopilan información de la literatura científica, de la experiencia nacional en este año de pandemia y han sido consensuadas con expertos. Se presentan como guías de manejo de modo de facilitar el trabajo de equipos de salud a cargo de la atención pediátrica.

Abstract Multisystem inflammatory syndrome temporally associated with COVID-19 (MIS-C) is a post-infectious complication described in children and adolescents with previous exposure to SARS-CoV-2. Because of its potential to evolve to severe disease -including cardiovascular impairment and multiple organ failure it requires a prompt diagnosis and appropriate management, including intensive care for most cases. These guidelines compile recent information from scientific literature, from our local clinical experiences during the past pandemic year, and have been discussed by experts. The recommendations provided are meant to help the clinical work of health teams attending the pediatric population.

Compromiso cardiovascular en pacientes con síndrome inflamatorio pediátrico multisistémico, asociado a infección por SARS-CoV-2 / Cardiovascular involvement in pediatric patients with SARS-CoV-2 associated to multisystemic inflammatory syndrome

INTRODUCCION: El Síndrome Inflamatorio Pediátrico Multisistémico (PIMS) ha emergido como una nueva enfermedad en niños, secundaria a infección por SARSCoV-2. Se caracteriza por presentar compromiso multiorgánico con parámetros inflamatorios elevados y manifestaciones clínicas graves, siendo el corazón el órgano más severamente comprometido. OBJETIVO: Describir las características clínicas y de laboratorio de 23 pacientes con diagnóstico de PIMS con compromiso cardiovascular hospitalizados en un centro único. MÉTODO: Se efectuó un estudio retrospectivo analizando los hallazgos clínicos y de laboratorio junto a las manifestaciones cardiovasculares que presentaron estos pacientes. RESULTADOS: 23/29 pacientes con PIMS (78%) presentaron manifestaciones digestivas y mucocutáneas. Las manifestaciones cardiovasculares fueron: Síndrome Kawasaki y "Kawasaki like" sin compromiso coronario en 15/23 (65%) y con compromiso coronario en 3 (13%). Shock en 9 pacientes (39%), injuria miocárdica- miocarditis en 8 (35%) y derrame pericárdico en 13 (56%). Trastornos del ritmo cardíaco se observaron en 6 pacientes (26%). La terapia más utilizada fue inmunoglobulina y corticoides. 18 /23 requirieron manejo en unidades de intermedio y/o intensivo. Un 70% de los pacientes se recuperó del compromiso cardiovascular antes del alta. CONCLUSIÓN: El compromiso cardiovascular en PIMS es la complicación más frecuente de esta enfermedad, que se acompaña de manifestaciones inmunológicas y hematológicas graves lo que hace necesario un tratamiento multidisciplinario para un mejor manejo de estos pacientes.

INTRODUCTION: Pediatric Multisystemic Inflammatory Syndrome (PIMS) has emerged as a new disease in children, secondary to SARSCoV-2 infection. It is characterized by multi-organ involvement with elevated inflammatory parameters and severe clinical manifestations, the heart being the organ most severely involved. OBJETIVE: to describe the clinical and laboratory characteristics of 23 patients diagnosed with PIMS with cardiovascular involvement hospitalized in a single center. METHOD: We conducted a retrospective study in which we analyzed the clinical and laboratory findings along with the cardiovascular manifestations presented by these patients. Results: 23/29 patients with PIMS and cardiovascular involvement were selected, 78% had digestive and mucocutaneous manifestations. Cardiovascular manifestations consisted of KawasakiKawasaki like syndrome without coronary involvement in 15/23 (65%) and coronary involvement in 3 (13%). Nine patients developed shock (39%), 8 (35%) myocardial injury in and 13 (56%) pericardial effusion.. Heart rhythm disorders were observed in 6 patients (26%). The main therapy was immunoglobulin and corticosteroids. 18 /23 required management in intermediate and/or intensive care unit. 70% of patients recovered from cardiovascular involvement before discharge. CONCLUSION: Cardiovascular involvement in PIMS is the most frequent complication of this disease, but it is associated with severe immunological and hematological manifestations, which makes necessary a multidisciplinary treatment for a better management

Espectro clínico de la infección en niños por virus SARS-CoV-2 en un centro de referencia pediátrico en plena pandemia. Reporte del Comité Clínico COVID, Hospital de Niños Roberto del Río, Santiago Chile

Resumen Introducción: La infección por virus SARS-CoV-2 responsable de la pandemia actual, es una entidad clínica y fisiopatológica nueva y en desarrollo, cuyo control aún es incierto mientras no contemos con una vacuna efectiva y de distribución universal. Descrita inicialmente como una enfermedad respiratoria mayoritariamente de adultos, los niños también pueden enfermar y se ha visto que en ellos las manifestaciones clínicas de enfermedad suelen diferir a las de los adultos expresándose como cuadros benignos en su mayoría. Si requieren hospitalización o algún tipo de asistencia, el cuadro se resuelve con tratamiento de soporte y sin complicaciones, mayoritariamente. Sin embargo, en el síndrome inflamatorio multisistémico asociado a COVID-19 (SIM-C) es de vital importancia la sospecha precoz y la derivación a un centro de alta complejidad para otorgar el soporte y tratamiento adecuado para lograr una buena y adecuada sobrevida. Objetivo: Describir el espectro clínico de enfermedad por virus SARS-CoV-2 en un centro de referencia pediátrico con la pandemia aún en desarrollo. Método: Se presenta la casuística de 537 pacientes con infección por SARS-CoV-2 atendidos entre marzo 1 y julio 15, 2020, con descripción de aquellos que fueran hospitalizados. Resultados: 127 (23%) de ellos fueron internados y de éstos 69% sintomáticos. Veintiséis pacientes (20%) de los hospitalizados presentaron SIM-C y sólo uno falleció por complicaciones de sus patologías de base.

Abstract Background: SARS-CoV-2 virus infection responsible for de pandemic in course, is a new clinical and physiopathological entity, whose control is still uncertain till we can provide an effective and universal vaccine. In the beginning it was described as a respiratory disease which affects mainly adults, children can have the disease too and in this group the disease can be different than the adult disease. Acute infection in children is mostly mild and when it requires hospital assistance it resolves with support therapy and without complications most of the time. However, in the Pediatric Inflammatory Multisystemic Syndrome is vital the early clinical suspect and refers to a tertiary center to bring support and properly treatment. Aim: To describe the clinical spectrum of SARS-CoV-2 virus disease in a pediatric referral center with the pandemic still in development. Method: A case series of 537 patients with SARS-CoV-2 infection treated between March 1 and July 15, 2020 is presented with a description of those who were hospitalized. Results: 127 (23%) of them were hospitalized and of these 69% were symptomatic. Twenty-six patients (20%) of those hospitalized presented PIMS, only one died for complications of his chronic diseases.

[Clinical manifestations of SARS-CoV-2 infection in children in the middle of pandemic season in a pediatric tertiary center. Report of local COVID Clinical Committee, Hospital de Niños Roberto del Río, Santiago Chile]. / Espectro clínico de la infección en niños por virus SARS-CoV-2 en un centro de referencia pediátrico en plena pandemia. Reporte del Comité Clínico COVID, Hospital de Niños Roberto del Río, Santiago Chile.

BACKGROUND: SARS-CoV-2 virus infection responsible for de pandemic in course, is a new clinical and physiopathological entity, whose control is still uncertain till we can provide an effective and universal vaccine. In the beginning it was described as a respiratory disease which affects mainly adults, children can have the disease too and in this group the disease can be different than the adult disease. Acute infection in children is mostly mild and when it requires hospital assistance it resolves with support therapy and without complications most of the time. However, in the Pediatric Inflammatory Multisystemic Syndrome is vital the early clinical suspect and refers to a tertiary center to bring support and properly treatment. AIM: To describe the clinical spectrum of SARS-CoV-2 virus disease in a pediatric referral center with the pandemic still in development. METHOD: A case series of 537 patients with SARS-CoV-2 infection treated between March 1 and July 15, 2020 is presented with a description of those who were hospitalized. RESULTS: 127 (23%) of them were hospitalized and of these 69% were symptomatic. Twenty-six patients (20%) of those hospitalized presented PIMS, only one died for complications of his chronic diseases.

Aneurismas y divertículos cardíacos congénitos: reporte de una serie pediátrica / Congenital cardiac aneurysms and diverticula: a pediatric series

Introduccion: Los aneurismas y divertículos cardíacos congénitos constituyen malformaciones poco frecuentes y generalmente comprometen el ventrículo izquierdo. Pueden presentarse en forma asintomática, causar embolización, arritmia, insuficiencia cardíaca, rotura o muerte súbita. La ecocardiografía Doppler color realiza el diagnóstico y detecta malformaciones asociadas. La terapia puede ser médica o quirúrgica dependiendo de la presentación clínica y de los hallazgos en cada paciente. Método: Estudio retrospectivo de 5 pacientes durante un período de diez años, uno con divertículo, cuatro con aneurismas, en los cuales se analizó sexo, edad, motivo de consulta, sintomatología, hallazgos al examen físico, malformaciones extracardíacas o cardíacas asociadas. La ecocardiografía confirmó el diagnóstico y analizó la localización, efecto sobre la función cardíaca y presencia de complicaciones. Se estudió el tipo de tratamiento elegido como terapia antiplaquetaria, antiarrítmica o quirúrgica, además del seguimiento. Resultados: De un total de 5 pacientes, tres eran hombres, la mediana de edad al diagnóstico fue de 13 meses; dos de diagnóstico antenatal. Soplo cardíaco (3/5) fue el principal hecho que motivó el estudio. La ubicación más frecuente fue en el ventrículo izquierdo y la malformación cardíaca asociada la comunicación interventricular (2 pacientes). La terapia elegida fue médica en todos los pacientes con aspirina y en un caso se agregó atenolol por taquicardia ventricular no sostenida. Ningún paciente falleció. Conclusion: Constituye la primera publicación sobre esta patología en nuestro país; si bien es una serie pequeña, aporta aspectos clínicos, diagnósticos y de seguimiento que ayudan a sospechar esta rara malformación en el paciente pediátrico.

Introduction: Congenital cardiac aneurysms and diverticula are rare cardiac malformations which mainly affects the left ventricle. Clinically, most are asymptomatic or may cause systemic embolization, arrhyth-mia, heart failure, ventricular wall rupture or sudden cardiac death. Doppler echocardiography establishes the diagnosis and can detect associated malformations. Treatment may be medical or surgical, depending on findings. Patients and Methods: Retrospective study of 5 patients followed for ten years. One patient presented with a diverticulum and four with aneurysms. We analyzed sex, age at diagnosis, symptoms, physical examination, and associated cardiac and extracardiac malformations. Echocardiography confirmed the diagnosis and established location, cardiac function, and presence of complications. We analyzed the treatments used: antiplatelet, anti-arrhythmic or surgical therapy, and follow up. Results: Three were males, the median age at diagnosis was 13 months; in two patients the diagnosis was made before birth. Heart murmur in 3 of 5 patients was the main presenting finding. The most frequent location was the left ventricle and the associated cardiac malformation was ventricular septal defect in 2 patients. All patients were treated with aspirin. One patient with non-sustained ventricular tachycardia received ateno-lol. There were no deaths. Conclusion: This is the first report of this disease in our country. Although it is a small series it provides important clinical aspects for the diagnosis, treatment and follow-up that help us suspect this rare malformation in pediatric patients.

Aspectos clínicos y ecocardiográficos de ventrículo izquierdo no compactado en niños / Clinical and echocadiographic features of non compacted left ventricle in children

Antecedentes: El ventrículo izquierdo no compactado (VINC) corresponde a una miocardiopatía caracterizada por trabeculaciones prominentes con recesos intertrabeculares en continuidad con la cavidad ventricular. Objetivo: Identificar características clínicas, métodos de diagnóstico, seguimiento y analizar índices fijos y variables de pruebas diagnósticas. Material y método: Ocho niños con diagnóstico de VINC entre octubre de 2001 a diciembre de 2004. Se registraron datos clínicos, electrocardiograma (ECG), ecocardiograma bidimensional Doppler color, en siete resonancias nucleares magnéticas (RNM) y biopsia miocárdica. Seguimiento a la totalidad del grupo. Comparación de proporciones según t de student e índices kappa para análisis de concordancia interobservador y cálculo de índices fijos y variables. Resultados: Edad media de 5,9 años. En 4 pacientes la primera manifestación clínica fue insuficiencia cardíaca, y ECG anormal en 8 niños. En 6 pacientes el compromiso ecocardiográfico fue de ventrículo izquierdo (VI) en forma aislada (p<0.01). La fracción de acortamiento de ventrículo izquierdo (FAVI) media fue de 25 por ciento. El radio no compactado/compactado promedio fue de 2.8, mientras que la localización de las trabeculaciones fueron: pared apical (100 por ciento), pared lateral (75 por ciento) Sensibilidad de un 100 por ciento con valor predictivo positivo de 0.83. En 2 niños la FAVI se recuperó en forma significativa durante el primer año de seguimiento. Un fallecimiento por insuficiencia cardíaca refractaria.Conclusiones: VINC constituye un nuevo tipo de enfermedad miocárdica cuyas manifestaciones clínicas no difieren de las de otra etiología, constituyendo la insuficiencia cardíaca la presentación más frecuente. La ecocardiografía es una buena técnica diagnóstica y presenta un alto grado de acuerdo con la RNM y los hallazgos histológicos.

Background: Isolated non-compactation of left ventricular myocardium is a rare congenital cardiomyopathy resulting from an arrest in normal endomyocardial embryogenesis. The characteristic echocardiographic findings consist of multiple, prominent myocardial trabeculations and deep intertrabecular recesses communicating with the left ventricular cavity. Aim: The purpose of this study was to identify the clinical characteristics and follow up in children with left ventricular no compaction (LVNC) and analyze fixed and variable indexes of different diagnostics test. Methods: Eight children with LVNC from October 2001 to December 2004 were included. Review of Clinical data, electrocardiogram and echocardiography were consigned. In seven patients Magnetic Resonance Imaging was done and myocardial biopsy in six. Proportion comparison with t student test, Kappa index comparison for concordance (acceptable agreement degree of >0.8) and fixed and variable calculation were made. Results: Six patients were male. Median age of presentation was 5.9 years (range 0.3 -11 years). In four patients the first clinical manifestation was heart failure, two in functional capacity III-IV (NYHA). Six patients presented ecocardiographic compromise of the left ventricle only (p< 0.01). Median shortening fraction (SF) at diagnosis was 25 percent (range 15 percent-30 percent) Average no compaction/ compaction ratio was 2.8 (range 2.1-4). Localization of the non compactation in the left ventricle was located at the apical wall (100 percent) and lateral wall (75 percent). In comparison to myocardial biopsy Echocardiography sensitivity was 100 percent with positive predictive value of 0.83. Median follow up was 30.7 months (range 1- 50 months). In two children SF improved during follow up. One patient required the implant of a cardiac defibrillator. One death was due to refractory heart failure. Conclusions: Heart failure was the most frequent presentation of LVNC and the cause of...

Intravenous amiodarone for incessant tachyarrhythmias in children: a randomized, double-blind, antiarrhythmic drug trial.

BACKGROUND: Intravenous (IV) amiodarone has proven efficacy in adults. However, its use in children is based on limited retrospective data. METHODS AND RESULTS: A double-blind, randomized, multicenter, dose-response study of the safety and efficacy of IV amiodarone was conducted in 61 children (30 days to 14.9 years; median, 1.6 years). Children with incessant tachyarrhythmias (supraventricular arrhythmias [n=26], junctional ectopic tachycardia [JET, n=31], or ventricular arrhythmias [n=4]) were randomized to 1 of 3 dosing regimens (low, medium, or high: load plus 47-hour maintenance) with up to 5 open-label rescue doses. The primary efficacy end point was time to success. Of 229 patients screened, 61 were enrolled during 13 months by 27 of 48 centers in 7 countries. Median time to success was significantly related to dose (28.2, 2.6, and 2.1 hours for the low-, medium-, and high-dose groups, respectively; P=0.028). There was no significant association with dose for any arrhythmia subgroup, including JET, but the subgroups were too small for an accurate assessment. Adverse events (AEs) were common (87%), leading to withdrawal of 10 patients. There were 5 deaths in the 30-day follow-up period (2 possibly related to the study drug). Dose-related AEs included hypotension (36%), vomiting (20%), bradycardia (20%), atrioventricular block (15%) and nausea (10%). CONCLUSIONS: In children, the overall efficacy of IV amiodarone, as measured by time to success, was dose related but not significantly for any arrhythmia subgroup. AEs were common and appeared to be dose related. Although efficacious for critically ill patients, the dose-related risks of IV amiodarone should be taken into account when treating children with incessant arrhythmias. Prospective, placebo-controlled trials would be helpful in assessing antiarrhythmic drug efficacy in children, because their results may differ from retrospective series and adult studies.