Variabilidad terapéutica en lactantes con bronquiolitis hospitalizados en unidades de cuidados intensivos latinoamericanas / Therapeutic variability in infants admitted to Latin-American pediatric intensive units due to acute bronchiolitis

Resumen: Objetivo: describir las terapias utilizadas en lactantes con bronquiolitis aguda admitidos en 20 Uni dades de Cuidados Intensivos (UCI) pediátricos miembros de LARed en 5 países latinoamerica nos. Pacientes y Método: Estudio observacional retrospectivo, multicéntrico, de datos del Registro Latinoamericano de Falla Respiratoria Aguda Pediátrica. Se incluyeron niños menores de 2 años ingresados a UCI pediátrica por bronquiolitis aguda comunitaria entre mayo-septiembre 2017. Se recolectaron datos demográficos, clínicos, soporte respiratorio, terapias utilizadas y resultados clí nicos. Se realizó análisis de subgrupos según ubicación geográfica, tipo financiación y presencia de academia. Resultados: Ingresaron al registro 1155 pacientes con falla respiratoria aguda. Seis casos fueron excluidos por no tener formulario completo. De los 1147 pacientes, 908 eran menores de 2 años. De ellos, 467 tuvieron diagnóstico de bronquiolitis aguda, correspondiendo a la principal causa de ingreso a UCI pediátrica por falla respiratoria aguda (51,4%). Las características demográficas y de gravedad entre los centros fueron similares. El soporte máximo respiratorio más frecuente fue cánula nasal de alto flujo (47%), seguido por ventilación mecánica no invasiva (26%) y ventilación mecánica invasiva (17%), con un coeficiente de variación (CV) amplio entre los centros. Hubo una gran dispersión en uso de terapias, siendo frecuente el uso de broncodilatadores, antibióticos y corticoides, con CV hasta 400%. El análisis de subgrupos mostró diferencias significativas en soporte respiratorio y tratamientos utilizados. Un paciente falleció en esta cohorte. Conclusión: Detectamos gran variabilidad en el soporte respiratorio y tratamientos entre UCI pediátricas latinoamericanas. Esta variabilidad no es explicada por disparidades demográficas ni clínicas. Esta heterogeneidad de tratamientos debería promover iniciativas colaborativas para disminuir la brecha entre la evidencia científica y la práctica asistencial.

Abstract: The objective of this study was to describe the management of infants with acute bronchiolitis admit ted to 20 pediatric intensive care units (PICU) members of LARed in 5 Latin American countries. Pa tients and Method: Retrospective, multicenter, observational study of data from the Latin American Registry of Acute Pediatric Respiratory Failure. We included children under 2 years of age admitted to the PICU due to community-based acute bronchiolitis between May and September 2017. Demo graphic and clinical data, respiratory support, therapies used, and clinical results were collected. A subgroup analysis was carried out according to geographical location (Atlantic v/s Pacific), type of insurance (Public v/s Private), and Academic v/s non-Academic centers. Results: 1,155 patients were included in the registry which present acute respiratory failure and 6 were excluded due to the lack of information in their record form. Out of the 1,147 patients, 908 were under 2 years of age, and out of those, 467 (51.4%) were diagnosed with acute bronchiolitis, which was the main cause of admission to the PICU due to acute respiratory failure. The demographic and severity characteristics among the centers were similar. The most frequent maximum ventilatory support was the high-flow nasal can nula (47%), followed by non-invasive ventilation (26%) and invasive mechanical ventilation (17%), with a wide coefficient of variation (CV) between centers. There was a great dispersion in the use of treatments, where the use of bronchodilators, antibiotics, and corticosteroids, representing a CV up to 400%. There were significant differences in subgroup analysis regarding respiratory support and treatments used. One patient of this cohort passed away. Conclusion: we detected wide variability in respiratory support and treatments among Latin American PICUs. This variability was not explained by demographic or clinical differences. The heterogeneity of treatments should encourage collabora tive initiatives to reduce the gap between scientific evidence and practice.

Fragilidad: en busca de herramientas de evaluación preoperatoria / Assessment of two frailty scales for the preoperative period

Background: In the perioperative context, a frailty evaluation scale must consider certain characteristics such as validation, execution speed, simplicity, the capacity to measure multiple dimensions and not being dependent on a cognitive or physical test that could not be performed prior to surgery. The test should select patients that could benefit from interventions aimed to improve their postoperative outcomes. Aim: To validate two frailty evaluation scales for the perioperative period. Material and Methods: The Risk Analysis Index with local modifications (RAI-M) were applied to 201 patients aged 73 ± 7 years (49% women) and the Edmonton frailty scale were applied in 151 patients aged 73 ± 7 years (49% women) in the preoperative period. Their results were compared with the Rockwood frailty index. Results: The Edmonton frail scale showed adequate psychometric properties and assessed multiple dimensions through 8 of the 11 original questions, achieving a discrimination power over 80% compared to the Rockwood Index. The RAI- M, demonstrated solid psychometric properties with a tool that examines 4 dimensions of frailty through 15 questions and reviewing the presence of 11 medical comorbidities. This scale had a discrimination power greater than 85% and it was significantly associated with prolongation of the planned hospital stay and mortality. Conclusions: RAI-M is a short and easily administered scale, useful to detect frailty in the preoperative period.

La colaboración para mejorar los cuidados médicos de nuestros niños. El desarrollo de una Red Pediátrica Latinoamericana: LARed / Collaboration as a tool to improve children´s healthcare through a Latin American Pediatric Network: LARed / A colaboração como ferramenta no melhoramento do cuidado médico das crianças através do desenvolvimento duma Rede Pediátrica Latino-Americana: LARed

Las redes colaborativas pediátricas son una probada y transformadora forma de acelerar la traslación de la evidencia a la práctica clínica y han estado en constante crecimiento durante el presente siglo. Han mostrado ser una herramienta para asegurar la innovación y mejoría del valor de nuestros cuidados en salud, con el poder de comprometer a los clínicos, investigadores, pacientes y familias en diferentes escenarios sanitarios. Inspirados en la experiencia de la Vermont Oxford Network, en 2014 un grupo de profesionales voluntarios e independientes de Uruguay formaron una red colaborativa de cuidados intensivos pediátricos llamada LARed. Comprometidos en mejorar la calidad y seguridad de la atención que brindaban a sus pacientes y familias, establecieron una comunidad de prácticas poderosa que se expandió exponencialmente al continente latinoamericano e involucrando a la fecha 30 centros de ocho países. Su filosofía se basa en cuatro pilares: medir, aprender, mejorar y compartir, de forma que los centros con mejores resultados se vuelven una guía hacia la excelencia del grupo en general. Para lograr sus objetivos LARed dedica sus recursos para coordinar iniciativas de investigación, educativas y de mejoría de calidad, combinando el esfuerzo colectivo entre pares y manteniendo una base de datos on-line (a la fecha con más de 2.000 niños) creada para analizar las intervenciones y los resultados de la práctica clínica del mundo real (transformando entonces la información en acción). Este reporte describe el desarrollo de LARed, explica sus objetivos, visión y misión, así como resume las actividades y programas desarrollados desde su creación.

Pediatric collaborative networks are a proven and transformational mean of accelerating the translation of evidence into clinical practice and have expanded steadily in this century. They have become a tool for innovation and improving value in healthcare, engaging clinicians, researchers, patients and families in different healthcare settings. Inspired by the Vermont Oxford Network experience, a group of Uruguayan health professional volunteers started a collaborative pediatric intensive care network called LARed in 2014. Committed to improving healthcare quality and safety, they set up a strong community that has expanded exponentially to the rest of Latin America and presently includes 30 pediatric intensive care units from 8 countries. The network's philosophy lies on 4 pillars: measure, learn, improve and share, so that the best-performing centers can become leaders in excellence to the general collaboration group. In order to better achieve these goals, LARed dedicates resources to research coordination, educational and quality improvement initiatives, combines collective peer efforts and manintains web-based online databases (over 2,000 children at present) set up to analyze real world practice interventions and outcomes, thus transforming information into action. This paper describes LARed development, explains its goals, vision and mission, and summarizes the activities and programs carried out since it was first created.

As redes colaborativas pediátricas são uma forma comprovada e transformadora de acelerar a transferência de evidências para a prática clínica, e elas tem crescido constantemente durante este século. Elas transformaram-se numa ferramenta para garantir a inovação e melhorar o valor dos cuidados de saúde, e tem envolvido médicos, pesquisadores, pacientes e famílias em diferentes contextos de saúde. Inspirado pela experiência da Rede Vermont Oxford, em 2014, um grupo de profissionais da saúde voluntários e independentes do Uruguai formou uma rede colaborativa de cuidados pediátricos intensivos chamada LARed. Comprometidos com a excelência da qualidade e segurança dos cuidados prestados aos seus pacientes e familiares, eles estabeleceram uma forte comunidade de práticas que se expandiram exponencialmente para o continente latino-americano e envolveram 30 centros de oito países até o momento. Sua filosofia é baseada em 4 pilares: medir, aprender, melhorar e compartilhar, de modo que os centros com os melhores resultados se tornem um guia para a excelência do grupo em geral. Para atingir seus objetivos, a LARed dedica seus recursos para coordenar iniciativas de pesquisa, educação e melhoria da qualidade, combina o esforço coletivo entre pares e mantem um banco de dados on-line (atualizado com mais de 2000 crianças) criado para analisar intervenções e resultados da prática clínica do mundo real (transformando a informação em ação). Este paper descreve o desenvolvimento de LARed, explica seus objetivos, visão e missão e também resume as atividades e programas desenvolvidos desde a sua criação.

Decreased lung compliance increases preload dynamic tests in a pediatric acute lung injury model / Una compliance pulmonar disminuida incrementa los test dinámicos de precarga en un modelo pediátrico de lesión pulmonar aguda

Background: Preload dynamic tests, pulse pressure variation (PPV) and stroke volume variation (SVV) have emerged as powerful tools to predict response to fluid administration. The influence of factors other than preload in dynamic preload test is currently poorly understood in pediatrics. The aim of our study was to assess the effect of tidal volume (V T) on PPV and SVV in the context of normal and reduced lung compliance in a piglet model. Material and method: Twenty large-white piglets (5.2 ± 0.4 kg) were anesthetized, paralyzed and monitored with pulse contour analysis. PPV and SVV were recorded during mechanical ventilation with a V T of 6 and 12 mL/kg (low and high V T, respectively), both before and after tracheal instillation of polysorbate 20. Results: Before acute lung injury (ALI) induction, modifications of V T did not significantly change PPV and SVV readings. After ALI, PPV and SVV were significantly greater during ventilation with a high V T compared to a low V T (PPV increased from 8.9 ± 1.2 to 12.4 ± 1.1%, and SVV from 8.5 ± 1.0 to 12.7 ± 1.2%, both P < 0.01). Conclusions: This study found that a high V T and reduced lung compliance due to ALI increase preload dynamic tests, with a greater influence of the latter. In subjects with ALI, lung compliance should be considered when interpreting the preload dynamic tests.

Introducción: Test dinámicos de precarga, variación de presión de pulso (PPV) y variación de volumen sistólico (SVV) han emergido como herramientas poderosas para predecir respuesta a la administración de fluidos. Actualmente la influencia de factores distintos a la precarga en la determinación de los test dinámicos de precarga es pobremente conocida en pediatría. Nuestro objetivo fue medir el efecto del volumen tidal (V T) sobre PPV y SVV en un contexto de compliance pulmonar normal y disminuida en un modelo porcino. Material y método: Veinte cerditos Large-White anestesiados y paralizados (5,2 ± 0,4 kg). PPV y SVV fueron medidos por análisis de contorno de pulso durante ventilación con V T de 6 y 12 mL/kg (V T bajo y alto, respectivamente), ambos previo y posterior a lesión pulmonar aguda (ALI) químicamente inducida con instilación traqueal de polisorbato 20. Resultados: Previo a inducción de ALI, PPV y SVV no tuvieron cambios significativos al modificar el V T. Sin embargo, después de ALI, PPV y SVV fueron significativamente mayores durante ventilación con V T alto, respecto a V T bajo (PPV aumentó de 8,9 ± 1,2 a 12,4 ± 1,1%, y SVV de 8,5 ± 1,0 a 12,7 ± 1,2%, ambos P < 0,01). Conclusiones: Este estudio encontró que un V T alto y una compliance pulmonar disminuida debido a ALI incrementan los test dinámicos de precarga, con una mayor influencia de esta última. En sujetos con ALI la compliance pulmonar debiera ser considerada al interpretar los test dinámicos de precarga.

Diferencia veno-arterial de dióxido de carbono como predictor de gasto cardiaco disminuido en modelo pediátrico experimental / Veno-arterial difference of carbondioxide as a predictor of low cardiac output in an experimental pediatric model

Background: Cardiac output (CO) measurement is not a standard of care for critically ill children, but it can be estimated by indirect methods such as veno-arterial pCO2 difference (ΔVACO2). Aim: To determine the correlation between CO and ΔVACO2 and evaluate the usefulness of ΔVACO2 in the diagnosis of low CO in an experimental pediatric model. Materials and Methods: Thirty piglets weighing 4.8 ± 0.35 kg were anesthetized and monitored with transpulmonary thermodilution. Lung injury was induced with tracheal instillation of Tween 20®. Serial measurements of central venous and arterial blood gases, as well as CO, were obtained at baseline, 1, 2 and 4 h after lung injury induction. Low cardiac output (LCO) was defined as CO lower than 2.5 Llminlm². Results: There was an inverse correlation between CO and ΔVACO2 (r = -0.36, p < 0.01). ΔVACO2 was 14 ± 8 mmHg in LCO state and 8 ± 6 mmHg when this condition was not present (p < 0.01). Area under the receiver operating characteristic (ROC) curves of ΔVACO2 and LCO state was 0.78 (0.68-0.86). The best cut-point was 8.9 mmHg to determine LCO with a sensibility 0.78, specificity 0.7, positive predictive value 0.27 and negative predictive value 0.96. Conclusions: In this model there was an inverse correlation between ΔVACO2 and CO. The best cutoff value to discard LCO was ΔVACO2 of 8.9 mmHg, indicating that under this value the presence of LCO is very unlikely.

Efectos protectores de la hipotermia moderada en modelo de injuria pulmonar inducida por ventilación mecánica / Protector effects of moderated hypothermia in model of pulmonary injury caused by mechanical ventilation

Se ha establecido que el empleo inapropiado de la ventilación mecánica (VM) es capaz de generar daño pulmonar y de amplificar una noxa pulmonar pre-existente. Éste fenómeno mecánico, denominado injuria pulmonar inducida por VM (VILI), es capaz de gatillar consecuencias biológicas locales y a distancia. La hipotermia ha sido empleada en situaciones clínicas que generan un desequilibrio entre la entrega y el consumo tisular de oxígeno, debido a su capacidad de reducir este último. Nuestro objetivo fue determinar el efecto de la hipotermia moderada (HM) sobre marcadores biológicos de VILI e intercambio gaseoso.Se emplearon 12 ratas Sprague-Dawley machos adultas. Tras ser anestesiadas se intubaron y ventilaron mecánicamente en modalidad presión control, PIM 40 cmH2O, ZEEP, FR 60/min, TIM 25 por ciento, FIO2 100 por ciento. Los animales se aleatorizaron a grupos normotermia (N) (37 ± 1ºC) y HM (34 ± 1ºC), medido a nivel de esófago torácico. Se registró gasometría arterial, gravimetría, análisis histológico y medición de concentración de proteínas, interleukina (IL)-1[beta] (IL-1b) y factor de necrosis tumoral (TNF)-[alfa] (TNF-a) en el sobrenadante del lavado bronco alveolar (LBA) y plasma.Los animales con HM redujeron relación peso húmedo/seco y la PaCO2, respecto a los animales normotérmicos, no siendo significativa la mejoría de la PaO2. Hubo además una reducción de los niveles sistémicos de citoquinas inflamatorias en el grupo HM. No hubo diferencias respecto al score histológico de daño pulmonar ni de concentración de proteínas en LBA. En este modelo experimental la HM provocó una reducción del agua extravascular pulmonar y citoquinas inflamatorias plasmáticas, lo que refleja menor daño, asociado a una disminución significativa en la PaCO2. Estos hechos ameritan la realización de nuevos estudios que demuestre su rol como terapia adyuvante al manejo ventilatorio de pulmones agudamente dañados, ampliando el tradicional rol de la HM en cuidados críticos.

The inadequate use of Mechanical Ventilation (MV) has proved to generate lung damage and to increase a pre-existing pulmonary injury. This mechanical event, called ventilator induced lung injury (VILI), can generate local and distant biological effects. Hypothermia has been used in clinical situations, which result in an imbalance between oxygen consumption (VO2) and delivery (DO2) due to its ability to reduce VO2. Our objective was to determine the effect of Moderate Hypothermia (MH) on biological markers of VILI and in gas exchange.Twelve Sprague-Dawley adult male rats were used. After anesthesia, the rats were randomly assigned to normothermia (37ºC) and MH (34ºC), which was induced by surface cooling. They were cannulated and mechanically ventilated with controlled pressure ventilation, PIP 40 cmH2O, ZEEP, (PEEP=0) RR 60/min, Ti 25 percent, FIO2 100 percent. The esophageal temperature was maintained within ± 1°C. Arterial blood gases, lung gravimetry, histological analysis and measurement of protein content, IL-1b and TNF-a were registered in the bronchoalveolar lavage (BAL) supernatant, both cytokines were also measured in plasma.The animals with MH showed a significant reduction in the wet lung weight/dry lung weight ratio and the PaCO2, in relation to the normothermic animals. There was also a reduction of the inflammatory systemic cytokines in the MH group. There were no differences in PaO2, histological score and protein content in BAL. In this experimental model, MH reduced extra vascular lung water, which reflects lesser damage associated to a significative reduction in PaCO2 and inflammatory systemic cytokines. These facts justify new studies, which would prove its role as an aid in the ventilatory management of severely damaged lungs, increasing the traditional role of MH in critical care.

Variación de presión de pulso en ventilación mecánica / Variation of pulse pressure in mechanical ventilation

La condición hemodinámica de los pacientes críticos puede presentar una amplia variedad de volumen circulante efectivo y función miocárdica. La insuflación de un volumen corriente es capaz de interferir en forma cíclica sobre la hemodinámica, emergiendo la monitorización hemodinámica funcional -reflejo directo de la interacción corazón-pulmón- como una valiosa herramienta para predecir la respuesta a fluidos y como fuente de información dinámica de la condición fisiológica de cada individuo.En el siguiente artículo se revisa en forma resumida los sustentos del empleo de la variación de presión de pulso en ventilación mecánica para la predicción de respuesta a volumen, como también sus limitaciones actualmente aceptadas.

Hemodynamic condition of critically ill patients may present a wide variation of effective circulating volume and miocardic function. The insufflation of an ordinary volume may interfere cyclically on hemodynamics, and functional hemodynamic monitoring (direct reflex of heart-lung interaction) emerges as a valuable tool for predicting the response to fluids and as a dynamic source of information concerning the physiological condition of each individual. In the current article, support for the use of pulse pressure variation in mechanical ventilation for predicting response to volume, and its currently accepted limitations are dealt with in an abridged review.