[Tissue perfusion monitoring in children with acute circulatory dysfunction: narrative review]. / Monitorización de la perfusión tisular en el niño con disfunción circulatoria aguda: revisión narrativa.

Sepsis is one of the main causes of admission to Intensive Care Units (ICU). The hemodynamic objectives usually sought during the resuscitation of the patient in septic shock correspond to macrohemodynamic parameters (heart rate, blood pressure, central venous pressure). However, persistent alterations in microcirculation, despite the restoration of macrohemodynamic parameters, can cause organ failure. This dissociation between the macrocirculation and microcirculation originates the need to evaluate organ tissue perfusion, the most commonly used being urinary output, lactatemia, central venous oxygen saturation (ScvO2), and veno-arterial pCO2 gap. Because peripheral tissues, such as the skin, are sensitive to disturbances in perfusion, noninvasive monitoring of peripheral circulation, such as skin temperature gradient, capillary refill time, mottling score, and peripheral perfusion index may be helpful as early markers of the existence of systemic hemodynamic alterations. Peripheral circulation monitoring techniques are relatively easy to interpret and can be used directly at the patient's bedside. This approach can be quickly applied in the intra- or extra-ICU setting. The objective of this narrative review is to analyze the various existing tissue perfusion markers and to update the evidence that allows guiding hemodynamic support in a more individualized therapy for each patient.

[Childhood and COVID-19: The indirect effects of the COVID-19 pandemic on the well-being of children and adolescents]. / Infancia y COVID-19: Los efectos indirectos de la pandemia COVID-19 en el bienestar de niños, niñas y adolescentes.

The impact of the COVID-19 pandemic has been overlooked in children and adolescents since many of the negative effects have been the result of containment and mitigation measures and will only be quantifiable in the medium and long term. Although the global response has been successful in reducing the lethality of the disease, the harmful effect on vulnerable populations, such as children and adolescents, is enormous and has been classified as catastrophic by international organizations. The pandemic has deeply affected the physical and mental health of children and adolescents, but also silently its negative effects extend across many areas such as schooling, familiar economy, child labor and food security. The third year of the pandemic is an opportunity to include the multidimen sional well-being of children and adolescents as a cornerstone of society's response to a global crisis, whether health, economic or political.

[Extreme electrolyte depletion associated with septic shock as a form of presentation of cystic fibrosis]. / Depleción electrolítica extrema asociada con shock séptico como forma de presentación de fibrosis quística.

In the pediatric emergency department, dehydrated children are one of the most frequent causes for consultation, however, the coexistence of hyponatremia with hypochloremia and metabolic alkalosis is rare. The presence of metabolic alkalosis due to chloride depletion has been reported as a form of presentation of Cystic Fibrosis (CF). OBJECTIVE: to describe a case of cystic fibrosis of unusual presen tation in a pediatric patient. CLINICAL CASE: we report a 3-month-old previously healthy male infant who presented with internal environment abnormalities consisting of metabolic alkalosis, hypona tremia, hypokalemia, and extreme hypochloremia associated with septic shock due to mixed viral- bacterial pneumonia (Rhino/enterovirus, Streptococcus pneumoniae, and Staphylococcus aureus). Cys tic fibrosis (CF) was suspected, thus the diagnosis was corroborated by sweat test and genetic study which showed the pathogenic variants c.2834C>T (p.Ser945Leu) and c.3484C>T (p.Arg1162X), both heterozygous. CONCLUSION: special attention should be paid to the existence of hypochloremia with metabolic alkalosis and hyponatremia associated or not with pulmonary disease, suspecting CF as the first option. This consideration becomes more relevant in those countries where the neonatal screening test is not widely available.

[About an epidemic, ventilators and intensive care. A Déjà vu?] / De una epidemia, ventiladores y cuidados intensivos. ¿Un Déjà vu?

The birth of intensive care was a process that took place in Copenhagen, Denmark, during and after the polio epidemic of 1952-1953. The fact that marks its beginning was that anesthesiologist Björn Ibsen was asked to help and "came out of the operating room", not without some controversy. Ib sen proposed and advocated the use of tracheostomy, suctioning and ventilation. Given the lack of positive pressure ventilators, this task was carried out by students who contributed 165,000 hours of manual ventilation. Few years later, in Gothenburg, Sweden, the anesthesiologist Göran Haglund, motivated by the case of a four years old boy with complicated appendicitis, created the first multi disciplinary pediatric intensive care unit in the world (1955). In Chile, during the 1950s, the concept of pediatric intensive care began to develop under the direction of physicians with a solid vision of the future. Given that the planet is experiencing a pandemic, it seems an appropriate moment to review the role of the polio epidemic in the development of positive pressure ventilation, the birth of intensive care medicine and intensive care units, in order to assess the role of the various tasks and innovations carried out.

Otto Frank y Ernest Starling. Más allá de una ley o un mecanismo. Breve reseña histórica / Otto Frank and Ernest Starling. Beyond a law or a mechanism. Brief historical relate

Resumen La ley o mecanismo de Frank-Starling describe la relación entre la longitud inicial de las fibras miocárdicas y la fuerza generada por su poder de contracción. Aunque ni Otto Frank (1895) como tampoco Ernest Starling (1915) fueron los primeros en descubrir que el volumen diastólico final regula el trabajo del corazón, su participación para este famoso epónimo fisiológico es indiscutible, y de ahí que sus nombres perduraran por más de un siglo en el ambiente de la fisiología, la cardiología y los cuidados intensivos, entre otras disciplinas. Se revisa la biografía de Otto Frank (1865-1944), un excepcional fisiólogo alemán con un amplio conocimiento en física, matemáticas y ciencias naturales, que formuló principios teóricos para la fisiología muscular y cardiovascular, además de muchas otras contribuciones metodológicas e instrumentales. También se examina la vida del gran médico y fisiólogo inglés Ernest Henry Starling (1866-1927), quien elaboró diversos y relevantes aportes científicos, más allá de sus afamadas publicaciones sobre la función circulatoria. Finalmente, el presente artículo comenta en forma breve sus principales y más importantes contribuciones, así como también aspectos menos conocidos de sus logros científicos.

Abstract Frank-Starling's law or mechanism describes the relationship between the initial length of myocardial fibers and the force generated by their contraction power. Although neither Otto Frank (1895) nor Ernest Starling (1915) were the first to discover that the final diastolic volume regulates the work of the heart, their participation for this famous physiological eponym is indisputable, enduring their names for more than a century in the environment of physiology, cardiology and intensive care, among other disciplines. The biography of Otto Frank (1865-1944) is reviewed, who was an exceptional German physiologist with extensive knowledge in physics, mathematics and natural sciences who formulated theoretical principles for muscular and cardiovascular physiology, in addition to many other methodological contributions in instrumentals. Also examined the life of the great English physician and physiologist Ernest Henry Starling (1866-1927), who produced various and relevant scientific contributions, beyond his famous publications on circulatory function. Finally, this article briefly comments on its main and most important contributions, as well as less known aspects of its scientific achievements.

Organ dysfunction syndrome and mitochondrial adaptation in the septic patient. / Síndrome de disfunción de órganos y adaptación mitocondrial en el paciente séptico.

The ability to maintain an adequate energy balance and to respond and adapt to environmental stress at the cellular level are cornerstones for the survival and evolution of organisms. Therefore, in the presence of various factors, a cellular protection response is triggered by activation of mitochondrial function-dependent signaling. However, this essential reaction for individual cell survival can be detrimental to organ function (maladaptation), transforming the close balance between the two into the pathogenetic axis of organ dysfunction and eventual recovery in septic patients. Macrocirculatory and microcirculatory disruption undoubtedly contributes to organ dysfunction in the early stage of septic shock, while intrinsic metabolic-bioenergetic failure (cytopathic hypoxia) perpetuates inadequate cellular function. Therefore, mitochondrial dysfunction is a key process in the induction of multiple organ dysfunction syndrome in the septic patient. This syndrome can be considered as a complex hypometabolic adaptive phenomenon in the face of excessive and prolonged inflammatory stimulus to achieve regulation of energy homeostasis and preservation of organ function. In the future, there should be a transition from the current consensus therapeutic options, which are limited to control of the infectious focus, hemodynamic and life support, to metabolic resuscitation based on the molecular and genetic alterations triggered by the infection.

Piedra angular para la sobrevida y la evolución de los organismos es su capacidad de mantener un adecuado balance energético, así como también que las células respondan y se adapten al estrés ambiental. Por ello, ante la presencia de diversos factores se origina una respuesta de protección celular mediante la activación de señalización dependiente de la función mitocondrial. Sin embargo, esta reacción, esencial para la supervivencia individual de las células, puede ser perjudicial para la función orgánica (adaptación inadecuada), transformando el estrecho equilibrio entre ambas en el eje patogénico de la disfunción orgánica y su eventual recuperación en el paciente séptico. Las alteraciones macrocirculatorias y microcirculatorias contribuyen, indudablemente, a la disfunción orgánica en la etapa precoz del choque séptico, mientras que la falla metabólica-bioenergética intrínseca (hipoxia citopática) perpetúa una función celular inadecuada. Por lo tanto, la disfunción mitocondrial es un proceso clave en la inducción del síndrome de disfunción multiorgánica en el paciente séptico. Este síndrome puede considerarse como un complejo fenómeno adaptativo hipometabólico ante un estímulo inflamatorio excesivo y prolongado, para lograr la regulación de la homeostasis energética y la preservación de la función de los órganos. En el futuro, debería producirse una transición entre las opciones terapéuticas actuales consensuadas, que se limitan al control del foco infeccioso y el soporte hemodinámico y vital, hacia una reanimación metabólica basada en las alteraciones moleculares y genéticas desencadenadas por la infección.

[Seventy years after the beginning of vaccination against pertussis. Brief historical review of the treatments used in its combat]. / A setenta años del inicio de la vacunación antipertussis. Breve revisión histórica de los tratamientos empleados en su combate.

For centuries, numerous treatments were used, of the most varied origins and based on the most unlikely foundations designed to hasten recovery and improve the survival of patients with whooping cough. In 1906, when the bacterial origin of whooping cough was identified, the hope for a potential treatment arose, however, only decades later, humanity would face a significant change with the con solidation of an effective vaccination. This article provides a historical review from the use of some of the most frequent treatments devised between the 18th-20th centuries for the cure of whooping cough. Some of the therapies offered in Chile in the first half of the last century are emphasized and detailed.

The obese child in the Intensive Care Unit. Update. / El niño obeso en la Unidad de Cuidados Intensivos. Puesta al día.

Given that childhood obesity is an epidemic, the frequency of critically-ill patients who are overweight or obese seen at intensive care units has increased rapidly. Adipose tissue is an endocrine organ that secretes a number of protein hormones, including leptin, which stands out because it regulates adipose tissue mass. The presence of arterial hypertension, metabolic syndrome, diabetes mellitus, respiratory disease and chronic kidney disease may become apparent and complicate the course of obese pediatric patients in the Intensive Care Unit. Obesity management is complex and should involve patients, their families and the medical community. It should be coordinated with comprehensive government health policies and implemented in conjunction with a change in cultural context.

Actualmente, la obesidad infantil constituye una epidemia. La frecuencia de pacientes críticos con sobrepeso u obesidad ha aumentado rápidamente en las unidades de cuidados intensivos. El tejido adiposo es un órgano endocrino que secreta varias hormonas proteicas, entre las que se destaca la leptina, la cual es reguladora de su masa. La presencia de hipertensión arterial, síndrome metabólico, diabetes mellitus, enfermedades respiratorias y enfermedad renal crónica se puede manifestar en el paciente pediátrico obeso durante su estadía en la Unidad de Cuidados Intensivos y complicar su evolución. El tratamiento de la obesidad es complejo y debe involucrar al paciente, a su familia y a la comunidad médica. Debe realizarse en coordinación con políticas sanitarias gubernamentales integrales y en conjunto con un cambio de marco cultural.

Ruptura gástrica idiopática en niño preescolar: informe de un caso / Idiopathic gastric rupture in toddler: case report

La ruptura gástrica idiopática es una patología muy poco frecuenteen niños. La gran mayoría de los casos ocurre en el período neonatal. Comunicamos el caso de una paciente preescolar de 2 años, sexo femenino, sin antecedentes mórbidos. Consultócon antecedente de 48 h de dolor abdominal, náuseas y vómitos.Ingresó al servicio de urgencia en malas condiciones generales, con un abdomen distendido y signos de irritación peritoneal. Se realizó laparotomía exploradora de emergencia que reveló ruptura gástrica en pared posterior ocasionada por múltiples perforaciones. Se efectuó gastrectomía parcial. Ingresó a UCIen shock. Recibió asistencia ventilatoria mecánica, reanimación con fluidos (260 ml/kg en 12 h), fármacos vasoactivos y tratamiento antibiótico con cefotaxima-metronidazol. El laboratorio evidenció leucopenia y trombopenia. El estudio etiológico fue negativo para ingesta de tóxicos y medicamentos. Se descartócolagenopatía y su gastrinemia fue normal. Su postoperatorio se caracterizó por persistencia de fiebre originada porcolección subfrénica izquierda (cultivo positivo para Candida galabrata). Se realizó limpieza quirúrgica mediante laparotomía y drenaje percutáneo de las colecciones residuales. Completótres semanas de terapia antibiótica y antifúngica con evolución satisfactoria. El control ambulatorio de la paciente a los 12 meses fue normal.