Cánula Nasal de Alto Flujo Asimétrica: una Revisión Narrativa / Asymmetrical High Flow Nasal Cannula: a Narrative Review

Los sistemas de Cánula nasal de alto flujo (CNAF) han sido ampliamente utilizados en el campo clínico como soporte no invasivo en el manejo de la falla respiratoria aguda (sobre todo hipoxémica) y cuidados post extubación. Clínica y fisiológicamente, las cánulas nasales de alto flujo son capaces de entregar un flujo de oxigeno alto que, debido a que ese gas se encuentra optimamente humidificado y calefaccionado, permite una mejor tolerancia por parte del paciente al ser comparada con las cánulas de oxigeno tradicionales. Por otra parte, este alto. Flujo es capaz de generar una presión positiva al final de la espiración (CPAP) en la vía área y favorecer tanto en barrido de dióxido de carbono (CO2) desde la vía aérea superior, lo que disminuye el trabajo respiratorio del paciente y mejora su confort.. Sin embargo; aún existe un alto porcentaje de pacientes que fracasan la terapia con CNAF y requiere soportes mas complejos como la ventilación mecánica, ya sea imvasiva o no. Estos resultados con la terapia CNAF pueden ser influidos por aspectos técnicos como, por ejemplo, la turbulencia que pueden generar estos sistemas a nivel de la región nasal. Por esta razón se han desarrollado nuevas tecnologías en el diseño y uso de interfaces para suministrar este alto flujo. Una de estas innovaciones es el uso de cánulas asimétricas, las que potencian los beneficios fisiológicos que entrega una cánula de alto flujo convencional. La presente revisión pretende exponer las principales diferencias que presenta el sistema de alto flujo convencional versus la nueva interface asimétrica.

High-flow nasal cannula (HFNC) systems have been widely used in the clinical field as non-invasive support in the management of acute respiratory failure (especially hypoxemic) and post-extubation care. Clinically and physiologically, high flow nasal cannulas are capable of delivering a high flow of oxygen which, because this gas is optimally humidified and heated, allows better tolerance by the patient when compared to traditional oxygen cannulas. . On the other hand, this high. Flow is capable of generating positive pressure at the end of expiration (CPAP) in the airway and favoring the sweep of carbon dioxide (CO2) from the upper airway, which reduces the patient's respiratory work and improves their comfort. .. However; There is still a high percentage of patients who fail therapy with HFNC and require more complex supports such as mechanical ventilation, whether invasive or not. These results with HFNC therapy can be influenced by technical aspects such as, for example, the turbulence that these systems can generate in the nasal region. For this reason, new technologies have been developed in the design and use of interfaces to provide this high flow. One of these innovations is the use of asymmetric cannulas, which enhance the physiological benefits provided by a conventional high-flow cannula. The present review aims to expose the main differences that the conventional high flow system presents versus the new asymmetric interface.

Molecular Bases of Protein Antigenicity and Determinants of Immunogenicity, Anergy, and Mitogenicity.

BACKGROUND: The immune system is able to recognize substances that originate from inside or outside the body and are potentially harmful. Foreign substances that bind to immune system components exhibit antigenicity and are defined as antigens. The antigens exhibiting immunogenicity can induce innate or adaptive immune responses and give rise to humoral or cell-mediated immunity. The antigens exhibiting mitogenicity can cross-link cell membrane receptors on B and T lymphocytes leading to cell proliferation. All antigens vary greatly in physicochemical features such as biochemical nature, structural complexity, molecular size, foreignness, solubility, and so on. OBJECTIVE: Thus, this review aims to describe the molecular bases of protein-antigenicity and those molecular bases that lead to an immune response, lymphocyte proliferation, or unresponsiveness. CONCLUSION: The epitopes of an antigen are located in surface areas; they are about 880-3,300 Da in size. They are protein, carbohydrate, or lipid in nature. Soluble antigens are smaller than 1 nm and are endocytosed less efficiently than particulate antigens. The more the structural complexity of an antigen increases, the more the antigenicity increases due to the number and variety of epitopes. The smallest immunogens are about 4,000-10,000 Da in size. The more phylogenetically distant immunogens are from the immunogen-recipient, the more immunogenicity increases. Antigens that are immunogens can trigger an innate or adaptive immune response. The innate response is induced by antigens that are pathogen-associated molecular patterns. Exogenous antigens, T Dependent or T Independent, induce humoral immunogenicity. TD protein-antigens require two epitopes, one sequential and one conformational to induce antibodies, whereas, TI non-protein-antigens require only one conformational epitope to induce low-affinity antibodies. Endogenous protein antigens require only one sequential epitope to induce cell-mediated immunogenicity.

Evaluación del Rendimiento y Producción de Humedad de los Humidificadores de Burbuja usados con Mascarillas Oxígeno de Concentración Variable / Evaluation of the Performance and Humidity Production of Bubble Humidifiers used with Variable Concentration Oxygen Masks

Introducción. Introducción. El uso de humidificadores de burbuja asociados a equipos de oxigenoterapia es una práctica común en los centros hospitalarios de nuestro país. Sin embargo, no se ha evaluado el aporte real de humedad que entregan estos equipos cuando son usados con sistemas de concentración variable a distintas concentraciones de oxígeno. Además, se han descrito problemas de funcionamiento en la entrega de oxígeno cuando se han ocupado este tipo de humidificador. Objetivo. Determinar el aporte real de humedad que entregan los humidificadores de burbuja al ser usados con sistemas de oxigenoterapia de concentración variable. Métodos. Se evaluaron 10 humidificadores de burbuja, marca Hudson RCI®, con válvula liberadora de presión, los cuales se conectaron a un sistema de oxigenoterapia de concentración variable (Marca Hudson RCI®, modelo MULTI-VENT). La medición de la humedad relativa (HR) se realizó en una cámara de acrílico, donde se conectó el inyector del sistema de oxigenoterapia. Para medir H.R. y temperatura se utilizó un higrómetro digital (Veto®, Italia) y un higrómetro análogo (Hygromat®, Alemania). Cada medición requirió un tiempo de 5 minutos para lograr un valor estable. Se realizaron mediciones de la humedad relativa y temperatura entregada por este sistema, con y sin humidificador, a concentraciones de oxígeno de 0.24, 0.26, 0.28, 0.3, 0.35, 0.4 y 0.5. Resultados. Para las la temperatura, no hubo diferencias entre las mediciones realizadas con y sin humidificador de burbuja. Para la humedad relativa, sólo hubo diferencias estadísticamente significativas a concentraciones de oxígeno altas (> 0.35), pero con escaso cambio en la entrega de humedad absoluta. Cuando se utilizó flujos operativos ≥ 6 L/min se activó la válvula liberadora de presión del humidificador. Conclusión. El uso de humidificadores de burbuja asociados a sistemas de oxigenoterapia de concentración variable no genera un aumento significativo de la humedad entregada a concentraciones bajas de oxigeno, por lo cual se podría prescindir de su uso.

Background. The use of bubble humidifiers associated with oxygen therapy equipment is a common practice in hospitals in our country. However, the real contribution of humidity delivered by these equipments when used with variable concentration systems at different oxygen concentrations has not been evaluated. In addition, operating problems have been described in the delivery of oxygen when this type of humidifier has been used. Objetive. Determine the real contribution of humidity delivered by bubble humidifiers when used with variable concentration oxygen therapy systems. Methods. 10 Hudson RCI® brand bubble humidifiers with a pressure release valve were evaluated, which were connected to a variable concentration oxygen therapy system (Hudson RCI® brand, MULTI-VENT model). The relative humidity (RH) was measured in an acrylic chamber, where the injector of the oxygen therapy system was connected. To measure R.H. and temperature, a digital hygrometer (Veto®, Italy) and an analog hygrometer (Hygromat®, Germany) were used. Each measurement required a time of 5 minutes to achieve a stable value. Measurements of the relative humidity and temperature delivered by this system were made, with and without a humidifier, at oxygen concentrations of 0.24, 0.26, 0.28, 0.3, 0.35, 0.4 and 0.5. Results. For temperature, there were no differences between the measurements made with and without a bubble humidifier. For relative humidity, there were only statistically significant differences at high oxygen concentrations (> 0.35), but with little change in absolute humidity delivery. When operating flows ≥ 6 L/min were used, the humidifier pressure relief valve was activated. Conclusion. The use of bubble humidifiers associated with variable concentration oxygen therapy systems does not generate a significant increase in the humidity delivered at low oxygen concentrations, so their use could be dispensed with.

Tannic Acid, as a Structural Moiety Coupled to a Protein Antigen, Exhibiting a Molecular-structure Adjuvant Activity for Antibody Specificity Enhancement.

BACKGROUND: An antigen is a small foreign substance, such as a microorganism structural protein, that may trigger an immune response once inside the body. Antigens are preferentially used rather than completely attenuated microorganisms to develop safe vaccines. Unfortunately, not all antigens are able to induce an immune response. Thus, new adjuvants to enhance the antigen's ability to stimulate immunity must be developed. OBJECTIVES: Therefore, this work aimed to evaluate the molecular-structure adjuvant activity of tannic acid (TA) coupled to a protein antigen in Balb/c mice. METHODS: Bovine serum albumin (BSA) was used as an antigen. The coupling of BSA and TA was mediated by carbodiimide crosslinking, and verified by SDS-PAGE. Forty-two Balb/c mice were divided into seven groups, including two controls without antigen, an antigen control, an adjuvant control, and two treatment groups. An additional group was used for macrophages isolation. A 30-day scheme was used to immunize the mice. The analysis of humoral immunity included immunoglobulin quantification, isotyping and antigen-antibody precipitation. The analysis of cell-mediated immunity included the quantification of nitric oxide from peritoneal macrophages and splenocytes' proliferation assay after treatment stimulation. RESULTS: No differences were found in the antibodies' concentration or isotypes induced with the conjugate or the pure BSA. However, an immunogenicity improvement (p < 0.05) was observed through the specific anti-BSA antibody titers in mice immunized with the conjugate. Besides, macrophage activation (p < 0.05) was detected when stimulated with the treatments containing TA. CONCLUSION: Tannic acid exhibited macrophages' activation properties. Moreover, when TA was incorporated into the structure of a protein antigen, such as BSA, an antibody specificity enhancement was observed. This was a consequence of antigen processing by activated antigen-presenting cells. These results showed the use of tannic acid as a novel candidate for vaccine molecular-structure adjuvant.

Impacto de la Pandemia por SARS-CoV-2 en el Perfil de Ingreso y Egreso de una Unidad de Cuidados Intensivos según Escala de Categorización Kinesiológica / Impact of the SARS-CoV-2 Pandemic on the Admission and Discharge Profile of an Intensive Care Unit according to the Kinesiological Categorization Scale

Introducción. La pandemia por coronavirus trajo consigo una modificación y una reestructuración de las unidades de cuidados intensivos(UCI). Además se produjo un cambio en el perfil de pacientes que ingresan y egresan en estas unidades. Objetivo. Valorar el impacto de la presente pandemia en el perfil de ingreso y egreso de pacientes en UCI según escala de categorización kinesiológica de la unidad. Métodos. Estudio observacional descriptivo que incluyó 50 sujetos de UCI que contaran con escala de categorización kinesiológica (ECK) al ingreso y egreso de la unidad. La ECK contemplo 3 item de evaluación: Función ventilatoria, manejod e secreciones, grado de cooperación y nivel de actividad. El registro de la ECK se planteó de manera retrospectiva para los periodos Julio-agosto 2018 (prepandemia) y Julio - Agosto 2020 (pandemia). Se utilizó estadística descriptiva, utilizando porcentaje y/o promedio para cada variable según corresponda. Resultados. Al observar la función ventilatoria, el requerimiento de soporte ventilatorio varió de un 64% a un 16% pre ­ pandemia, y de un 100% a un 88% durante la pandemia. Respecto al manejo de secreciones, se observó que los sujetos con tos efectiva varío desde un 60% a un 22% en el periodo pandemia Por otra parte, los pacientes que requirieron succión traqueal de manera constante en pandemia, se mantuvo. entre un 88% a un 92% durante la estadía en UCI. En relación al grado de cooperación, un 78% de los pacientes con COVID-19 ingresó con una dependencia severa o nula cooperación, y al momento del egreso de UCI un 54% se mantenía en la misma condición. Respecto al nivel de actividad, durante el periodo pandemia, un 100% de los ingresos y un 96% de los egresos presentó dependencia total. Conclusión. La pandemia causada por SARS-CoV-2 ha influido directamente en el perfil de ingreso y egreso de pacientes UCI, lo cual enfrentó al personal de salud a un aumento considerable en la carga de trabajo.

Introduction. The coronavirus led to a modification and a building of new intensive care units (ICU). In addition, there was a change in the profile of patients admitted and discharged from these units. Objetive. Assess the impact of this pandemy on the admission and discharge profile of patients in the ICU according to a kinesiological categorization scale of the unit. Methods. Descriptive observational study that included 50 ICU subjects who had a Kinesiology Categorization Scale (ECK) at admission and discharge from the unit. The ECK contemplates 3 evaluation elements: ventilatory function, management and secretions, degree of cooperation and level of activity. The ECK registry was considered retrospectively for the periods July-August 2018 (pre-pandemy) and July-August 2020 (pandemy). Descriptive statistics was developed, using percentage and/or average for each variable as appropriate. Results: Looking at ventilatory function, the requirement for ventilatory support varied from 64% to 16% pre-pandemic, and from 100% to 88% during the pandemic. Regarding the management of secretions, it was shown that the subjects with effective cough varied from 60% to 22% in the pandemic period. On the other hand, the patients who required tracheal suctioning constantly in the pandemic were maintained. between 88% and 92% during the ICU stay. Regarding the degree of cooperation, 78% of the patients with COVID-19 were admitted with a severe dependency or no cooperation, and at the time of discharge from the ICU, 54% were pressed in the same condition. Regarding the level of activity, during the pandemic period, 100% of income and 96% of expenses presented total dependency. Conclusion. The pandemy caused by SARS-CoV-2 has directly influenced the admission and discharge profile of ICU patients, which confronted health personnel with a considerable increase in workload.