Decúbito prono en pacientes COVID-19 con síndrome de distrés respiratorio agudo y ventilación mecánica invasiva / Prone positioning in Covid-19 patients with acute respiratory distress syndrome and invasive mechanical ventilation

Objetivos: Identificar eventos adversos secundarios al decúbito prono (DP) en pacientes con COVID-19 con síndrome de distrés respiratorio agudo (SDRA) moderado/severo, analizar los factores de riesgo para el desarrollo de úlceras por presión (UPP) en DP y describir la evolución oximétrica de estos pacientes durante el DP. Método: Estudio descriptivo retrospectivo realizado sobre 63 pacientes ingresados en la UCI de un hospital de segundo nivel, con neumonía por SARS-CoV-2, SDRA moderado/severo, ventilación mecánica invasiva, que precisaron maniobras de DP, durante marzo y abril de 2020. Se usó un muestreo no probabilístico consecutivo y se analizaron las variables seleccionadas a través de una regresión logística. Resultados: Se realizaron un total de 139 sesiones de pronación. La mediana de sesiones fue de 2 [1-3] y la duración de 22 h [15-24] por sesión. La aparición de eventos adversos ocurrió en 84,9% de los casos, siendo los fisiológicos (por ejemplo, hiper/hipotensión) los más frecuentes. Al comparar pacientes pronados que mantuvieron la integridad cutánea (34 de 63 pacientes, 54%) vs. los que desarrollaron UPP (29 de 63, 46%), estos últimos presentaron los siguientes factores de riesgo: mayor edad, ser hipertensos, prealbúmina < 21 mg/dL, mayor número de sesiones de prono y mayor gravedad al ingreso. Se observó un incremento significativo entre la PaO2/FiO2 previa al DP y en los diferentes cortes temporales durante el prono, además de una caída significativa tras despronar. Conclusiones: Existe una alta incidencia de eventos adversos debidos al DP, siendo los de tipo fisiológico los más frecuentes. La identificación de varios factores de riesgo para el desarrollo de UPP ayudará a prevenir la aparición de estas lesiones durante la pronación. La terapia de DP en pacientes COVID-19 con SDRA moderado/severo ha demostrado una mejora en los parámetros de oxigenación.(AU)

Objective: To identify adverse events related to prone positioning in COVID-19 patients with severe disease and acute respiratory distress syndrome, to analyze the risk factors associated with the development of anterior pressure ulcers, to determine whether the recommendation of prone positioning is associated with improved clinical outcomes. Methods: Retrospective study performed in 63 consecutive patients with COVID-19 pneumonia admitted to intensive care unit on invasive mechanical ventilation and treated with prone positioning between March and April 2020. Association between prone-related pressure ulcers and selected variables was explored by the means of logistic regression. Results: A total of 139 proning cycles were performed. The mean number of cycles were 2 [1-3] and the mean duration per cycle was of 22 hours [15-24]. The prevalence of adverse events this population was 84.9%, being the physiologic ones (i.e., hypo/hypertension) the most prevalent. 29 out of 63 patients (46%) developed prone-related pressure ulcers. The risk factors for prone-related pressure ulcers were older age, hypertension, levels of pre-albumin < 21 mg/dL, the number of proning cycles and severe disease. We observed a significant increase in the PaO2/FiO2 at different time points during the prone positioning, and a significant decrease after it. Conclusions: There is a high incidence of adverse events due to PD, with the physiological type being the most frequent. The identification of the main risk factors for the development of prone-related pressure ulcers will help to prevent the occurrence of these lesions during the prone positioning. Prone positioning offered an improvement in the oxygenation in these patients.(AU)

Prone positioning in COVID-19 patients with acute respiratory distress syndrome and invasive mechanical ventilation.

OBJECTIVE: To identify adverse events related to prone positioning in COVID-19 patients with severe disease and acute respiratory distress syndrome, to analyze the risk factors associated with the development of anterior pressure ulcers, to determine whether the recommendation of prone positioning is associated with improved clinical outcomes. METHODS: Retrospective study performed in 63 consecutive patients with COVID-19 pneumonia admitted to intensive care unit on invasive mechanical ventilation and treated with prone positioning between March and April 2020. Association between prone-related pressure ulcers and selected variables was explored by the means of logistic regression. RESULTS: A total of 139 proning cycles were performed. The mean number of cycles were 2 [1-3] and the mean duration per cycle was of 22h [15-24]. The prevalence of adverse events this population was 84.9 %, being the physiologic ones (i.e., hypo/hypertension) the most prevalent. 29 out of 63 patients (46%) developed prone-related pressure ulcers. The risk factors for prone-related pressure ulcers were older age, hypertension, levels of pre-albumin <21mg/dl, the number of proning cycles and severe disease. We observed a significant increase in the PaO2/FiO2 at different time points during the prone positioning, and a significant decrease after it. CONCLUSIONS: There is a high incidence of adverse events due to PD, with the physiological type being the most frequent. The identification of the main risk factors for the development of prone-related pressure ulcers will help to prevent the occurrence of these lesions during the prone positioning. Prone positioning offered an improvement in the oxygenation in these patients.

[Prone positioning in Covid-19 patients with acute respiratory distress syndrome and invasive mechanical ventilation]. / Decúbito prono en pacientes COVID-19 con síndrome de distrés respiratorio agudo y ventilación mecánica invasiva.

Objective: To identify adverse events related to prone positioning in COVID-19 patients with severe disease and acute respiratory distress syndrome, to analyze the risk factors associated with the development of anterior pressure ulcers, to determine whether the recommendation of prone positioning is associated with improved clinical outcomes. Methods: Retrospective study performed in 63 consecutive patients with COVID-19 pneumonia admitted to intensive care unit on invasive mechanical ventilation and treated with prone positioning between March and April 2020. Association between prone-related pressure ulcers and selected variables was explored by the means of logistic regression. Results: A total of 139 proning cycles were performed. The mean number of cycles were 2 [1-3] and the mean duration per cycle was of 22 hours [15-24]. The prevalence of adverse events this population was 84.9%, being the physiologic ones (i.e., hypo/hypertension) the most prevalent. 29 out of 63 patients (46%) developed prone-related pressure ulcers. The risk factors for prone-related pressure ulcers were older age, hypertension, levels of pre-albumin < 21 mg/dL, the number of proning cycles and severe disease. We observed a significant increase in the PaO2/FiO2 at different time points during the prone positioning, and a significant decrease after it. Conclusions: There is a high incidence of adverse events due to PD, with the physiological type being the most frequent. The identification of the main risk factors for the development of prone-related pressure ulcers will help to prevent the occurrence of these lesions during the prone positioning. Prone positioning offered an improvement in the oxygenation in these patients.

Adecuación del esfuerzo terapéutico en unidades de cuidados intensivos pediátricos: opinión y actitud de los profesionales / Suitability of therapeutic effort in paediatric intensive care units: Opinion and attitude of professionals

OBJETIVOS: Conocer la opinión y describir la actitud ante la adecuación del esfuerzo terapéutico de diferentes profesionales sanitarios. MÉTODO: Estudio multicéntrico, observacional y transversal realizado con enfermeras y médicos que desarrollan su labor asistencial en las unidades de cuidados intensivos pediátricos de cuatro hospitales de la Comunidad de Madrid. Se utilizó un cuestionario de elaboración propia pilotado para valorar su viabilidad y se habilitó una urna clausurada en el control de enfermería para depositarlo en ella. El análisis se realizó con el programa SPPS 21.0. RESULTADOS: El 98,9% de los encuestados declararon estar a favor de la adecuación del esfuerzo terapéutico. Los médicos consideran que la decisión se toma por consenso del equipo multidisciplinar más los padres del niño (48,8%). El 51,1% de las enfermeras opinan que se realiza por consenso de los médicos más los padres y el 65,5% afirman que nunca les consultan en la toma de decisiones de pacientes a su cargo. Al 75% de los médicos siempre o casi siempre les consultan. El 57% de las enfermeras y el 83% de los médicos se sienten capacitados para la toma de decisiones sobre la adecuación del esfuerzo terapéutico. El 77,2% de los profesionales creen que la adecuación se aplica en menos ocasiones de las necesarias. CONCLUSIONES: Existen diferencias entre médicos y enfermeras tanto en la percepción del modelo de toma de decisiones como en el modo de actuación. Los profesionales no siguen ningún protocolo ni circuito de toma de decisiones consensuado

OBJECTIVE: To determine the opinion and describe the attitude of different health professionals on suitability of therapeutic effort. METHOD: Multi-centre, cross-sectional observational study carried out with nurses and doctors who work in the paediatric intensive care units of four hospitals in the Madrid region. A self-administered questionnaire, previously piloted to assess its viability, was used and a sealed box was set up at the nursing station to hand it in. The analysis was performed using SPSS 21.0 software. RESULTS: The 98.9% of the respondents were in favour of suitability of therapeutic effort. Doctors consider that the decision is made with the agreement of the multidisciplinary staff and the child's parents (48.8%). Of the nurses, 51.1% believe that the decision is made by agreement with the doctors and parents. Of the nurses, 65.5% state that they are never asked about decision-making for their patients. Of the doctors, 75% are always or almost always asked. Fifty-seven percent of the nurses and 83% of the doctors feel capable of making decisions about suitability of therapeutic effort. Of the professionals, 77.2% believe that suitability is used less often than required. CONCLUSIONS: There are differences between doctors and nurses both in the perception of the decision-making model and in the way to proceed. Professionals seem not to follow any protocols or circuits in the decision-making process

Suitability of therapeutic effort in paediatric intensive care units: Opinion and attitude of professionals. / Adecuación del esfuerzo terapéutico en unidades de cuidados intensivos pediátricos: opinión y actitud de los profesionales.

OBJECTIVE: To determine the opinion and describe the attitude of different health professionals on suitability of therapeutic effort. METHOD: Multi-centre, cross-sectional observational study carried out with nurses and doctors who work in the paediatric intensive care units of four hospitals in the Madrid region. A self-administered questionnaire, previously piloted to assess its viability, was used and a sealed box was set up at the nursing station to hand it in. The analysis was performed using SPSS 21.0 software. RESULTS: The 98.9% of the respondents were in favour of suitability of therapeutic effort. Doctors consider that the decision is made with the agreement of the multidisciplinary staff and the child's parents (48.8%). Of the nurses, 51.1% believe that the decision is made by agreement with the doctors and parents. Of the nurses, 65.5% state that they are never asked about decision-making for their patients. Of the doctors, 75% are always or almost always asked. Fifty-seven percent of the nurses and 83% of the doctors feel capable of making decisions about suitability of therapeutic effort. Of the professionals, 77.2% believe that suitability is used less often than required. CONCLUSIONS: There are differences between doctors and nurses both in the perception of the decision-making model and in the way to proceed. Professionals seem not to follow any protocols or circuits in the decision-making process.

Drenaje torácico / Thoracic drainage

La patología pleural supone un problema clínico frecuente. En algunos casos, eltratamiento incluye drenaje de la cavidad que puede efectuarse mediante toracocentesisevacuadoras, pero en ocasiones exige mantener un drenaje permanentede la cavidad pleural. El drenaje torácico consiste en la colocación de una sondaen el espacio pleural para evacuar la presencia de aire, líquido o sangre, lo cualproduce un colapso pulmonar de grado variable con repercusión clínica en funciónde la reserva ventilatoria previa de paciente y el grado de colapso. Existenvarios modelos de tubos torácicos, así como sistemas de drenaje pleural, y su lugarde inserción dependerá del tipo de patología ante la que nos encontremos.Enfermería es fundamental en todo el proceso, tanto en la preparación del paciente,inserción, y mantenimiento adecuado para el éxito del tratamiento, comodurante la extracción y posteriores cuidados. Resulta fundamental que dichos profesionalesconozcan el material utilizado así como su mantenimiento. Una buenatécnica de cura del punto-orificio de inserción prevendrá numerosas complicacionesque podrían resultar fatales para el paciente. Se crea un protocolo de actuaciónen los cuidados de enfermería de los pacientes portadores de drenaje torácicotanto en los cambios de apósito como en cura del drenaje para servir dereferente, de guía de actuación sistemática y homogénea [1-24](AU)

Pleural pathology is a frequent clinical problem. In some cases, treatment includesdraining the cavity which can be carried out by thoracentesis evacuators, but onoccasions treatment requires maintaining a drainage permanently inside the pleuralcavity. Pleural drainage consists in inserting a catheter in the pleural sack todrain the presence of air, liquid or blood which causes a variable degree of lungcollapse having a clinical consequence in function of the reserve breathing capacitythe patient previously had and the degree of collapse. There are variousmodels of thoracic tubes as well as systems to drain the pleural cavity and theirspot for insertion depends on the type of pathology being dealt with for thepatient under treatment. Nursing is fundamental in this entire process, includingin the preparation of the patient for this treatment, the insertion of the catheterand the adequate maintenance so that this procedure succeeds as well as duringthe removal of the catheter and the subsequent care required. It is fundamentalthat the nursing professionals know the materials used as well as their maintenance.A good technique to cure the punt/orifice where a catheter is inserted willprevent numerous complications which could be deadly for the patient. Theauthors create a procedural protocol for nurses to use when treating patients whohave thoracic drains; this protocol deals with changing the catheters as well as theentire process related to how to treat patients with a pleural drain. This protocolshould serve as reference material and as a guide to a systematic and homogenousworking procedure [1-24](AU)

The N-terminal POZ domain of GAGA mediates the formation of oligomers that bind DNA with high affinity and specificity.

The Drosophila GAGA factor self-oligomerizes both in vivo and in vitro. GAGA oligomerization depends on the presence of the N-terminal POZ domain and the formation of dimers, tetramers, and oligomers of high stoichiometry is observed in vitro. GAGA oligomers bind DNA with high affinity and specificity. As a consequence of its multimeric character, the interaction of GAGA with DNA fragments carrying several GAGA binding sites is multivalent and of higher affinity than its interaction with fragments containing single short sites. A single GAGA oligomer is capable of binding adjacent GAGA binding sites spaced by as many as 20 base pairs. GAGA oligomers are functionally active, being transcriptionally competent in vitro. GAGA-dependent transcription activation depends strongly on the number of GAGA binding sites present in the promoter. The POZ domain is not necessary for in vitro transcription but, in its absence, no synergism is observed on increasing the number of binding sites contained within the promoter. These results are discussed in view of the distribution of GAGA binding sites that, most frequently, form clusters of relatively short sites spaced by small variable distances.

The interaction of zinc(II) ions with antiparallel-stranded d(GA)n DNA homoduplexes.

In the presence of specific metal-ions (namely zinc but also cadmium, cobalt and manganese), d(GA x TC)n DNA sequences can form non-B-DNA conformations. At low metal-ion concentration they form [GA(GA x TC)] intramolecular triplexes but, upon increasing the metal concentration, the formation of (GA x GA) intramolecular hairpins is detected. In this paper we address the question of the specific effects of zinc on the structure of the d(GA x TC)n sequences. In the presence of zinc, the DMS-reactivity of the (GA x GA) hairpins is strongly reduced suggesting a direct interaction of the metal-ion with the N7-group of the guanines. This effect is specific for antiparallel-stranded d(GA)n homoduplexes. No such strong decrease in DMS-reactivity is observed in B-DNA duplexes or in d(GGA)n and d(GGGA)n homoduplexes. In addition, the thermal stability of antiparallel-stranded d(GA)n homoduplexes increases in the presence of zinc. On the contrary, the melting temperature of similar B-DNA molecules decreases upon increasing the zinc concentration. Altogether, these result indicate that zinc plays an specific role on the stabilization of the (GA x GA) intramolecular hairpins.

The GAGA factor of Drosophila binds triple-stranded DNA.

The Drosophila GAGA factor binds specifically to simple repeating d(GA.TC)n DNA sequences. These sequences are known to be capable of forming triple-stranded DNA as well as other non-B-DNA conformations. Here, it is shown that GAGA binds to a d[CT(GA.TC)]22 intermolecular triplex with similar specificity and affinity as to a regular double-stranded B-form d(GA.TC)22 sequence. The interaction of GAGA with triplex DNA cannot, however, stimulate transcription in vitro. The affinity of GAGA for triplexes of the purine motif, such as a d[AG(GA.TC)]22 intermolecular triplex, is significantly lower. The DNA binding domain of GAGA is sufficient for efficient binding to triplex DNA. Based on the reported solution structure of the complex of GAGA-DNA binding domain with double-stranded DNA, a model for its interaction with triplex DNA is proposed in which most of the protein-DNA contacts observed in duplex DNA are maintained, especially those occurring through the minor groove. The higher negative charge of the triplex is likely to have also an important contribution to both the specificity and affinity of the interaction.

Formation of triple-stranded DNA at d(GA.TC)n sequences prevents nucleosome assembly and is hindered by nucleosomes.

Simple repeating d(GA.TC)n DNA sequences are frequently found at eukaryotic promoters, and in some cases they have been shown to be nucleosome free in vivo. These sequences show a high degree of structural polymorphism and are capable of adopting several types of non-B-DNA conformations. Here we show that the structural versatility of these sequences affects their ability to be packed into nucleosomes. Nucleosome assembly onto short double-stranded DNA fragments carrying d(GA.TC)n sequences of different length (n = 10 and n = 22) is very efficient. However, when the simple repeating sequence is forming a [CT(GA.TC)] triplex, nucleosome assembly is either prevented, as in the case of the d(GA.TC)22 sequence, or results in the destabilization of the triple-stranded conformation, as in the case of the d(GA.TC)10 sequence. Similarly, formation of triple-stranded DNA is hindered when the sequence is organized as nucleosomes. Efficient formation of triplex DNA occurs only at relatively high ionic strength (0.6 M NaCl), when the nucleosome is partially destabilized, and results in the disruption of the nucleosomal particle. These results indicate that nucleosome assembly and triplex formation are competing processes.

Zinc(II) ions selectively interact with DNA sequences present at the TFIIIA binding site of the Xenopus 5S-RNA gene.

It has been known for some time that zinc, as well as most transition metal ions, is capable of binding to the DNA bases. However, little is known about the presence and distribution of metal binding sites along naturally occurring genomic DNA molecules. In this paper, the interaction of zinc with the Xenopus 5S-RNA gene has been studied and several metal binding sites have been identified on the basis of the changes in chemical reactivity observed in the presence of the metal. The strongest zinc-binding sites of the Xenopus 5S-RNA gene correspond to GGG trinucleotide repeats. Some GG dinucleotides also show a significant affinity for zinc. Interestingly, the binding site for TFIIIA, a zinc-finger transcription factor, contains several sites with strong zinc affinity. In particular, a TGGGA sequence which is essential for the binding of TFIIIA shows the strongest affinity for zinc. The conformational properties of this DNA sequence, together with the high electronegative potential of GGG runs, is likely to determine its strong affinity for zinc. The possible biological relevance of these results is discussed.

Elsamicin A can convert the Z-form of poly[d(G-C)] and poly[(G-m5C)] back to B-form DNA.

The interaction of poly[(G-C)] and poly[d(G-m5C)] with the antitumor antibiotic elsamicin A, which binds to alternating guanine + cytosine tracts in DNA, has been studied under the B and Z conformations. Both the rate and the extent of the B-to-Z transition are diminished by the antibiotic, as inferred by spectroscopic methods under ionic conditions that otherwise favor the left-handed conformation of the polynucleotides. Moreover, elsamicin converts the Z-form DNA back to the B-form. The circular dichroism data indicate that elsamicin binds to poly[d(G-C)] and poly[d(G-m5C)] to form a right-handed bound elsamicin region(s). The transition can be followed by changes of the molar ellipticity at 250 nm, thus providing a convenient wavelength to monitor the Z-to-B conformational change of the polymers as elsamicin is added. The elsamicin A effect might be explained by a model in which the antibiotic binds preferently to a B-form DNA, playing a role as an allosteric effector on the equilibrium between the B and Z conformations, thus favoring the right-handed one.

Avaliacao qualitativa do refluxo entero-gastrico com o emprego de Tc99 HIDA. / Quantitative evaluation of entero-gastric reflux with the use of Tc99 HIDA

Os autores utilizaram o Tc99 HIDA para evidenciar o refluxo entero-gastrico em 24 pacientes, seis assintomaticos e 18 submetidos previamente a cirurgia por ulceras gastroduodenais, por varias tecnicas (vagotomia troncular e piloroplastia, gastrectomia com reconstrucao e BI e BII). Nos controles nao observaram refluxo em nenhum caso. Nos pacientes previamente operados observaram refluxo em sete dos 18 pacientes estudados.Concluem que o metodo e de facil realizacao, sem morbidade na serie e de boa resolucao na evidenciacao do refluxo entero-gastrico