[Clinical evolution of patients with infection associated with orthopedic devices in treatment with continuous negative pressure]. / Evolución clínica de los pacientes con infección asociada a dispositivos ortopédicos en tratamiento con presión negativa continua.

Objective: To describe the use of negative pressure therapy with (TPNi) and without instillation (TPNs) as adjuvant treatment in the management of orthopedic device-associated infections (IADO). Method: Analytic observational study of records of patients with IADO managed with TPNi and TPNs with 0.9% saline solution, in patients > 18 years, operated on in 2018-2021. Clinical characteristics of infection, infectious agent as well as sociodemographic variables were evaluated. TPN was performed with the V.A.C. VERAFLO™ system. Analysis with χ2, Fisher and t-Student. Statistically accepted value p < 0.05. Results: Sample 40 patients. 75% male. Fractures 42.5% exposed and 57.5% closed. 92.5% applied prophylactic antibiotic (30-120 min). 35% plate implants, 12.5% centromedullary nail, 10% knee prosthesis and 12.5% hip. 47.5% bleeding < 500 ml. 72.5% surgical time of 2-4 hours. Previous hospitalization time, TPNs 3 weeks 55.9% and 4 weeks 26.5%; TPNi, 3 weeks 50% and 4 weeks 33.3%. Conservation of the implant 73.5% TPNs and 50% TPNi (p = 0.341). Wound closure 91.2% with TPNs and 100% with TPNi (p = 1.000). Conclusions: The use of TPNs and TPNi were useful as adjuvant treatments in the management of IADO, in addition they allowed to preserve the implant and wound closure in a large part of the patients.

Objetivo: Describir el uso de la terapia de presión negativa con (TPNi) y sin instilación (TPNs) como tratamiento adyuvante en el manejo de infecciones asociadas a dispositivo ortopédico (IADO). Método: Estudio observacional analítico de expedientes de pacientes con IADO manejados con TPNi y TPNs con solución salina al 0.9%, mayores de 18 años, operados en el periodo 2018-2021. Se evaluaron las características clínicas de infección, el agente infeccioso y las variables sociodemográficas. La TPN se realizó con sistema V.A.C.VERAFLO™. Para los análisis se emplearon las pruebas χ2, Fisher y t de Student. Valor estadísticamente aceptado: p < 0.05. Resultados: La muestra fue de 40 pacientes, el 75% masculinos. Fracturas: 42.5% expuestas y 57.5% cerradas. En el 92.5% se aplicó antibiótico profiláctico (30-120 min). Implantes: 35% placas, 12.5% clavo centromedular, 10% prótesis de rodilla y 12.5% cadera. El 47.5% con sangrado < 500 ml. En el 72.5% un tiempo quirúrgico de 2-4 horas. Tiempo de hospitalización previa: TPNs 3 semanas 55.9% y 4 semanas 26.5%; TPNi 3 semanas 50% y 4 semanas 33.3%. Conservación del implante: 73.5% TPNs y 50% TPNi (p = 0.341). Cierre de herida: 91.2% con TPNs y 100% con TPNi (p = 1.000). Conclusiones: El uso de TPNs y TPNi fue útil como tratamiento adyuvante en IADO, y además permitieron conservar el implante y el cierre de la herida en la mayoría de los pacientes.

Interventional device tracking under MRI via alternating current controlled inhomogeneities.

PURPOSE: To introduce alternating current-controlled, conductive ink-printed marker that could be implemented with both custom and commercial interventional devices for device tracking under MRI using gradient echo, balanced SSFP, and turbo spin-echo sequences. METHODS: Tracking markers were designed as solenoid coils and printed on heat shrink tubes using conductive ink. These markers were then placed on three MR-compatible test samples that are typically challenging to visualize during MRI scans. MRI visibility of markers was tested by applying alternating and direct current to the markers, and the effects of applied current parameters (amplitude, frequency) on marker artifacts were tested for three sequences (gradient echo, turbo spin echo, and balanced SSFP) in a gel phantom, using 0.55T and 1.5T MRI scanners. Furthermore, an MR-compatible current supply circuit was designed, and the performance of the current-controlled markers was tested in one postmortem animal experiment using the current supply circuit. RESULTS: Direction and parameters of the applied current were determined to provide the highest conspicuity for all three sequences. Marker artifact size was controlled by adjusting the current amplitude, successfully. Visibility of a custom-designed, 20-gauge nitinol needle was increased in both in vitro and postmortem animal experiments using the current supply circuit. CONCLUSION: Current-controlled conductive ink-printed markers can be placed on custom or commercial MR-compatible interventional tools and can provide an easy and effective solution to device tracking under MRI for three sequences by adjusting the applied current parameters with respect to pulse sequence parameters using the current supply circuit.

EDEN (Electrocardiographic Radial Depth Navigation): A Novel Approach to Navigate Inside Heart Muscle.

BACKGROUND: Intramyocardial guidewire navigation is a novel technique that allows free transcatheter movement within ventricular muscle. Guidewire radial depth, between endocardial and epicardial surfaces, is ambiguous by x-ray and echocardiography. OBJECTIVES: The aim of this study was to develop a simple tool, EDEN (Electrocardiographic Radial Depth Navigation), to indicate radial depth during intramyocardial guidewire navigation. Combined with routine imaging, EDEN facilitates a new family of intramyocardial catheter procedures to slice, reshape, pace, and ablate the heart. METHODS: We mapped intramyocardial electrograms of left and right ventricular walls and septum during open- and closed-chest swine procedures (N = 53), including MIRTH (Myocardial Intramural Remodeling by Transvenous Tether) ventriculoplasty. We identified radial depth-dependent features on unipolar electrograms. We developed a machine learning-based classifier to indicate categorical position, and modeled the findings in silico to test understanding of the physiology. RESULTS: EDEN signatures distinguished 5 depth zones throughout left and right ventricular free walls and interventricular septum. Relative ST-segment elevation magnitude best discriminated position and was maximum (40.1 ± 6.5 mV) in the midmyocardium. Subendocardial positions exhibited dominant Q waves with lower-amplitude ST segments (16.8 ± 5.8 mV), whereas subepicardial positions exhibited dominant R waves with lower-amplitude ST segments (15.7 ± 4.8 mV). EDEN was unaffected by pacing-induced left bundle branch block. ST-segment elevation declined over minutes and reappeared after submillimeter guidewire manipulation. Modeling recapitulated EDEN features. The machine learning-based classifier was 97% accurate. EDEN successfully guided MIRTH ventriculoplasty. CONCLUSIONS: EDEN provides a simple and reproducible real-time reflection of categorical guidewire-tip radial depth during intramyocardial guidewire navigation. Used in tandem with x-ray, EDEN enables novel, transcatheter, intramyocardial therapies such as MIRTH, SESAME (Septal Surfing Along Midline Endocardium), and cerclage ventriculoplasty.

Reshaping the Ventricle From Within: MIRTH (Myocardial Intramural Remodeling by Transvenous Tether) Ventriculoplasty in Swine.

MIRTH (Myocardial Intramural Remodeling by Transvenous Tether) is a transcatheter ventricular remodeling procedure. A transvenous tension element is placed within the walls of the beating left ventricle and shortened to narrow chamber dimensions. MIRTH uses 2 new techniques: controlled intramyocardial guidewire navigation and EDEN (Electrocardiographic Radial Depth Navigation). MIRTH caused a sustained reduction in chamber dimensions in healthy swine. Midventricular implants approximated papillary muscles. MIRTH shortening improved myocardial contractility in cardiomyopathy in a dose-dependent manner up to a threshold beyond which additional shortening reduced performance. MIRTH may help treat dilated cardiomyopathy. Clinical investigation is warranted.

Impact of Vasodilation on Oxygen-Enhanced Functional Lung MRI at 0.55 T.

BACKGROUND: Oxygen-enhanced magnetic resonance imaging (OE-MRI) can be used to assess regional lung function without ionizing radiation. Inhaled oxygen acts as a T1-shortening contrast agent to increase signal in T1-weighted (T1w) images. However, increase in proton density from pulmonary hyperoxic vasodilation may also contribute to the measured signal enhancement. Our aim was to quantify the relative contributions of the T1-shortening and vasodilatory effects of oxygen to signal enhancement in OE-MRI in both swine and healthy volunteers. METHODS: We imaged 14 anesthetized female swine (47 ± 8 kg) using a prototype 0.55 T high-performance MRI system while experimentally manipulating oxygenation and blood volume independently through oxygen titration, partial occlusion of the vena cava for volume reduction, and infusion of colloid fluid (6% hydroxyethyl starch) for volume increase. Ten healthy volunteers were imaged before, during, and after hyperoxia. Two proton density-weighted (PDw) and 2 T1w ultrashort echo time images were acquired per experimental state. The median PDw and T1w percent signal enhancement (PSE), compared with baseline room air, was calculated after image registration and correction for lung volume changes. Differences in median PSE were compared using Wilcoxon signed rank test. RESULTS: The PSE in PDw images after 100% oxygen was similar in swine (1.66% ± 1.41%, P = 0.01) and in healthy volunteers (1.99% ± 1.79%, P = 0.02), indicating that oxygen-induced pulmonary vasodilation causes ~2% lung proton density increase. The PSE in T1w images after 100% oxygen was also similar (swine, 9.20% ± 1.68%, P < 0.001; healthy volunteers, 10.10% ± 3.05%, P < 0.001). The PSE in T1w enhancement was oxygen dose-dependent in anesthetized swine, and we measured a dose-dependent PDw image signal increase from infused fluids. CONCLUSIONS: The contribution of oxygen-induced vasodilation to T1w OE-MRI signal was measurable using PDw imaging and was found to be ~2% in both anesthetized swine and in healthy volunteers. This finding may have implications for patients with regional or global hypoxia or vascular dysfunction undergoing OE-MRI and suggest that PDw imaging may be useful to account for oxygen-induced vasodilation in OE-MRI.

Dynamic pressure-volume loop analysis by simultaneous real-time cardiovascular magnetic resonance and left heart catheterization.

BACKGROUND: Left ventricular (LV) contractility and compliance are derived from pressure-volume (PV) loops during dynamic preload reduction, but reliable simultaneous measurements of pressure and volume are challenging with current technologies. We have developed a method to quantify contractility and compliance from PV loops during a dynamic preload reduction using simultaneous measurements of volume from real-time cardiovascular magnetic resonance (CMR) and invasive LV pressures with CMR-specific signal conditioning. METHODS: Dynamic PV loops were derived in 16 swine (n = 7 naïve, n = 6 with aortic banding to increase afterload, n = 3 with ischemic cardiomyopathy) while occluding the inferior vena cava (IVC). Occlusion was performed simultaneously with the acquisition of dynamic LV volume from long-axis real-time CMR at 0.55 T, and recordings of invasive LV and aortic pressures, electrocardiogram, and CMR gradient waveforms. PV loops were derived by synchronizing pressure and volume measurements. Linear regression of end-systolic- and end-diastolic- pressure-volume relationships enabled calculation of contractility. PV loops measurements in the CMR environment were compared to conductance PV loop catheter measurements in 5 animals. Long-axis 2D LV volumes were validated with short-axis-stack images. RESULTS: Simultaneous PV acquisition during IVC-occlusion was feasible. The cardiomyopathy model measured lower contractility (0.2 ± 0.1 mmHg/ml vs 0.6 ± 0.2 mmHg/ml) and increased compliance (12.0 ± 2.1 ml/mmHg vs 4.9 ± 1.1 ml/mmHg) compared to naïve animals. The pressure gradient across the aortic band was not clinically significant (10 ± 6 mmHg). Correspondingly, no differences were found between the naïve and banded pigs. Long-axis and short-axis LV volumes agreed well (difference 8.2 ± 14.5 ml at end-diastole, -2.8 ± 6.5 ml at end-systole). Agreement in contractility and compliance derived from conductance PV loop catheters and in the CMR environment was modest (intraclass correlation coefficient 0.56 and 0.44, respectively). CONCLUSIONS: Dynamic PV loops during a real-time CMR-guided preload reduction can be used to derive quantitative metrics of contractility and compliance, and provided more reliable volumetric measurements than conductance PV loop catheters.

Transcatheter Myotomy to Relieve Left Ventricular Outflow Tract Obstruction: The Septal Scoring Along the Midline Endocardium Procedure in Animals.

BACKGROUND: Left ventricular outflow tract obstruction complicates hypertrophic cardiomyopathy and transcatheter mitral valve replacement. Septal reduction therapies including surgical myectomy and alcohol septal ablation are limited by surgical morbidity or coronary anatomy and high pacemaker rates, respectively. We developed a novel transcatheter procedure, mimicking surgical myotomy, called Septal Scoring Along the Midline Endocardium (SESAME). METHODS: SESAME was performed in 5 naive pigs and 5 pigs with percutaneous aortic banding-induced left ventricular hypertrophy. Fluoroscopy and intracardiac echocardiography guided the procedures. Coronary guiding catheters and guidewires were used to mechanically enter the basal interventricular septum. Imparting a tip bend to the guidewire enabled intramyocardial navigation with multiple df. The guidewire trajectory determined the geometry of SESAME myotomy. The myocardium was lacerated using transcatheter electrosurgery. Cardiac function and tissue characteristics were assessed by cardiac magnetic resonance at baseline, postprocedure, and at 7- or 30-day follow-up. RESULTS: SESAME myotomy along the intended trajectory was achieved in all animals. The myocardium splayed after laceration, increasing left ventricular outflow tract area (753 to 854 mm2, P=0.008). Two naive pigs developed ventricular septal defects due to excessively deep lacerations in thin baseline septa. No hypertrophy model pig, with increased septal thickness and left ventricular mass compared with naive pigs, developed ventricular septal defects. One animal developed left axis deviation on ECG but no higher conduction block was seen in any animal. Coronary artery branches were intact on angiography with no infarction on cardiac magnetic resonance late gadolinium imaging. Cardiac magnetic resonance chamber volumes, function, flow, and global strain were preserved. No myocardial edema was evident on cardiac magnetic resonance T1 mapping. CONCLUSIONS: This preclinical study demonstrated feasibility of SESAME, a novel transcatheter myotomy to relieve left ventricular outflow tract obstruction. This percutaneous procedure using available devices, with a safe surgical precedent, is readily translatable into patients.

Influencia de la estructura social en las prácticas de cuidado en infantes menores de un año / Influence of social structure in care practices in infants under one year / Influência da estrutura social em práticas de cuidado em menores de um ano

Objetivo: Conocer la influencia de la estructura social en las prácticas de cuidado en infantes, con la participación de madres pertenecientes al programa de FAMI en el barrio Aeropuerto de Cúcuta, aplicando la teoría de la diversidad y universalidad de Madeleine Leninger representada en el modelo del sol naciente. Materiales y Métodos: investigación de tipo cualitativa ­ etnográfica, la muestra se tomó por conveniencia y a priori conformada por ocho mujeres de estrato socioeconómico 2 pertenecientes al programa FAMI, a quienes se aplicaron entrevistas a profundidad que fueron grababas utilizando una videograbadora para facilitar su análisis, todo esto previo consentimiento de las informantes. Resultados: se pueden destacar que el cuidado de los infantes está influenciado por: las familias, sus conocidos (amigos y vecinos) y las costumbres de cada uno, que se van trasmitiendo de generación; también se identificó como factor relevante la economía del hombre como único proveedor del sustento, lo que hace limitante el acceso a los cuidados del niño. Conclusiones: Los resultados obtenidos permiten determinar que las expresiones, situaciones y los hechos en la práctica de cuidado de los infantes están influenciadas por la estructura social en los factores tecnológicos, la familia y factores sociales, los valores culturales y modos de vida, factores políticos y legales y lo económico. Las prácticas de cuidado no están influenciadas por la religión y la educación; así mismo, se identifican elementos de éstos factores contenidos en los sistemas genéricos y profesionales, siendo enfermería quien articula e integra conocimientos para determinar acciones de cuidado.

Objective: To determine the influence of social structure on infant care practices, with the participation of mothers belonging to the program in the district¨ FAMI Aeropuerto de Cúcuta¨, applying the theory of diversity and universality of Madeleine Leninger represented in the model ¨rising sun¨. Materials and Methods: a qualitative research - ethnographic, the sample was taken for convenience and a priori consists of eight women socioeconomic FAMI 2 belonging to the program, who have applied depth interviews that were recorded using a VCR to facilitate analysis, all this with the consent of the informants. Results: We may note that the care of infants is influenced by family, acquaintances (friends and neighbors) and customs of each one is transmitted from generation to generation, also identified as a relevant factor the economy of man as sole breadwinner, making limiting access to child care. Conclusions: The results can determine whether the expressions, situations and events in the practice of caring for infants is influenced by the social structure, in the technological factors, family and social factors, cultural values and ways of life, political, legal factors and the economy of the family . Care practices are not influenced by religion and education, likewise, it can be identified elements of these factors contained in generic systems and health professionals who articulates and integrates nursing knowledge to determine care actions.

Objetivo: determinar a influência da estrutura social sobre as práticas de cuidados infantis, com a participação de mães pertencentes ao programa no aeroporto distrito ¨FAMI Cucuta¨, aplicando a teoria da diversidade e universalidade da Madeleine Leninger representada no modelo ¨subindo sol¨. Materiais e Métodos: a pesquisa qualitativa - etnográfica, a amostra foi colhida por conveniência e, a priori, é composto por oito mulheres socioeconômicos¨ FAMI 2 ¨pertencentes ao programa, que aplicou entrevistas em profundidade, que foram foram gravação usando um gravador de vídeo para facilitar a análise, tudo isso com o consentimento dos informantes. Resultados: Pode-se notar que o cuidado das crianças é influenciado por familiares, conhecidos (amigos e vizinhos) e os costumes de cada um, a ser transmitida de geração, também identificado como um fator relevante na economia do homem como arrimo, fazendo com que a limitação do acesso ao cuidado da criança. Conclusões: Os resultados podem determinar se as expressões, situações e acontecimentos na prática de cuidar de crianças são influenciados pela estrutura social nos fatores tecnológicos, sociais e familiares fatores, valores culturais e modos de vida, os fatores políticos e jurídica e económica. Práticas de cuidados não são influenciados pela religião e educação, da mesma forma, identifica os elementos desses fatores contidos em sistemas genéricos e os profissionais de saúde que articula e integra conhecimentos de enfermagem para identificar ações de cuidado.

[An immunoenzymatic test for IgG antibody levels against 10 serotypes of Streptococcus pneumoniae]. / Estandarización en Colombia de una prueba ELISA para la evaluación de los niveles séricos de anticuerpos IgG contra diez serotipos de Streptococcus pneumoniae.

INTRODUCTION: Streptococcus pneumoniae is a major cause of morbi-mortality in early childhood and elderly. However, a test to measure the antibody responses after specific vaccination is not available in Colombia. OBJECTIVE: An immunoenzymatic test was standardized for the measurement of serum IgG levels against 10 serotypes of S. pneumoniae in response to the specific vaccination. MATERIAL AND METHODS: Capsular polysaccharides 1, 3, 4, 5, 6B, 9V, 14, 18, 19F, 23F of S. pneumoniae were used as antigens in a solid-phase ELISA. These responses were characterized in a randomized selected healthy individuals from a Colombian population. RESULTS: The reference and control sera showed great reactivity against all the polysaccharides evaluated, especially against polysaccharide 14 and 19F. The lowest reactivity in these two sera was observed against polysaccharide 3 and 4. Among the children evaluated, polysaccharide 5/19F showed the highes pre-vaccination reactivity, and polysaccharide 14/19F showed the highest post-vaccination reactivity. Among the adults, polysaccharides 14 and 19F showed the greatest reactivity pre- and post-vaccination. For all the polysaccharides (excepting polysaccharide 5), an inverse association among high polysaccharide-specific pre-vaccination- and the increase of post-vaccination-IgG levels was observed. CONCLUSION: This ELISA test reliably quantifies the serum levels of specific IgG against 10 serotypes of S. pneumoniae. According to the responses by healthy individuals, the current study validates parameters used internationally as an adequate the response to the 23-valent pneumococcal vaccine.

Estandarización en Colombia de una prueba ELISA para la evaluación de los niveles séricos de anticuerpos IgG contra diez serotipos de Streptococcus pneumoniae / An immunoenzymatic test for IgG antibody levels against 10 serotypes of Streptococcus pneumoniae

Introducción. Streptococcus pneumoniae es causante de gran morbimortalidad en niños pequeños y ancianos. Sin embargo, en Colombia no está disponible una prueba que evalúe la respuesta humoral a la vacunación específica contra este microorganismo Objetivo. Estandarizar en Colombia un ensayo inmunoenzimático para evaluar los niveles séricos de anticuerpos IgG contra diez serotipos de S. pneumoniae en respuesta a la vacunación específica y caracterizar esta respuesta en individuos sanos de nuestra población. Materiales y métodos. Se hizo un ELISA en fase sólida utilizando como antígenos los polisacáridos capsulares 1, 3, 4, 5, 6B, 9V, 14, 18, 19F y 23F de S. pneumoniae. Resultados. Los sueros de referencia y control reaccionaron fuertemente contra los polisacáridos evaluados, especialmente contra 14 y 19F. En los cinco niños sanos evaluados, los polisacáridos 5 y 19F presentaron los mayores títulos antes de la vacunación. Antes de la vacunación en los niños, y antes y después de la vacunación en los adultos, los polisacáridos 14 y 19F reaccionaron fuertemente. Para todos los polisacáridos, excepto para el 5, existe una relación inversa entre títulos altos de anticuerpos IgG antes de la vacunación y la razón de incremento de los títulos después de la misma. Conclusión. Esta prueba ELISA cuantifica de forma confiable los niveles de IgG sérica contra diez serotipos de S. pneumoniae y, de acuerdo con los resultados obtenidos en individuos sanos de nuestra población, en este trabajo se validan los parámetros internacionales para considerar adecuada la respuesta a la vacuna 23-valente contra este microorganismo.

Introduction. Streptococcus pneumoniae is a major cause of morbi-mortality in early childhood and elderly. However, a test to measure the antibody responses after specific vaccination is not available in Colombia. Objective. An immunoenzymatic test was standardized for the measurement of serum IgG levels against 10 serotypes of S. pneumoniae in response to the specific vaccination. Material and methods. Capsular polysaccharides 1, 3, 4, 5, 6B, 9V, 14, 18, 19F, 23F of S. pneumoniae were used as antigens in a solid-phase ELISA. These responses were characterized in a randomized selected healthy individuals from a Colombian population. Results. The reference and control sera showed great reactivity against all the polysaccharides evaluated, especially against polysaccharide 14 and 19F. The lowest reactivity in these two sera was observed against polysaccharide 3 and 4. Among the children evaluated, polysaccharide 5/19F showed the highes pre-vaccination reactivity, and polysaccharide 14/19F showed the highest post-vaccination reactivity. Among the adults, polysaccharides 14 and 19F showed the greatest reactivity pre- and post-vaccination. For all the polysaccharides (excepting polysaccharide 5), an inverse association among high polysaccharide-specific pre-vaccination- and the increase of post-vaccination-IgG levels was observed. Conclusion. This ELISA test reliably quantifies the serum levels of specific IgG against 10 serotypes of S. pneumoniae. According to the responses by healthy individuals, the current study validates parameters used internationally as an adequate the response to the 23-valent pneumococcal vaccine.