DISEÑO DE ESTRUCTURAS CELULARES BASE ACERO INOXIDABLE CON PROPIEDADES SIMILARES A LAS DEL HUESO HUMANO (CELLULAR STRUCTURE DESIGN BASE STAINLESS STEEL WITH SIMILAR PROPERTIES LIKE THE HUMAN BONE)

Se presentan propuestas de diseño y fabricación de estructuras celulares triplemente periódicas (TPMS), sobre giróides tipo Schoen simple y doble. El objetivo de este trabajo es poder fabricar estructuras auto-soportadas con características similares al hueso humano. Las estructuras celulares tipo giroide se pueden diseñar a voluntad para dar características de densidad y resistencia en los niveles del hueso trabecular humano. En el presente trabajo se fabricaron estructuras TPMS empleando la tecnología de sinterización de metales por láser (DMLS), empleando polvo de acero inoxidable 17-4. El diseño se realizó mediante Matlab. Se realizaron pruebas de compresión obteniendo resultados en módulo elástico (400 – 850 MPa) similares a los del hueso trabecular. Modificando desde la ecuación el parámetro t y el número de celdas, gracias a esto, fue posible controlar la densidad (1.17 - 1.99 g/cm3) y el módulo de Young resultantes de las piezas fabricadas.Palabras Clave: Prótesis, estructuras celulares, giroide, biocompatibilidad, impresión 3D. AbstractDesign and manufacturing proposals are presented for the triple periodical minimal surfaces (TPMS), mostly about Schoen’s gyroid simple and double. The goal of this paper is to can create auto-supported structures with similar characteristics to the human bone and in a personalized way. The gyroid cellular structures can be design to desire to give the density and resistant characteristics in the levels of the the trabecular bone. In this paper TPMS were built with DMLS technology, using stainless steel powder 17-4. The design was done in Matlab and some other programs. Compression test were done obtaining results in yield strength (400-850 MPa) similar to the trabecular bone. Modifiying the parameter “t” and the number of cells in the equation that describe both kinds of gyroids, it was possible to control the density (1.17 – 1.99 g/ cm3) and the young modulus in the manufactured samples.Keywords: Prosthesis, cellular structures, gyroid, biocompatibility, 3D printing

Use of Pulse Pressure Variation as Predictor of Fluid Responsiveness in Patients Ventilated With Low Tidal Volume: A Systematic Review and Meta-Analysis

Introduction: Pulse pressure variation (PPV) has been shown to be useful to predict fluid responsiveness in patients ventilated at tidal volume (Vt) >8 mL kg−1. Nevertheless, most conditions in critical care force to use lower Vt. Thus, we sought to evaluate the operative performance of PPV when a Vt ⩽8 mL kg−1 is used during mechanical ventilation support. Methods: We searched PubMed and Embase databases for articles evaluating the operative performance of PPV as a predictor of fluid responsiveness in critical care and perioperative adult patients ventilated with tidal volume ⩽8 mL kg−1 without respiratory effort and arrhythmias, between January 1990 and January 2019. We included cohort and cross-sectional studies. Two authors performed an Independently selection using predefined terms of search. The fitted data of sensitivity, specificity, and area under the curve (AUC) were assessed by bivariate and hierarchical analyses. Results: We retrieved 19 trials with a total of 777 patients and a total of 935 fluid challenges. The fitted sensitivity of PPV to predict fluid responsiveness during mechanical ventilation at Vt ⩽8 mL kg−1 was 0.65 (95% confidence interval [CI]: 0.57-0.73), the specificity was 0.79 (95% CI: 0.73-0.84), and the AUC was 0.75. The diagnostic odds ratio was 5.5 (95% CI: 3.08-10.01, P < .001) by the random-effects model. Conclusions: Pulse pressure variation shows a fair operative performance as a predictor of fluid responsiveness in critical care and perioperative patients ventilated with a tidal volume ⩽8 mL kg−1 without respiratory effort and arrhythmias

5to. Congreso Internacional de Ciencia, Tecnología e Innovación para la Sociedad. Memoria académica

El V Congreso Internacional de Ciencia, Tecnología e Innovación para la Sociedad, CITIS 2019, realizado del 6 al 8 de febrero de 2019 y organizado por la Universidad Politécnica Salesiana, ofreció a la comunidad académica nacional e internacional una plataforma de comunicación unificada, dirigida a cubrir los problemas teóricos y prácticos de mayor impacto en la sociedad moderna desde la ingeniería. En esta edición, dedicada a los 25 años de vida de la UPS, los ejes temáticos estuvieron relacionados con la aplicación de la ciencia, el desarrollo tecnológico y la innovación en cinco pilares fundamentales de nuestra sociedad: la industria, la movilidad, la sostenibilidad ambiental, la información y las telecomunicaciones. El comité científico estuvo conformado formado por 48 investigadores procedentes de diez países: España, Reino Unido, Italia, Bélgica, México, Venezuela, Colombia, Brasil, Estados Unidos y Ecuador. Fueron recibidas un centenar de contribuciones, de las cuales 39 fueron aprobadas en forma de ponencias y 15 en formato poster. Estas contribuciones fueron presentadas de forma oral ante toda la comunidad académica que se dio cita en el Congreso, quienes desde el aula magna, el auditorio y la sala de usos múltiples de la Universidad Politécnica Salesiana, cumplieron respetuosamente la responsabilidad de representar a toda la sociedad en la revisión, aceptación y validación del conocimiento nuevo que fue presentado en cada exposición por los investigadores. Paralelo a las sesiones técnicas, el Congreso contó con espacios de presentación de posters científicos y cinco workshops en temáticas de vanguardia que cautivaron la atención de nuestros docentes y estudiantes. También en el marco del evento se impartieron un total de ocho conferencias magistrales en temas tan actuales como la gestión del conocimiento en la universidad-ecosistema, los retos y oportunidades de la industria 4.0, los avances de la investigación básica y aplicada en mecatrónica para el estudio de robots de nueva generación, la optimización en ingeniería con técnicas multi-objetivo, el desarrollo de las redes avanzadas en Latinoamérica y los mundos, la contaminación del aire debido al tránsito vehicular, el radón y los riesgos que representa este gas radiactivo para la salud humana, entre otros

Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

Summary Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

Fracturas de cadera: satisfacción posquirúrgica al año en adultos mayores atendidos en Méderi-Hospital Universitario Mayor, Bogotá, D.C.

Introduction: World aging increases the incidence of hip fracture in adults over sixty years of age, pathology of economic and social burden being a challenge for public health. This study seeks to assess patient degree of satisfaction with health care services and assess outcomes. Materials and methods: Exploratory, observational, descriptive cross-sectional study, with a telephone survey in patients 65 years or older, one year after hip fracture surgical intervention in Méderi-Hospital Universitario Mayor, Bogotá. Results: Of 287 patients 116 met the inclusion-exclusion criteria and accepted to participate. Age ranges between 65 and 99 years with a mean of 81,3 ± 8,17. Women and men represent respectively 76 % and 24 % of the sample. Mortality a year after is 28 %, gender: 23 % women and 43 % men. 29,3 % of the patients reentered the hospital, 50 % recovered their previous functional capacity. 81 % express as good the inpatient care by orthopedic service. 64 % does not grade inpatient care by rehabilitation services because it was not given. 70 % are satisfied with the outpatient services of orthopedic and rehabilitation. Conclusions: This study represents a novel and unique approach as it gives voice to the patient allowing assessment of the health services. Suggests the degree of pain as a tracer of quality of life and brings upon compulsory attention to implement health services improvement programs for hip fractures in the elderly.Introdução: o envelhecimento populacional mundial tem aumentado a incidência de fraturas de quadril, mudanças que gera um alto impacto económico, social e constitui um desafio para a saúde pública. O estudo busca avaliar a satisfação com o manejo pós-cirúrgico em idosos com fraturas de quadril no ano posterior à intervenção e conhecer os desenlaces neste tempo. Materiais e métodos: estudo exploratório, observacional, descritivo, de corte transversal, mediante questionário por telefone em adultos de 65 ou mais anos, um ano após da intervenção cirúrgica por fraturas de quadril em Méderi – Hospital Universitário Mayor, de Bogotá D.C. Descrevem-se variáveis avaliativas de satisfação e atenção em saúde, assim como outras relacionadas. Resultados: de 287 pacientes, 116 cumprem os critérios de inclusão e aceitam participar. O rango de idade oscila entre 65 e 99 anos, média de 81,3 ± 8,17. As mulheres e os homens representam respetivamente 76% e 24% da amostra. Mortalidade anual 28%, por gênero: 23% mulheres e 3% homens. 29,3% apresenta reingressos hospitalários, 50% recupera a sua habilidade para a marcha. 81% considera boa a atenção intra-hospitalar por ortopedia. 64% não qualifica o serviço intra-hospitalar por fisioterapia já que não o recebe. 70% expressa satisfação com os serviços ambulatórios de ortopedia e reabilitação. Conclusões: estudo novo e único que dá voz como sujeito ativo ao paciente para avaliar o sistema de saúde, sugere o grau de dor como elemento traçador de qualidade de vida e obriga a implementar programas e serviços para idosos com fraturas de quadril.Introducción: el envejecimiento poblacional mundial ha aumentado la incidencia de fracturas de cadera, este cambio genera un alto impacto económico, social y constituye un reto para la salud pública. Este estudio busca evaluar la satisfacción con el manejo posquirúrgico en adultos mayores con fracturas de cadera al año de la intervención y conocer los desenlaces en este tiempo. Materiales y métodos: estudio exploratorio, observacional, descriptivo de corte transversal, mediante encuesta telefónica en adultos de 65 o más años, un año después de intervención quirúrgica por fracturas de cadera en Méderi - Hospital Universitario Mayor, de Bogotá. Se describen variables evaluativas de satisfacción y atención en salud, así como otras relacionadas. Resultados: de 287 pacientes, 116 cumplen los criterios de inclusión y aceptan participar. El rango de edad oscila entre 65 y 99 años, media de 81,3 ± 8,17. Las mujeres y los hombres representan, respectivamente, 76 % y 24 % de la muestra. Mortalidad anual 28 %, por género: 23 % mujeres y 43 % hombres. 29,3 % presenta reingresos hospitalarios, 50 % recupera su habilidad para la marcha. 81 % considera buena la atención intrahospitalaria por ortopedia. 64 % no califica el servicio intrahospitalario por fisioterapia ya que no lo recibe. 70 % expresa satisfacción con los servicios ambulatorios de ortopedia y rehabilitación. Conclusiones: estudio novedoso y único que da voz como sujeto activo al paciente para evaluar el sistema de salud, sugiere el grado de dolor como elemento trazador de calidad de vida y obliga a implementar programas y servicios para adultos mayores con fracturas de cadera

Fraturas de quadril: Satisfação pós-cirúrgica no ano seguinte em idosos atendidos em Méderi-Hospital Universitário Mayor, Bogotá, D.C.

Introducción: el envejecimiento poblacional mundial ha aumentado la incidencia de fracturas de cadera, este cambio genera un alto impacto económico, social y constituye un reto para la salud pública. Este estudio busca evaluar la satisfacción con el manejo posquirúrgico en adultos mayores con fracturas de cadera al año de la intervención y conocer los desenlaces en este tiempo. Materiales y métodos: estudio exploratorio, observacional, descriptivo de corte transversal, mediante encuesta telefónica en adultos de 65 o más años, un año después de intervención quirúrgica por fracturas de cadera en Méderi - Hospital Universitario Mayor, de Bogotá. Se describen variables evaluativas de satisfacción y atención en salud, así como otras relacionadas. Resultados: de 287 pacientes, 116 cumplen los criterios de inclusión y aceptan participar. El rango de edad oscila entre 65 y 99 años, media de 81,3 ± 8,17. Las mujeres y los hombres representan, respectivamente, 76 % y 24 % de la muestra. Mortalidad anual 28 %, por género: 23 % mujeres y 43 % hombres. 29,3 % presenta reingresos hospitalarios, 50 % recupera su habilidad para la marcha. 81 % considera buena la atención intrahospitalaria por ortopedia. 64 % no califica el servicio intrahospitalario por fisioterapia ya que no lo recibe. 70 % expresa satisfacción con los servicios ambulatorios de ortopedia y rehabilitación. Conclusiones: estudio novedoso y único que da voz como sujeto activo al paciente para evaluar el sistema de salud, sugiere el grado de dolor como elemento trazador de calidad de vida y obliga a implementar programas y servicios para adultos mayores con fracturas de cadera.Introdução: o envelhecimento populacional mundial tem aumentado a incidência de fraturas de quadril, mudanças que gera um alto impacto económico, social e constitui um desafio para a saúde pública. O estudo busca avaliar a satisfação com o manejo pós-cirúrgico em idosos com fraturas de quadril no ano posterior à intervenção e conhecer os desenlaces neste tempo. Materiais e métodos: estudo exploratório, observacional, descritivo, de corte transversal, mediante questionário por telefone em adultos de 65 ou mais anos, um ano após da intervenção cirúrgica por fraturas de quadril em Méderi – Hospital Universitário Mayor, de Bogotá D.C. Descrevem-se variáveis avaliativas de satisfação e atenção em saúde, assim como outras relacionadas. Resultados: de 287 pacientes, 116 cumprem os critérios de inclusão e aceitam participar. O rango de idade oscila entre 65 e 99 anos, média de 81,3 ± 8,17. As mulheres e os homens representam respetivamente 76% e 24% da amostra. Mortalidade anual 28%, por gênero: 23% mulheres e 3% homens. 29,3% apresenta reingressos hospitalários, 50% recupera a sua habilidade para a marcha. 81% considera boa a atenção intra-hospitalar por ortopedia. 64% não qualifica o serviço intra-hospitalar por fisioterapia já que não o recebe. 70% expressa satisfação com os serviços ambulatórios de ortopedia e reabilitação. Conclusões: estudo novo e único que dá voz como sujeito ativo ao paciente para avaliar o sistema de saúde, sugere o grau de dor como elemento traçador de qualidade de vida e obriga a implementar programas e serviços para idosos com fraturas de quadril.Introduction: World aging increases the incidence of hip fracture in adults over sixty years of age, pathology of economic and social burden being a challenge for public health. This study seeks to assess patient degree of satisfaction with health care services and assess outcomes. Materials and methods: Exploratory, observational, descriptive cross-sectional study, with a telephone survey in patients 65 years or older, one year after hip fracture surgical intervention in Méderi-Hospital Universitario Mayor, Bogotá. Results: Of 287 patients 116 met the inclusion-exclusion criteria and accepted to participate. Age ranges between 65 and 99 years with a mean of 81,3 ± 8,17. Women and men represent respectively 76 % and 24 % of the sample. Mortality a year after is 28 %, gender: 23 % women and 43 % men. 29,3 % of the patients reentered the hospital, 50 % recovered their previous functional capacity. 81 % express as good the inpatient care by orthopedic service. 64 % does not grade inpatient care by rehabilitation services because it was not given. 70 % are satisfied with the outpatient services of orthopedic and rehabilitation. Conclusions: This study represents a novel and unique approach as it gives voice to the patient allowing assessment of the health services. Suggests the degree of pain as a tracer of quality of life and brings upon compulsory attention to implement health services improvement programs for hip fractures in the elderly

Fraturas de quadril: Satisfação pós-cirúrgica no ano seguinte em idosos atendidos em Méderi-Hospital Universitário Mayor, Bogotá, D.C.

Introducción: el envejecimiento poblacional mundial ha aumentado la incidencia de fracturas de cadera, este cambio genera un alto impacto económico, social y constituye un reto para la salud pública. Este estudio busca evaluar la satisfacción con el manejo posquirúrgico en adultos mayores con fracturas de cadera al año de la intervención y conocer los desenlaces en este tiempo. Materiales y métodos: estudio exploratorio, observacional, descriptivo de corte transversal, mediante encuesta telefónica en adultos de 65 o más años, un año después de intervención quirúrgica por fracturas de cadera en Méderi - Hospital Universitario Mayor, de Bogotá. Se describen variables evaluativas de satisfacción y atención en salud, así como otras relacionadas. Resultados: de 287 pacientes, 116 cumplen los criterios de inclusión y aceptan participar. El rango de edad oscila entre 65 y 99 años, media de 81,3 ± 8,17. Las mujeres y los hombres representan, respectivamente, 76 % y 24 % de la muestra. Mortalidad anual 28 %, por género: 23 % mujeres y 43 % hombres. 29,3 % presenta reingresos hospitalarios, 50 % recupera su habilidad para la marcha. 81 % considera buena la atención intrahospitalaria por ortopedia. 64 % no califica el servicio intrahospitalario por fisioterapia ya que no lo recibe. 70 % expresa satisfacción con los servicios ambulatorios de ortopedia y rehabilitación. Conclusiones: estudio novedoso y único que da voz como sujeto activo al paciente para evaluar el sistema de salud, sugiere el grado de dolor como elemento trazador de calidad de vida y obliga a implementar programas y servicios para adultos mayores con fracturas de cadera.Introduction: World aging increases the incidence of hip fracture in adults over sixty years of age, pathology of economic and social burden being a challenge for public health. This study seeks to assess patient degree of satisfaction with health care services and assess outcomes. Materials and methods: Exploratory, observational, descriptive cross-sectional study, with a telephone survey in patients 65 years or older, one year after hip fracture surgical intervention in Méderi-Hospital Universitario Mayor, Bogotá. Results: Of 287 patients 116 met the inclusion-exclusion criteria and accepted to participate. Age ranges between 65 and 99 years with a mean of 81,3 ± 8,17. Women and men represent respectively 76 % and 24 % of the sample. Mortality a year after is 28 %, gender: 23 % women and 43 % men. 29,3 % of the patients reentered the hospital, 50 % recovered their previous functional capacity. 81 % express as good the inpatient care by orthopedic service. 64 % does not grade inpatient care by rehabilitation services because it was not given. 70 % are satisfied with the outpatient services of orthopedic and rehabilitation. Conclusions: This study represents a novel and unique approach as it gives voice to the patient allowing assessment of the health services. Suggests the degree of pain as a tracer of quality of life and brings upon compulsory attention to implement health services improvement programs for hip fractures in the elderly.Introdução: o envelhecimento populacional mundial tem aumentado a incidência de fraturas de quadril, mudanças que gera um alto impacto económico, social e constitui um desafio para a saúde pública. O estudo busca avaliar a satisfação com o manejo pós-cirúrgico em idosos com fraturas de quadril no ano posterior à intervenção e conhecer os desenlaces neste tempo. Materiais e métodos: estudo exploratório, observacional, descritivo, de corte transversal, mediante questionário por telefone em adultos de 65 ou mais anos, um ano após da intervenção cirúrgica por fraturas de quadril em Méderi – Hospital Universitário Mayor, de Bogotá D.C. Descrevem-se variáveis avaliativas de satisfação e atenção em saúde, assim como outras relacionadas. Resultados: de 287 pacientes, 116 cumprem os critérios de inclusão e aceitam participar. O rango de idade oscila entre 65 e 99 anos, média de 81,3 ± 8,17. As mulheres e os homens representam respetivamente 76% e 24% da amostra. Mortalidade anual 28%, por gênero: 23% mulheres e 3% homens. 29,3% apresenta reingressos hospitalários, 50% recupera a sua habilidade para a marcha. 81% considera boa a atenção intra-hospitalar por ortopedia. 64% não qualifica o serviço intra-hospitalar por fisioterapia já que não o recebe. 70% expressa satisfação com os serviços ambulatórios de ortopedia e reabilitação. Conclusões: estudo novo e único que dá voz como sujeito ativo ao paciente para avaliar o sistema de saúde, sugere o grau de dor como elemento traçador de qualidade de vida e obriga a implementar programas e serviços para idosos com fraturas de quadril

Variables influencing the prediction of fluid responsiveness: a systematic review and meta-analysis

Abstract Introduction Prediction of fluid responsiveness in acutely ill patients might be influenced by a number of clinical and technical factors. We aim to identify variables potentially modifying the operative performance of fluid responsiveness predictors commonly used in clinical practice. Methods A sensitive strategy was conducted in the Medline and Embase databases to search for prospective studies assessing the operative performance of pulse pressure variation, stroke volume variation, passive leg raising (PLR), end-expiratory occlusion test (EEOT), mini-fluid challenge, and tidal volume challenge to predict fluid responsiveness in critically ill and acutely ill surgical patients published between January 1999 and February 2023. Adjusted diagnostic odds ratios (DORs) were calculated by subgroup analyses (inverse variance method) and meta-regression (test of moderators). Variables potentially modifying the operative performance of such predictor tests were classified as technical and clinical. Results A total of 149 studies were included in the analysis. The volume used during fluid loading, the method used to assess variations in macrovascular flow (cardiac output, stroke volume, aortic blood flow, volume‒time integral, etc.) in response to PLR/EEOT, and the apneic time selected during the EEOT were identified as technical variables modifying the operative performance of such fluid responsiveness predictor tests (p < 0.05 for all adjusted vs. unadjusted DORs). In addition, the operative performance of fluid responsiveness predictors was also influenced by clinical variables such as the positive end-expiratory pressure (in the case of EEOT) and the dose of norepinephrine used during the fluid responsiveness assessment for PLR and EEOT (for all adjusted vs. unadjusted DORs). Conclusion Prediction of fluid responsiveness in critically and acutely ill patients is strongly influenced by a number of technical and clinical aspects. Such factors should be considered for individual intervention decisions

Changes of operative performance of pulse pressure variation as a predictor of fluid responsiveness in endotoxin shock.

Several limitations regarding pulse pressure variation (PPV) use have been reported. Our aim was to describe changes in the PPV operative performance as a predictor of fluid responsiveness during the development of a swine endotoxin shock model and to assess hemodynamic variables associated with PPV changes. A swine porcine endotoxin shock model was established (Escherichia Coli 055:B5 endotoxin) in 7 pigs, and 3 pigs were included in the control group. The endotoxin was infused until the mean arterial pressure (MAP) dropped below 50 mmHg (TH0); then, the model animal was reanimated with fluids and vasopressors. We performed fluid challenges every hour for 6 h. ROC curve analysis and a linear mixed model were performed. The area under the curve of PPV decreased from 0.95 (0.81-1.00) to 0.60 (0.17-1.00) at TH0. Its cutoff increased from 10.5 to 22.00% at TH0. PPV showed an inverse relationship with stroke volume, mean systemic filling pressure, MAP, and systemic vascular resistance (SVR) (p