Role of inorganic cations in the excitonic properties of lead halide perovskites.

We theoretically investigate lead iodide perovskites of general formula APbI3 for a series of metallic cations (namely Cs+, Rb+, K+, Na+ and Li+) by means of density functional theory, the GW method and the Bethe-Salpeter equation including spin-orbit coupling. We demonstrate that the low-energy edges (up to 1.3 eV) of the absorption spectra are dominated by weakly bound excitons, with binding energies Eb of ∼ 30-80 meV, and the corresponding intensities increase as metallic cations become lighter. The middle parts of the spectra (1.8-2.4 eV), on the other hand, contain optical dipole transitions comprising more confined excitons (Eb ∼ 150-200 meV) located at PbI3. These parts of the spectra correspond to the optical-gain wavelengths which are experimentally achieved in optically pumped perovskite lasers. Finally, the higher energy parts, from about 2.8 eV (LiPbI3) to 4.3 eV (CsPbI3), contain optical transitions with very confined excitons (Eb ∼ 220-290 meV) located at halide atoms and the empty states of the metallic cations.

Implementation of a new Single-Pass Whole-Body Computed Tomography Protocol: Is it safe, effective and efficient in patients with severe trauma?

PURPOSE: The objective of this study was to evaluate the implementation of a new single-pass whole-body computed tomography Protocol in the management of patients with severe trauma. METHODS: This was a descriptive evaluation of polytrauma patients who underwent whole-body computed tomography. Patients were divided into three groups: 1. Blunt trauma hemodynamically stable 2. Blunt trauma hemodynamically unstable and 3. Penetrating trauma. Demographics, whole-body computed tomography parameters and outcome variables were evaluated. RESULTS: Were included 263 patients. Median injury severity score was 22 (IQR: 16-22). Time between arrival to the emergency department and completing the whole-body computed tomography was under 30 minutes in most patients [Group 1: 28 minutes (IQR: 14-55), Group 2: 29 minutes (IQR: 16-57), and Group 3: 31 minutes (IQR: 13-50; p= 0.96)]. 172 patients (65.4%) underwent non-operative management. The calculated and the real survival rates did not vary among the groups either [Group 1: TRISS 86.4% vs. real survival rate 85% (p= 0.69); Group 2: TRISS 69% vs. real survival rate 74% (p= 0.25); Group 3: TRISS 93% vs. real survival rate 87% (p= 0.07)]. CONCLUSION: This new single-pass whole-body computed tomography protocol was safe, effective and efficient to decide whether the patient with severe trauma requires a surgical intervention independently of the mechanism of injury or the hemodynamic stability of the patient. Its use could also potentially reduce the rate of unnecessary surgical interventions of patients with severe trauma including those with penetrating trauma.

INTRODUCCIÓN: El objetivo de este estudio fue evaluar la implementación de un nuevo protocolo de tomografía computarizada corporal total para el manejo de pacientes con trauma severo. MÉTODOS: Este estudio es una evaluación descriptiva de pacientes que recibieron tomografía computarizada corporal total. Los pacientes fueron divididos en 3 grupos: 1. Trauma cerrado hemodinámicamente estables, 2. Trauma cerrado hemodinámicamente inestables y 3. Trauma penetrante. Se evaluaron las características demográficas, parámetros relacionados con la técnica y los desenlaces de los pacientes. RESULTADOS: Se incluyeron 263 pacientes. La mediana del puntaje de severidad de la lesión fue 22 (RIQ: 16-22). El tiempo entre el ingreso a urgencias y completar la tomografía corporal total fue menor a 30 minutos en la mayoría de pacientes [Grupo 1: 28 minutos (RIQ: 14-55), Grupo 2: 29 minutos (RIQ: 16-57), y Grupo 3: 31 minutos (RIQ: 13-50; p= 0.96). 172 pacientes (65.4%) recibieron manejo no operatorio. Las tasas de supervivencia calculadas y reales no difirieron entre ninguno de los grupos [Grupo 1: TRISS 86.4% vs. Tasa real de supervivencia 85% (p= 0.69); Grupo 2: TRISS 69% vs. Tasa real de supervivencia 74% (p= 0.25); Grupo 3: TRISS 93% vs. Tasa real de supervivencia 87% (p= 0.07)]. CONCLUSIÓN: Este nuevo protocolo de tomografía corporal total de un solo pase fue seguro, efectivo y eficiente para definir si los pacientes con trauma severo requieren o no una intervención quirúrgica. Su uso podría reducir la tasa de intervenciones quirúrgicas innecesarias en estos pacientes incluyendo los que se presentan con trauma penetrante.

Resuscitative endovascular balloon of the aorta is feasible in penetrating chest trauma with major hemorrhage: Proposal of a new institutional deployment algorithm.

BACKGROUND: Resuscitative endovascular balloon occlusion of the aorta (REBOA) is an emerging option for hemorrhage control, but its use is limited in scenarios such as penetrating chest trauma. The aim of this study was to describe the use of REBOA as a resuscitative adjunct in these cases with major hemorrhage and to propose a new clinical management algorithm. METHODS: This was a prospective, observational study conducted at a single Level I trauma center in Colombia. We included all patients older than 14 years with severe trauma who underwent REBOA from January 2015 to December 2019. Patients received REBOA if they were in hemorrhagic shock and were unresponsive to resuscitation. RESULTS: A total of 56 patients underwent REBOA placement of which 37 had penetrating trauma and 23 had chest trauma. All patients were hemodynamically unstable upon arrival to the emergency department, with a median systolic blood pressure of 69 mm Hg (interquartile range [IQR], 57-90 mm Hg) and median Injury Severity Score was 25 (IQR, 25-41). All REBOAs were deployed and inflated in zone 1, median inflation time was 40 minutes (IQR, 26-55 minutes), and no adverse neurologic outcomes were observed. Fifteen patients had REBOA and a median sternotomy. Eleven patients had concomitant abdominal wounds. Overall mortality was 28.6%, and there was no significant difference between penetrating versus blunt trauma patients (21.6% vs. 42.1%, p = 0.11). The survival rate of thoracic injured patients was similar to the predicted survival (65.2% vs. 63.3%). CONCLUSION: Resuscitative endovascular balloon occlusion of the aorta can be used safely in penetrating chest trauma, and the implementation of a REBOA management algorithm is feasible with a well-trained multidisciplinary team. LEVEL OF EVIDENCE: Therapeutic, level V.

Implementation of a new Single-Pass Whole-Body Computed Tomography Protocol: Is it safe, effective and efficient in patients with severe trauma? / Implementación de un nuevo protocolo de Tomografía Computarizada Corporal Total de un solo pase: ¿Es seguro, efectivo y eficiente en pacientes con trauma severo?

Abstract Purpose: The objective of this study was to evaluate the implementation of a new single-pass whole-body computed tomography Protocol in the management of patients with severe trauma. Methods: This was a descriptive evaluation of polytrauma patients who underwent whole-body computed tomography. Patients were divided into three groups: 1. Blunt trauma hemodynamically stable 2. Blunt trauma hemodynamically unstable and 3. Penetrating trauma. Demographics, whole-body computed tomography parameters and outcome variables were evaluated. Results: Were included 263 patients. Median injury severity score was 22 (IQR: 16-22). Time between arrival to the emergency department and completing the whole-body computed tomography was under 30 minutes in most patients [Group 1: 28 minutes (IQR: 14-55), Group 2: 29 minutes (IQR: 16-57), and Group 3: 31 minutes (IQR: 13-50; p= 0.96)]. 172 patients (65.4%) underwent non-operative management. The calculated and the real survival rates did not vary among the groups either [Group 1: TRISS 86.4% vs. real survival rate 85% (p= 0.69); Group 2: TRISS 69% vs. real survival rate 74% (p= 0.25); Group 3: TRISS 93% vs. real survival rate 87% (p= 0.07)]. Conclusion: This new single-pass whole-body computed tomography protocol was safe, effective and efficient to decide whether the patient with severe trauma requires a surgical intervention independently of the mechanism of injury or the hemodynamic stability of the patient. Its use could also potentially reduce the rate of unnecessary surgical interventions of patients with severe trauma including those with penetrating trauma.

Resumen Introducción: El objetivo de este estudio fue evaluar la implementación de un nuevo protocolo de tomografía computarizada corporal total para el manejo de pacientes con trauma severo. Métodos: Este estudio es una evaluación descriptiva de pacientes que recibieron tomografía computarizada corporal total. Los pacientes fueron divididos en 3 grupos: 1. Trauma cerrado hemodinámicamente estables, 2. Trauma cerrado hemodinámicamente inestables y 3. Trauma penetrante. Se evaluaron las características demográficas, parámetros relacionados con la técnica y los desenlaces de los pacientes. Resultados: Se incluyeron 263 pacientes. La mediana del puntaje de severidad de la lesión fue 22 (RIQ: 16-22). El tiempo entre el ingreso a urgencias y completar la tomografía corporal total fue menor a 30 minutos en la mayoría de pacientes [Grupo 1: 28 minutos (RIQ: 14-55), Grupo 2: 29 minutos (RIQ: 16-57), y Grupo 3: 31 minutos (RIQ: 13-50; p= 0.96). 172 pacientes (65.4%) recibieron manejo no operatorio. Las tasas de supervivencia calculadas y reales no difirieron entre ninguno de los grupos [Grupo 1: TRISS 86.4% vs. Tasa real de supervivencia 85% (p= 0.69); Grupo 2: TRISS 69% vs. Tasa real de supervivencia 74% (p= 0.25); Grupo 3: TRISS 93% vs. Tasa real de supervivencia 87% (p= 0.07)]. Conclusión: Este nuevo protocolo de tomografía corporal total de un solo pase fue seguro, efectivo y eficiente para definir si los pacientes con trauma severo requieren o no una intervención quirúrgica. Su uso podría reducir la tasa de intervenciones quirúrgicas innecesarias en estos pacientes incluyendo los que se presentan con trauma penetrante.

The Challenge of Implementing the "Stop the Bleed" Campaign in Latin America.

BACKGROUND: Currently, several initiatives have emerged to empower the public to act as immediate responders in front of hemorrhaging victims. We aimed to evaluate the effectiveness of implementing the Stop the Bleed campaign and the association between the instructors' background and the theoretical and practical competences achieved by the participants in Latin America. METHODS: Medical students and general surgeons taught both allied health students and nonallied health students at a local university; the training had a master class followed by a practical component and a written test, as well as tourniquet placement was tested. RESULTS: 265 individuals received the training, and data were available for 243. Of these, 126 (52.07%) were women and the median age was 21 (IQR: 20-22) years. 121 (49.79%) were trained by general surgeons (group A) and 122 (50.21%) by medical students (group B). After the training, more than 98% of all participants perceived that they would most likely be capable of aiding correctly a bleeding victim by applying direct pressure and more than 90% of them felt confident in being able to apply a tourniquet. There were no statistically significant differences among both groups when comparing their post-training competence evaluations [Theoretical test score: group A = 5 (IQR: 4-5); group B = 5 (IQR: 4-5); P = 0.41] and [Practical competency of tourniquet deployment: group A = 119 (66.39%) versus group B = 120 (65.83%); P = 0.93]. CONCLUSIONS: The Stop the Bleed campaign can be effectively implemented in Latin America, and it can be taught by prequalified medical students without altering the learning objectives of the course.

Uso de la tomografía corporal total en pacientes con trauma grave: ¿es efectiva y segura para definir el manejo no operatorio? / Use of total body tomography in patients with severe trauma: is it effective and safe to define non-operative management?

Introducción. La tomografía corporal (TC) total en la evaluación de pacientes con trauma grave, puede ser una herramienta eficaz y segura para decidir entre un tratamiento quirúrgico y uno no quirúrgico, pero aún no son claras las implicaciones diagnósticas y los riesgos asociados con esta técnica.Métodos. Se incluyeron pacientes mayores de 15 años con trauma grave que fueron sometidos a TC total. Se evaluaron la seguridad, la efectividad y la eficiencia por medio de los parámetros de incidencia de nefropatía inducida por los medios de contraste, dosis total de radiación por paciente, proporción de casos en los que la TC total cambió el manejo, y el retraso en el diagnóstico. Resultados. Se incluyeron 263 pacientes, 83 % sufrieron trauma cerrado y 17 % sufrieron trauma penetrante. La gravedad de la lesión fue mayor en estos últimos y, sin embargo, el trauma cerrado con inestabilidad hemodinámica se presentó con mayores grados de choque. El 65 % de los pacientes recibió tratamiento selectivo no operatorio. Entre los subgrupos, no hubo diferencias significativas en el tiempo entre el ingreso a la sala de urgencias y la toma de la TC total (p=0,96) y, en la mayoría de los casos, el tiempo entre la práctica de la TC total y el diagnóstico de presencia o ausencia de heridas fue menor de 25 minutos. La mediana de radiación total estuvo por debajo de 20 mSv en todos los grupos. No hubo diferencias significativas en la mortalidad (p=0,17). Conclusión. La TC total es una herramienta segura y eficiente para decidir entre un tratamiento quirúrgico y uno no quirúrgico en los casos de trauma grave, independientemente del mecanismo de la lesión o la estabilidad hemodinámica al ingreso

Introduction: Total body tomography (CT) in the evaluation of patients with severe trauma may be an effective and safe tool to decide between a surgical or non-operative management, but the diagnostic implications and risks associated with this technique are still unclear.Methods: Patients older than 15 years with severe trauma who underwent total CT were included. Safety, effectiveness and efficiency were evaluated through the parameters of incidence of contrast-induced nephropathy, total radiation dose per patient, proportion of cases in which the total CT changed the management, and the delay in the diagnosis.Results: 263 patients were included, 83% presented with blunt trauma and 17% with penetrating trauma. The severity of the injury was higher in the latter, however, the blunt trauma with hemodynamic instability presented with higher degrees of shock. Non-operative management was selected in 65% of patients. Among the subgroups, there was no significant difference in the time between admission to the emergency room and taking the total CT (p=0.96), and in most cases, the time between the total CT and the diagnosis of presence or absence of injury was less than 25 minutes. The median total radiation was below than 20 mSv in all groups. There were no significant difference in mortality (p=0.170. Conclusion: Total CT is a safe and efficient tool to decide between a surgical and a non-operative management in patients with severe trauma, regardless of the mechanism of injury or hemodynamic stability at admission

La laparotomía de control de daños en pacientes sin trauma reduce el número de ostomías / Damage control laparotomy in non-trauma patients reduces the number of ostomies

Introducción. El objetivo de este estudio fue evaluar si la laparotomía de control de daños con ligadura y reconstrucción intestinal diferida, en pacientes con peritonitis secundaria a compromiso de víscera hueca, reduce el número de ostomías. Métodos. Se incluyeron todos los pacientes menores de 18 años de edad que ingresaron a la clínica con sospecha de peritonitis de origen no traumático y que se sometieron a laparotomía entre enero del 2003 y diciembre del 2018. Se evaluaron las características sociodemográficas, comorbilidades, escalas de gravedad fisiológica, técnicas de reconstrucción intestinal y resultados clínicos. Resultados. Se incluyeron 306 pacientes, distribuidos en tres grupos: 1) 120 (39,2 %) sometidos a resección y anastomosis, 2) 87 (28,4 %) sometidos a ostomía, y 3) 99 (32,3 %) sometidos inicialmente a ligadura intestinal. Los pacientes sometidos a ligadura intestinal presentaron mayor compromiso fisiológico al ingreso a la unidad de cuidado intensivo, con puntuación APACHE II: 14 (rango intercuartílico, RIC=10-18) en el grupo 1, 13 (RIC=11-18) en el grupo 2, y 18 (RIC=14-24) en el grupo 3 (p<0,01). Sin embargo, más de la mitad se reconstruyeron en la siguiente laparotomía: anastomosis mecánica (16/99; 16,1 %), anastomosis manual (49/99; 49,5 %), ostomía (34/99; 34,3 %). Además, estos pacientes sometidos a ligadura intestinal tuvieron un número significativamente mayor de nuevas laparotomías, y de días de asistencia respiratoria mecánica, de estancia en la unidad de cuidado intensivo y de estancia hospitalaria. No hubo diferencias estadísticamente significativas en la mortalidad entre los subgrupos: (grupo 1=19 (15,8 %), grupo 2=16 (18,4 %), grupo 3=19 (19,2 %) (p=0,79). Conclusión. En este estudio, se logró evitar la ostomía como técnica de reconstrucción definitiva en más de la mitad de los pacientes con peritonitis que se sometieron a laparotomía de control de daños con ligadura intestinal

Introduction. The objective of this study was to evaluate if the damage control laparotomy with ligation and delayed intestinal reconstruction (DR), in patients with peritonitis secondary to compromised hollow viscera, reduces the number of ostomies.Methods. All patients under 18 years of age who entered the clinic with suspected non-traumatic peritonitis and who underwent laparotomy between January 2003 and December 2018 were included. Sociodemographic characteristics, comorbidities, severity scales physiological, intestinal reconstruction techniques and clinical results were evaluated.Results. A total of 306 patients were included, divided into three groups: 1) 120 (39.2 %) underwent resection and anastomosis, 2) 87 (28.4 %) underwent ostomy, and 3) 99 (32.3 %) underwent initial to intestinal ligation. Patients undergoing intestinal ligation presented greater physiological compromise upon admission to the intensive care unit, with an APACHE II score: 14 (interquartile range, IQR= 10-18) in group 1, 13 (IQR = 11-18) in the group 2, and 18 (IQR = 14-24) in group 3 (p<0.01). However, more than half were reconstructed in the following laparotomy: mechanical anastomosis (16/99; 16.1 %), manual anastomosis (49/99; 49.5 %), ostomy (34/99; 34.3 %). Also, they had a significantly greater number of new laparotomies, and of days of mechanical respiratory assistance, of stay in the intensive care unit and of hospital stay. There were no statistically significant differences in mortality between the subgroups: group 1= 19 (15.8 %), group 2= 16 (18.4 %), group 3= 19 (19.2 %) (p= 0.79). Conclusion. In this study, it was possible to avoid the ostomy as the definitive reconstruction technique in more than half of the patients with peritonitis who underwent damage control laparotomy with intestinal ligation

Balón de reanimación endovascular de aorta para pacientes en riesgo o en choque hemorrágico: experiencia en un centro de trauma de Latinoamérica / Resuscitative endovascular balloon occlusion of the aorta in patients in danger of hemorrhagic shock: experience in a Latin American trauma center

Introducción. La maniobra de reanimación mediante el denominado "balón de reanimación endovascular de aorta"(Resuscitative Endovascular Balloon Occlusion of the Aorta, REBOA), es un procedimiento para obtener el control proximal de la hemorragia. Nuestra hipótesis es que puede usarse como una maniobra emergente para el manejo del choque hemorrágico y como una intervención para prevenir la aparición de hemorragia masiva en los pacientes en riesgo. Materiales y métodos. Se recolectaron los datos de una cohorte prospectiva de pacientes entre el 2014 y 2018 en un centro de trauma de nivel I del suroccidente colombiano. Los datos se presentaron, de acuerdo con su distribución de normalidad, en medias y desviaciones estándar o medianas y rangos intercuartílicos. Resultados. Se incluyeron 70 pacientes, 27 considerados en riesgo de choque hemorrágico (mujeres embarazadas con placentación anormal) y 43 con choque hemorrágico (pacientes de trauma sometidos a cirugía y oclusión aórtica con balón). En el primer grupo, ningún paciente requirió transfusión masiva y no se reportaron muertes. En el último, hubo aumento significativo de la presión arterial sistémica después del procedimiento de 50,1 ± 22,5 a 107 mm Hg (rango: 87-129) y la mortalidad fue del 30,2 %. Conclusión. Esta muestra de pacientes sometidos a reanimación mediante oclusión aórtica con REBOA es la más grande reportada hasta ahora en Latinoamérica. Esta es una herramienta eficaz para el manejo de pacientes en choque hemorrágico o en riesgo de uno

Introduction: Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) is a procedure that involves placement of an endovascular balloon in the aorta to obtain proximal control of hemorrhage. We hypothesize that the REBOA can be used as an emergent maneuver for the management of patients with hemorrhagic shock and as a prophylactic intervention to prevent the appearance of massive hemorrhage in populations at risk. Methods: Data were collected from a prospective cohort of patients in the period between 2014 and 2018, at a level I trauma center in Southwestern Colombia. The data was presented according to their distribution of normality, in means and standard deviations or medians and interquartile ranges. Results: Seventy patients were included, 27 considered at risk of hemorrhagic shock (pregnant women with abnormal placentation) and 43 with hemorrhagic shock (trauma patients undergoing surgery and REBOA). In the first group, no patient required massive transfusion and no deaths were reported. In the latter, there was a significant increase in blood pressure [SBP pre-REBOA: 50.1 ± 22.5, post-REBOA SBP: 107 (87-129)] and mortality was 30.2%. Conclusion: Our experience in the use of REBOA is the largest reported in Latin America. This is an effective tool for the management of patients at or at risk of hemorrhagic shock

Control prehospitalario de la hemorragia en pacientes de trauma: una estrategia de prevención secundaria factible para países de bajos y medianos ingresos / Prehospital control of hemorrhage in trauma patients: a feasible secondary prevention strategy in countries of low and median income

Introducción. La hemorragia no controlada es la principal causa prevenible de muerte en trauma. No hay precedentes locales que estimen el efecto de estrategias de prevención que involucren al público en la atención inicial de las víctimas. Objetivo. Evaluar si es factible implementar programas de entrenamiento para el control prehospitalario básico del sangrado en pacientes de trauma, en un país de bajos a medianos ingresos. Métodos. Cirujanos y estudiantes de medicina se encargaron de desplegar el curso "Stop the bleed" en estudiantes universitarios del suroccidente colombiano. Se hizo una evaluación antes y después de hacer el entrenamiento. Se usó la prueba t de Student y un análisis de regresión logística ordinal, para determinar los factores que estuvieron asociados a obtener mejores puntajes en la evaluación del curso. Resultados. Se entrenaron 265 estudiantes, con una edad media de 21,4 ± 4 años, de los cuales 136 (51,5 %) eran mujeres. Después de recibir el entrenamiento un participante tuvo 15,6 veces la oportunidad de obtener mayor puntaje de calificación con respecto al periodo preentrenamiento [IC95%: 15,1-16,2 (p<0,001)], 99,4 y 95,2 %, respectivamente, estarían dispuestos a tomar medidas y colocar un torniquete a una víctima de sangrado (p<0,001). Conclusión. Es factible para los países con recursos limitados hacer el entrenamiento en control básico del sangrado. Este se puede llevar a cabo de manera eficaz, tanto por instructores con un bagaje amplio en técnicas de control del sangrado como por instructores con menor nivel de formación, pero con un entrenamiento adecuado

Background: uncontrolled hemorrhage is the leading cause of preventable death in trauma. There are no local precedents that estimate the effect of prevention strategies that involve the public in the initial care of victims. Our objective was to evaluate if it is feasible to implement training programs for the basic control of prehospital bleeding in trauma patients, in a low to a middle-income country. Methods: Surgeons and medical students deploying the Stop the bleed course in a Colombian southwestern university, evaluation was performed before and after the training. A T-test and an ordinal logistic regression analysis were used to determine the factors associated with better scores in the course evaluation. Results: of the 265 students, were women 136 (51.5%), age was 21.4± 4. After receiving the training, a participant had 15.6 times the chance of obtaining a higher score than the pre-training period [95% CI: 15.1-16.2 (p <0.001)]. 99.4% and 95.2% respectively, would be willing to take actions and place a tourniquet on a bleeding victim (p <0.001). Conclusion: in a low to a middle-income country is feasible to perform the Bleeding Control Basic training. This can be done effectively by instructors with a broad background in bleeding control techniques as well as by instructors with less experience, but with adequate training