Management of peri-surgical anemia in elective surgery. Conclusions and recommendations according to Delphi-UCLA methodology.

INTRODUCTION: Preoperative anemia affects approximately one third of surgical patients. It increases the risk of blood transfusion and influences short- and medium-term functional outcomes, increases comorbidities, complications and costs. The "Patient Blood Management" (PBM) programs, for integrated and multidisciplinary management of patients, are considered as paradigms of quality care and have as one of the fundamental objectives to correct perioperative anemia. PBM has been incorporated into the schemes for intensified recovery of surgical patients: the recent Enhanced Recovery After Surgery 2021 pathway (in Spanish RICA 2021) includes almost 30 indirect recommendations for PBM. OBJECTIVE: To make a consensus document with RAND/UCLA Delphi methodology to increase the penetration and priority of the RICA 2021 recommendations on PBM in daily clinical practice. MATERIAL AND METHODS: A coordinating group composed of 6 specialists from Hematology-Hemotherapy, Anesthesiology and Internal Medicine with expertise in anemia and PBM was formed. A survey was elaborated using Delphi RAND/UCLA methodology to reach a consensus on the key areas and priority professional actions to be developed at the present time to improve the management of perioperative anemia. The survey questions were extracted from the PBM recommendations contained in the RICA 2021 pathway. The development of the electronic survey (Google Platform) and the management of the responses was the responsibility of an expert in quality of care and clinical safety. Participants were selected by invitation from speakers at AWGE-GIEMSA scientific meetings and national representatives of PBM-related working groups (Seville Document, SEDAR HTF section and RICA 2021 pathway participants). In the first round of the survey, the anonymized online questionnaire had 28 questions: 20 of them were about PBM concepts included in ERAS guidelines (2 about general PBM organization, 10 on diagnosis and treatment of preoperative anemia, 3 on management of postoperative anemia, 5 on transfusion criteria) and 8 on pending aspects of research. Responses were organized according to a 10-point Likter scale (0: strongly disagree to 10: strongly agree). Any additional contributions that the participants considered appropriate were allowed. They were considered consensual because all the questions obtained an average score of more than 9 points, except one (question 14). The second round of the survey consisted of 37 questions, resulting from the reformulation of the questions of the first round and the incorporation of the participants' comments. It consisted of 2 questions about general organization of PBM programme, 15 questions on the diagnosis and treatment of preoperative anemia; 3 on the management of postoperative anemia, 6 on transfusional criteria and finally 11 questions on aspects pending od future investigations. Statistical treatment: tabulation of mean, median and interquartiles 25-75 of the value of each survey question (Tables 1, 2 and 3). RESULTS: Except for one, all the recommendations were accepted. Except for three, all above 8, and most with an average score of 9 or higher. They are grouped into: 1.- "It is important and necessary to detect and etiologically diagnose any preoperative anemia state in ALL patients who are candidates for surgical procedures with potential bleeding risk, including pregnant patients". 2.- "The preoperative treatment of anemia should be initiated sufficiently in advance and with all the necessary hematinic contributions to correct this condition". 3.- "There is NO justification for transfusing any unit of packed red blood cells preoperatively in stable patients with moderate anemia Hb 8-10g/dL who are candidates for potentially bleeding surgery that cannot be delayed." 4.- "It is recommended to universalize restrictive criteria for red blood cell transfusion in surgical and obstetric patients." 5.- "Postoperative anemia should be treated to improve postoperative results and accelerate postoperative recovery in the short and medium term". CONCLUSIONS: There was a large consensus, with maximum acceptance,strong level of evidence and high recommendation in most of the questions asked. Our work helps to identify initiatives and performances who can be suitables for the implementation of PBM programs at each hospital and for all patients.

Resumen ejecutivo del documento de consenso sobre el manejo de la anemia perioperatoria en España / Executive summary of the consensus document on the management of perioperative anemia in Spain

La anemia perioperatoria constituye un factor independiente de riesgo de morbimortalidad posoperatoria. Sin embargo, persisten barreras conceptuales, logísticas y administrativas que dificultan la implementación generalizada de protocolos para su manejo. El coordinador del proyecto convocó a un grupo multidisciplinar de ocho profesionales para elaborar un documento de consenso sobre el manejo de la anemia perioperatoria, con base a en serie puntos claves (PCs) relativos a su prevalencia, consecuencias, diagnóstico y tratamiento. Estos PCs fueron evaluados utilizando una escala Likert de 5 puntos, desde «totalmente en desacuerdo [1]» a «totalmente de acuerdo [5]». Cada PC se consideró consensuado si recibía una puntuación de 4 o 5 por al menos siete participantes (> 75%). A partir de los 36 PCs consensuados, se construyeron algoritmos diagnóstico-terapéuticos que pueden facilitar la implementación de programas de identificación precoz y manejo adecuado de la anemia perioperatoria, adaptados a las características de las instituciones hospitalarias de nuestro país.(AU)

Perioperative anemia is an independent risk factor for postoperative morbidity and mortality. However, conceptual, logistical and administrative barriers persist that hinder the widespread implementation of protocols for their management. The project coordinator convened a multidisciplinary group of 9 experienced professionals to develop perioperative anemia management algorithms, based on a series of key points (KPs) related to its prevalence, consequences, diagnosis and treatment. These KPs were assessed using a 5-point Likert scale, from “strongly disagree [1]” to “strongly agree [5]”. For each KP, consensus was reached when receiving a score of 4 or 5 from at least 7 participants (>75%). Based on the 36 KPs agreed upon, diagnostic-therapeutic algorithms were developed that we believe can facilitate the implementation of programs for early identification and adequate management of perioperative anemia, adapted to the characteristics of the different institutions in our country.(AU)

Executive summary of the consensus document on the management of perioperative anemia in Spain.

Perioperative anemia is an independent risk factor for postoperative morbidity and mortality. However, conceptual, logistical and administrative barriers persist that hinder the widespread implementation of protocols for their management. The project coordinator convened a multidisciplinary group of 8 experienced professionals to develop perioperative anemia management algorithms, based on a series of key points (KPs) related to its prevalence, consequences, diagnosis and treatment. These KPs were assessed using a 5-point Likert scale, from "strongly disagree [1]" to "strongly agree [5]". For each KP, consensus was reached when receiving a score of 4 or 5 from at least 7 participants (>75%). Based on the 36 KPs agreed upon, diagnostic-therapeutic algorithms were developed that we believe can facilitate the implementation of programs for early identification and adequate management of perioperative anemia, adapted to the characteristics of the different institutions in our country.

European beech dieback after premature leaf senescence during the 2018 drought in northern Switzerland.

During the particularly severe hot summer drought in 2018, widespread premature leaf senescence was observed in several broadleaved tree species in Central Europe, particularly in European beech (Fagus sylvatica L.). For beech, it is yet unknown whether the drought evoked a decline towards tree mortality or whether trees can recover in the longer term. In this study, we monitored crown dieback, tree mortality and secondary drought damage symptoms in 963 initially live beech trees that exhibited either premature or normal leaf senescence in 2018 in three regions in northern Switzerland from 2018 to 2021. We related the observed damage to multiple climate- and stand-related parameters. Cumulative tree mortality continuously increased up to 7.2% and 1.3% in 2021 for trees with premature and normal leaf senescence in 2018, respectively. Mean crown dieback in surviving trees peaked at 29.2% in 2020 and 8.1% in 2019 for trees with premature and normal leaf senescence, respectively. Thereafter, trees showed first signs of recovery. Crown damage was more pronounced and recovery was slower for trees that showed premature leaf senescence in 2018, for trees growing on drier sites, and for larger trees. The presence of bleeding cankers peaked at 24.6% in 2019 and 10.7% in 2020 for trees with premature and normal leaf senescence, respectively. The presence of bark beetle holes peaked at 22.8% and 14.8% in 2021 for trees with premature and normal leaf senescence, respectively. Both secondary damage symptoms occurred more frequently in trees that had higher proportions of crown dieback and/or showed premature senescence in 2018. Our findings demonstrate context-specific differences in beech mortality and recovery reflecting the importance of regional and local climate and soil conditions. Adapting management to increase forest resilience is gaining importance, given the expected further beech decline on dry sites in northern Switzerland.

Long-term soil water limitation and previous tree vigor drive local variability of drought-induced crown dieback in Fagus sylvatica.

Ongoing climate warming is increasing evapotranspiration, a process that reduces plant-available water and aggravates the impact of extreme droughts during the growing season. Such an exceptional hot drought occurred in Central Europe in 2018 and caused widespread defoliation in mid-summer in European beech (Fagus sylvatica L.) forests. Here, we recorded crown damage in 2021 in nine mature even-aged beech-dominated stands in northwestern Switzerland along a crown damage severity gradient (low, medium, high) and analyzed tree-ring widths of 21 mature trees per stand. We aimed at identifying predisposing factors responsible for differences in crown damage across and within stands such as tree growth characteristics (average growth rates and year-to-year variability) and site-level variables (mean canopy height, soil properties). We found that stand-level crown damage severity was strongly related to soil water availability, inferred from tree canopy height and plant available soil water storage capacity (AWC). Trees were shorter in drier stands, had higher year-to-year variability in radial growth, and showed higher growth sensitivity to moisture conditions of previous late summer than trees growing on soils with sufficient AWC, indicating that radial growth in these forests is principally limited by soil water availability. Within-stand variation of post-drought crown damage corresponded to growth rate and tree size (diameter at breast height, DBH), i.e., smaller and slower-growing trees that face more competition, were associated with increased crown damage after the 2018 drought. These findings point to tree vigor before the extreme 2018 drought (long-term relative growth rate) as an important driver of damage severity within and across stands. Our results suggest that European beech is less likely to be able to cope with future climate change-induced extreme droughts on shallow soils with limited water retention capacity.

Efecto de la suplementación con vitamina D en los efectos secundarios musculoesqueléticos relacionados con los inhibidores de la aromatasa para el cáncer de mama: cohorte B-ABLE / Effect of vitamin D supplementation on aromatase inhibitor-related musculoskeletal side effects for breast cancer: B-ABLE cohort

Objetivo: Evaluar el efecto de la suplementación con vitamina D en las complicaciones musculoesqueléticas relacionadas con el tratamiento con inhibidores de la aromatasa (IA) en pacientes con cáncer de mama. Material y métodos: Estudio observacional prospectivo de mujeres en tratamiento con IA, reclutadas en la cohorte B-ABLE. Las pacientes con niveles séricos iniciales de 25(OH)D (25-hidroxivitamina D) <30 ng/ml recibieron una dosis de 16.000 UI de calcifediol oral cada 2 semanas. La artralgia y la pérdida ósea relacionadas con los IA se evaluaron a los 3 meses y al año de seguimiento, respectivamente. Los análisis de asociación del status de vitamina D a los 3 meses con eventos musculoesqueléticos se realizaron mediante modelos de regresión lineal multivariante ajustados. Además, se evaluó la asociación del dolor incidente, definido como pacientes sin dolor articular inicial, pero con una escala visual analógica (EVA) >0 a los 3 meses, mediante regresión logística. Resultados: La suplementación con vitamina D al inicio del tratamiento con IA disminuyó el riesgo tanto de artralgia incidente como de su empeoramiento. El umbral efectivo de 25(OH)D en suero para reducir el dolor articular se estableció en 40 ng/ml. Sin embargo, este umbral no se relacionó significativamente con los cambios óseos al año de seguimiento. No obstante, los niveles de vitamina D se correlacionaron inversamente con la pérdida ósea de la columna lumbar (CL) (β=0,177% [IC 95%: 0,014 a 0,340]). Conclusiones: La administración de suplementos de vitamina D con el objetivo de alcanzar niveles séricos de 25OHD de al menos 40 ng/ml es protectora para la artralgia. Los niveles de vitamina D a los tres meses podrían predecir el riesgo de pérdida ósea en CL al año de tratamiento con IA. Por lo tanto, se recomiendan dosis altas de vitamina D en estas pacientes, que son más propensas a sufrir afecciones musculoesqueléticas. (AU)

Objetive: To assess the effect of vitamin D supplementation on musculoskeletal complications related to aromatase inhibitor (AI) treatment in patients with breast cancer. Material and methods: Prospective observational study of women undergoing AI treatment, recruited in the B-ABLE cohort. Patients with baseline serum 25 (OH) D (25-hydroxyvitamin D) levels <30 ng/ml received a 16,000 IU dose of oral calcifediol every 2 weeks. Arthralgia and bone loss related to AIs were assessed at 3 months and 1 year of followup, respectively. The association analyzes of vitamin D status at 3 months with musculoskeletal events were carried out using adjusted multivariate linear regression models. In addition, the association of incident pain, defined as patients without initial joint pain, but with a visual analog scale (VAS) >0 at 3 months, was evaluated using logistic regression. Results: Vitamin D supplementation at the start of AI treatment decreased the risk of both incident arthralgia and its worsening. The effective threshold of 25 (OH) D in serum to reduce joint pain was established at 40 ng/ml. However, this threshold was not significantly related to bone changes at one year of follow-up. However, vitamin D levels were inversely correlated with lumbar spine bone loss (LS) (β=0.177% [95% CI: 0.014 to 0.340]). Conclusions: Vitamin D supplementation aimed at achieving serum 25(OH)D levels of at least 40 ng/ml is protective for arthralgia. Vitamin D levels at three months could predict the risk of bone loss in LS at one year of AI treatment. Therefore, high doses of vitamin D are recommended in these patients, who are more prone to musculoskeletal conditions. (AU)

Antibodies to M-type phospholipase A2 receptor (PLA2R) in membranous lupus nephritis.

BACKGROUND: Antibodies to M-type phospholipase A2 receptor (a-PLA2R) have been identified in most patients with idiopathic membranous nephropathy, but the prevalence in membranous lupus nephritis (MLN) is still unclear. The objective of this study was to assess the prevalence of a-PLA2R antibodies in a large cohort of patients with lupus nephritis. METHODS: a-PLA2R antibodies were measured by ELISA in serum from patients with systemic lupus erythematosus ( n = 190), of whom 37 had a biopsy-proven MLN. Positive samples were confirmed by commercial ELISA kit, Western blot and immunohistochemistry in renal tissue. RESULTS: A total of 10 from 190 patients (5.3%) with systemic lupus erythematosus had circulating a-PLA2R measured by in-house ELISA assay. The antibodies were detected in 7 patients with MLN (18.9%) and 3 patients with non-renal lupus disease (3.2%). PLA2R staining was detected in the kidney biopsy of 5 of the 7 (71.4%) patients with MLN. a-PLA2R levels were associated with active disease but not proteinuria levels. Presence of a-PLA2R antibodies at baseline was associated with worse remission rates and longer time to remission compared to those patients serologically negative. CONCLUSIONS: a-PLA2R antibodies can be detected with low prevalence in MLN patients, but their detection is associated with a worse renal prognosis.

Strain intermittency due to avalanches in ferroelastic and porous materials.

The avalanche statistics in porous materials and ferroelastic domain wall systems has been studied for slowly increasing compressive uniaxial stress with stress rates between 0.2 and 17 kPa s-1. Velocity peaks [Formula: see text] are calculated from the measured strain drops and used to determine the corresponding Energy distributions [Formula: see text]. Power law distributions [Formula: see text] have been obtained over 4-6 decades. For most of the porous materials and domain wall systems an exponent [Formula: see text] was obtained in good agreement with mean-field theory of the interface pinning transition. For charcoal, shale and calcareous schist we found significant deviations of the exponents from mean-field values in agreement with recent acoustic emission experiments.

Foro de debate: seguridad de las alternativas a la transfusión alogénica en el paciente quirúrgico y/o crítico / Forum for debate: Safety of allogeneic blood transfusion alternatives in the surgical/critically ill patient

Estos últimos años han aparecido alertas de seguridad, no siempre bien sustentadas, que cuestionan el uso de algunas alternativas farmacológicas a la transfusión de sangre alogénica y/o lo restringen en indicaciones establecidas. Asistimos también a la preconización de otras alternativas, incluyendo productos hemáticos y fármacos antifibrinolíticos, sin que haya una base científica sólida que lo justifique. Por iniciativa del Grupo de Estudios Multidisciplinares sobre Autotransfusión y del Anemia Working Group España se reunió a un panel multidisciplinar de 23 expertos del área de cuidados de la salud en un foro de debate para: 1) analizar las diferentes alertas de seguridad en torno a ciertas alternativas a la transfusión; 2) estudiar los antecedentes que las han propiciado, la evidencia que las sustentan y las consecuencias que conllevan para la práctica clínica, y 3) emitir una valoración argumentada de la seguridad de cada alternativa a la transfusión cuestionada, según el uso clínico de la misma. Los integrantes del foro mantuvieron contactos por vía telemática y una reunión presencial en la que presentaron y discutieron las conclusiones sobre cada uno de los elementos examinados. Se elaboró un primer documento que fue sometido a 4 rondas de revisión y actualización hasta alcanzar un consenso, unánime en la mayoría de los casos. Presentamos la versión final del documento, aprobada por todos los miembros del panel, esperando sea de utilidad para nuestros colegas

In recent years, several safety alerts have questioned or restricted the use of some pharmacological alternatives to allogeneic blood transfusion in established indications. In contrast, there seems to be a promotion of other alternatives, based on blood products and/or antifibrinolytic drugs, which lack a solid scientific basis. The Multidisciplinary Autotransfusion Study Group and the Anemia Working Group España convened a multidisciplinary panel of 23 experts belonging to different healthcare areas in a forum for debate to: 1) analyze the different safety alerts referred to certain transfusion alternatives; 2) study the background leading to such alternatives, the evidence supporting them, and their consequences for everyday clinical practice, and 3) issue a weighted statement on the safety of each questioned transfusion alternative, according to its clinical use. The members of the forum maintained telematics contact for the exchange of information and the distribution of tasks, and a joint meeting was held where the conclusions on each of the items examined were presented and discussed. A first version of the document was drafted, and subjected to 4 rounds of review and updating until consensus was reached (unanimously in most cases). We present the final version of the document, approved by all panel members, and hope it will be useful for our colleagues

[Implementation of blood sparing programs in Spain: results of a survey of departments of anesthesiology and resuscitation]. / Implementación de los programas de ahorro de sangre en España: resultados de la encuesta a los servicios de anestesiología y reanimación.

The objective of this article is to determine the availability of a perioperative transfusion management program (Patient Blood Management [PBM]) in various hospitals through a survey that included a description of the preanesthesia visit, the availability and use of the various blood-sparing techniques and the factors limiting their implementation in elective surgery. The survey included 42 questions, directed at the representative departments of anesthesiology of hospitals in Spain (n=91). The survey was conducted from September to November 2012. We analyzed the 82 surveys in which all the questions were answered (90%). Preoperative consultations are routinely performed (>70%) in 87% of the hospitals. The time from the consultation to surgery varied between 1 week and 2 months for 74% of the patients scheduled for orthopedic or trauma surgery, 78% of those scheduled for oncologic surgery and 77% of those scheduled for cardiac surgery. Almost all hospitals (77, 94%) had a transfusion committee, and 90% of them had an anesthesiologist on the committee. Seventy-nine percent of the hospitals had a blood-sparing program, and the most widely used technique was the use of antifibrinolytic agents (75% of hospitals), followed by intraoperative and postoperative blood recovery in equal proportions (67%). Optimization of preoperative hemoglobin was routinely performed with intravenous iron in 39% of the hospitals and with recombinant erythropoietin in 28% of the hospitals. The absence of a well-established circuit and the lack of involvement and collaboration with the surgical team were the main limiting factors in implementing PBM. Currently, the implementation of PBM in Spain could be considered acceptable, but it could also be improved, especially in the treatment of preoperative anemia. The implementation of PBM requires multidisciplinary collaboration among all personnel responsible for perioperative care, including the health authorities.

[The first pillar of patient blood management. Types of anemia and diagnostic parameters]. / Primer pilar del "Patient Blood Management". Tipos de anemia y parámetros diagnósticos.

Patient Blood Management (PBM) is the design of a personalized, multimodal multidisciplinary plan for minimizing transfusion and simultaneously achieving a positive impact on patient outcomes. The first pillar of PBM consists of optimizing the erythrocyte mass. The best chance for this step is offered by preoperative preparation. In most cases, a detailed medical history, physical examination and laboratory tests will identify the cause of anemia. A correct evaluation of parameters that assess the state and function of iron, such as ferritin levels, and the parameters that measure functional iron, such as transferrin saturation and soluble transferrin receptor levels, provide us with essential information for guiding the treatment with iron. The new blood count analyzers that measure hypochromia (% of hypochromic red blood cells and reticulocyte hemoglobin concentrations) provide us useful information for the diagnosis and follow-up of the response to iron treatment. Measuring serum folic acid and vitamin B12 levels is essential for treating deficiencies and thereby achieving better hemoglobin optimization.

[Algorithm for treating preoperative anemia]. / Algoritmo para el tratamiento de la anemia preoperatoria.

Hemoglobin optimization and treatment of preoperative anemia in surgery with a moderate to high risk of surgical bleeding reduces the rate of transfusions and improves hemoglobin levels at discharge and can also improve postoperative outcomes. To this end, we need to schedule preoperative visits sufficiently in advance to treat the anemia. The treatment algorithm we propose comes with a simple checklist to determine whether we should refer the patient to a specialist or if we can treat the patient during the same visit. With the blood count test and additional tests for iron metabolism, inflammation parameter and glomerular filtration rate, we can decide whether to start the treatment with intravenous iron alone or erythropoietin with or without iron. With significant anemia, a visit after 15 days might be necessary to observe the response and supplement the treatment if required. The hemoglobin objective will depend on the type of surgery and the patient's characteristics.

[Therapeutic approach to postoperative anemia]. / Aproximación terapéutica a la anemia postoperatoria.

Postoperative anemia is a common finding in patients who undergo major surgery, and it can affect early rehabilitation and the return to daily activities. Allogeneic blood transfusion is still the most widely used method for restoring hemoglobin levels rapidly and effectively. However, the potential risks of transfusions have led to the review of this practice and to a search for alternative measures for treating postoperative anemia. The early administration of intravenous iron appears to improve the evolution of postoperative hemoglobin levels and reduce allogeneic transfusions, especially in patients with significant iron deficiency or anemia. What is not clear is whether this treatment heavily influences rehabilitation and quality of life. There is a lack of well-designed, sufficiently large, randomized prospective studies to determine whether postoperative or perioperative intravenous iron treatment, with or without recombinant erythropoietin, has a role in the recovery from postoperative anemia, in reducing transfusions and morbidity rates and in improving exercise capacity and quality of life.

[Treatment of preoperative anemia in major orthopedic surgery]. / Tratamiento de la anemia preoperatoria en cirugía ortopédica mayor.

The prevalence of preoperative anemia in major orthopedic surgery is high and is the main predictive factor for allogeneic blood transfusion. The scheduling of a preoperative visit with sufficient notice (at least 3 weeks before surgery), with a blood count test and a basic iron metabolism study, enables us to treat the anemia and/or improve preoperative hemoglobin levels, thereby reducing the need for transfusion and the risks associated with transfusions. Intravenous iron and/or erythropoietin are treatments for optimizing preoperative anemia, with good levels of scientific evidence.

[Treatment of anemia in Patient Blood Management from an economic perspective]. / Tratamiento de la anemia en el "Patient Blood Management" desde una perspectiva económica.

The liberal use of transfusions is not only a risk for patients but also represents a significant healthcare expenditure. The rational use of allogeneic blood transfusions and the use of transfusion alternatives, such as the optimization of preoperative hemoglobin levels, can offer substantial savings to health departments by reducing the cost of transfusions and the morbidity related to the transfusions.

Forum for debate: Safety of allogeneic blood transfusion alternatives in the surgical/critically ill patient.

In recent years, several safety alerts have questioned or restricted the use of some pharmacological alternatives to allogeneic blood transfusion in established indications. In contrast, there seems to be a promotion of other alternatives, based on blood products and/or antifibrinolytic drugs, which lack a solid scientific basis. The Multidisciplinary Autotransfusion Study Group and the Anemia Working Group España convened a multidisciplinary panel of 23 experts belonging to different healthcare areas in a forum for debate to: 1) analyze the different safety alerts referred to certain transfusion alternatives; 2) study the background leading to such alternatives, the evidence supporting them, and their consequences for everyday clinical practice, and 3) issue a weighted statement on the safety of each questioned transfusion alternative, according to its clinical use. The members of the forum maintained telematics contact for the exchange of information and the distribution of tasks, and a joint meeting was held where the conclusions on each of the items examined were presented and discussed. A first version of the document was drafted, and subjected to 4 rounds of review and updating until consensus was reached (unanimously in most cases). We present the final version of the document, approved by all panel members, and hope it will be useful for our colleagues.

Criticality in the slowed-down boiling crisis at zero gravity.

Boiling crisis is a transition between nucleate and film boiling. It occurs at a threshold value of the heat flux from the heater called CHF (critical heat flux). Usually, boiling crisis studies are hindered by the high CHF and short transition duration (below 1 ms). Here we report on experiments in hydrogen near its liquid-vapor critical point, in which the CHF is low and the dynamics slow enough to be resolved. As under such conditions the surface tension is very small, the experiments are carried out in the reduced gravity to preserve the conventional bubble geometry. Weightlessness is created artificially in two-phase hydrogen by compensating gravity with magnetic forces. We were able to reveal the fractal structure of the contour of the percolating cluster of the dry areas at the heater that precedes the boiling crisis. We provide a direct statistical analysis of dry spot areas that confirms the boiling crisis at zero gravity as a scale-free phenomenon. It was observed that, in agreement with theoretical predictions, saturated boiling CHF tends to zero (within the precision of our thermal control system) in zero gravity, which suggests that the boiling crisis may be observed at any heat flux provided the experiment lasts long enough.

Optimización del paciente quirúrgico con riesgo de transfusión. «Patient Blood Management»: el nuevo paradigma de la medicina perioperatoria / Optimization of surgical patients at risk of transfusion. Patient blood management: the new paradigm of perioperative medicine

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Implementación de los programas de ahorro de sangre en España: resultados de la encuesta a los servicios de anestesiología y reanimación / Implementation of blood sparing programs in Spain: results of a survey of departments of anesthesiology and resuscitation

El objetivo de este artículo es conocer la disponibilidad de un programa de gestión de la transfusión perioperatoria («Patient Blood Management») en distintos hospitales a través de una encuesta que incluía una descripción de la visita preanestésica, la disponibilidad y utilización de las diferentes técnicas de ahorro de sangre y los factores limitantes de su implementación para cirugía programada. La encuesta constaba de 42 preguntas dirigidas a servicios de anestesiología representativos de los hospitales del territorio español (n = 91), y se realizó durante los meses de septiembre a noviembre de 2012. Fueron analizadas las 82 encuestas que contestaron a todas las preguntas (90%). La consulta preoperatoria se realizó de forma habitual (> 70%) en el 87% de los hospitales. El tiempo desde la consulta hasta la cirugía osciló entre 1 semana y 3 meses en el 74% de pacientes programados para cirugía ortopédica y traumatológica, en el 78% de cirugía oncológica y en el 77% de cirugía cardíaca. Casi la totalidad de hospitales, 77 (94%), disponen de comité de transfusión, con presencia del anestesiólogo en el 90% de ellos. Se dispone de un programa de ahorro de sangre en el 79% de los hospitales y la técnica más frecuentemente utilizada es el uso de antifibrinolíticos en el 75% de los hospitales, seguida de la recuperación de sangre intra y postoperatoria en parecida proporción (67%). La optimización de la hemoglobina preoperatoria se realiza con hierro intravenoso de forma habitual en el 39% de los hospitales y con eritropoyetina recombinante en el 28%. La ausencia de un circuito bien establecido y la falta de implicación y colaboración con el equipo quirúrgico se presentan como los principales factores limitantes de la implantación del «Patient Blood Management». En la actualidad, su aplicación en España se puede considerar aceptable, pero podrían mejorarse aspectos, especialmente en el tratamiento de la anemia preoperatoria. La implementación del «Patient Blood Management» requiere colaboración multidisciplinar de todo el personal responsable de la atención perioperatoria, incluidas las autoridades sanitarias (AU)

The objective of this article is to determine the availability of a perioperative transfusion management program (Patient Blood Management [PBM]) in various hospitals through a survey that included a description of the preanesthesia visit, the availability and use of the various blood-sparing techniques and the factors limiting their implementation in elective surgery. The survey included 42 questions, directed at the representative departments of anesthesiology of hospitals in Spain (n=91). The survey was conducted from September to November 2012. We analyzed the 82 surveys in which all the questions were answered (90%). Preoperative consultations are routinely performed (>70%) in 87% of the hospitals. The time from the consultation to surgery varied between 1 week and 2 months for 74% of the patients scheduled for orthopedic or trauma surgery, 78% of those scheduled for oncologic surgery and 77% of those scheduled for cardiac surgery. Almost all hospitals (77, 94%) had a transfusion committee, and 90% of them had an anesthesiologist on the committee. Seventy-nine percent of the hospitals had a blood-sparing program, and the most widely used technique was the use of antifibrinolytic agents (75% of hospitals), followed by intraoperative and postoperative blood recovery in equal proportions (67%). Optimization of preoperative hemoglobin was routinely performed with intravenous iron in 39% of the hospitals and with recombinant erythropoietin in 28% of the hospitals. The absence of a well-established circuit and the lack of involvement and collaboration with the surgical team were the main limiting factors in implementing PBM. Currently, the implementation of PBM in Spain could be considered acceptable, but it could also be improved, especially in the treatment of preoperative anemia. The implementation of PBM requires multidisciplinary collaboration among all personnel responsible for perioperative care, including the health authorities (AU)