Intrathecal analgesia and restrictive perioperative fluid management within enhanced recovery pathway: hemodynamic implications.

BACKGROUND: Intrathecal analgesia and avoidance of perioperative fluid overload are key items within enhanced recovery pathways. Potential side effects include hypotension and renal dysfunction. STUDY DESIGN: From January 2010 until May 2010, all patients undergoing colorectal surgery within enhanced recovery pathways were included in this retrospective cohort study and were analyzed by intrathecal analgesia (IT) vs none (noIT). Primary outcomes measures were systolic and diastolic blood pressure, mean arterial pressure, and heart rate for 48 hours after surgery. Renal function was assessed by urine output and creatinine values. RESULTS: One hundred and sixty-three consecutive colorectal patients (127 IT and 36 noIT) were included in the analysis. Both patient groups showed low blood pressure values within the first 4 to 12 hours and a steady increase thereafter before return to baseline values after about 24 hours. Systolic and diastolic blood pressure and mean arterial pressure were significantly lower until 16 hours after surgery in patients having IT compared with the noIT group. Low urine output (<0.5 mL/kg/h) was reported in 11% vs 29% (IT vs noIT; p = 0.010) intraoperatively, 20% vs 11% (p = 0.387), 33% vs 22% (p = 0.304), and 31% vs 21% (p = 0.478) for postanesthesia care unit and postoperative days 1 and 2, respectively. Only 3 of 127 (2.4%) IT and 1 of 36 (2.8%) noIT patients had a transitory creatinine increase >50%; no patients required dialysis. CONCLUSIONS: Postoperative hypotension affects approximately 10% of patients within an enhanced recovery pathway and is slightly more pronounced in patients with IT. Hemodynamic depression persists for <20 hours after surgery; it has no measurable negative impact and therefore cannot justify detrimental postoperative fluid overload

Readmissions Within 48 Hours of Discharge: Reasons, Risk Factors, and Potential Improvements.

Hospital readmission rate is an important quality metric and has been recognized as a key measure of hospital value-based purchasing programs. This study aimed to assess the risk factors for hospital readmission with a focus on potentially preventable early readmissions within 48 hours of discharge. This is a retrospective cohort study. This study was conducted at a tertiary academic facility with a standardized enhanced recovery pathway. Consecutive patients undergoing elective major colorectal resections between 2011 and 2016 were included. Univariable and multivariable risk factors for overall and early (<48 hours) readmissions were identified. Specific surgical and medical reasons for readmission were compared between early and late readmissions. In total, 526 of 4204 patients (12.5%) were readmitted within 30 days of discharge. Independent risk factors were ASA score (≥3; OR, 1.5; 95% CI, 1.1-2), excess perioperative weight gain (OR, 1.7; 95% CI, 1.3-2.3), ileostomy (OR, 1.4; 95% CI, 1-2), and transfusion (OR, 2; 95% CI, 1.4-3), or reoperation (OR, 11.4; 95% CI, 7.4-17.5) during the index stay. No potentially preventable risk factor for early readmission (128 patients, 24.3% of all readmissions, 3% of total cohort) was identified, and index hospital stay of ≤3 days was not associated with increased readmission (OR, 0.9; 95% CI, 0.7-1.2). Although ileus and small-bowel obstruction (early: 43.8% vs late: 15.5%, p < 0.001) were leading causes for early readmissions, deep infections (3.9% vs 16.3%, p < 0.001) and acute kidney injury (0% vs 5%, p = 0.006) were mainly observed during readmissions after 48 hours. Risk of underreporting due to loss of follow-up and the potential co-occurrence of complications were limitations of this study. Early hospital readmission was mainly due to ileus or bowel obstruction, whereas late readmissions were related to deep infections and acute kidney injury. A suspicious attitude toward potential ileus-related symptoms before discharge and dedicated education for ostomy patients are important. A short index hospital stay was not associated with increased readmission rates. See Video Abstract at http://links.lww.com/DCR/B237. REINGRESOS DENTRO DE LAS 48 HORAS POSTERIORES AL ALTA: RAZONES, FACTORES DE RIESGO Y POSIBLES MEJORAS: La tasa de reingreso hospitalario es una métrica de calidad importante y ha sido reconocida como una medida clave de los programas hospitalarios de compras basadas en el valor.Evaluar los factores de riesgo para el reingreso hospitalario con énfasis en reingresos tempranos potencialmente prevenibles dentro de las 48 horas posteriores al alta.Estudio de cohorte retrospectivo.Institución académica terciaria con programa de recuperación mejorada estandarizado.Pacientes consecutivos sometidos a resecciones colorrectales mayores electivas entre 2011 y 2016.Se identificaron factores de riesgo uni y multivariables para reingresos totales y tempranos (<48 horas). Se compararon razones médicas y quirúrgicas específicas para el reingreso entre reingresos tempranos y tardíos.En total, 526/4204 pacientes (12,5%) fueron readmitidos dentro de los 30 días posteriores al alta. Los factores de riesgo independientes fueron puntuación ASA (≥3, OR 1.5; IC 95% 1.1-2), aumento de peso perioperatorio excesivo (OR 1.7; IC 95% 1.3-2.3), ileostomía (OR 1.4, IC 95%: 1-2) y transfusión (OR 2, IC 95% 1.4-3) o reoperación (OR 11.4; IC 95% 7.4-17.5) durante la estadía índice. No se identificó ningún factor de riesgo potencialmente prevenible para el reingreso temprano (128 pacientes, 24.3% de todos los reingresos, 3% de la cohorte total), y la estadía hospitalaria índice de ≤ 3 días no se asoció con un aumento en el reingreso (OR 0.9; IC 95% 0.7-1.2) Mientras que el íleo / obstrucción del intestino delgado (temprano: 43.8% vs. tardío: 15.5%, p < 0.001) fueron las principales causas de reingresos tempranos, infecciones profundas (3.9% vs 16.3%, p < 0.001) y lesión renal aguda (0 vs 5%, p = 0.006) se observaron principalmente durante los reingresos después de 48 horas.Riesgo de subregistro debido a la pérdida en el seguimiento, posible co-ocurrencia de complicaciones.El reingreso hospitalario temprano se debió principalmente a íleo u obstrucción intestinal, mientras que los reingresos tardíos se relacionaron con infecciones profundas y lesión renal aguda. Es importante tener una actitud suspicaz hacia los posibles síntomas relacionados con el íleo antes del alta y una educación específica para los pacientes con ostomía. La estadía hospitalaria índice corta no se asoció con mayores tasas de reingreso. Consulte Video Resumen en http://links.lww.com/DCR/B237

Ordering a Normal Diet at the End of Surgery-Justified or Overhasty?

Early re-alimentation is advocated by enhanced recovery pathways (ERP). This study aimed to assess compliance to ERP-set early re-alimentation policy and to compare outcomes of early fed patients and patients in whom early feeding was withhold due to the independent decision making of the surgeon. For this purpose, demographic, surgical and outcome data of all consecutive elective colorectal surgical procedures (2011⁻2016) were retrieved from a prospectively maintained institutional ERP database. The primary endpoint was postoperative ileus (POI). Surgical 30-day outcome and length of stay were compared between patients undergoing the pathway-intended early re-alimentation pattern and patients in whom early re-alimentation was not compliant. Out of the 7103 patients included, 1241 (17.4%) were not compliant with ERP re-alimentation. Patients with delayed re-alimentation presented with more postoperative complications (37 vs. 21%, p < 0.001) and a prolonged length of hospital stay (8 ± 7 vs. 5 ± 4 days, p < 0.001). While male gender (odds ratio (OR) 1.24; 95% confidence interval (CI) 1.04⁻1.32), fluid overload (OR 1.38; 95% CI 1.16⁻1.65) and high American Society of Anaesthesiologists (ASA) score (OR 1.51; 95% CI 1.27⁻1.8) were independent risk factors for POI, laparoscopy (OR 0.51; 95% CI 0.38⁻0.68) and ERP compliant diet (OR 0.46; 95% CI 0.36⁻0.6) were both protective. Hence, this study provides further evidence of the beneficial effect of early oral feeding after colorectal surgery

Intraoperative Fluid Management a Modifiable Risk Factor for Surgical Quality - Improving Standardized Practice.

We aimed to determine a safe zone of intraoperative fluid management associated with the lowest postoperative complication rates without increased acute kidney injury (AKI) risk for elective colorectal surgery patients. Elective colorectal surgeries between 2018 and 2020 were included. Unadjusted odds ratios for postoperative ileus, prolonged length of stay (LOS), and AKI were plotted against the rate of intraoperative ringer's lactate (RL) infusion (mL/kg/h) and total intraoperative volume. Binary logistic regression analysis, including fluid volumes as a confounder, was used to identify risk factors for postoperative complications. A total of 2,900 patients were identified. Of them, 503 (17.3%) patients had ileus, 772 (26.6%) patients had prolonged LOS, and 240 (8.3%) patients had AKI. The intraoperative fluid resuscitation rate (mg/kg/h) was less impactful on postoperative ileus, LOS, and AKI than the total amount of intraoperative fluid. A total fluid administration range between 300 mL and 2.7 L was associated with the lowest complication rate. Total intraoperative RL ≥2.7 L was independently associated with a higher risk of ileus (adjusted OR 1.465;95% CI 1.154-1.858) and prolonged LOS (adjusted OR 1.300;95% CI 1.047-1.613), but not AKI. Intraoperative RL≤300 ml was not associated with an increased risk of AKI. Total intraoperative RL≥2.7L was independently associated with postoperative ileus and prolonged LOS in elective colorectal surgery patients. A new potential standard for intraoperative fluids will require anesthesia case planning (complexity and duration) to ensure total fluid volume meets this new opportunity to improve care

Stellar populations of classical and pseudo-bulges for a sample of isolated spiral galaxies

In this paper we present the stellar population synthesis results for a sample of 75 bulges in isolated spiral Sb-Sc galaxies, using the spectroscopic data from the Sloan Digital Sky Survey and the STARLIGHT code. We find that both pseudo-bulges and classical bulges in our sample are predominantly composed of old stellar populations, with mean mass-weighted stellar age around 10 Gyr. While the stellar population of pseudo-bulges is, in general, younger than that of classical bulges, the difference is not significant, which indicates that it is hard to distinguish pseudo-bulges from classical bulges, at least for these isolated galaxies, only based on their stellar populations. Pseudo-bulges have star formation activities with relatively longer timescale than classical bulges, indicating that secular evolution is more important in this kind of systems. Our results also show that pseudo-bulges have a lower stellar velocity dispersion than their classical counterparts, which suggests that classical bulges are more dispersion-supported than pseudo-bulges.Comment: 10 pages, 8 figures. Accepted for publication in Astrophysics & Space Scienc

Measurement of 7Li(n,γ0)8Li cross sections at En=1.5-1340 eV

The 7Li(n,γ)8Li cross section is important in inhomogeneous big bang models, and as a constraint on model parameters used to determine the solar 7Be(p,γ)8B reaction rate. Values of the 7Li(n,γ0)8Li reaction cross section were measured for neutron energies between 1.5 and 1340 eV at the Oak Ridge Electron Linear Accelerator. The normalization of the cross section was determined by measuring the gamma-ray yield from the 7Li(n,γ0)8Li reaction relative to that from the 10B(n,αγ)7Li reaction. The cross section was found to have the inverse neutron-velocity relationship (1/υ) indicative of s-wave capture. These results help resolve ambiguities in previous measurements

Revealing Nanoscale Chemical Heterogeneities in Polycrystalline Mo-BiVO4 Thin Films

Indexación: Scopus.The activity of polycrystalline thin film photoelectrodes is impacted by local variations of the material properties due to the exposure of different crystal facets and the presence of grain/domain boundaries. Here a multi-modal approach is applied to correlate nanoscale heterogeneities in chemical composition and electronic structure with nanoscale morphology in polycrystalline Mo-BiVO4. By using scanning transmission X-ray microscopy, the characteristic structure of polycrystalline film is used to disentangle the different X-ray absorption spectra corresponding to grain centers and grain boundaries. Comparing both spectra reveals phase segregation of V2O5 at grain boundaries of Mo-BiVO4 thin films, which is further supported by X-ray photoelectron spectroscopy and many-body density functional theory calculations. Theoretical calculations also enable to predict the X-ray absorption spectral fingerprint of polarons in Mo-BiVO4. After photo-electrochemical operation, the degraded Mo-BiVO4 films show similar grain center and grain boundary spectra indicating V2O5 dissolution in the course of the reaction. Overall, these findings provide valuable insights into the degradation mechanism and the impact of material heterogeneities on the material performance and stability of polycrystalline photoelectrodes. © 2020 The Authors. Published by Wiley-VCH GmbHhttps://onlinelibrary-wiley-com.recursosbiblioteca.unab.cl/doi/10.1002/smll.20200160

Multimode mean-field model for the quantum phase transition of a Bose-Einstein condensate in an optical resonator

We develop a mean-field model describing the Hamiltonian interaction of ultracold atoms and the optical field in a cavity. The Bose-Einstein condensate is properly defined by means of a grand-canonical approach. The model is efficient because only the relevant excitation modes are taken into account. However, the model goes beyond the two-mode subspace necessary to describe the self-organization quantum phase transition observed recently. We calculate all the second-order correlations of the coupled atom field and radiation field hybrid bosonic system, including the entanglement between the two types of fields.Comment: 10 page

The Similarity Hypothesis in General Relativity

Self-similar models are important in general relativity and other fundamental theories. In this paper we shall discuss the ``similarity hypothesis'', which asserts that under a variety of physical circumstances solutions of these theories will naturally evolve to a self-similar form. We will find there is good evidence for this in the context of both spatially homogenous and inhomogeneous cosmological models, although in some cases the self-similar model is only an intermediate attractor. There are also a wide variety of situations, including critical pheneomena, in which spherically symmetric models tend towards self-similarity. However, this does not happen in all cases and it is it is important to understand the prerequisites for the conjecture.Comment: to be submitted to Gen. Rel. Gra

N-body simulations of gravitational dynamics

We describe the astrophysical and numerical basis of N-body simulations, both of collisional stellar systems (dense star clusters and galactic centres) and collisionless stellar dynamics (galaxies and large-scale structure). We explain and discuss the state-of-the-art algorithms used for these quite different regimes, attempt to give a fair critique, and point out possible directions of future improvement and development. We briefly touch upon the history of N-body simulations and their most important results.Comment: invited review (28 pages), to appear in European Physics Journal Plu