16 research outputs found

    Magnetic inflation and stellar mass. III. revised parameters for the component stars of NSVS 07394765

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    We perform a new analysis of the M-dwarf–M-dwarf eclipsing binary system NSVS 07394765 in order to investigate the reported hyper-inflated radius of one of the component stars. Our analysis is based on archival photometry from the Wide Angle Search for Planets, new photometry from the 32 cm Command Module Observatory telescope in Arizona and the 70 cm telescope at Thacher Observatory in California, and new high-resolution infrared spectra obtained with the Immersion Grating Infrared Spectrograph on the Discovery Channel Telescope. The masses and radii we measure for each component star disagree with previously reported measurements. We show that both stars are early M-type main-sequence stars without evidence for youth or hyper-inflation ( = - ☉ M M + 1 0.661 0.036 0.008 , = - ☉ M M + 2 0.608 0.028 0.003 , = - ☉ + R1 0.599 0.019 R 0.032 , = - ☉ + R2 0.625 0.027 R 0.012 ), and we update the orbital period and eclipse ephemerides for the system. We suggest that the likely cause of the initial hyper-inflated result is the use of moderate-resolution spectroscopy for precise radial velocity measurements.Published versio

    Blood volume and hemoglobin mass in long-term heart transplant recipients with and without Anemia

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    Background!#!In systolic chronic heart failure, a heterogeneous blood volume (BV) regulation can be found with plasma volume expansion in many cases, possibly leading to pseudoanemia. Little is known about the volume status after heart transplantation (HTX). So far, anemia of HTX recipients was solely investigated using hemoglobin-concentration that may be misleading in a clinical context. The objective of the study was whether a difference in plasma volume and red cell volume can be observed in clinically stable heart transplant recipients compared to matched control subjects. Secondary, the aim was to describe anemia in the long-term after HTX based on quantitative data.!##!Methods!#!Blood volume and its constituents red cell volume and plasma volume were quantified using an abbreviated carbon monoxide rebreathing method (aCORM) with focus on its primary measure total hemoglobin mass (Hbmass) and coincidental anemia in 36 (7 women) heart transplant recipients. For comparison, a matched control group of 46 (5 women) healthy subjects was selected.!##!Results!#!Neither Hbmass nor blood volumes were significantly different in HTX patients compared to matched healthy control group subjects. The prevalence of anemia 6.3 ± 4.3 years after transplantation was 19%. Hbmass and red cell volume were significantly lower in anemic HTX patients compared to non-anemic patients while plasma volume was not expanded. Various immunosuppressant regimens did not have an effect on Hbmass, plasma volume or red cell volume.!##!Conclusions!#!There was no difference in blood volumes and Hbmass between HTX patients and control subjects. The pathophysiologic blood volume regulation in chronic heart failure does not seem to be longer active in long-term HTX recipients. However, in the long-term after HTX, anemia occurs in a considerable number of patients as true anemia without a clear association with immunosuppression.!##!Trial registration!#!German registry for clinical studies, DRKS00006078. Registered 09 May 2014, https://www.drks.de/drks_web/navigate.do?navigationId=trial . HTML&TRIAL_ID=DRKS00006078

    Thrombotic circuit complications during venovenous extracorporeal membrane oxygenation in COVID-19

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    The novel coronavirus SARS-CoV-2 and the resulting disease COVID-19 causes pulmonary failure including severe courses requiring venovenous extracorporeal membrane oxygenation (V-V ECMO). Coagulopathy is a known complication of COVID-19 leading to thrombotic events including pulmonary embolism. It is unclear if the coagulopathy also increases thrombotic circuit complications of the ECMO. Aim of the present study therefor was to investigate the rate of V-V ECMO complications in COVID-19. We conducted a retrospective registry study including all patients on V-V ECMO treated at our centre between 01/2018 and 04/2020. COVID-19 cases were compared non- COVID-19 cases. All circuit related complications resulting in partial or complete exchange of the extracorporeal system were registered. In total, 66 patients were analysed of which 11 (16.7%) were SARS-CoV-2 positive. The two groups did not differ in clinical parameters including age (COVID-19 59.4 vs. non-COVID-19 58.1 years), gender (36.4% vs. 40%), BMI (27.8 vs. 24.2) and severity of illness as quantified by the RESP Score (1pt. vs 1pt.). 28 days survival was similar in both groups (72.7% vs. 58.2%). While anticoagulation was similar in both groups (p = 0.09), centrifugal pump head thrombosis was more frequent in COVID-19 (9/11 versus 16/55 p < 0.01). Neither the time to first exchange (p = 0.61) nor blood flow at exchange (p = 0.68) did differ in both groups. D-dimer levels prior to the thrombotic events were significantly higher in COVID-19 (mean 15.48 vs 26.59, p = 0.01). The SARS-CoV-2 induced infection is associated with higher rates of thrombotic events of the extracorporeal system during V-V ECMO therapy

    Admission blood glucose level and outcome in patients requiring venoarterial extracorporeal membrane oxygenation

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    Background!#!Patients with cardiogenic shock or cardiac arrest undergoing venoarterial extracorporeal membrane oxygenation (V-A ECMO) frequently present with blood glucose levels out of normal range. The clinical relevance of such findings in the context of V-A ECMO is unknown. We therefore investigated the prognostic relevance of blood glucose at time of cannulation for V-A ECMO.!##!Methods!#!We conducted a single-center retrospective registry study. All patients receiving V-A ECMO from October 2010 to January 2020 were included if blood glucose level at time of cannulation were documented. Patients were divided in five groups according to the initial blood glucose level ranging from hypoglycemic (< 80 mg/dl), normoglycemic (80-140 mg/dl), to mild (141-240 mg/dl), moderate (241-400 mg/dl), and severe (> 400 mg/dl) hyperglycemia, respectively. Clinical presentation, arterial blood gas analysis, and survival were compared between the groups.!##!Results!#!392 patients met inclusion criteria. Median age was 62 years (51.5-70.0), SAPS II at admission was 54 (43.5-63.0), and 108/392 (27.6%) were female. 131/392 were discharged alive (hospital survival 33.4%). At time of cannulation, survivors had higher pH, hemoglobin, calcium, bicarbonate but lower potassium and lactate levels compared to non-survivors (all p < 0.01). Outcome of patients diagnosed with particularly high (> 400 mg/dl) and low (< 80 mg/dl) blood glucose at time of V-A ECMO cannulation, respectively, was worse compared to patients with normoglycemic, mildly or moderately elevated values (p = 0.02). Glucose was independently associated with poor outcome after adjustment for other predictors of survival and persisted in all investigated subgroups.!##!Conclusion!#!Arterial blood glucose at time of V-A ECMO cannulation predicts in-hospital survival of patients with cardiac shock or after ECPR. Whether dysglycemia represents a potential therapeutic target requires further evaluation in prospective studies

    Carboxyhemoglobin (CO-Hb) Correlates with Hemolysis and Hospital Mortality in Extracorporeal Membrane Oxygenation: A Retrospective Registry

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    Background: Patients supported with extracorporeal membrane oxygenation (ECMO) may develop elevated carboxyhemoglobin (CO-Hb), a finding described in the context of hemolysis. Clinical relevance of elevated CO-Hb in ECMO is unclear. We therefore investigated the prognostic relevance of CO-Hb during ECMO support. Methods: Data derives from a retrospective single-center registry study. All ECMO patients in a medical ICU from October 2010 through December 2019 were considered. Peak arterial CO-Hb value during ECMO support and median CO-Hb values determined by point-of-care testing for distinct time intervals were determined. Groups were divided by CO-Hb (p p = 0.003), 48–72 h (51.5% vs. 36.8%, p = 0.003), or >72 h (56.9% vs. 31.1%, p < 0.001) after ECMO cannulation. Peak CO-Hb was independently associated with lower hospital survival after adjustment for confounders. Conclusions: In ECMO, CO-Hb correlates with hemolysis and hospital survival. If high CO-Hb measured should trigger a therapeutic intervention in order to reduce hemolysis has to be investigated in prospective trials

    Long-term survival and health-related quality of life in patients with severe acute respiratory distress syndrome and veno-venous extracorporeal membrane oxygenation support

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    Background!#!There is limited information about the long-term outcome of patients suffering from acute respiratory distress syndrome (ARDS) supported with veno-venous extracorporeal membrane oxygenation (VV ECMO). Most studies focused on short- to mid-term follow-up. We aimed to investigate long-term survival and health-related quality of life (HRQL) in these patients.!##!Methods!#!We report retrospective data from a single-centre registry of patients with severe ARDS treated with VV ECMO at the Interdisciplinary Medical Intensive Care Unit at the Medical Centre, University of Freiburg, Germany, between 10/2010 and 06/2019. Follow-up data of all patients that survived the index hospitalisation were collected by telephone interviews from 02/2020 till 09/2020. Long-term survival, HRQL (Short-Form Health Survey-36 (SF-36), St. Georges Respiratory Questionnaire (SGRQ), Hospital Anxiety and Depression Scale (HADS)) and the return to work rate were documented.!##!Results!#!In total, 289 patients were treated with VV ECMO during the study period (median age 55 years, 67% males, hospital survival 45%). After a median duration of 3.9 years, follow-up assessment was complete in 94 of 129 hospital survivors (73%). Fifty-three patients completed the HRQL assessment. Hospital survivors showed a high 6- and 12-month survival rate (89% and 85%, respectively). Estimated survival rate of those discharged alive from ICU was 68.5% (95%-CI 56.9-80.1%) after 9.7 years. These patients reported high levels of HRQL (median SF-36 total score 73) and only few pulmonary (median SGRQ total score 19) and mental limitations (median HAD-D score 2 and HAD-A score 3). In total, 80% of the patients were able to resume employment.!##!Conclusion!#!This analysis of VV ECMO patients showed favourable long-term survival and high levels of HRQL suggesting promising prospects for VV ECMO survivors

    Impact of pulse pressure on clinical outcome in extracorporeal cardiopulmonary resuscitation (eCPR) patients

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    Background!#!Hemodynamic response to successful extracorporeal cardiopulmonary resuscitation (eCPR) is not uniform. Pulse pressure (PP) as a correlate for myocardial damage or recovery from it, might be a valuable tool to estimate the outcome of these patients.!##!Methods!#!We report retrospective data of a single-centre registry of eCPR patients, treated at the Interdisciplinary Medical Intensive Care Unit at the Medical Centre, University of Freiburg, Germany, between 01/2017 and 01/2020. The association between PP of the first 10 days after eCPR and hospital survival was investigated. Moreover, patients were divided into three groups according to their PP [low (0-9 mmHg), mid (10-29 mmHg) and high (≄ 30 mmHg)] at each time point.!##!Results!#!One hundred forty-three patients (age 63 years, 74.1% male, 40% OHCA, average low flow time 49 min) were analysed. Overall hospital survival rate was 28%. A low PP both early after eCPR (after 1, 3, 6 and 12 h) and after day 1 to day 8 was associated with reduced hospital survival. At each time point (1 h to day 5) the classification of patients into a low, mid and high PP group was able to categorize the patients for a low (5-20%), moderate (20-40%) and high (50-70%) survival rate. A multivariable analysis showed that the mean PP of the first 24 h was an independent predictor for survival (p = 0.008).!##!Conclusion!#!In this analysis, PP occurred to be a valuable parameter to estimate survival and maybe support clinical decision making in the further course of patients after eCPR

    Machine learning using the extreme gradient boosting (XGBoost) algorithm predicts 5-day delta of SOFA score at ICU admission in COVID-19 patients

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    Background: Accurate risk stratification of critically ill patients with coronavirus disease 2019 (COVID-19) is essential for optimizing resource allocation, delivering targeted interventions, and maximizing patient survival probability. Machine learning (ML) techniques are attracting increased interest for the development of prediction models as they excel in the analysis of complex signals in data-rich environments such as critical care. Methods: We retrieved data on patients with COVID-19 admitted to an intensive care unit (ICU) between March and October 2020 from the RIsk Stratification in COVID-19 patients in the Intensive Care Unit (RISC-19-ICU) registry. We applied the Extreme Gradient Boosting (XGBoost) algorithm to the data to predict as a binary out- come the increase or decrease in patients’ Sequential Organ Failure Assessment (SOFA) score on day 5 after ICU admission. The model was iteratively cross-validated in different subsets of the study cohort. Results: The final study population consisted of 675 patients. The XGBoost model correctly predicted a decrease in SOFA score in 320/385 (83%) critically ill COVID-19 patients, and an increase in the score in 210/290 (72%) patients. The area under the mean receiver operating characteristic curve for XGBoost was significantly higher than that for the logistic regression model (0.86 vs . 0.69, P < 0.01 [paired t -test with 95% confidence interval]). Conclusions: The XGBoost model predicted the change in SOFA score in critically ill COVID-19 patients admitted to the ICU and can guide clinical decision support systems (CDSSs) aimed at optimizing available resources
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