Association between potassium concentrations, variability and supplementation, and in‑hospital mortality in ICU patients: a retrospective analysis

BACKGROUND: Serum potassium concentrations are commonly between 3.5 and 5.0 mmol/l. Standardised protocols for potassium range and supplementation in the ICU are lacking. The purpose of this retrospective analysis of ICU patients was to investigate potassium concentrations, variability and supplementation, and their association with in-hospital mortality. METHODS: ICU patients ≥ 18 years, with ≥ 2 serum potassium values, treated at the Charité - Universitätsmedizin Berlin between 2006 and 2018 were eligible for inclusion. We categorised into groups of mean potassium concentrations:  3.5-4.0, > 4.0-4.5, > 4.5-5.0, > 5.0-5.5, > 5.5 mmol/l and potassium variability: 1st, 2nd and ≥ 3rd standard deviation (SD). We analysed the association between the particular groups and in-hospital mortality and performed binary logistic regression analysis. Survival curves were performed according to Kaplan-Meier and tested by Log-Rank. In a subanalysis, the association between potassium supplementation and in-hospital mortality was investigated. RESULTS: In 53,248 ICU patients with 1,337,742 potassium values, the lowest mortality (3.7%) was observed in patients with mean potassium concentrations between > 3.5 and 4.0 mmol/l and a low potassium variability within the 1st SD. Binary logistic regression confirmed these results. In a subanalysis of 22,406 ICU patients (ICU admission: 2013-2018), 12,892 (57.5%) received oral and/or intravenous potassium supplementation. Potassium supplementation was associated with an increase in in-hospital mortality in potassium categories from > 3.5 to 4.5 mmol/l and in the 1st, 2nd and ≥ 3rd SD (p < 0.001 each). CONCLUSIONS: ICU patients may benefit from a target range between 3.5 and 4.0 mmol/l and a minimal potassium variability. Clear potassium target ranges have to be determined. Criteria for widely applied potassium supplementation should be critically discussed. Trial registration German Clinical Trials Register, DRKS00016411. Retrospectively registered 11 January 2019, http://www.drks.de/DRKS00016411

A Recurrent Neural Network Model for Predicting Activated Partial Thromboplastin Time After Treatment With Heparin: Retrospective Study

Background: Anticoagulation therapy with heparin is a frequent treatment in intensive care units and is monitored by activated partial thromboplastin clotting time (aPTT). It has been demonstrated that reaching an established anticoagulation target within 24 hours is associated with favorable outcomes. However, patients respond to heparin differently and reaching the anticoagulation target can be challenging. Machine learning algorithms may potentially support clinicians with improved dosing recommendations. Objective: This study evaluates a range of machine learning algorithms on their capability of predicting the patients' response to heparin treatment. In this analysis, we apply, for the first time, a model that considers time series. Methods: We extracted patient demographics, laboratory values, dialysis and extracorporeal membrane oxygenation treatments, and scores from the hospital information system. We predicted the numerical values of aPTT laboratory values 24 hours after continuous heparin infusion and evaluated 7 different machine learning models. The best-performing model was compared to recently published models on a classification task. We considered all data before and within the first 12 hours of continuous heparin infusion as features and predicted the aPTT value after 24 hours. Results: The distribution of aPTT in our cohort of 5926 hospital admissions was highly skewed. Most patients showed aPTT values below 75 s, while some outliers showed much higher aPTT values. A recurrent neural network that consumes a time series of features showed the highest performance on the test set. Conclusions: A recurrent neural network that uses time series of features instead of only static and aggregated features showed the highest performance in predicting aPTT after heparin treatment

Monoclonal antibody A7-superparamagnetic iron oxide as contrast agent of MR imaging of rectal carcinoma

Superparamagnetic iron oxide (SPIO)-based colloid has been used clinically as a tissue-specific magnetic resonance contrast agent. We coupled monoclonal antibody A7 (Mab A7), which reacts specifically with human colorectal carcinoma, to Ferumoxides (SPIO) and examined the accumulation of this conjugate in xenografted tumours in nude mice. We examined in vitro immunoreactivity of Mab A7 coupled to Ferumoxides and its in vivo distribution in nude mice with human colorectal carcinoma. Magnetic resonance imaging of tumour-bearing nude mice was performed 72 h after injection of A7-Ferumoxides. A7-Ferumoxides retained binding activities that were nearly identical to intact Mab A7. More of the radiolabelled A7-Ferumoxides accumulated in the tumour than normal mouse IgG-Ferumoxides from 12 h onwards after injection (P<0.05). Both A7-Ferumoxides and normal mouse IgG-Ferumoxides disappeared from blood linearly over time. The accumulation levels in normal tissue decreased linearly over time but were lower than levels in tumours from 6 h. In magnetic resonance T2-weighted imaging of the tumour-bearing nude mice, signal intensity was reduced at the margin of the tumour by injection of A7-Ferumoxides. Mab A7 coupled to Ferumoxides is potentially suitable as a magnetic resonance contrast agent for detecting local recurrence of rectal carcinoma

Challenging Varieties of Capitalism's Account of Business Interests: The New Social Market Initiative and German Employers' Quest for Liberalization, 2000-2014

Do employers in coordinated market economies (CME's) actively defend the non-liberal, market- constraining institutions upon which their strategic coordination and competitive success depends? This paper revisits the debate over firms' employer preferences with an in-depth examination of employers in Germany - a paradigmatic CME and crucial "test case" for Varieties of Capitalism. It is based on interviews with key officials and an in-depth examination of a large-scale campaign - the New Social Market Initiative or INMS - founded and funded by German metalworking employers to shape public opinion. The paper argues that German employers have a strong preference for liberalization: they have pushed hard for the liberalization of labor markets, the reduction of government expenditures, the expansion of market-oriented freedoms, and cuts to social protection, employment protection and benefit entitlements. I find no empirical support for the claim that the INSM is an attempt to appease discontented firms within employers' associations. On the contrary: for many employers, the Agenda 2010 reforms did not go far enough. Following the discrediting of the Anglo-American model in the financial crisis, far-reaching concessions by employees, and the unexpected revitalization of the German economy, employers have moderated their demands - but liberalization remains their default preference. This paper also addresses the role of ideas and the conditions under which employer campaigns can influence policy.Verteidigen Arbeitgeber in koordinierten Marktwirtschaften aktiv die nichtliberalen, marktbeschränkenden Institutionen, von denen ihre Möglichkeiten zur strategischen Koordination und ihr Erfolg im Wettbewerb abhängen? Mit einer umfassenden Untersuchung der Präferenzen von Arbeitgebern in Deutschland, das als typisches Beispiel einer koordinierten Marktwirtschaft und wegweisender "Testfall" für die Theorie über Spielarten des Kapitalismus gilt, greift dieses Discussion Paper die Debatte über die Präferenzen von Unternehmen in ihrer Eigenschaft als Arbeitgeber auf. Es basiert auf Interviews mit führenden Arbeitgeberfunktionären sowie einer detaillierten Untersuchung der Initiative Neue Soziale Marktwirtschaft (INSM): einer groß angelegten, von deutschen Metallarbeitgebern initiierten und finanzierten Kampagne zur öffentlichen Meinungsbildung. Der Beitrag belegt eine deutliche Präferenz deutscher Arbeitgeber für die Liberalisierung. Mit Nachdruck haben sie sich für eine Liberalisierung der Arbeitsmärkte, eine Senkung der Staatsausgaben und eine Ausweitung marktorientierter Gestaltungsfreiheiten ebenso eingesetzt wie für Einschnitte bei der sozialen Sicherung, dem Kündigungsschutz und den Versorgungsansprüchen. Die Behauptung, die INSM sei ein Versuch, unzufriedene Unternehmen innerhalb der Arbeitgeberverbände zu beschwichtigen, lässt sich durch die empirischen Befunde nicht stützen. Im Gegenteil: Vielen Arbeitgebern gingen die Reformen im Zuge der Agenda 2010 nicht weit genug. Zwar haben die deutschen Arbeitgeber nach der Diskreditierung des angloamerikanischen Modells während der Finanzkrise, weitreichenden Zugeständnissen seitens der Arbeitnehmer sowie der unerwarteten Wiederbelebung der deutschen Wirtschaft ihre Forderungen gemäßigt - doch bleibt ihre grundlegende Präferenz für die Liberalisierung bestehen. Dieser Beitrag befasst sich außerdem mit der Rolle von Ideen sowie den Bedingungen, unter denen Arbeitgeberkampagnen politische Maßnahmen beeinflussen können