Zusammenfassung: Die Hyponatriämie ist eine der häufigsten Elektrolytstörungen in Notaufnahmen und bei hospitalisierten Patient*innen. Die Serum-Natriumkonzentration wird über die Osmoregulation sowie die Volumenregulation kontrolliert. Beides erfolgt über die Freisetzung von antidiuretischem Hormon (ADH). Die inadäquate ADH-Freisetzung (SIADH) kann durch Tumore, Pneumonien, Medikamenteneinnahme oder Drogenkonsum getriggert werden. Auch übermäßige Flüssigkeitsaufnahme kann zur Abnahme der Serum-Natriumkonzentration führen. Rasche Veränderungen in der Serum-Natriumkonzentration führen zu Zellschwellung bzw. Zellschrumpfung, was sich vor allem in neurologischen Symptomen widerspiegelt. Entscheidend ist hierbei die Geschwindigkeit, mit welcher die Hyponatriämie eintritt, und wie lange die Hyponatriämie schon besteht. In der Diagnostik der Hyponatriämie sind neben der laborchemischen Bestimmung auch eine klinische Untersuchung sowie Harnanalysen von zentraler Bedeutung.

Acute kidney injury (AKI) is common in critically ill patients and is associated with increased morbidity and mortality. Its complications often require renal replacement therapy (RRT). Invasive mechanical ventilation (IMV) and infections are considered risk factors for the occurrence of AKI. The use of IMV and non-invasive ventilation (NIV) has changed over the course of the pandemic. Concomitant with this change in treatment a reduction in the incidences of AKI and RRT was observed. We aimed to investigate the impact of IMV on RRT initiation by comparing critically ill patients with and without COVID-19. Furthermore, we wanted to investigate the rates and timing of RRT as well as the outcome of patients, who were treated with RRT. A total of 8,678 patients were included, of which 555 (12.8%) in the COVID-19 and 554 (12.8%) in the control group were treated with RRT. In the first week of ICU stay the COVID-19 patients showed a significantly lower probability for RRT initiation (day 1: p < 0.0001, day 2: p = 0.021). However, after day 7 a reversed HR was found. In mechanically ventilated patients the risk was significantly higher for the initiation of RRT over the entire stay. While in non-COVID-19 patients this was a non-significant trend, in COVID-19 patients the risk for RRT was significantly increased. The median delay between initiation of IMV and requirement of RRT was observed to be longer in COVID-19 patients (5 days [IQR: 2–11] vs. 2 days [IQR: 1–5]). The analysis restricted to patients with RRT showed a significantly higher risk for ICU death in patients requiring IMV compared to patients without IMV. The analysis demonstrated that IMV as well as COVID-19 are associated with an increased risk for initiation of RRT. The association between IMV and risk of RRT initiation was given for all investigated time intervals. Additionally, COVID-19 patients showed an increased risk for RRT initiation during the entire ICU stay within patients admitted to an ICU due to respiratory disease. In COVID-19 patients treated with RRT, the risk of death was significantly higher compared to non-COVID-19 patients.

Sepsis is defined as a dysregulated host response to an infection, leading to life-threatening organ dysfunction. While sepsis is most commonly the result of a bacterial infection, it may also be caused by viral pathogens. The aim of this study was to describe differences in organ dysfunction patterns and inflammatory markers between bacterial and viral sepsis. In this prospective multicenter cohort study, adults meeting SEPSIS-3 criteria were recruited from four Austrian ICUs between 1 August 2021 and 1 April 2024, excluding those who were immunocompromised within the preceding 12 months. Ninety patients were enrolled, of whom 57 had bacterial and 33 viral sepsis. Inflammatory markers, including IL-6 and PCT, were higher at ICU admission in bacterial sepsis. Adjusted linear regression confirmed bacterial etiology as the only significant predictor of higher 48 h peak IL-6 and PCT values. Patients with viral sepsis typically fulfilled SEPSIS-3 criteria through respiratory and cardiovascular SOFA components, while other organ dysfunctions were less frequent. Significant differences in the phenotype of bacterial and viral sepsis were observed, characterized by distinct inflammatory profiles and differing patterns of organ dysfunction. These findings may support the improved differentiation of bacterial and viral etiologies in sepsis.

Summary: Introduction: A small percentage of patients infected with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV‑2) showed severe respiratory deterioration requiring treatment with extracorporeal membrane oxygenation (ECMO). During the pandemic surges availability of ECMO devices was limited and resources had to be used wisely. The aim of this analysis was to determine the incidence and outcome of venovenous (VV) ECMO patients in Tyrol, when criteria based on the Extracorporeal Life Support Organization (ELSO) guidelines for VV-ECMO initiation were established. Methods: This is a secondary analysis of the Tyrol-CoV-ICU-Reg, which includes all patients admitted to an intensive care unit (ICU) during the coronavirus disease 2019 (COVID-19) pandemic in Tyrol. Of the 13 participating departments, VV-ECMO was performed at 4 units at the University Hospital Innsbruck. Results: Overall, 37 (3.4%) of 1101 patients were treated with VV-ECMO during their ICU stay. The hospital mortality rate was approximately 40% (n = 15). Multiorgan failure due to sepsis was the most common cause of death. No significant difference in survival rates between newly initiated and experienced centers was observed. The median survival time of nonsurvivors was 27 days (interquartile range, IQR: 22–36 days) after initiation of VV-ECMO. Acute kidney injury meeting the Kidney Disease: Improving Global Outcomes (KDIGO) criteria occurred in 48.6%. Renal replacement therapy (RRT) was initiated in 12 (32.4%) patients after a median of 18 days (IQR: 1–26 days) after VV-ECMO start. The median length of ICU and hospital stays were 38 days (IQR: 30–55 days) and 50 days (IQR: 37–83 days), respectively. Discussion: Despite a rapidly increased demand and the resulting requirement to initiate an additional ECMO center, we could demonstrate that a structured approach with interdisciplinary collaboration resulted in favorable survival rates similar to multinational reports.

Sepsis causes millions of deaths each year. Rapid, targeted therapy can reduce mortality rates. Both bacterial and viral pathogens can trigger sepsis, but the utility of commonly used inflammatory markers for differentiation remains controversial. Moreover, little is known about the time courses of alternative inflammatory parameters. The aim of this prospective, two-center observational study was to investigate the differences in the course of soluble Neuropilin-1 (sNRP-1) levels between bacterial and viral sepsis over a 7-day period. To be included, adult patients had to meet the SEPSIS-3 criteria and be diagnosed with either a bacterial or viral pathogen. Immunosuppressed patients were excluded. While IL-6, PCT, and CRP levels decreased consistently over time, sNRP-1 levels remained elevated in the bacterial group throughout the entire ICU stay. PCT (p < 0.001) and CRP (p = 0.016) levels were significantly associated with the course of sNRP-1. The AUC of sNRP-1 was 0.777 for discriminating between bacterial and viral infections on day 1. sNRP-1 remained stable and significantly higher in bacterial than in viral infections. Furthermore, the AUC values for discrimination ranged from acceptable to good, depending on the day of the ICU stay. sNRP-1 may serve as a potential tool to differentiate between bacterial and viral pathogens in sepsis.

Purpose This study aimed to compare a high (HBF) and low (LBF) bicarbonate (HCO₃⁻) replacement fluid over 96 h after continuous veno-venous hemofiltration (CVVH) initiation using regional citrate anticoagulation to determine which fluid achieved better acid–base balance. Methods In this prospective, randomized, controlled, open-label, cross-over, single-center trial, patients were randomized to initially receive either LBF (22 mmol/l HCO₃⁻) or HBF (30 mmol/l HCO₃⁻) for 48 h (first phase), followed by changing to the other fluid for a further 48 h (second phase). Intracorporeal pH and HCO₃⁻ changes were analyzed by calculating the rates of levels outside the standard values (excursion rates). Generalized estimating equations were performed to estimate the odds ratios for at least one pH/HCO₃⁻ excursion. Time to normalization within the first phase for pH and HCO₃⁻ was assessed using Kaplan–Meier curves and log-rank tests. Results A total of 88 patients were included. The rates for at least one pH and HCO₃⁻ excursion were higher in patients treated with HBF compared to LBF (pH: first phase 52% vs. 41%; second phase 48% vs. 34%; HCO₃⁻: first phase 68% vs. 43%; second phase 73% vs. 43%). Adjusted odds ratios were 1.78 (95% CI 1.12–2.82; p = 0.015) for pH and 3.60 (95% CI 2.16–5.99; p < 0.001) for HCO₃⁻. The time to normalization of pH in acidotic patients and of HCO₃⁻ in patients with low HCO₃⁻ did not differ significantly between HBF and LBF (p = 0.102, p = 0.468). Conclusion LBF showed significantly lower rates of pH and HCO₃⁻ excursions compared to HBF and no significant differences to the pH normalization in acidotic patients were observed. ClinicalTrials.gov-identifier NCT04071171.