Electrical impedance tomography (EIT) is a bedside monitoring tool that noninvasively visualizes local ventilation and arguably lung perfusion distribution. This article reviews and discusses both methodological and clinical aspects of thoracic EIT. Initially, investigators addressed the validation of EIT to measure regional ventilation. Current studies focus mainly on its clinical applications to quantify lung collapse, tidal recruitment, and lung overdistension to titrate positive end-expiratory pressure (PEEP) and tidal volume. In addition, EIT may help to detect pneumothorax. Recent studies evaluated EIT as a tool to measure regional lung perfusion. Indicator-free EIT measurements might be sufficient to continuously measure cardiac stroke volume. The use of a contrast agent such as saline might be required to assess regional lung perfusion. As a result, EIT-based monitoring of regional ventilation and lung perfusion may visualize local ventilation and perfusion matching, which can be helpful in the treatment of patients with acute respiratory distress syndrome (ARDS).

The degradation of muscle mass and loss of functional proteins due to catabolism are associated with adverse outcomes in critically ill patients. While an adequate supply of protein within a medical nutrition concept is suggested to minimize proteolysis, the specificities on appropriate dosage and timing are still under debate. The current study aimed to evaluate the effect of two different quantities of protein as part of a standardized energetically controlled nutrition therapy for the preservation of muscle mass in the later phase of critical illness. A randomized controlled trial was conducted in 42 critically ill patients (age 65 ± 15; 12 females; SAPS 45 ± 11; TISS 20 ± 7; SOFA-score 7 ± 3). The subjects were randomly assigned to either the intervention (1.8 g protein/kg body weight [BW]/d) or standard (1.2 g protein/kg BW/d) group. Nutrient supply via enteral and/or parenteral nutrition was calculated based on the individual energy expenditure measured by indirect calorimetry and target protein content. Quadriceps muscle layer thickness (QMLT) was observed through sonography at inclusion, and during the follow-up period, two and four weeks after inclusion. The measurement points were fixed on two sides at the midpoint and two-thirds between the anterior superior iliac spine and top of the patella. The data were analyzed descriptively wherein chi-squared tests or unpaired two-samle t-tests checked group differences. Daily changes in muscle mass were estimated using a linear mixed model. All data are shown as the mean ± standard deviation (SD). Actual protein intake reached 1.5 ± 0.5 g and 1.0 ± 0.5 g/kg BW/d in the intervention and standard group, respectively. Mean values of all measurements of QMLT at inclusion (day 13 ± 2 after ICU admission) were 13.5 ± 7.4 mm and 13.4 ± 7.1 mm in the intervention and standard group, respectively (P = 0.967). In both the groups, QMLT decreased over time (P < 0.001), while the estimated mean values of daily QMLT changes were -0.15 ± 0.08 mm (intervention) and -0.28 ± 0.08 mm (standard) without significant between-group differences (intervention effect, P = 0.368; time x intervention effect, P = 0.242). Illness scores and clinical outcomes showed no group differences. In this single-center trial the increased amounts of protein (1.5 g vs. 1.0 g/kg BW/d) provided through medical nutrition therapy in the late phase of critical illness did not achieve a statistically significant impact on the loss of muscle mass in long-term immobilized ICU patients. Larger multi-center trials are needed to evaluate whether observed numerical differences in muscle mass could be a true finding, and will translate into improved clinical outcomes. German Clinical Trials Register (http://www.drks.de/), DRKS-ID: DRKS00013594.

Background: Recently, a randomized controlled trial (RCT) demonstrated rapid but individually variable hemodynamic improvement with therapeutic plasma exchange (TPE) in patients with septic shock. Prediction of clinical efficacy in specific sepsis treatments is fundamental for individualized sepsis therapy. Methods: In the original RCT, patients with septic shock of < 24 h duration and norepinephrine (NE) requirement ≥ 0.4 μg/kg/min received standard of care (SOC) or SOC + one single TPE. Here, we report all clinical and biological endpoints of this study. Multivariate mixed-effects modeling of NE reduction was performed to investigate characteristics that could be associated with clinical response to TPE. Results: A continuous effect of TPE on the reduction in NE doses over the initial 24 h was observed (SOC group: estimated NE dose reduction of 0.005 µg/kg/min per hour; TPE group: 0.018 µg/kg/min per hour, p = 0.004). Similarly, under TPE, serum lactate levels, continuously decreased over the initial 24 h in the TPE group, whereas lactate levels increased under SOC (p = 0.001). A reduction in biomarkers and disease mediators (such as PCT (p = 0.037), vWF:Ag (p < 0.001), Angpt-2 (p = 0.009), sTie-2 (p = 0.005)) along with a repletion of exhausted protective factors (such as AT-III (p = 0.026), Protein C (p = 0.012), ADAMTS-13 (p = 0.008)) could be observed in the TPE but not in the SOC group. In a multivariate mixed effects model, increasing baseline lactate levels led to greater NE dose reduction effects with TPE as opposed to SOC (p = 0.004). Conclusions: Adjunctive TPE is associated with the removal of injurious mediators and repletion of consumed protective factors altogether leading to preserved hemodynamic stabilization in refractory septic shock. We identified that baseline lactate concentration as a potential response predictor might guide future designing of large RCTs that will further evaluate TPE with regard to hard endpoints. Trial registration Retrospectively registered 18th January 2020 at clinicaltrials.gov (Identifier: NCT04231994).

Zusammenfassung: Hintergrund: Sepsis ist eine akut lebensbedrohliche multiple Organdysfunktion, ausgelöst durch eine Infektion. Methodik: Bei der vorliegenden Leitlinie handelt es sich um ein Update der S3-Leitlinie „Sepsis – Prävention, Diagnose, Therapie und Nachsorge“ (AMWF-Register-Nr.: 079–001) der Deutschen Sepsis-Gesellschaft (DSG) vom 31.12.2018. Dabei wurde das Update der „Surviving sepsis campaign (SSC): international guidelines for management of sepsis and septic shock 2021“ vom 04.10.2021 als Referenzleitlinie zugrunde gelegt. Die DSG-Leitlinienkommission verglich jede Empfehlung zu den zugrunde liegenden PICO-Fragen der DSG-Leitlinie 2018 (Literaturrecherche bis 12/2018) mit denen der SSC-Leitlinie 2021 (Literaturrecherche bis 07/2019) und bewertete die in der Zwischenzeit neu verfügbare publizierte Datenlage (Literaturrecherche bis 12/2024) mittels systematischer Aktualisierungsrecherchen und Literaturbewertungen unter Befolgung des Regelwerkes des GRADE-Systems und der AWMF. Ergebnisse: Insgesamt wurden 88 PICO-Fragen u. a. zur Diagnose und Therapie der Infektion und des Organversagens adressiert. Davon wurden 2 als Statements, 29 als Expertenkonsens und 57 als evidenzbasierte Empfehlungen (26 mit starkem und 31 mit schwachem Empfehlungsgrad) konsentiert. Im Vergleich zur Vorgänger-Leitlinie 2018 wurden 43 Empfehlungen überprüft, aber beibehalten. 16 Empfehlungen wurden geändert, und 29 Empfehlungen wurden neu ausgesprochen. Schlussfolgerung: Angesichts fehlender Evidenz für zahlreiche Maßnahmen zur stationären Versorgung von Patienten mit Sepsis oder septischem Schock wurden alte und neue Wissenslücken offenbart. Bei den evidenzbasierten Empfehlungen war die zugrunde liegende Evidenzqualität nach GRADE nur bei 5 Empfehlungen hoch, bei 18 Empfehlungen moderat, bei 17 Empfehlungen niedrig und bei 16 sehr niedrig. Diese Evidenzlücken können nur durch zukünftige multizentrische, nichtkommerzielle klinische Prüfungen geschlossen werden. Das Update der S3-Leitlinie Sepsis beinhaltet einige Aktualisierungen zu Empfehlungen der Vorgängerleitlinie. Diese Aktualisierungen werden in einige der fall- und einrichtungsbezogenen QS-Indikatoren des QS-Verfahrens 2025 einfließen müssen. Beeinträchtigungen in der gesundheitsbezogenen Lebensqualität müssen bei Überlebenden mehr in den Fokus der ambulanten Versorgung gerückt werden.

Acute respiratory distress syndrome (ARDS) is a life-threatening form of respiratory failure defined by dysregulated immune homeostasis and alveolar epithelial and endothelial damage. Up to 40% of ARDS patients develop pulmonary superinfections, contributing to poor prognosis and increasing mortality. Understanding what renders ARDS patients highly susceptible to pulmonary superinfections is therefore essential. We hypothesized that ARDS patients who develop pulmonary superinfections display a distinct pulmonary injury and pro-inflammatory response pattern. Serum and BALF samples from 52 patients were collected simultaneously within 24 h of ARDS onset. The incidence of pulmonary superinfections was determined retrospectively, and the patients were classified accordingly. Serum concentrations of the epithelial markers soluble receptor for advanced glycation end-products (sRAGE) and surfactant protein D (SP-D) and the endothelial markers vascular endothelial growth factor (VEGF) and angiopoetin-2 (Ang-2) as well as bronchoalveolar lavage fluid concentrations of the pro-inflammatory cytokines interleukin 1ß (IL-1ß), interleukin 18 (IL-18), interleukin 6 (IL-6), and tumor necrosis factor-alpha (TNF-a) were analyzed via multiplex immunoassay. Inflammasome-regulated cytokine IL-18 and the epithelial damage markers SP-D and sRAGE were significantly increased in ARDS patients who developed pulmonary superinfections. In contrast, endothelial markers and inflammasome-independent cytokines did not differ between the groups. The current findings reveal a distinct biomarker pattern that indicates inflammasome activation and alveolar epithelial injury. This pattern may potentially be used in future studies to identify high-risk patients, enabling targeted preventive strategies and personalized treatment approaches.