Day-to-day variability in euvolemic body mass.

Short-term variability in body mass is a common, everyday phenomenon; however, data on body mass variability are scarce. While the physiological variability of body mass is negligible in healthy individuals, it could have implications for therapy in patients with impaired volume homeostasis, for example, patients with kidney failure undergoing kidney replacement therapy. We analyzed a long-term dataset comprising 9521 days of standardized body mass measurements from one healthy male individual and assessed the variability in body mass as a positive or negative relative difference in body mass measured on subsequent days. The average and median relative differences were zero, with a standard deviation (SD) of 0.53% for the one-day interval, increasing to 0.69% for the 7-day interval, and this variability was constant throughout the observation period. A body mass variability of approximately 0.6% (±450 mL in a 75-kg patient) should be taken into consideration when weight-dependent treatment prescriptions, e.g. the ultrafiltration rates in patients on hemodialysis, are being set. Consequently, a "soft target weight", considering the longitudinal variation of volume markers, such as body mass, might improve treatment quality.

Reduced COVID-19 morbidity and mortality in hemodialysis patients across the various Omicron sublineages-A retrospective analysis.

Introduction: Hemodialysis (HD) patients are a COVID-19 high risk population due to comorbidities and impaired immune response. Vaccines, advent of effective treatment and the emergence of novel variants have fundamentally changed the pandemic. We aimed to assess temporal changes of COVID-19 in HD patients of our catchment area, and risk factors for severe and fatal course. Methods and materials: We retrospectively collected data from 274 patients admitted to the Medical University Graz, Austria for HD between 1st of May 2020 and 31st of August 2022. We analyzed clinical and demographic data between different COVID-19 waves and assessed factors associated with hospitalization, ICU admission and mortality by logistic regression. To further evaluate the dialysis at-risk population, we collected demographic and vaccination data between August 2021 and August 2022. Results: Time of infection and SARS-CoV-2 sequencing data allowed for distinction of five separate waves of infection with different impact on the dialysis population: While in the initial four waves frequencies of hospitalization, necessity of critical care and mortality were around 60%, 10% and 20%, respectively. These events became rare during the large fifth wave, when Omicron had become the dominant variant. Although only 16.9% had to be hospitalized, this resulted in 29 hospital admissions, due to the high prevalence of COVID-19 during the Omicron era. Furthermore, we observed similar clinical outcomes with BA.4/5 as with BA.1/BA.2 Omicron sublineages. The proportion of previously infected increased simultaneously with the number of vaccination doses in our dialysis population. Vaccination at time of positivity and infection with an Omicron variant conferred protection against hospitalization and mortality in univariate analysis, but only infection with an Omicron variant remained a robust predictor for these outcomes in multivariable analysis. Discussion: While a fourth of our at-risk population became infected during the Omicron wave, mortality was almost non-existent. Several concomitant factors have contributed to the decrease of COVID-19 severity in HD patients. This trend appears to be continued with BA.4/5, which was equally mild as BA.1 and BA.2 in our well vaccinated dialysis population.

Differences in bioimpedance-derived fluid status between two versions of the Body Composition Monitor.

OBJECTIVES: The Body Composition Monitor (BCM) (Fresenius Medical Care) measures body impedances in alternating currents to subsequently calculate fat and lean tissue mass, fluid compartments, and overhydration (OH). The aim of this study was to investigate differences between two versions of the BCM (an older version, 3.2.5, and a newer version, 3.3.3). METHODS: Between September 2021 and December 2021, 28 hemodialysis patients were included to undergo BCM measurements before each of 14 consecutive dialysis sessions with versions 3.2.5 and 3.3.3 devices. Measurements were performed according to instructions provided by the manufacturer. Differences between BCM devices were tested for statistical significance using paired Wilcoxon tests, neglecting clustering. RESULTS: A total of 288 measurement pairs of 27 patients were left after exclusion of 43 flawed data points. The mean difference in OH between both BCM devices was 0.548 L (higher for version 3.2.5). Analysis of impedance data revealed differences in the high-frequency spectrum, quantifiable by the intracellular resistance, Ri (median Ri version 3.2.5 = 1750.3 Ω; Ri version 3.3.3 = 1612.45 Ω; P < 0.001), and the time delay, Td (median Td version 3.2.5 = 1.85 ns; Td version 3.3.3 = 8.88 nanoseconds; P < 0.001). CONCLUSIONS: This study finds that results between the two versions of the BCM differed in a clinically meaningful fashion and that the newer version 3.3.3 device had a bias toward less OH. Circulating BCM devices should be checked for versions and only devices of the same version should be used for each patient to ensure better within-patient consistency.

Ultrafiltration-induced decrease in relative blood volume is larger in hemodialysis patients with low specific blood volume: Results from a dialysate bolus administration study.

INTRODUCTION: Prescribing the ultrafiltration in hemodialysis patients remains challenging and might benefit from the information on absolute blood volume, estimated by intradialytic dialysate bolus administration. Here, we aimed at determining the relationship between absolute blood volume, normalized for body mass (specific blood volume, Vs), and ultrafiltration-induced decrease in relative blood volume (∆RBV) as well as clinical parameters including body mass index (BMI). METHODS: This retrospective analysis comprised 77 patients who had their dialysate bolus-based absolute blood volume extracted routinely with an automated method. Patient-specific characteristics and ∆RBV were analyzed as a function of Vs, dichotomizing the data above or below a previously proposed threshold of 65 ml/kg for Vs. Statistical methodology comprised descriptive analyses, two-group comparisons, and correlation analyses. FINDINGS: Median Vs was 68.6 ml/kg (54.9 ml/kg [Quartile 1], 83.4 ml/kg [Quartile 3]). Relative blood volume decreased by 6.3% (2.6%, 12.2%) over the entire hemodialysis session. Vs correlated inversely with BMI (rs  = -0.688, p < 0.001). ∆RBV was 9.8% in the group of patients with Vs <65 ml/kg versus 6.0% in the group of patients with Vs ≥65 ml/kg (p = 0.024). The two groups did not differ significantly regarding their specific ultrafiltration volume, normalized for body mass, which amounted to 34.1 ml/kg and 36.0 ml/kg in both groups, respectively (p = 0.630). ∆RBV correlated inversely with Vs (rs  = -0.299, p = 0.008). DISCUSSION: The present study suggests that patients with higher BMI and lower Vs experience larger blood volume changes, despite similar ultrafiltration requirements. These results underline the clinical plausibility and importance of dialysate bolus-based absolute blood volume determination in the assessment of target weight, especially in view of a previous study where intradialytic morbid events could be decreased when the target weight was adjusted, based on Vs.

Isavuconazole Treatment in a Mixed Patient Cohort with Invasive Fungal Infections: Outcome, Tolerability and Clinical Implications of Isavuconazole Plasma Concentrations.

Isavuconazole (ISA) is a triazole antifungal agent recommended for treatment of invasive aspergillosis or mucormycosis. The objective of this study was to evaluate ISA levels in a real world setting in a mixed patient cohort including patients with non-malignant diseases and extracorporeal treatments, and to correlate findings with efficacy and safety outcomes. We investigated 33 ISA treatment courses in 32 adult patients with hematological and other underlying diseases and assessed the clinical response, side effects and ISA trough plasma concentrations. ISA treatment led to complete and partial response in 87% of patients and was well tolerated. The median ISA plasma concentration was 3.05 µg/mL (range 1.38-9.1, IQR 1.93-4.35) in patients without renal replacement therapy (RRT) or extracorporeal membrane oxygenation (ECMO) and significantly lower in patients with RRT including cases with additional ECMO or Cytosorb® adsorber therapy (0.88 µg/mL, range 0.57-2.44, IQR 0.71-1.21). After exclusion of values obtained from four patients with ECMO or Cytosorb® adsorber the median concentration was 0.91 µg/mL (range 0.75-2.44, IQR 0.90-1.36) in the RRT group. In addition to previous recommendations we propose to monitor ISA trough plasma concentrations in certain circumstances including RRT, other extracorporeal treatments and obesity.