Methods for dose quantification in continuous renal replacement therapy: towards a more precise approach

Periodic dose assessment is quintessential for dynamic dose adjustment and quality control of continuous renal replacement therapy (CRRT) in critically ill patients with acute kidney injury (AKI). The flows‐based methods to estimate dose are easy and reproducible methods to quantify (estimate) CRRT dose at the bedside. In particular, quantification of effluent flow and, mainly, the current dose (adjusted for dialysate, replacement, blood flows, and net ultrafiltration) is routinely used in clinical practice. Unfortunately, these methods are critically influenced by several external unpredictable factors; the estimated dose often overestimates the real biological delivered dose quantified through the measurement of urea clearance (the current effective delivered dose). Although the current effective delivered dose is undoubtedly more precise than the flows‐based dose estimation in quantifying CRRT efficacy, some limitations are reported for the urea‐based measurement of dose. This article aims to describe the standard of practice for dose quantification in critically ill patients with AKI undergoing CRRT in the intensive care unit. Pitfalls of current methods will be underlined, along with solutions potentially applicable to obtain more precise results in terms of (a) adequate marker solutes that should be used in accordance with the clinical scenario, (b) correct sampling procedures depending on the chosen indicator of transmembrane removal, (c) formulas for calculations, and (d) quality controls and benchmark indicators

Fluid balance in critically ill children with lower respiratory tract viral infection: a cohort study

Abstract Background Increasing evidence has associated positive fluid balance of critically ill patients with poor outcomes. The aim of this study was to explore the pattern of daily fluid balances and their association with outcomes in critically ill children with lower respiratory tract viral infection. Methods A retrospective single-center study was conducted, in children supported with high-flow nasal cannula, non-invasive ventilation, or invasive ventilation. Median (interquartile range) daily fluid balances, cumulative fluid overload (FO) and peak FO variation, indexed as the % of admission body weight, over the first week of Pediatric Intensive Care Unit admission, and their association with the duration of respiratory support were assessed. Results Overall, 94 patients with a median age of 6.9 (1.9–18) months, and a respiratory support duration of 4 (2–7) days, showed a median (interquartile range) daily fluid balance of 18 (4.5–19.5) ml/kg at day 1, which decreased up to day 3 to 5.9 (− 14 to 24.9) ml/kg and increased to 13 (− 11 to 29.9) ml/kg at day 7 (p = 0.001). Median cumulative FO% was 4.6 (− 0.8 to 11) and peak FO% was 5.7 (1.9–12.4). Daily fluid balances, once patients were stratified according to the respiratory support, were significantly lower in those requiring mechanical ventilation (p = 0.003). No correlation was found between all examined fluid balances and respiratory support duration or oxygen saturation, even after subgroup analysis of patients with invasive mechanical ventilation, or respiratory comorbidities, or bacterial coinfection, or of patients under 1 year old. Conclusions In a cohort of children with bronchiolitis, fluid balance was not associated with duration of respiratory support or other parameters of pulmonary function

Impact of mechanical power and positive end expiratory pressure on central vs. mixed oxygen and carbon dioxide related variables in a population of female piglets

Abstract Introduction The use of the pulmonary artery catheter has decreased overtime; central venous blood gases are generally used in place of mixed venous samples. We want to evaluate the accuracy of oxygen and carbon dioxide related parameters from a central versus a mixed venous sample, and whether this difference is influenced by mechanical ventilation. Materials and Methods We analyzed 78 healthy female piglets ventilated with different mechanical power. Results There was a significant difference in oxygen‐derived parameters between samples taken from the central venous and mixed venous blood (Sv¯O2 = 74.6%, ScvO2 = 83%, p < 0.0001). Conversely, CO2‐related parameters were similar, with strong correlation. Ventilation with higher mechanical power and PEEP increased the difference between oxygen saturations, (Δ[ScvO2−Sv¯O2 ] = 7.22% vs. 10.0% respectively in the low and high MP groups, p = 0.020); carbon dioxide‐related parameters remained unchanged (p = 0.344). Conclusions The venous oxygen saturation (central or mixed) may be influenced by the effects of mechanical ventilation. Therefore, central venous data should be interpreted with more caution when using higher mechanical power. On the contrary, carbon dioxide‐derived parameters are more stable and similar between the two sampling sites, independently of mechanical power or positive end expiratory pressures

A Role of Circuit Clotting and Strategies to Prevent It during Blood Purification Therapy with oXiris Membrane: An Observational Multicenter Study

Introduction: Membrane fouling is a significant complication potentially reducing clinical effects of extracorporeal blood purification (EBP) in critically ill septic patients with acute kidney injury. Although fascinating, the effect of heparin coating in preventing membrane fouling is currently unknown. This multicenter prospective study aims to preliminary describe the incidence, associated factors, and clinical consequences of premature circuit clotting in a cohort of adult critically ill septic patients treated with EBP using a high biocompatible heparin-coated hemodiafilter characterized by advanced adsorption properties. Methods: This study was a retrospective analysis of prospectively entered data in the oXirisNet Registry; overall, 97 septic patients undergoing EBP with oXiris between May 2019 and March 2020 were enrolled in this study. Patients were divided into two groups according to the occurrence of filter clotting (premature vs. nonpremature). Logistic regression analysis was used to identify factors associated with premature circuit clotting. Results: Premature clotting occurred in 18 (18.6%) patients. Results of the multivariate logistic regression analysis demonstrated that hematocrit (p = 0.02, odds ratio [OR] 1.15 [1.05; 1.30]), serum procalcitonin (PCT) (p = 0.03, OR 1.1 [1.05; 1.2]), and anticoagulation strategy (p = 0.05 at Wald's test) were independent predictors of circuit clotting. Systemic anticoagulation (p = 0.02, OR 0.03 [0.01; 0.52]) and regional citrate anticoagulation (p = 0.10, OR 0.23 [0.04; 1.50]) were both protective factors if compared to no-anticoagulation strategy. Patients with nonpremature circuit clotting showed more rapid recovery from hemodynamic instability, pulmonary hypo-oxygenation, and electrolyte disorders and greater improvement of inflammatory markers and SOFA scores. Conclusion: Although in this study the incidence of premature circuit clotting was relatively low (18.6%) compared to previously reported values (54%), membrane clotting in adult critically ill septic patients could cause clinically relevant interferences with treatment performances. Prevention of clotting should be based on avoiding higher patients' hematocrit, high serum PCT, and no-anticoagulation strategy which resulted as independent predictors of circuit clotting