Assessment of Fluid Status by Bioimpedance Analysis and Central Venous Pressure Measurement and Their Association with the Outcomes of Severe Acute Kidney Injury.

Justina Karpavičiūtė,Inga Skarupskienė,Edita Žiginskienė,Vilma Balčiuvienė,Inga Arūnė Bumblytė,Rūta Vaičiūnienė

doi:10.3390/medicina57060518

Abstract

Background and Objectives: Fluid disbalance is associated with adverse outcomes in critically ill patients with acute kidney injury (AKI). In this study, we intended to assess fluid status using bioimpedance analysis (BIA) and central venous pressure (CVP) measurement and to evaluate the association between hyperhydration and hypervolemia with the outcomes of severe AKI. Materials and Methods: A prospective study was conducted in the Hospital of the Lithuanian University of Health Sciences Kauno Klinikos. Forty-seven patients treated at the Intensive Care Unit (ICU) with severe AKI and a need for renal replacement therapy (RRT) were examined. The hydration level was evaluated according to the ratio of extracellular water to total body water (ECW/TBW) of bioimpedance analysis and volemia was measured according to CVP. All of the patients were tested before the first hemodialysis (HD) procedure. Hyperhydration was defined as ECW/TBW > 0.39 and hypervolemia as CVP > 12 cm H2O. Results: According to bioimpedance analysis, 72.3% (n = 34) of patients were hyperhydrated. According to CVP, only 51.1% (n = 24) of the patients were hypervolemic. Interestingly, 69.6% of hypovolemic/normovolemic patients were also hyperhydrated. Of all study patients, 57.4% (n = 27) died, in 29.8% (n = 14) the kidney function improved, and in 12.8% (n = 6) the demand for RRT remained after in-patient treatment. A tendency of higher mortality in hyperhydrated patients was observed, but no association between hypervolemia and outcomes of severe AKI was established. Conclusions: Three-fourths of the patients with severe AKI were hyperhydrated based on bioimpedance analysis. However, according to CVP, only half of these patients were hypervolemic. A tendency of higher mortality in hyperhydrated patients was observed.

Highlights

And adequate fluid restoration is fundamental to increase intravascular volume and maintain organ perfusion in the treatment of critically ill patients [1]
The hydration status was evaluated according to the ratio of extracellular water (ECW) and total body water (TBW), calculated by InBody S10, Biospace Co., Ltd. analyzer
A total of 47 severe acute kidney injury (AKI) patients treated in the Intensive Care Unit (ICU) of HLUHS KK were involved in the study

Summary

Introduction

And adequate fluid restoration is fundamental to increase intravascular volume and maintain organ perfusion in the treatment of critically ill patients [1]. Several observational studies have linked a positive fluid balance, especially before the onset of renal replacement therapy, to the occurrence of acute kidney injury (AKI) and mortality [5,6,7,8]. Several methods exist to evaluate fluid status: physical examination, chest radiography, chest ultrasound, central venous pressure (CVP), and bioimpedance analysis (BIA). Fluid disbalance is associated with adverse outcomes in critically ill patients with acute kidney injury (AKI). We intended to assess fluid status using bioimpedance analysis (BIA) and central venous pressure (CVP) measurement and to evaluate the association between hyperhydration and hypervolemia with the outcomes of severe AKI. A tendency of higher mortality in hyperhydrated patients was observed, but no association between hypervolemia and outcomes of severe AKI was established.

Objectives

Methods

Conclusion