Intravenous Fluid Challenge Decreases Intracellular Volume: A Bioimpedance Spectroscopy-Based Crossover Study in Healthy Volunteers

Abstract

The effects of intravenous fluid therapy on fluid compartments and hemodynamics of the human body remain enigmatic. We therefore tested the efficacy of bioimpedance spectroscopy in a crossover study, where 15 males received 0.5 ml/kg/min ELO-MEL-isoton (osmolarity = 302 mosmol/l) during 60 minutes, or nothing at all. In group “Fluid”, fluid load increased from −0.2 ± 1.0 l extracellular volume at baseline to its maximum of 1.0 ± 0.9 l in minute 70, and remained continuously elevated throughout minute 300. In group “Zero”, fluid load decreased from 0.5 ± 1.1 l at baseline to its minimum of −1.1 ± 1.1 l in minute 300. In group “Fluid”, intracellular volume decreased from 26.8 ± 3.9 l at baseline to its minimum of 26.0 ± 3.9 l in minute 70, and remained continuously decreased throughout minute 300. In group “Zero”, intracellular volume increased from 26.5 ± 3.8 l at baseline to its maximum of 27.1 ± 3.9 l in minute 120, and decreased thereafter. In group “Fluid” compared to “Zero”, systolic blood pressure was significantly higher, from minute 50–90. In conclusion, intravenous fluid therapy caused a clinically meaningful, sustained increase in fluid load, and a decrease in intracellular volume. These data raise interest in studying fluid administration by the gastrointestinal route, perhaps even when managing critical illness.

Empagliflozin in posttransplantation diabetes mellitus: A prospective, interventional pilot study on glucose metabolism, fluid volume, and patient safety

“…Secondary study outcomes included laboratory parameters, anthropometric measurements, blood pressure readings, and medications. Bioimpedance spectroscopy‐based assessment of fluid volume status and body composition was performed with the body composition monitor (BCM; Fresenius Medical Care, Bad Homburg, Germany), as previously described . Details on the sample size calculation, OGTT‐derived parameters (including insulin sensitivity and resistance), and BCM measurements are provided in the supplemental material.…”

Characteristics of bioimpedance-determined fluid shifts according to intradialytic blood pressure difference

“…A recently introduced equipment called a BCM utilizes a well-established technical solution to assess the absolute volume of the body fluid distribution (ECW, ICW, and TBW) using 50 multiple, discrete frequencies from 3 to 1000 kHz [ 16 ]. Despite the above advantages, the BCM cannot elucidate the changes of IVF and ISF absolute values during HD.…”

“…BCM measurement has been recommended that subjects should be resting in a supine position for at least 5 min, before the BCM-measurement is started, such that fluid volume equilibration has taken place [ 14 ]. We measured the various fluid spaces before HD and 1–4 h of HD, and 30 min after HD using a portable, whole-body ankle-to-wrist BIS (BCM; Fresenius AG software version 3.2; Bad Homburg, Germany) [ 16 ] at mid-week (Wednesday–Thursday). The BCM instrument returns measurements on overhydration (OH), TBW, ECW, ICW, urea distribution volume (V urea ) in liters (L).…”

An objective measure for the assessment and management of fluid shifts in acute major burns

“…Infused fluid volumes therefore need to be reduced if R i (ICF) is stable and R 0 (ECF) is trending upward. However, in a recent study, intracellular volume actually decreased (~ 0.8 L over 70 min) upon rapid infusion of intravenous fluid (~ 2 L in ~ 60 min) into healthy male volunteers [ 47 ]. It was suggested that the infusion of fluid was responsible for the increase in ECF.…”