Detection limit of methods to assess fluid status changes in dialysis patients

Abstract

Technical systems for an accurate and practicable fluid management of dialysis patients are urgently needed, since current clinical methods are partially subjective, imprecise, and time consuming. Such new systems should not only allow the determination of the target normohydration weight, but also must be able to detect clinically relevant changes in fluid volume ( approximately 1 l). This study focuses on the systematic analysis of the detection limit of several candidate methods for fluid management. In a cohort of 16 new dialysis patients, several candidate methods were applied in parallel during each treatment of the initial weight reduction phase: the measurement of vena cava diameter (VCD), vena cava collapsibility index (CI), the blood volume drop during an ultrafiltration (UF) bolus (Deltarelative blood volume (RBV)-), the rebound after the UF bolus (DeltaRBV+), and the extracellular fluid volume determined with whole body bioimpedance spectroscopy (BIS). A clinical reference method was used to manage the fluid status of patients. All methods showed significant correlations with predialysis weight. The detection limits W(lim) of candidate methods for changes in fluid status were assessed as W(lim)=0.87 kg+/-0.64 kg (BIS), 1.74 kg+/-1.56 kg (VCD), 2.3 kg+/-1.0 kg (DeltaRBV-), 7.4 kg+/-8.5 kg (CI), 40 kg+/-108 kg (DeltaRBV+). Only BIS shows a satisfactorily low detection limit W(lim), whereas W(lim) was rated as critical for the VCD and DeltaRBV- methods, and as unacceptable for the CI and DeltaRBV+ methods. Bioimpedance spectroscopy appears to be the most promising method for a practical fluid management system in dialysis.

Biological variation of high sensitivity cardiac troponin-T in stable dialysis patients: implications for clinical practice

“…Patients also underwent a standard 12-lead electrocardiogram and whole body, multi-frequency bioimpedance analysis using the Body Composition Monitor BCM ® (Fresenius Medical Care, Asia-Pacific) at each visit to measure intraand extra-cellular volume. This instrument has a detection limit for change in extracellular volume of 0.87 L ± 0.64 L [20,21].…”

Extracellular Fluid Excess Is Significantly Associated With Coronary Artery Calcification in Patients With Chronic Kidney Disease

“…The clinical assessment of ECF status is relatively difficult because the physical signs of edema are of limited value in diagnosing excess intravascular volume and tissue hydration status 7, 8. Bioelectrical impedance analysis (BIA) is a method of assessing ECF status by measuring the impedance of the body to applied electric currents of different frequencies 9, 10.…”

The effect of crystalloid infusion on body water content and intra-abdominal pressure in patients undergoing orthopedic surgery under spinal anesthesia

“…Moreover, VE connected with surgeryrelated inflammatory response results in interstitial edema, increasing intra-abdominal pressure (IAP). [7][8][9][10] Regrettably, the adjustment and control of fluid overload is difficult and BIA seems to be a more user-friendly method for managing perioperative fluid therapy.…”