Rationale for the Use of Blood Volume and Temperature Control Devices during Hemodialysis

Abstract

Despite substantial progress in blood purification techniques over the last three decades, treatment-related hypotensive episodes remain one of the major problems in hemodialysis therapy. There are two main reasons for hypotension occurring during dialysis treatments. First, hypovolemia is frequently induced by rapid fluid removal from the blood compartment which is in excess of refilling of fluids from the interstitial space. Second, many patients fail to support blood pressure by adequate vasoconstriction or increased heart rate as a response to hypovolemia. The capacity to respond adequately to volume contraction may be reduced due to patient- or treatment-related factors, among which heat accumulation within the body plays a major role. Recently, two newer technical developments became commercially available for use in hemodialysis therapy: devices for blood volume and blood temperature control were designed to reduce the incidence of intradialytic hypotension. Although blood volume and temperature measurements are easy to perform today, there is some uncertainty in the dialysis community how and when their use may be helpful and in which patients it is indicated. This review critically discusses the application of blood volume- and temperature-measuring devices with regard to their usefulness in the clinical setting.

Flash Glucose Monitoring to Assess Glycemic Control and Variability in Hemodialysis Patients: The GIOTTO Study

“…In fact, it is well known that there may be a time lag between glucose readings in blood and in the interstitial fluid (27). In addition, hemodialysis patients may undergo volume changes among the intracellular, interstitial, and intravascular compartments, especially during hemodialysis sessions (28), but partially also in the interdialytic periods due to factors such as systemic inflammation, endothelial dysfunction, hypoalbuminemia, and increased capillary permeability, leading to intravascular fluid overload (29). These phenomena may further affect the possible difference between glucose measurement in blood and in the interstitial fluid.…”

Dialysis Patients and Cardiovascular Problems: Can Technology Help Solve the Complex Equation?

“…In general, the uremic population is confronted with vascular impairment attributed to arterial stiffness, making it harder to regulate the fl uid status/regulation. This aspect of vascular dysfunction is further aggravated by dialysis therapies when large unphysiological changes in hemodynamic responses occur in response to rapid fl uid removal by ultrafi ltration; attaining normovolemia in a controlled, gradual manner would clearly be less damaging to the patient [49,50] . Online blood volume monitoring helps regulate the fl uid removal during the treatment: ideally, the ultrafi ltration rate is adjusted automatically, preferably according to the patient's plasma refi lling rate.…”

Separate and combined effects of cold dialysis and intradialytic exercise on the thermoregulatory responses of hemodialysis patients: a randomized-cross-over study

“…This leads to attenuated heat dissipation from the skin surface despite the fact that metabolic heat production remains relatively stable [5]. Consequently, heat is accumulated (this is typically referred to as "increased body heat storage") and, soon, core temperature rises during a typical session of hemodialysis [6]. This increased heat storage (S) offsets the vasoconstrictive response to hypovolemia [7] and it is one of the responsible contributing factor which leading to the intradialytic hypotension causing patient discomfort and increased mortality [8,9].…”