Estudio del volumen sanguíneo absoluto y relleno vascular en pacientes en hemodiálisis crónica. Análisis de factores implicados

Abstract

Intradialytic hypotension is a common complication in chronic hemodialysis associated with adverse clinical outcomes, and despite efforts to reduce its incidence, it remains highly prevalent in all hemodialysis units. This justifies developing new strategies to limit its frequency and magnitude. The main trigger for these events is a decrease in plasma volume inadequately compensated by vascular refilling from the interstitial to the intravascular compartment. Therefore, a better understanding of the physiology and determinants of vascular refilling could contribute to developing new models that improve fluid removal while limiting intradialytic hypotension events. Various authors have attempted to quantify vascular refilling for years, limited by the need for invasive testing. Thus, the available data in this field is traditionally based on animal and hemorrhage models. Recently, a new dilutional model proposed by Kron et al. allows the measurement of vascular refilling and absolute blood volume simply and routinely in clinical practice. The main objective of this research is to explore the utility of the dilutional model and conduct a comprehensive analysis of vascular refilling and its potential relationship with comorbidities, medications, and dialysis technique parameters to reduce intradialytic hypotension events. In order to achieve a comprehensive understanding of factors that may influence vascular refilling and its role in intradialytic hypotension, a series of interrelated studies has been conducted. These analyze how vascular refilling is modified under traditional scenarios to improve tolerance to the technique: adjustment of technique-related parameters (reducing dialysate temperature), adjustment of dialysis fluid composition (increasing dialysate Na+ concentration), adjustment of pharmacological prescriptions (anti-hypertensive medications), and individualization of the treatment. Finally, a new strategy is proposed to improve tolerance to the technique, establishing a minimum tolerated ABV for each patient and adjusting volume extraction to avoid exceeding this limit.