Year: 2013
Type: article
Abstract: Patients with kidney failure need dialysis treatments three times a week to remove excess fluid, excess substances, and waste products.In 20% to 30% of these treatments, significant drop in blood pressure, i.e., hypotension, occurs.Repeating intradialytic hypotension increases mortality of a patient.There were about 400,000 dialysis patients in US in 2009 [1].Therefore, reducing intradialytic hypotension remains critical challenge to improve patient outcomes.Current practice on dialysis is based on estimating fluid amount to be removed and fluid removal rate, then reacting to hypotension, if it occurs, by adjusting the prescription, e.g., fluid removal rate, and treating the patient.There have been various implementations of automatic feedback control of dialysis.However, these methods are not using dynamic models that are based on physiological components of the cardiovascular system.Therefore, they do not provide insight into hemodynamics of a patient during dialysis.We propose a better approach of developing dynamic models that are based on physiological components of the cardiovascular system, such as the heart, arteries, arterioles, capillaries, and veins, and laws of physics that govern their behavior to be used in future development of an optimal adaptive control system that removes a prescribed amount of fluid over the shortest period of time without invoking intradialytic hypotension.We started by using a model developed by Grodins in 1959 [2] as a basis to build more elaborated models needed to describe hemodynamic of a dialysis patient.We performed parameter sensitivity analysis on the Grodins model to verify that model parameters that have the most influential on blood pressure and cardiac output are the same as the ones in the cardiovascular system that the body uses its actuators, i.e., the heart, arterioles, and veins, to manipulate to control its blood pressure and cardiac output.We also performed blood volume sensitivity analysis to verify that hemodynamic variables, i.e., pressures and volumes, at locations of the cardiopulmonary receptors, i.e., the heart and the veins, are the most sensitive to change in blood volume.In order to explain compensatory mechanisms against reduction in blood volume during dialysis, we developed a multiple systemic vii Mathematics vs. the Nature ......
Author: Hemasilpin, Nat
Institution: University of Cincinnati
Language: English
Subfield: Nephrology
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W2566863069