title: Model-based computation of total stressed blood volume from a preload reduction manoeuvre.
abstract: Total stressed blood volume is an important parameter for both doctors and engineers. From a medical point of view, it has been associated with the success or failure of fluid therapy, a primary treatment to manage acute circulatory failure. From an engineering point of view, it dictates the cardiovascular system's behavior in changing physiological situations. Current methods to determine this parameter involve repeated phases of circulatory arrests followed by fluid administration. In this work, a more straightforward method is developed using data from a preload reduction manoeuvre. A simple six-chamber cardiovascular system model is used and its parameters are adjusted to pig experimental data. The parameter adjustment process has three steps: (1) compute nominal values for all model parameters; (2) determine the five most sensitive parameters; and (3) adjust only these five parameters. Stressed blood volume was selected by the algorithm, which emphasizes the importance of this parameter. The model was able to track experimental trends with a maximal root mean squared error of 29.2%. Computed stressed blood volume equals 486 ± 117 ml or 15.7 ± 3.6 ml/kg, which matches previous independent experiments on pigs, dogs and humans. The method proposed in this work thus provides a simple way to compute total stressed blood volume from usual hemodynamic data.
authors: University of Liège (ULg), GIGA-Cardiovascular Sciences, Liège, Belgium. Electronic address: a.pironet@ulg.ac.be.
authors: Antoine
authors: A
authors: Pironet
authors: University of Liège (ULg), GIGA-Cardiovascular Sciences, Liège, Belgium. Electronic address: tdesaive@ulg.ac.be.
authors: Thomas
authors: T
authors: Desaive
authors: University of Canterbury, Department of Mechanical Engineering, Christchurch, New Zealand. Electronic address: geoff.chase@canterbury.ac.nz.
authors: J
authors: J
authors: Geoffrey Chase
authors: University of Liège (ULg), GIGA-Cardiovascular Sciences, Liège, Belgium. Electronic address: ph.morimont@chu.ulg.ac.be.
authors: Philippe
authors: P
authors: Morimont
authors: University of Liège (ULg), GIGA-Cardiovascular Sciences, Liège, Belgium. Electronic address: pc.dauby@ulg.ac.be.
authors: Pierre C
authors: PC
authors: Dauby
mesh_terms: D000818:Animals; D001810:Blood Volume / Q000502:physiology*; D002319:Cardiovascular System; D005440:Fluid Therapy; D006439:Hemodynamics / Q000502:physiology*; D023421:Models, Animal; D008962:Models, Theoretical; D013552:Swine
keywords: Cardiovascular system; Fluid therapy; Mathematical model; Parameter identification; Stressed blood volume