title: Evaluation of a model-based hemodynamic monitoring method in a porcine study of septic shock.
abstract: BACKGROUND
  The accuracy and clinical applicability of an improved model-based system for tracking hemodynamic changes is assessed in an animal study on septic shock.
  
  
  METHODS
  This study used cardiovascular measurements recorded during a porcine trial studying the efficacy of large-pore hemofiltration for treating septic shock. Four Pietrain pigs were instrumented and induced with septic shock. A subset of the measured data, representing clinically available measurements, was used to identify subject-specific cardiovascular models. These models were then validated against the remaining measurements.
  
  
  RESULTS
  The system accurately matched independent measures of left and right ventricle end diastolic volumes and maximum left and right ventricular pressures to percentage errors less than 20% (except for the 95th percentile error in maximum right ventricular pressure) and all R(2) > 0.76. An average decrease of 42% in systemic resistance, a main cardiovascular consequence of septic shock, was observed 120 minutes after the infusion of the endotoxin, consistent with experimentally measured trends. Moreover, modelled temporal trends in right ventricular end systolic elastance and afterload tracked changes in corresponding experimentally derived metrics.
  
  
  CONCLUSIONS
  These results demonstrate that this model-based method can monitor disease-dependent changes in preload, afterload, and contractility in porcine study of septic shock.
authors.affiliation: Department of Mechanical Engineering, Centre of Bioengineering, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand. james.revie@hotmail.com
authors.forename: James A
authors.initials: JA
authors.lastname: Revie
authors.forename: David
authors.initials: D
authors.lastname: Stevenson
authors.forename: J Geoffrey
authors.initials: JG
authors.lastname: Chase
authors.forename: Chris J
authors.initials: CJ
authors.lastname: Pretty
authors.forename: Bernard C
authors.initials: BC
authors.lastname: Lambermont
authors.forename: Alexandre
authors.initials: A
authors.lastname: Ghuysen
authors.forename: Philippe
authors.initials: P
authors.lastname: Kolh
authors.forename: Geoffrey M
authors.initials: GM
authors.lastname: Shaw
authors.forename: Thomas
authors.initials: T
authors.lastname: Desaive
mesh_terms: D000818:Animals; D002302:Cardiac Output; D003198:Computer Simulation; D006439:Hemodynamics; D008955:Models, Cardiovascular; D015233:Models, Statistical; D009200:Myocardial Contraction; D015203:Reproducibility of Results; D012772:Shock, Septic / Q000503:physiopathology*; D013552:Swine; D013997:Time Factors; D014655:Vascular Resistance