title: Evaluation of a novel closed-loop fluid-administration system based on dynamic predictors of fluid responsiveness: an in silico simulation study.
abstract: BACKGROUND
  Dynamic predictors of fluid responsiveness have made automated management of fluid resuscitation more practical. We present initial simulation data for a novel closed-loop fluid-management algorithm (LIR, Learning Intravenous Resuscitator).
  
  
  METHODS
  The performance of the closed-loop algorithm was tested in three phases by using a patient simulator including a pulse-pressure variation output. In the first phase, LIR was tested in three different hemorrhage scenarios and compared with no management. In the second phase, we compared LIR with 20 practicing anesthesiologists for the management of a simulated hemorrhage scenario. In the third phase, LIR was tested under conditions of noise and artifact in the dynamic predictor.
  
  
  RESULTS
  In the first phase, we observed a significant difference between the unmanaged and the LIR groups in moderate to large hemorrhages in heart rate (76 ± 8 versus 141 ± 29 beats/min), mean arterial pressure (91 ± 6 versus 59 ± 26 mm Hg), and cardiac output (CO; (6.4 ± 0.9 versus 3.2 ± 1.8 L/min) (P < 0.005 for all comparisons). In the second phase, LIR intervened significantly earlier than the practitioners (16.0 ± 1.3 minutes versus 21.5 ± 5.6 minutes; P < 0.05) and gave more total fluid (2,675 ± 244 ml versus 1,968 ± 644 ml; P < 0.05). The mean CO was higher in the LIR group than in the practitioner group (5.9 ± 0.2 versus 5.2 ± 0.6 L/min; P < 0.05). Finally, in the third phase, despite the addition of noise to the pulse-pressure variation value, no significant difference was found across conditions in mean, final, or minimum CO.
  
  
  CONCLUSIONS
  These data demonstrate that LIR is an effective volumetric resuscitator in simulated hemorrhage scenarios and improved physician management of the simulated hemorrhages.
authors: Department of Anesthesiology & Perioperative Care, University of California, Irvine 101 S City Drive, Orange, CA 92868, USA.
authors: Joseph
authors: J
authors: Rinehart
authors: Brenton
authors: B
authors: Alexander
authors: Yannick
authors: Y
authors: Le Manach
authors: Christoph
authors: C
authors: Hofer
authors: Benoit
authors: B
authors: Tavernier
authors: Zeev N
authors: ZN
authors: Kain
authors: Maxime
authors: M
authors: Cannesson
mesh_terms: D000465:Algorithms; D001794:Blood Pressure / Q000502:physiology; D002302:Cardiac Output / Q000502:physiology; D005440:Fluid Therapy / Q000379:methods*; D006339:Heart Rate / Q000502:physiology; D006470:Hemorrhage / Q000503:physiopathology / Q000628:therapy; D006801:Humans; D016544:Patient Simulation; D015532:Rehydration Solutions / Q000008:administration & dosage / Q000627:therapeutic use; D014882:Water-Electrolyte Balance / Q000502:physiology
chemical_list: D015532:Rehydration Solutions