title: Computational simulation of passive leg-raising effects on hemodynamics during cardiopulmonary resuscitation.
abstract: OBJECTIVE
  The passive leg-raising (PLR) maneuver has been used for patients with circulatory failure to improve hemodynamic responsiveness by increasing cardiac output, which should also be beneficial and may exert synergetic effects during cardiopulmonary resuscitation (CPR). However, the impact of the PLR maneuver on CPR remains unclear due to difficulties in monitoring cardiac output in real-time during CPR and a lack of clinical evidence.
  
  
  METHODS
  We developed a computational model that couples hemodynamic behavior during standard CPR and the PLR maneuver, and simulated the model by applying different angles of leg raising from 0° to 90° and compression rates from 80/min to 160/min.
  
  
  RESULTS
  The simulation results showed that the PLR maneuver during CPR significantly improves cardiac output (CO), systemic perfusion pressure (SPP) and coronary perfusion pressure (CPP) by ∼40-65% particularly under the recommended range of compression rates between 100/min and 120/min with 45° of leg raise, compared to standard CPR. However, such effects start to wane with further leg lifts, indicating the existence of an optimal angle of leg raise for each person to achieve the best hemodynamic responses.
  
  
  CONCLUSIONS
  We developed a CPR-PLR model and demonstrated the effects of PLR on hemodynamics by investigating changes in CO, SPP, and CPP under different compression rates and angles of leg raising. Our computational model will facilitate study of PLR effects during CPR and the development of an advanced model combined with circulatory disorders, which will be a valuable asset for further studies.
authors.affiliation: Interdisciplinary Program for Bioengineering, Seoul National University Graduate School, Seoul 08826, Republic of Korea.
authors.forename: Dong Ah
authors.initials: DA
authors.lastname: Shin
authors.affiliation: Interdisciplinary Program for Bioengineering, Seoul National University Graduate School, Seoul 08826, Republic of Korea.
authors.forename: Jiheum
authors.initials: J
authors.lastname: Park
authors.affiliation: Department of Biomedical Engineering, Seoul National University College of Medicine, Seoul 03080, Republic of Korea; Department of Biomedical Engineering, Seoul National University Hospital, Seoul 03080, Republic of Korea; Institute of Medical and Biological Engineering, Medical Research Center, Seoul National University College of Medicine, Seoul 03080, Republic of Korea. Electronic address: ljch@snu.ac.kr.
authors.forename: Jung Chan
authors.initials: JC
authors.lastname: Lee
authors.affiliation: Department of Emergency Medicine, Seoul National University College of Medicine, Seoul 03080, Republic of Korea.
authors.forename: Sang Do
authors.initials: SD
authors.lastname: Shin
authors.affiliation: Department of Biomedical Engineering, Seoul National University College of Medicine, Seoul 03080, Republic of Korea; Department of Biomedical Engineering, Seoul National University Hospital, Seoul 03080, Republic of Korea; Institute of Medical and Biological Engineering, Medical Research Center, Seoul National University College of Medicine, Seoul 03080, Republic of Korea.
authors.forename: Hee Chan
authors.initials: HC
authors.lastname: Kim
mesh_terms: D016887:Cardiopulmonary Resuscitation; D003198:Computer Simulation; D006439:Hemodynamics; D006801:Humans; D007866:Leg / Q000502:physiology*; D008991:Monitoring, Physiologic / Q000379:methods*
keywords: Cardiopulmonary resuscitation; Computational model; Hemodynamic responsiveness; Passive leg raising