title: Whole body periodic acceleration (pGz) improves survival and allows for resuscitation in a model of severe hemorrhagic shock in pigs.
abstract: BACKGROUND
  Whole body periodic acceleration (pGz), the repetitive, head-foot sinusoidal motion of the body, increases pulsatile shear stress on the vascular endothelium producing increased release of endothelial derived nitric oxide (eNO) into circulation. Based upon prior CPR investigations, we hypothesized that pGz instituted prior to and during hemorrhagic shock (HS) should improve survival.
  
  
  METHODS
  Sixteen anesthetized male pigs, 23 ± 5 kg, were randomized to receive 1 h pGz or no pGz (CONT) prior to and during severe controlled graded HS up to 2-1/2 h. HS was induced by removing blood at 10 mL/kg increments from the circulation at 30-min intervals up to a maximum blood loss of 50 mL/kg. Thirty minutes after maximum blood loss, shed blood and lactated Ringers solution was infused intravenously.
  
  
  RESULTS
  All animals survived up to 30 mL/kg blood loss. Survival and return to normal blood pressure to 120 min was achieved in 50% of animals receiving pGz compared with none in CONT. Cardiac output, blood pressure, and oxygen delivery decreased equally in both groups but oxygen consumption was significantly lower with pGz than CONT during all hemorrhage time points. Regional blood flow (RBF) was preserved in brain, heart, kidneys, ileum, and stomach in both groups up to 40 mL/kg of blood loss. After 40 mL/kg blood loss, RBF was much better preserved in pGz than CONT.
  
  
  CONCLUSIONS
  pGz applied 1 h prior to and during severe graded hemorrhagic shock delays onset of irreversible shock, enabling potential restoration of blood loss and survival.
authors.affiliation: Division of Neonatology, Mount Sinai Medical Center, Miami Beach, Florida 33140, USA.
authors.forename: Jorge I
authors.initials: JI
authors.lastname: Bassuk
authors.forename: Heng
authors.initials: H
authors.lastname: Wu
authors.forename: Jaqueline
authors.initials: J
authors.lastname: Arias
authors.forename: Paul
authors.initials: P
authors.lastname: Kurlansky
authors.forename: Jose A
authors.initials: JA
authors.lastname: Adams
mesh_terms: D000818:Animals; D001784:Blood Gas Analysis; D001794:Blood Pressure; D001804:Blood Transfusion, Autologous / Q000379:methods; D002302:Cardiac Output; D004195:Disease Models, Animal; D006323:Heart Arrest / Q000503:physiopathology; D006439:Hemodynamics / Q000502:physiology; D006470:Hemorrhage / Q000209:etiology / Q000401:mortality; D020896:Hypovolemia; D008297:Male; D010100:Oxygen / Q000097:blood; D019106:Postoperative Hemorrhage / Q000150:complications* / Q000628:therapy; D012039:Regional Blood Flow; D015427:Reperfusion Injury / Q000150:complications; D012151:Resuscitation / Q000379:methods*; D012771:Shock, Hemorrhagic / Q000209:etiology*; D015996:Survival Rate; D013552:Swine; D014655:Vascular Resistance / Q000502:physiology
chemical_list: D010100:Oxygen