title: Resuscitation from hemorrhagic shock: fluid selection and infusion strategy drives unmeasured ion genesis.
abstract: BACKGROUND
  This study compares unmeasured ion generation by different resuscitation fluids and strategies for hemorrhagic shock (HS).
  
  
  METHODS
  A rectus crush injury and 40% hemorrhage initiated controlled HS in 24 minipigs. Pigs (n = 8/gp) were untreated (NON) or bolused (10 cc/kg bw) with HBOC-201 (HBOC), or 6% Hetastarch (HEX) after 20 minutes of HS. Additional boluses occurred for hypotension (mean arterial pressure [MAP] <60 mm Hg) or tachycardia (heart rate [HR] >baseline) for 4 hours; other therapy was withheld, simulating delayed evacuation. Hemodynamics, acid-base parameters, and strong ion difference (SID) and strong ion gap (SIG), were assessed. Data are means +/- SD or percent; significance for p < 0.05.
  
  
  RESULTS
  Initial MAP was similar (p > 0.05) as was ultimate survival (p > 0.05). By 30 minutes, MAP was higher with HBOC (63 +/- 8; p = 0.01) versus HEX (37 +/- 5) or NON (35 +/- 4). HBOC required less fluid than HEX (515 +/- 58 versus 830 +/- 45 mL, p = 0.019). Lactate was similar between groups (p > 0.05). pH was highest in HBOC by 180 minutes (p < 0.05). SID was constant in NON, decreased in HEX, but increased in HBOC (p < 0.05 by 60 minutes). SIG remained unchanged in NON and HEX, but declined in HBOC (p < 0.05 by 30 minutes).
  
  
  CONCLUSIONS
  HBOC resuscitation required the least fluid. Unmeasured anions were prevalent in HEX and NON (+ SIG), whereas HBOC liberated unmeasured cations (- SIG); differences were inapparent when only evaluating pH. Only HBOC increased the SID, electrochemically promoting alkalosis. Resuscitation fluid differences may aid care in high lactate conditions where an induced counterbalancing metabolic alkalosis may be beneficial.
authors.affiliation: Department of Surgery, Section of Trauma, Surgical Critical Care and Surgical Emergencies, Yale University School of Medicine, New Haven, Connecticut 06520, USA. Lewis.Kaplan@yale.edu
authors.forename: Lewis J
authors.initials: LJ
authors.lastname: Kaplan
authors.forename: Nora
authors.initials: N
authors.lastname: Philbin
authors.forename: Francoise
authors.initials: F
authors.lastname: Arnaud
authors.forename: Jennifer
authors.initials: J
authors.lastname: Rice
authors.forename: Feng
authors.initials: F
authors.lastname: Dong
authors.forename: Daniel
authors.initials: D
authors.lastname: Freilich
mesh_terms: D000136:Acid-Base Equilibrium / Q000187:drug effects*; D000818:Animals; D001802:Blood Substitutes / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D005440:Fluid Therapy / Q000379:methods*; D006454:Hemoglobins / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D006863:Hydrogen-Ion Concentration / Q000187:drug effects; D006895:Hydroxyethyl Starch Derivatives / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D007262:Infusions, Intravenous / Q000379:methods; D012771:Shock, Hemorrhagic / Q000628:therapy*; D013552:Swine
chemical_list: D001802:Blood Substitutes; D006454:Hemoglobins; D006895:Hydroxyethyl Starch Derivatives; C096798:HBOC 201