title: Preferential effects of low volume versus high volume replacement with crystalloid fluid in a hemorrhagic shock model in pigs.
abstract: BACKGROUND
  Fluid resuscitation is a core stone of hemorrhagic shock therapy, and crystalloid fluids seem to be associated with lower mortality compared to colloids. However, as redistribution starts within minutes, it has been suggested to replace blood loss with a minimum of a three-fold amount of crystalloids. The hypothesis was that in comparison to high volume (HV), a lower crystalloid volume (LV) achieves a favorable coagulation profile and exerts sufficient haemodynamics in the acute phase of resuscitation.
  
  
  METHODS
  In 24 anaesthetized pigs, controlled arterial blood loss of 50 % of the estimated blood volume was either (n = 12) replaced with a LV (one-fold) or a HV (three-fold) volume of a balanced, acetated crystalloid solution at room temperature. Hemodynamic parameters, dilution effects and coagulation profile by standard coagulation tests and thromboelastometry at baseline and after resuscitation were determined in both groups.
  
  
  RESULTS
  LV resuscitation increased MAP significantly less compared to the HV, 61 ± 7 vs. 82 ± 14 mmHg (p < 0.001) respectively, with no difference between lactate and base excess between groups. Haematocrit after fluid replacement was 0.20 vs. 0.16 (LV vs. HV, p < 0.001), suggesting a grade of blood dilution of 32 vs. 42 % (p < 0.001) compared to baseline values. Compared to LV, HV resulted in decreased core temperature (37.5 ± 0.2 vs. 36.0 ± 0.6 °C, p < 0.001), lower platelet count (318 ± 77 vs. 231 ± 53 K/μL, p < 0.01) and lower plasma fibrinogen levels (205 ± 19 vs. 168 ± 24 mg/dL, p < 0.001). Thromboelastometric measurements showed a significant impairment on viscoelastic clot properties following HV group. While prothrombin time index decreased significantly more in the HV group, activated partial thromboplastin time did not differ between both groups. HV did not result in hyperchloraemic acidosis.
  
  
  CONCLUSIONS
  Coagulation parameters represented by plasma fibrinogen and ROTEM parameters were also less impaired with LV. With regrad to hematocrit, 60 % of LV remained intracascular , while in HV only 30 % remained in circulation within the first hour of administration. In the acute setting of 50 % controlled blood loss, a one fold LV crystalloid replacement strategy is sufficient to adequately raise blood pressure up to a mean arterial pressure >50 mm Hg. The concept of damage control resuscitation (DCR) with permissive hypotension may be better met by using LV as compared to a three fold HV resuscitation strategy.
  
  
  CONCLUSIONS
  High volume administration of an acetated balanced crystalloid does not lead to hyperchloraemic acidosis, but may negatively influence clinical parameters, such as higher blood pressure, lower body temperature and impaired coagulation parameters, which could potentially increase bleeding after trauma. Replacement of acute blood loss with just an equal amount of an acetated balanced crystalloid appears to be the preferential treatment strategy in the acute phase after controlled bleeding.
authors.affiliation: Ludwig Boltzmann Institute for Experimental and Clinical Traumatology, AUVA Research Centre, Donaueschingenstrasse 13, A-1200, Vienna, Austria. martin.ponschab@auva.at.|Department of Anaesthesiology and Intensive Care, AUVA Trauma Hospital, Linz, Austria. martin.ponschab@auva.at.
authors.forename: Martin
authors.initials: M
authors.lastname: Ponschab
authors.affiliation: Ludwig Boltzmann Institute for Experimental and Clinical Traumatology, AUVA Research Centre, Donaueschingenstrasse 13, A-1200, Vienna, Austria. herbert.schoechl@medical-education.at.|Department of Anaesthesiology and Intensive Care, AUVA Trauma Centre, Salzburg, Austria. herbert.schoechl@medical-education.at.
authors.forename: Herbert
authors.initials: H
authors.lastname: Schöchl
authors.affiliation: Ludwig Boltzmann Institute for Experimental and Clinical Traumatology, AUVA Research Centre, Donaueschingenstrasse 13, A-1200, Vienna, Austria. claudia.keibl@trauma.lbg.ac.at.
authors.forename: Claudia
authors.initials: C
authors.lastname: Keibl
authors.affiliation: Department I/10, Federal Ministry of the Interior, Vienna, Republic of Austria. henrik.fischer@utanet.at.
authors.forename: Henrik
authors.initials: H
authors.lastname: Fischer
authors.affiliation: Ludwig Boltzmann Institute for Experimental and Clinical Traumatology, AUVA Research Centre, Donaueschingenstrasse 13, A-1200, Vienna, Austria. heinz.redl@trauma.lbg.ac.at.
authors.forename: Heinz
authors.initials: H
authors.lastname: Redl
authors.affiliation: Ludwig Boltzmann Institute for Experimental and Clinical Traumatology, AUVA Research Centre, Donaueschingenstrasse 13, A-1200, Vienna, Austria. c.schlimp@gmx.at.|Department of Anaesthesiology and Intensive Care, AUVA Trauma Hospital, Klagenfurt, Austria. c.schlimp@gmx.at.
authors.forename: Christoph J
authors.initials: CJ
authors.lastname: Schlimp
mesh_terms: D000818:Animals; D000077324:Crystalloid Solutions; D004195:Disease Models, Animal; D005440:Fluid Therapy / Q000379:methods*; D007552:Isotonic Solutions / Q000008:administration & dosage*; D008297:Male; D012771:Shock, Hemorrhagic / Q000097:blood / Q000503:physiopathology / Q000628:therapy*; D013552:Swine; D016896:Treatment Outcome
chemical_list: D000077324:Crystalloid Solutions; D007552:Isotonic Solutions