1892 TRANSFUSION Volume 46, November 2006 Blackwell Publishing IncMalden, USATRFTransfusion0041-11322006 American Association of Blood BanksNovember 2006461118921898Original Article BLOOD VISCOSITY AND PFC EMULSIONJOUAN-HUREAUX ET AL. ABBREVIATIONS: ANH = acute normovolemic hemodilution; FCD = functional capillary density; HAS = human albumin solution; HS = hemorrhagic shock; MFG = modified fluid gelatin; PFC(s) = perfluorocarbon(s). From the Laboratory of Hematology and Physiology, EA 3452, Faculty of Pharmacy, Henri Poincaré-Nancy 1 University, Nancy; Laboratory of Cellular and Tissue Mechanics and Engineering, UMR-CNRS-INPL-UHP 7563, IFR 111, Faculty of Medicine, 54505 Vandoeuvre-lès-Nancy; Colloids and Interfaces, Charles Sadron (CNRS, UPR 22) Institutes, Louis Pasteur University, Strasbourg; Anesthesia Reanimation Pole, CHU de Nancy, Nancy; Mixed Unit UHP-INSERM U-684, Faculty of Medicine, Vandoeuvre-lès-Nancy, France. Address reprint requests to: Patrick Menu, Laboratoire de mécanique et d’ingénierie cellulaire et tissulaire, UMR-CNRS- INPL-UHP 7563, IFR 111, Faculté de Médicine, 54505 Vandoeuvre-lès-Nancy Cedex, France; e-mail: menu@medecine. uhp-nancy.fr. *Both authors contributed equally to this work. Received for publication December 20, 2005; revision received April 14, 2006, and accepted April 17, 2006. doi: 10.1111/j.1537-2995.2006.01000.x TRANSFUSION 2006;46:1892-1898. BLOOD CONSERVATION AND TRANSFUSION ALTERNATIVES Effects of a new perfluorocarbon emulsion on human plasma and whole-blood viscosity in the presence of albumin, hydroxyethyl starch, or modified fluid gelatin: an in vitro rheologic approach Valérie Jouan-Hureaux,* Sandra Audonnet-Blaise,* Diana Lacatusu, Marie-Pierre Krafft, Pascale Dewachter, Ghislaine Cauchois, Jean-François Stoltz, Dan Longrois, and Patrick Menu BACKGROUND: Artificial oxygen carriers such as perfluorocarbon (PFC) emulsions have reached Phase III clinical trials as alternatives to homologous blood, but their rheologic effects have not been characterized. In this study, the rheologic effects of PFC emulsion in the presence of clinically used volume expanders were investigated. STUDY DESIGN AND METHODS: The effects of a new PFC emulsion (small droplet size with narrow size distribution) at two PFC concentrations (4 and 8 g/dL) on plasma and whole-blood viscosity in the presence of human albumin solution (HAS), hydroxyethyl starch (HES), or modified fluid gelatin (MFG) were investigated. Three hematocrit (Hct) levels were investigated: 30, 20, and 13 percent. Plasma, PFC emulsions, and whole- blood viscosity, with a Couette viscometer, and RBC elongation, with an ektacytometer, were measured for shear rates of 0.2 to 128 per second. RESULTS: The two PFC concentrations increased plasma and whole-blood viscosities. Viscosity values similar to physiologic ones (Hct level, 40%) were observed at: 1) Hct level of 13 percent, with 4 or 8 g per dL MFG-PFC; 2) Hct level of 20 percent, with 4 g per dL MFG-PFC; and 3) Hct level of 30 percent, with 4 g per dL HES-PFC and 4 and 8 g per dL HAS-PFC. RBC deformability was unchanged. CONCLUSION: It is concluded that this new PFC emulsion increases plasma and blood viscosity and that among the three studied volume expanders, the interaction with MFG can result in viscosity values above the physiologic one even at low Hct values. The possible consequences of the increased viscosity at low Hct values are discussed. evere acute blood loss resulting in hemorrhagic shock (HS) can lead to severe tissue damage responsible for high morbidity and mortality. 1-3 The recovery of physiologic macrohemodynamic variables such as arterial pressure and cardiac output, as well as the fast restoration of microvascular perfusion and oxygen supply to vital organs, are the major aims of pri- mary therapy of HS. Intravenous (IV) volume replacement with an acellular fluid may restore cardiac output but fails to promote microvascular perfusion. 4 Severe hemodilu- tion, due to massive infusion of volume expanders, may further impair tissue oxygenation because of decreased oxygen transport. Survival from shock is directly depen- dent on the restitution of adequate blood oxygen-carrying capacity once the hematocrit (Hct) level decreases below S