title: Survival in a rat model of lethal hemorrhagic shock is prolonged following resuscitation with a small volume of a solution containing a drag-reducing polymer derived from aloe vera.
abstract: Drag-reducing polymers (DRP) increase tissue perfusion at constant driving pressure. We sought to evaluate the effects of small-volume resuscitation with a solution containing a DRP in a rat model of hemorrhage. Anesthetized rats were hemorrhaged at a constant rate over 25 min. In protocol A, total blood loss was 2.45 mL/100 g, whereas in protocol B, total blood loss was 3.15 mL/100 g. Five minutes after hemorrhage, the animals were resuscitated with 7 mL/kg of either normal saline (NS) or NS containing 50 microg/mL of an aloe vera-derived DRP. In protocol B, a third group (CON) was not resuscitated. Whole-body O2 consumption (Vo2) and CO2 production (Vco2) were measured using indirect calorimetry. In protocol A, 5/10 rats in the NS group and 8/10 rats in the DRP group survived for 4 h (P = 0.14). Mean arterial pressure was higher in the DRP-treated group than in the NS-treated group 45 min after resuscitation (89 +/- 8 vs. 68 +/- 5 mmHg, respectively; P < 0.05). In protocol B, survival rates over 2 h in the DRP, NS, and CON groups were 5/15, 1/14, and 0/7, respectively (P < 0.05). Compared with NS-treated rats, those resuscitated with DRP achieved a higher peak Vo2 (9.0 +/- 1.0 vs. 6,3+/- 1.0 mL/kg/min) and Vco2 (9.0 +/- 1.1 vs. 6.0 +/- 1.0 mL/kg/min) after resuscitation. We conclude that resuscitation with a small volume of DRP prolongs survival in rats with lethal hemorrhagic shock.
authors.affiliation: Department of Critical Care Medicine and Surgery, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, USA.
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Macias
authors.forename: Marina V
authors.initials: MV
authors.lastname: Kameneva
authors.forename: Jyrki J
authors.initials: JJ
authors.lastname: Tenhunen
authors.forename: Juan-Carlos
authors.initials: JC
authors.lastname: Puyana
authors.forename: Mitchell P
authors.initials: MP
authors.lastname: Fink
mesh_terms: D000504:Aloe / Q000378:metabolism*; D000818:Animals; D002151:Calorimetry; D004195:Disease Models, Animal; D006863:Hydrogen-Ion Concentration; D007773:Lactates / Q000378:metabolism; D008297:Male; D010100:Oxygen / Q000378:metabolism; D010101:Oxygen Consumption; D010936:Plant Extracts / Q000627:therapeutic use*; D011108:Polymers / Q000737:chemistry / Q000627:therapeutic use*; D011773:Pyruvates / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012771:Shock, Hemorrhagic / Q000188:drug therapy* / Q000401:mortality*; D013997:Time Factors
chemical_list: D007773:Lactates; D010936:Plant Extracts; D011108:Polymers; D011773:Pyruvates; D010100:Oxygen