EFFICACY OF OSMOLALITY AND IONIC COMPOSITION OF RESUSCITATION FLUIDS FOR TREATMENT OF ACUTE BLOOD-LOSS IN THE SPONTANEOUSLY HYPERTENSIVE RAT (SHR)

The spontaneously hypertensive rat (SHR) has a deficient glucose mobil ization in response to blood loss. Treatment of blood loss with hypert onic glucose might consequently be advantageous in SHR, but the import ance of osmolality as compared to ionic composition of resuscitation f luids is still not fully elucidated. Therefore, SHR (n = 32) were subj ected to hemorrhage (30% of calculated blood volume) followed by treat ment with (1) hypertonic saline (HS; 4.5 ml/kg of 7.5% NaCl, 2,400 mOs m/L), (2) hypertonic glucose (HG; 4.5 ml/kg of 42.3% solution, 2,400 m Osm/L), and (3) normal saline (NS; 37.5 ml/kg of 0.9% NaCl) to provide an equal sodium load as with HS. All fluid regimens increased (P < 0. 001 vs. control) mean arterial pressure (MAP). Hemodilution was more p ronounced after HS and NS than after HG. Hypernatremia was evoked by H S. The hyperglycemic response to hemorrhage was intensified by HG, but it was accompanied by increased blood lactate levels. All three treat ment regimens prolonged posthemorrhagic times until death (P < 0.01-0. 05) (mean values: NS 363 min; HS 170 min; HG 146 min; nontreated contr ols 60 min). It is concluded, on the basis of hemodynamic, metabolic, and times-until-death data, that although treatment with small-volume HS seems superior to small-volume HG, an equal load of sodium given as NS is more effective for resuscitation after blood loss than HS in SH R. (C) 1993 Wiley-Liss, Inc.