Splanchnic mucosal perfusion effects of hypertonic versus isotonic resuscitation of hemorrhagic shock

A porcine hemorrhagic shock (HS) model was used to assess the splanchnic mucosal and systemic effects of hypertonic versus isotonic crystalloid resuscitation. Animals were bled to a mean arterial pressure of 40 mm Hg for 1 hour and then resuscitated with equivalent sodium loads of LR, 7.5 per cent hypertonic saline (HSS), or 7.5 per cent HSS with 6 per cent Dextran (HSD). Intestinal mucosal blood flow (IMBF) was measured by a laser Doppler flow probe placed on the mucosa of the small bowel. Following resuscitation the cardiac output (CO) (relative to baseline values) was significantly higher with HSD (158 17 per cent) and HSS (137 24 per cent) than with LR (84 27 per cent) (P < 0.005). There was prompt restoration of IMBF with both HSD (126 31 per cent) and HSS (106 22 per cent) (vs baseline). Resuscitation with LR was associated with a persistent reduction in IMBF (52 16 per cent) despite restoration of mean arterial pressure and cardiac output to baseline levels (P < 0.05). Thus, hypertonic saline solutions may serve an adjunctive role in the resuscitation of hemorrhagic shock by restoring intestinal nutrient blood flow and, thereby, preventing gut barrier impairment, bacterial translocation, and organ failure.