The effect of hyperosmolar infusions on survival after hemorrhage

Hyperglycemia has previously been reported beneficial for survival after hemorrhage. In the present investigation, rats depleted of liver glycogen after 24 h food deprivation were infused either A: isotonic NaCl (300 mosm/kg H2O), B: glucose (1,800 mosm/kg), C: Xylose (2,000 mosm/kg) or D: NaCl (1,800 mosm/kg), during 60 min hemorrhage, and observed for recovery or death for seven days. During hemorrhage, all animals given hyperosmolar infusions had higher serum osmolality and greater plasma refill compared to group A. Increments in serum osmolality correlated inversely to hematocrit developments, p less than 0.05. Only 2/18 animals given isotonic NaCl survived, while survival in the other groups were 14/18 (glucose infused), 20/22 (xylose infused) and 20/20 (hypertonic NaCl). Best survival was noted in the groups with the highest final osmolality, and largest reduction in hematocrits; groups C and D, while significantly more animals given glucose died compared to group D. It is concluded that induction of hyperosmolality during the early phase of hemorrhage is associated with increased survival in hemorrhage, irrespective of hyperosmolar agent infused. The benefits of hyperglycemic hyperosmolality is primarily related to the osmolar properties of this solute, and not the immediate need for glucose as substrate.