Dose Response Effects of Hypertonic Saline and Dextran on Cardiovascular Responses in Sheep
LETTERMAN ARMY INST OF RESEARCH PRESIDIO OF SAN FRANCISCO CA
Pagination or Media Count:
Despite the established efficacy of 7.5 NaCl6 dextran-70 in the treatment of hypovolemia, the optimal formulation of a hyperosmotichyperoncotic small volume resuscitation solution has yet to be defined. The present study investigates the cardiovascular effects of hypertonic saline ranging from 3.75-25 NaCl HS and dextran-70 D-70 ranging from 3 to 24. HS and D-70 were studied alone or in specific combinations at a dose of 4 mLkg, in euvolemic sheep. Blood samples were collected before, during and up to 60 min after infusion of the test solutions. Dose-dependent effects of HS were immediate increases in cardiac output CO of 30-85, falling to 10-35 over baseline after 60 min. HS concentrations over 3.75 significantly reduced systemic vascular resistance, but HS had no significant effect on mean arterial pressure MAP. Plasma volume PV expansion with HS was an immediate, but transient increase of 12-35. Infusion of D-70 induced sustained 10-20 increases in CO and 10-30 increases in PV, peaking 10 min post-infusion. D-70 also resulted in small 5-12 mmHg increases in MAP. Cardio-vascular effects of D-70 correlated with a dose-dependent increase in plasma dextran concentrations.
- Stress Physiology