We evaluated the hemodynamic effects of IV and intraaortic (aortic root) administration of 7.5% NaCl
solution on hemodynamics in anesthetized cats with severe
hypovolemia.
Hypovolemic shock was induced by exsanguinating cats to a mean arterial blood pressure of 50 mm of Hg, which was maintained for 30 minutes prior to treatment. Shed blood volume was 38.4 +/- 2.1 ml/kg of
body weight. The cats were treated with a small volume (4 ml/kg) of
0.9% NaCl solution IV, 7.5% NaCl
solution IV, or 7.5% NaCl
solution administered into the aortic root. The IV administration of
0.9% NaCl solution did not improve hemodynamics. The IV administration of 7.5% NaCl
solution induced rapid restoration of arterial blood pressure, aortic blood flow, and cardiac contractility. Total peripheral vascular resistance decreased. The administration of 7.5% NaCl
solution into the aortic root induced a further deterioration in hemodynamics resulting in death in 3 cats and a marked improvement in hemodynamics similar to that observed after IV administration of 7.5% NaCl
solution in 2 cats. The duration of the beneficial hemodynamic effects after IV or intra-aortic administration of 7.5% NaCl
solution did not exceed 60 minutes. Results of these studies suggested that either the IV or intra-aortic administration of 7.5% NaCl
solution in cats can induce beneficial hemodynamic effects that may be of value in the field
resuscitation of
hypovolemic patients.