Hemodynamic effects of hypertonic hydroxyethyl starch 6% solution and isotonic hydroxyethyl starch 6% solution after declamping during abdominal aortic aneurysm repair

Fluid resuscitation with hypertonic hydroxyethyl starch solutions (HES) is effective in haemorrhagic shock due to the rapid mobilisation of fluids int o the intravascular compartment. Declamping of the abdominal aorta with acu te redistribution of blood into the vessels of the lower body half causes d eclamping-induced hypotension. Usually large amount of fluids or vasopresso rs are necessary to restore hemodynamic stability. Therefore, infusion of a hypertonic colloid solution may be an attractive option to achieve hemodyn amic stability. This study was conducted to determine the amount of fluid o f either hypertonic HES (HES 6%;7.2% NaCl) or isotonic HES (HES 6%;0.9% NaC l) needed to attain best wedge pressure (PCWP) cardiac index (CI) relation after declamping. Thirty-two high-risk patients undergoing elective abdomin al aneurysm resection were enrolled in a prospective, randomised, double bl inded study. The individual optimised PCWP/Cl relation was determined after induction of anaesthesia. After declamping, both solutions were titrated i n small boluses of 100 mL until the previously determined best wedge was re ached. The amount of fluid after declamping was significantly reduced in th e hypertonic HES- group 162 mL vs. 265 mL in the control group (P < 0.05). Resuscitation time was shortened, and cardiac index was slightly higher in the treatment group. The use of hypertonic HES-solution after aortic declam ping led to a significant reduction of fluids necessary to attain optimised PCWP/Cl relation. In this clinical trial with moderate blood loss in high- risk patients, hypertonic HES applied in a titrated fashion restored hemody namic stability faster and without volume overload.