BACKGROUND: It is important to maintain adequate intravascular volume during off-pump coronary artery bypass surgery (OPCAB) to prevent hypotension. The aim of this study was to assess the effect of acute volume loading with new colloid solution, 6% hydroxyethyl starch (HES) 130/0.4 on hemodynamics and coagulation in patients undergoing OPCAB.

METHODS: With the IRB approval, forty patients undergoing OPCAB were allocated to two groups receiving 10 ml/kg of Plasma solution A (Control group, n = 21) or HES 130/0.4 (HES group, n = 19) for 30 min before pericardiotomy. We measured hemodynamic variables and coagulation parameters at 10 min after anesthesia induction (T1), 10 min after fluid loading (T2), 10 min after Y-graft formation (T3), and after sternum closure. Amount of infused fluid, blood loss, tranfusion and urine output were recorded intraoperatively and for 16 hr after surgery. Thromboelastography and electrolytes were also measured.

RESULTS: Both groups were similar in demographic data and fluid/blood volume during and after surgery. Cardiac index and right ventricular ejection fraction were maintained throughout the surgery in HES group but were decreased in Control group. The ratio of arterial oxygen partial pressure to inhaled oxygen fraction was increased in HES group after surgery. Thromboelastography and other parameters didn't demonstrate significant differences between the groups.

CONCLUSIONS: Acute HES loading before pericardiotomy could prevent the decrease of cardiac index and right ventricular ejection fraction in OPCAB patients. Additionally, it showed desirable effects on oxygenation without adverse effects on coagulation.