During CPB , COP was reduced by @ % in the HES-group -LSB- ( @ @ ) vs ( @ @ ) mmHg , P < @ -RSB- while it was reduced by more than @ % of the pre-CPB value -LSB- @ @ vs ( @ @ ) mmHg , P < @ -RSB- in the crystalloid group ( P < @ HES-group vs. crystalloid group ) .