Systemic and renal regional hemodynamics during acute normovolemic hemodilution. Values represent mean ± standard error. *P < 0.05 versus baseline. †P < 0.05 versus control. #P < 0.05 versus colloid. BL = baseline; CO = cardiac output; CVP = central venous pressure; H1 = hematocrit 25%; H2 = hematocrit 20%; H3 = hematocrit 15%; HR = heart rate in beats/minute (bpm); Ht = hematocrit; MAP = mean arterial blood pressure; PAP = pulmonary artery pressure; PCWP = pulmonary capillary wedge pressure; SV = stroke volume; SVR = systemic vascular resistance; RBF = renal blood flow; RVR = renal vascular resistance.