Kidney oxygen consumption per sodium reabsorbed as an index of metabolic cost. Oxygen consumption per sodium reabsorbed (VO2/TNa+) measured at baseline (t0) and resuscitation (t2) in the control (C) group (n = 5), nonresuscitation (NR) group (n = 8), HES130/0.4 resuscitation group (n = 8), HES200/0.5 resuscitation group (n = 8) and Ringer's lactate (RL) resuscitation group (n = 6). *P < 0.05 versus baseline. Testing was performed using the Student paired t test. Data are presented as mean ± standard error of the mean.