Fig. 5. Mean arterial pressure (mmHg) during the trial in patients with controlled hyperventilation (CH, closed diamond) and spontaneous breathing (SB, open diamond). Data are expressed as the mean ± SD. # and ##= differences from the corresponding reference value, at P < 0.05 and 0.01, respectively. * P < 0.05. ** P < 0.01. *** P < 0.001.