Figure 2. Individual (dotted lines) and mean (solid line) GR90291 concentration-time profiles. The single arrow indicates the point at which the remifentanil infusion rate was doubled, and the double arrow indicates the end of the infusion. The Y axes have different scales in the three graphs. (A) The patients with renal failure who received the low-dose infusion (0.0125 micro gram [center dot] kg sup -1 [center dot] min sup -1 for 1 h followed by 0.025 micro gram [center dot] kg sup -1 [center dot] min sup -1 for 3 h). (B) The patients with renal failure who received the high-dose infusion (0.025 micro gram [center dot] kg sup -1 [center dot] min sup -1 for 1 h followed by 0.05 micro gram [center dot] kg sup -1 [center dot] min sup -1 for 3 h). (C) The controls who received the high-dose infusion (0.025 micro gram [center dot] kg sup -1 [center dot] min sup -1 for 1 h followed by 0.05 micro gram [center dot] kg sup -1 [center dot] min sup -1 for 3 h).