Mean A Mean B p Valid N Std.Dev. Std.Dev. mean difference Confidence Confidence Intraop.amount fentanylµgkg-1 3.34 7.49 <0.0000001 24 0.82 1.96 4.15 5.02 3.28 Intraop.amount fentanyl µgkg-1min-1 0.02 0.04 0.0000004 24 0.007 0.014 0.020 0.026 0.013

Table 2: Intraoperative amount of fentanyl by group.