Fig. 1. Upper dermatome blocked to cold sensation at 10 and 20 min postspinal for the phenylephrine group (  cross-hatched bars ) and the ephedrine group (  open bars ). Data are expressed as median (interquartile range). There was a difference between the groups at 10 min (  P = 0.01) and at 20 min postspinal (  P = 0.001) (Mann–Whitney U test).