Patients receiving injectable lidocaine experienced pain that was similar ( 50.1 5.9 mm ; 95 % confidence interval [ CI ] 45.2-55 .1 ) to those receiving the transdermal lidocaine/tetracaine patch ( 60.1 mm 11.0 ; 95 % CI = 55.2-68 .1 ) , p = 0.04 , with a power of 80 % to detect a difference of 20 mm at p 0.05 ; although this was statistically significant , it was not clinically significant .