Group 1 included 0.5 % tetracaine ( n = 6 ) ; group 2 , 4 % lidocaine ( n = 8 ) ; group 3 , 0.75 % bupivacaine ( n = 8 ) ; group 4 , 0.5 % tetracaine + 4 % lidocaine ( n = 5 ) ; and group 5 , 0.5 % tetracaine + 0.75 % bupivacaine ( n = 7 ) .
