Average pain queried on POD 1 for subjects receiving perineural ropivacaine ( n = 30 ) was a median ( interquartile ) of 2 ( 0-3 ) , compared with 4 ( 1-5 ) for subjects receiving saline ( n = 30 ; 95 % confidence interval difference in medians , -4.0 to -0.3 ; P = 0.021 ] .