During follow similar reductions were observed between groups without any statistical significance , with mean differences pre-postintervention of urea ( 49.6 52.3 SC vs. 50.3 52.3 IV , P = .96 ) ; creatinine ( 0.68 0.66 SC vs. 0.60 0.49 IV , P = .58 ) , and osmolarity ( 15.6 24.4 SC vs. 21.1 31 IV , P = .43 ) .