RT Journal Article SR Electronic T1 The use of 50% nitrous oxide improves successful intravenous access in obese and growth-limited children in an outpatient setting JF Evidence Based Medicine JO Evid Based Med FD BMJ Publishing Group Ltd SP 144 OP 145 DO 10.1136/ebmed-2011-100334 VO 17 IS 5 A1 David Rosen YR 2012 UL http://ebm.bmj.com/content/17/5/144.abstract AB