This investigation, unlike previous studies, will include a wider age range of children, as well as a variety of painful or anxiety provoking minor procedures commonly performed in the PED. We are choosing to include a variety of pre-defined minor procedures, rather than a single procedure, in order to assess the feasibility and benefit of nitrous oxide for the many minor procedures performed routinely on a daily basis in a pediatric emergency department. It will allow us to quantify our rate of effectiveness in decreasing pain and/or anxiety with the use of high concentration (>50%) nitrous oxide and to expand the use of nitrous oxide if shown to be superior to standard management in the reduction of procedural pain and anxiety.