Data collection occurs at three time points: pre- procedure, intra-procedure and post-procedure. The pre-procedural data collection will include: 1) a pain score using a standard number scale ranging from 0-10 for children >6 years or 10-point Wong-Baker faces pain scale for children < 6 years measured at the time of triage by the triage nurse and 2) demographics including age, gender, procedure type, adjunctive pain medication (including the use of local anesthesia) and anxiety score using the Modified Yale Preoperative Anxiety Scale (M-YPAS) performed by a research assistant (medical student or college student who will be trained in data collection) in the treatment room after the provider has described the procedure to the patient and parent. Intra-procedural data collection will include: comfort score measured on the Face, Legs, Activity, Cry, Consolability (FLACC) Pain Scale and anxiety score measured on the M-YPAS. The FLACC Scale is a 10 point scoring system with 10 indicating the highest level of pain. Both scoring scales are validated scales of pain (FLACC) and anxiety (M-YPAS). The FLACC score and the M-YPAS score will be documented by a research assistant (medical student or college student who will be trained in data collection). The post-procedure data collection will include: mask tolerance, level of holding the child required in order to complete the procedure, length of procedure, highest nitrous oxide concentration used, patient recovery time back-to-baseline, adverse events, and independent rating of the success of the procedure by both the provider performing the procedure and the provider administering the nitrous oxide. At the end of the visit, a research assistant blinded to the patient's group assignment will document the parent's satisfaction with the encounter.