Continuous-flow delivery of nitrous oxide and oxygen: a safe and cost-effective technique for inhalation analgesia and sedation of pediatric patients.

Nitrous oxide (N2O) safely and rapidly alleviates the pain and distress of minor procedures in the emergency department (ED). We have found self-administration in children does not consistently achieve acceptable analgesia and sedation. The equipment generally available for ED use is designed for adults and delivers 50% N2O through a demand valve that requires an inspiratory effort of -3 to -5 cm of water to activate gas flow. This is difficult for young children who are crying, have more shallow respirations than adults, or cannot follow instructions. In collaboration with the Departments of Anesthesiology, Dentistry, and Respiratory Therapy, we constructed a continuous-flow system for delivering N2O and oxygen (O2). The following is a description of the components, assembly, and use of a continuous-flow machine that safely and inexpensively delivers N2O and O2 to children.