Hospitals that care for children are establishing medical emergency or rapid response teams as system solutions for preventing unexpected but foreseeable respiratory and cardiac arrest on inpatient units. Typically, an experienced team of doctors and nurses responds quickly to a direct request by any level of staff or even a parent for assistance with a child whose physiologic parameters meet predetermined criteria or whose condition causes concern to them. Several pediatric studies comparing outcomes before and after introduction of these rapid response systems reported reductions in rates of respiratory or cardiac arrest and death but no prospective study has compared pediatric hospitals that have implemented rapid response teams to hospitals that have not.