Ketamine is a commonly used anesthetic drug,but its clinical use declined in the late 1990s due to its postoperative nightmares,extrapyramidal syndrome,and a tendency to abuse.As an isomer of ketamine,esketamine is applied in a smaller dose than racemic ketamine,with strong analgesic and sedative effects,fewer cardiovascular and psychiatric adverse reactions.It has a significant application value in pediatric anesthesia with fast metabolism and high clearance rate in vivo,slight impact on children's respiratory and circulation,and rapid awakening and recovery.