Efficacy of nalmefene antagonizing postoperative respiratory depression in children with congenital heart disease 【Abstract】Objective To evaluate the efficacy of nalmefene antagonizing postoperative respiratory depression in children with congenital heart disease．Methods Sixty ASA I orⅡchildren aged 3—6 years with congenital heart disease included in this study were randomly divided into 3 groups according to the drugs after surgery．ALL the patients were sent into CICU when the operation was over. After 10min when the patients’ vital sign was stable, the patients in groupⅠ (nalmefene groupⅠ)were injected with nalmefene (0.25ug/kg) and group Ⅱ(nalmefene groupⅡ) were injected with nalmefene (0.25ug/kg) twice，while patients were not given drug in group C (control group)．Blood pressure(BP)，heart rate(HR),pulse oxygen saturation(Sp02) before and after administration, duration of respiratory recovery, duration of extubation, duration of monitoring in CICU and adverse effects (including nausea, vomiting, fever, restlessness，wound pain) were observed．Results Compare to group C, duration of respiratory recovery, extubation, and monitoring in CICU in groupⅠand groupⅡ was shorter（P<0.05）. No significant difference was detected in BP, HR， Sp02 before and after administration among three groups(P>0.05)．Incidence of postoperative nausea and vomiting in groupⅠand groupⅡ were lower than that in group C（P<0.05）. No significant difference was detected in other postoperative adverse effects(P>0.05).Conclusion Nalmefene is effective and safe for antagonixing the postoperative respiratory depression in congenital heart disease surgery children.