Methods Six hundred and fourty patients requiring long-term intravenous infusion entered the study. The placed PICCs were made of soft silicon rubber with outer diameter of0.8mm(Fr3),1.2mm(Fr4)or1.6mm (Fr5)(Becton Dickenson,UT,USA).

• 方法640例有长期输液适应证的患者参加本研究；材料为美国B-D公司生产的一次性PICC(peripherallyinsertedcentralcatheter)；导管由柔软的硅胶材料制成；外径为0.；8mm(3Fr)、1