The Central Venous Catheter Related Complications in Critically Ill Patients

Inclusion Criteria: * Age \> 18 years old and \<80 years old; * Central venous catheter is required to be placed through the internal jugular vein, subclavian vein or femoral vein; * Catheter placement is estimated to be ≥ 72 hours. Exclusion Criteria: * The central venous catheter has been placed before entering the department; * There is obvious trauma or infection at the site of implantation; * There is already a blood vessel thrombus in the site before implantation; * Recently, deep vein thrombosis or catheter-related thrombosis has occurred.