Patients will be followed for up to 6 months or until the catheter is removed, or until the study ends. A standardised data tracking form will be used to assess baseline characteristics as well as number of times urokinase was used. Nursing documentation regarding each PICC flushing (standard documentation as per hospital protocol) will be evaluated for number of discrete attempts made to troubleshoot lines without use of urokinase. Positive blood culture results will be recorded for each patient.