Outpatient High-Dose Urokinase Lock: A Quick Answer to Blocked Tunneled Cuffed Catheters

Abstract

ABSTRACT Introduction: Tunneled Cuffed Catheters (TCC) in haemodialysis are often lost to thrombotic complications. Thrombolytic agents like urokinase are used for thrombolysis of blocked catheters. Inpatient administration of such thrombolytic agents is problematic and expensive for patients and increases burden on hospitals. Aim: To evaluate the efficay and safety of high-dose urokinase lock used for thrombolysis of TCCs on outpatient basis and whether thromolysed catheters achieve adequete survival. Materials and Methods: Catheters inserted over a 12-month period, starting September 2017 were followed prospectively (n=183 TCCs). Catheter dysfunction was defined as inability to aspirate blood from any one port or blood-flow of <250 mL/min or high arterial/venous pressures. Non-mechanical or non-positional flow-dysfunction was treated with urokinase lock (50,000 units/port) with 5000 U/mL of heparin, total lock volume equal to the catheter dead volume. The solution was kept for 24 hours. Patency rates, need for repeat locks and overall survival was evaluated. Kaplan-meier survival analysis and binary logistic regression was done to evaluate survival and factors associated with need for urokinase rescue. Results: There were 57 episodes of flow-dysfunction during the 16-month follow-up period (n=159 TCCs, as rest were lost to follow-up). Flow improved in 48 (84.2%) and was completely restored in 41 (71.9%) cases. Seventeen (29.8%) cases needed repeat locks. Twenty-two catheters were lost to flow-related dysfunction. Overall survival of catheters needing urokinase rescue was non-inferior to catheters not needing such intervention (p=0.78). No prelock coagulopathy or postlock bleeding episodes were seen. Conclusion: Urokinase lock protocol has high efficacy and safety. It allows acceptable survival of TCCs developing thrombotic dysfunction.

Keywords

• catheter lock
• catheter thrombosis
• fibrinolytic agents
• haemodialysis
• vascular access