Comparing incidence of thrombosis in PICC and midlines and evaluating the role of anticoagulation, site of insertion, and risk factors

Background: Benefits of using peripherally inserted central venous catheters (PICCs) have often overshadowed the risk of catheter thrombosis (CT). Quality improvement models should be implemented to reduce this complication rate. Methods: Incidence rate of CT was the main outcome. Predictors included age, lumen size, major surgery, previous venous thromboembolism, body mass index, catheter infection, thrombophilia, critically-ill and inferior-vena-cava filters/pacemaker/implantable-cardioverter-defibrillator. The contributions of anticoagulation and the catheter insertion site were considered. Results: Among 1683 subjects, 1560 received PICCs (5.83% CT), and 123 had midlines (4.88% CT). Ninety-two CT cases were compared to 1591 controls. A summated risk score was created using variables from our multivariate logistic model that showed significance as predictors in incidence of thrombosis. The risk score model, divided into 3 tertiles, correctly classified 94.5% of cases and distinguished high-risk patients. No difference between vein insertion sites was noted. The basilic vein was associated with 5.5% CT versus 5.3% with non-basilic vein insertions. Similarly, the brachial vein was associated with 4.8% CT versus 5.6% for nonbrachial vein insertions. Finally, the cephalic vein resulted in 7.6% CT versus 5.4% for non-cephalic vein insertions. When anticoagulation was used at the time of catheter insertion, the incidence rate was 22.8% versus 77.2% when it was not used. No statistical difference was noted, when compared to controls. Conclusion: Identified risk factors are associated with increased rate of thrombosis. A clinical prediction score can objectively identify high risk patients. Our results suggest no statistical difference in thrombosis event between vein insertion sites or use of prophylactic anticoagulation.