Annals for Hospitalist Inpatient Notes - How I TreatCatheter-Related Deep Venous Thrombosis

Abstract

With growing use of peripherally inserted central catheters (PICCs), upper-extremity deep venous thrombosis (DVT) is becoming more common. In a study of hospitalized medical patients, upper-extremity DVT accounted for half of all hospital-onset cases and most of these events were associated with PICCs (1). In a systematic review and meta-analysis, these catheters were found to be associated with a 2.5-fold risk for thrombosis compared with other central venous catheters. Of note, risk for DVT with PICCs was greater in patients with cancer and those with critical illness (2). Because hospitalists often care for and treat patients with PICCs and because most cases of upper-extremity DVT result from PICC use, appropriate treatment of DVT related to these devices is important to ensure patient safety. However, surveys of hospitalists have found that their approach to managing PICC-related DVT is often not concordant with guidelines. In this How I Treat article, I outline a pragmatic approach for managing catheter-related DVT. Once the diagnosis of catheter-related DVT has been confirmed, my strategy is guided by considering 3 main questions: 1. Do I still need the catheter? 2. What is the optimal strategy for anticoagulation? 3. Are more advanced interventions, such as thrombolysis, warranted? Do I Still Need the Catheter? When catheter-related DVT occurs, many clinicians remove the catheter and replace it with another device in the contralateral arm. However, this approach is counterproductive. Published evidence (including validated risk scores for PICC-related thrombosis) shows that placing a catheter in a patient who has had recent DVT (within 30 days) is among the strongest predictors of risk for recurrent thrombosis. Rather than reflexively remove the device and risk this event, hospitalists should ask the following questions: Is the catheter still necessary? That is, is there an appropriate clinical indication for continued central venous access? Is the catheter still functional? Specifically, does it still aspirate and infuse intravenous agents? Is the tip of the catheter located at the cavoatrial junction? If the answer to all 3 questions is affirmative, the catheter should be left in place and use should be continued. However, if it is not functional, removal is suggested. When a catheter is partly functional (for example, it infuses but does not aspirate), the decision is less clear. Inability to aspirate may indicate a ball valve thrombosis or fibrin sheath at the catheter tip that occludes the catheter on aspiration. In such cases (especially when the device is still needed), I err toward using the partly functional catheter to avoid the thrombotic risk associated with placing another device. However, I always evaluate the position of the catheter s tip to ensure that it terminates at the cavoatrial junction by obtaining a plain chest x-ray. Location of the tip elsewhere (for example, proximal superior vena cava) substantially increases risk for clot propagation, and removal is then warranted. What Is the Optimal Strategy for Anticoagulation? Unless risk for bleeding is high, all catheter-related DVT should be treated with systemic anticoagulation at treatment doses. Guidelines recommend at least 3 months of uninterrupted anticoagulation with warfarin or low-molecular-weight heparin; the latter is preferred in patients with cancer (3). A catheter removal strategy without anticoagulation is associated with high risk for DVT recurrence and is not recommended unless risk for bleeding is substantial. Although data regarding the value of anticoagulation beyond 3 months are limited, continued treatment may be considered if the catheter will remain in place. Although 1 prospective study suggests rivaroxaban may be effective for treating catheter-related DVT (4), evidence supporting use of direct oral anticoagulants in this setting is insufficient. As a result, these agents cannot currently be recommended for treatment of catheter-related DVT. Are More Advanced Interventions, Such as Thrombolysis, Warranted? If thrombosis is extensive (for example, it spans the axillary and subclavian veins), symptoms are severe, or the patient does not improve despite therapeutic anticoagulation, I consult interventional radiology for consideration of catheter-directed lysis. Compared with anticoagulation alone, catheter-directed lysis resolves thrombosis faster and has a lower incidence of postthrombotic syndrome. In a recent systematic review of 16 studies that included patients with upper-extremity DVT, infusion of tissue plasminogen activator for 12 to 24 hours in the affected vein led to substantial reduction in clot burden with no procedure-related pulmonary embolism and low incidence of postthrombotic syndrome (5). Important drawbacks to lysis include increased risk for bleeding and the possibility of thromboembolism when the thrombus is instrumented; therefore, careful discussion regarding risks and benefits with radiology is necessary. Angiography to evaluate the extent of thrombosis (especially for thrombi in the chest veins) is often performed. Summary As use of PICCs and central venous catheters becomes more common, hospitalists will increasingly have to manage thrombotic complications associated with these devices. A systematic approach that focuses on what to do with the catheter, how best to anticoagulate, and whether advanced interventions are warranted can help improve management of patients who experience these adverse events.