Nursebob’s MICU/CCU Survival Guide

Central Venous Catheter Occlusions


1. Central line complications.

            A. Thrombotic occlusions

                        a. Venous thrombosis.

            B. Catheter related infection

            C. Nonthrombotic occlusion.

                        a. Mechanical obstruction

                                    -Kinked intravenous tubing

                                    -Air leaks

                                    -Clogged filter

                                    -Improperly placed port-access device

                                    -Catheter malpositioning

                        b. Drug precipation

                                    -Drug crystallization

                                    -Drug-drug incompatibilities

                                    -Drug-solution incompatibilities

                                    -Treatment usually depends on whether the precipitates are likely to dissolve with a change in pH.

                                                -For substances that dissolve in acidic or alkaline environments, 0.1 N HCl or 1 mEq/mL NaHCO3, respectively, may be used.

                                                -The use of incompatible drugs or solutions should be avoided

                        c. Lipid Residue.

                                    -Lipid residue also may accumulate after administration of lipid-containing, TPN mixtures

                                    -Lipid occlusions may be treated with 70% ethanol or with 0.1 mMol/mL NaOH.

                        d. Catheter malposition or migration.

                                    -May be repositioned using various interventions (such as patient positioning, fluoroscopic catheter guidance, partial catheter withdrawal).

                                    -Malpositioning is caused by a thrombus, a thrombolytic agent may be used

2. Assessment of central venous catheter occlusions

            A. Inability to infuse or withdraw fluid, or by sluggish flow.
            B. Partial occlusions often enable infusion but not aspiration of fluid through the catheter.
            C. Occlusions may occur soon after catheter insertion or during prolonged use.

            D. Multiple factors.

                        a. Thrombotic and nonthrombotic obstructions may occur jointly.


3. Thrombotic Occlusions

            A. Thrombosis may occur, as a result of the body's reaction to insertion of the catheter.

            B. Usually at the tip of the catheter.

            C. Types of thrombotic occlusions

                        a. Intraluminal thrombus forms within the lumen of the CVL

                                    -May result in either partial or complete occlusion.

                        b. Mural thrombus forms when the fibrin from a vessel-wall injury binds to the fibrin covering the catheter surface

                                    -May lead to venous thrombus formation.

                        c. Fibrin sheath (or fibrin sleeve) forms when fibrin adheres to the external surface of the catheter.

                                    -Thrombus may become trapped between the sheath and the catheter tip.

                        d. Fibrin tail (or fibrin flap) forms when fibrin adheres to the end of the catheter

                                    - Often acts as a one-way valve, permitting infusion but not withdrawal of fluid from the catheter.


4. Risk factors for thrombotic occlusions
            A. Venous stasis

            B. Hyper coagulability

            C. Trauma to the vessel wall

            D. Catheter characteristics may contribute to an increased risk of thrombosis.

                        a. Catheters with left-sided placement

                        b. Larger diameters are more susceptible.

                        c. Risk is also higher with polyvinylchloride and polyethylene catheters relative to the newer polyurethane and silicone


5. Signs and symptoms of thrombotic occlusions

            A. Majority of thrombi develop without symptoms

                        a. Catheter may seem sluggish.

                        b. Infusion pump alarms may sound frequently

                        c. Clots may appear on the exterior of the catheter.

                        d. May be possible to infuse but not withdraw fluid.

                        e. Imaging may help confirm a diagnosis of thrombotic occlusion


6. Treatment of thrombotic occlusions
            A. Catheter salvage is preferred over catheter replacement.

            B Fibrinolytic agents - compounds act as thrombolytics by activating plasminogen to form plasmin, which degrades fibrin and thus breaks up thrombi.

                        a. Alteplase

                        b. Streptokinase

                        c. Urokinase.