Evidence-Based Management of a Patient With an EKOS Catheter.

Abstract

Q: What are the evidence-based recommendations for nursing management of a patient with an EKOS catheter?A: Sara Knippa, MS, RN, ACCNS-AG, CCRN, PCCN, and Shannon Vernon, BSN, RN, CCRN, reply:Catheter-directed thrombolysis (CDT) is a targeted alternative to systemic thrombolysis. It can be used for patients experiencing thrombotic problems such as deep vein thrombosis, pulmonary embolism, and peripheral arterial occlusion. In CDT, an infusion catheter is inserted into the artery or vein through a sheath and guided to the site of the thrombus. A thrombolytic agent, often alteplase, is continually infused through the catheter directly to the clot for a particular amount of time.1Therapy using an EKOS catheter, as part of the EkoSonic Endovascular System (Boston Scientific), takes CDT a step further by adding intravessel ultrasound. The EkoSonic Endovascular System (EKOS) consists of a specialized catheter (see Figure) and a control unit. The catheter delivers small ultrasound waves, which assist the thrombolytic medication to dissolve the clot.2 The technique of applying ultrasound waves while administering a thrombolytic medication is called ultrasound-assisted or ultrasound-accelerated thrombolysis (USAT); the EKOS equipment is prominently used for USAT.1Some question remains regarding the benefit of USAT compared with that of CDT in various clinical situations. The intended benefit of the ultrasound waves is to dissolve the clot faster or to require a lower dose of the thrombolytic drug, thereby decreasing the risk of bleeding and other complications. Most USAT systems, however, are more expensive than CDT. Does the extra expense translate into improved clinical outcomes? Some initial support exists for the clinical benefit of USAT in patients with arterial thromboembolic disease3 and deep vein thrombosis,4 but more evidence is needed. Recent studies suggest that CDT and USAT are not significantly different in patients with pulmonary embolism.5,6 Until definitive data are available, nurses may use both USAT and CDT in clinical practice.Very little definitive information is available to provide an evidence-based approach to nursing care for patients receiving thrombolytic therapy in conjunction with USAT.1 Therefore, from a nursing perspective, the best approach is to understand how a USAT system functions and how to troubleshoot any problems, and to focus on the most common complications that occur with any thrombolytic drug. These steps will allow nurses to appropriately target assessments and interventions.Nurses should be familiar with the USAT system that their organization uses. The ultrasound therapy must be running in order for the system to be effective. For example, with the EKOS system, the ultrasound should not run without infusions instilling through both lumens of the catheter (see Figure): the thrombolytic agent infuses through the drug lumen, and normal or heparinized saline infuses through the coolant lumen. The thrombolytic infusion does not stop, regardless of the status of the ultrasound. The ultrasound can be paused when necessary (eg, for Doppler assessment, during ultrasound diagnostic tests), but otherwise the nurse should verify that the ultrasound is running at all times; to do so, one can look for the blinking yellow light on the console.7,8Complications may stem from vascular access, thrombolytic drug administration, and contrast used for imaging. The EKOS catheter and sheath can be removed at the bedside or in a procedural area. Staff who can remove the catheter and sheath should receive specific training in this process. In addition, an inferior vena cava filter may need to be placed after removal of the catheter and sheath in order to reduce the patient’s risk of pulmonary embolism.7Manufacturer recommendations provide a stable starting point for the development of facility-specific guidelines for the care of patients receiving USAT. Additional strategies that may be helpful when evidence-based guidelines are not available include reaching out to other facilities who are using the equipment, reaching out to national organizations, and working with a hospital or unit-based practice committee to create a facility-specific guideline or resource.Because patients requiring this therapy may be infrequent, facilities would benefit from creating relevant resources that nurses can reference quickly at the point of care.9 When specific evidence-based guidelines are not available, nurses can use their existing, related knowledge to anticipate complications and provide safe care.