Critical Care Medicine | 2019
159: USE OF TISSUE PLASMINOGEN ACTIVATOR VIA PURGE SYSTEM IN A CATHETER-BASED VENTRICULAR ASSIST DEVICE
Abstract
Learning Objectives: Temporary ventricular support is increasingly used for the treatment of cardiogenic shock. When device complications present, patient prognosis and complexity may make reoperation for device exchange undesirable. We report a case describing the use of tissue plasminogen activator (tPA) to resolve a low purge flow rate in a catheter based ventricular assist device. Methods: A 23-year-old woman with peripartum cardiomyopathy diagnosed eight months earlier presented with decompensated heart failure, pneumonia and a right atrium mass. Despite maximum medical management, diagnostic heart catheterization demonstrated elevated ventricular filling pressures, elevated pulmonary artery (PA) pressures and decreased cardiac output. An Impella 5.0 (Abiomed, Danvers, MA) was inserted via right axillary cut down to decrease PA pressures to bridge to potential transplant. The Impella purge system was primed with unfractionated heparin (UFH) 50 units/mL in dextrose 5% sterile water. Additionally, systemic UFH was titrated to a goal anti-factor Xa level: 0.35–0.5 units/mL. Purge pressures of 347–437 mmHg (normal reference range: 300–700 mmHg) were present with a purge flow rate of 16–18 ml/h. Beginning on post-operative day 5, purge pressures progressively increased to above 900 mmHg and purge flow rate decreased to 1–3 ml/h. In an attempt to avoid reoperation, the heparin purge solution was replaced with 4 mg of tPA diluted in 100 mL of dextrose 5% sterile water and systemic UFH was continued. Resolution began within 3 hours and by 15 hours, the tPA solution resulted in a return of purge pressures below 500 mmHg and a purge flow rate of 13.7 ml/h. During this time, the patient experienced an episode of self-limited epistaxis. The tPA solution was replaced with the heparin purge solution and the device continued to operate within normal parameters until the Impella was weaned and removed. Results: This case demonstrates that a high purge pressure and low flow rate state may be successfully resolved with a tPA purge solution with minimal adverse effects. Only one case report exists in which a similar method resolved high purge pressures in a centrally cannulated Impella LD device. In patients with significant comorbidities and anticipated procedure difficulty, tPA therapy may be a viable alternative in the absence of indications for emergent device exchange. CCMCritical Care MedicineCrit Care Med0090-3493Lippincott Williams & WilkinsHagerstown, MDCCM