Heart failure patients are sometimes so winded they can barely speak, turn in bed, or take a few steps, but after receiving artificial ultrafiltration to relieve fluid overload, they begin talking, walking, and feeling more comfortable.
It works very well, says Kathryn McBroom, RN, nurse manager of operations and education on the cardiology step-down unit at Duke University Hospital in Durham, N.C. Patients feel better and their symptoms seem decreased when we use that.
Duke began using the Aquadex FlexFlow fluid removal system, from CHF Solutions Inc., for heart failure patients resistant to diuretics a little over a year ago. Physicians also order Aquapheresis (CHFs term for ultrafiltration) for patients at end of life to help them feel more comfortable and have an opportunity to go home and spend time with family.
How Aquapheresis works
Aquadex FlexFlow, which hit the market in 2002, filters the blood, removing excess fluid and sodium, and then returns the blood to the body and collects the fluid in a bag. Clinicians can set the rate from zero to 500 mL/hr, in increments of 10.
The device uses a simple pressure difference to push the blood through tiny holes in the walls of filtration fibers, according to the manufacturers description. Only appropriately sized elements fit through the pores for removal. Everything else remains in the blood and is returned to the patient. No chemicals are used. At any given time, about 33 cc of blood is outside the body.
Aquadex FlexFlow can be used with central or peripheral venous access lines. Duke usually inserts peripheral lines, but on rare occasions may insert a central line, which has larger pores. Many providers, including those at Medical City Dallas Hospital and Ochsner Medical Center West Bank in Gretna, La., regularly use central lines. Nurses follow a heparin protocol. Heparin levels must fall within therapeutic range before starting Aquapheresis.
A digital screen walks users through the steps. The bag requires periodic emptying. Alarms trigger if a change in pressure occurs, such as if a line becomes kinked.
How providers are using Aquapheresis
Hospitals use Aquapheresis in different ways. Many facilities, such as Medical City Dallas Hospital, use it in the ICU or step-down units. Good Samaritan Hospital Good Health Center in Baltimore gives Aquapheresis as an outpatient treatment, taking off 2-3 liters during a six-hour session.
At Duke, patients receive the treatment for 24 to 72 hours on the step-down unit. Nurses monitor vital signs every 15 minutes for the first hour, then every 30 to 60 minutes for four hours and then every two hours for the remainder of the treatment.
If the systolic blood pressure falls below 90 or the heart rate increases above 130 beats per minute for two consecutive five-minute observation periods, the nurse decreases the rate by 100 or places it at zero for 30 minutes. But McBroom says the nurses rarely need to do that.
Patients can sit up in their chairs or walk to the bathroom using the units battery backup.
Patients are taken off diuretics while receiving Aquapheresis. Once they resume diuretic therapy, the drugs seem to work better, says Cynthia Bither, NP, MSN, heart failure and heart transplant nurse practitioner at Washington (D.C.) Hospital Center. Aquapheresis does not alter electrolyte balance.
The Ultrafiltration vs. IV Diuretics for Patients Hospitalized for Acute Decompensated Congestive Heart Failure: A Prospective Randomized Clinical Trial (UNLOAD) study reported in the Feb. 13, 2007, Journal of American College of Cardiology that mechanical fluid removal with Aquapheresis was a safe and effective therapy in patients with decompensated heart failure.
At 48 hours, the Aquapheresis group had a 38% greater weight loss and 28% greater net fluid loss than patients who were randomized to the diuretic group. Ninety days following hospital discharge, the Aquapheresis group had a 43% reduction in readmissions for heart failure and a 52% reduction in emergency department visits, compared to those receiving standard care.
McBroom also has seen positive outcomes. Patients feel better after this procedure and their activity level is improved, she says.
Debra Anscombe Wood, RN, is a Nursing Spectrum contributing writer.