Healthcare Professionals
Aquapheresis with the Aquadex
FlexFlow was designed to be a powerful tool for healthcare professionals
dealing with patients with fluid overload.
Distinguishing Features
of the Aquadex FlexFlow:
- simplicity of operation - only one required
user setting
- peripheral and central venous access options
- can be quickly transported, setup, and operated
in numerous clinical locations (inpatient and outpatient)
- removes excess fluid ISOTONICALLY, therefore,
removes the greatest possible amount of sodium per unit of fluid
withdrawn
- clinically shown to reduce length of stay and
readmissions compared to standard diuretic care
Frequently Asked Questions
Q:
What does it do?
A: Removes excess salt and water from patients with fluid overload by filtering blood withdrawn from and returned to a patient's veins.
The Aquadex FlexFlow is highly automated and
has only one required setting, the rate that you want the fluid
to be removed - settable from 0 to 500 mL/hr in increments of 10.
This is the rate at which the excess fluid will be pulled off and
how quickly the collection bag will fill. The average is 250 mL/hr.
One can think of the Aquadex FlexFlow as a mechanical diuretic. But unlike diureric drugs, the Aquadex FlexFlow can remove the excess fluid in a controllable and predictable fashion.
For more details, go to "Aquapheresis and How It Works".
Q:
How does it do it?
A: It uses a technique in which blood containing excess fluid is
withdrawn and passed through a special filter (hemofilter). The
filter removes the excess fluid from a patient's blood. The filtered
blood is returned to the patient and the removed fluid is collected
in a bag for later disposal.
The Aquadex FlexFlow filter uses a simple pressure difference (i.e. higher pressure inside vs. lower pressure outside) to selectively push elements in the blood through tiny holes (pores) in the walls of the numerous filter fibers. This is referred to as convective transport (because it uses only pressure and size).
It is the walls of these fibers that make up the filter membrane and it is through their tiny embedded pores that the excess fluid from the blood passes. Literally, only appropriately sized elements of the blood fit through the filter's pores and are removed, all others remain in the blood and are returned to the patient.
Only a small pressure difference is used to drive this size-based separation process. No other chemical forces or concentration gradients are created by the Aquadex FlexFlow that could cause an electrolyte imbalance. That is, because the removed fluid on the other side of the filter is in chemical equilibrium with the blood, no diffusive transport occurs, only convective transport and that's why the fluid removed is always ISOTONIC to blood.
For more details, go to "Aquapheresis and How It Works".
Q:
What are the specifications of your filter?
A: The filter is made up of hundreds of hollow fiber tubes of polysulfone
membrane material with the following properties:
Filter Mechanical Properties:
| Surface area (approx.): |
0.12 square meters |
| Max Removal Rate: |
500 mL/hr |
| Blood Volume (approx.): |
7 mL |
UF 500
Set Blood Volume (approx.):
|
33 mL
|
| Access
port priming volume (approx.):
|
2 mL
|
Filter Coefficients*: (37±1°C, blood
flow rate 40 mL/min., UFR 8.3 mL/min.)
| Urea Sieving (saline) |
0.98 |
| Creatinine Sieving (saline) |
0.98 |
| Vitamin B12 Sieving (saline) |
0.98 |
| Albumin Sieving, 65,000 MW Daltons (**) |
<0.02 |
| Ultrafiltration (**) |
5.6 mL/hr/mmHg |
Transmembrane Pressure, TMP (**)
at a UF rate of 500 ml/hr.
|
100 mmHg |
* Typical values obtained from laboratory testing
of post-sterilization lots. Results may vary based on clinical
and patient conditions.
** bovine blood, albumin concentration 6 ±0.2 g/dl
Performance specifications of a similar polysulfone
membrane in a 1.25 square meter device:
Sieving coefficients***:
| B12 |
1,355 MW-Daltons |
.96 |
| Inulin |
5,000 MW-Daltons |
.79 |
| Cytochrome-C |
12,384 MW - Daltons |
.50 |
| Myoglobin |
17,000 MW-Daltons |
.50 |
| Albumin |
65,000 MW-Daltons |
<.001 |
*** bovine blood, blood flow @ 200 mL/min,TMP
@ 100 mmHg and plasma protein level = 5.0 g/dl
Q:
On whom can I use it? / What's its indication for use?
A: The Aquadex FlexFlow removes fluid only. It is targeted for patients
with fluid overload who have failed diuretic therapy and not for
those with End Stage Renal Disease (ESRD) or chronic renal failure.
If a patient needs dialysis, they should be on dialysis.
For more details, go to "Aquapheresis
Prescription".
Q:
What's different about the Aquadex FlexFlow and other hemofiltration/hemodialysis/CVVH
machines?
| A: |
1. |
No clinically significant impact on electrolyte
balance, blood pressure or heart rate. |
| |
2. |
Can be used in numerous and diverse settings
(inpatient or outpatient) - ICU/CCU/MICU, telemetry, stepdown,
observation, ER, etc. |
| |
3. |
Uses peripheral venous access for withdrawal
and return of venous blood. |
| |
4. |
Small, transportable, and easy to set up -
circuit loading and priming takes 10 minutes, can operate on
AC power or battery (up to 30 minutes). |
| |
5. |
Highly automated operation, only one setting,
and autonomously and intelligently attempts to maintain and
reestablish blood flow without stopping and alarming. |
| |
6. |
Designed for operation with floor and general
medical practitioners in mind. |
| |
7. |
Blood circuit designed to minimize clotting
and the need for anticoagulation. From the tips of the catheters,
through our connectors and filter, and back into the patient,
the Aquadex FlexFlow's blood circuit was optimally designed
to keep the blood flowing and the path from clotting. |
| |
8. |
Minimal chance of hypotension. Blood flow is
10-40 mL/min and the total filter set volume is 33 mL. This
is combined with the Aquadex FlexFlow's ability to precisely
control the rate of removal to match the rate of fluid becoming
available in the patient. |
 |
|
|
Q:
Can I use it with central access?
A: Aquadex FlexFlow can be used with central or peripheral venous
access. Venous access site and catherter choosen are based on what
is the best for each individual patient and the total treatment
plan for that patient.
For more details, go to "Aquapheresis
Prescription".
Q:
You claim to not significantly affect electrolyte balance/blood
chemistry Explain how this works?
A: We do not use replacement fluid and filtration is based solely
on size (blood cells, proteins, etc. cannot fit through the filter's
pores) and uses only the slightly higher pressure on the inside
of the fibers than on the outside (transmembrane pressure) to selectively
push across the membrane (convection). The filter does not create
any other gradients or forces to selectively extract out particular
electrolytes.
Therefore, since the electrolytes can move freely across the filter
membrane, they equalize. The levels of electrolytes in the blood
are the same as that in the extracted fluid. It's ISOTONIC.
The fluid removed is made up of water, electrolytes
and "small and medium molecules". Some of those are important,
but there are large stores of these in the fluid overloaded patient.
Since the fluid removed has the same electrolyte concentrations
as those in the blood, their overall concentrations in the patient
are not changed over the course of therapy. Therefore, the therapy
neither improves nor worsens electrolyte balance, it keeps it constant.
Q:
How long can we leave the catheters in a patient?
A: Depends on national and local institutional standard practice
of care for peripheral and midline venous access and the fluid removal
treatment plan worked out for each patient.
Q:
Dialysis is an inflammatory stimulus, inducing cytokine production
and complement activation. Don't you use the same filter material.
Is this a problem?
A: Aquapheresis Therapy with the Aquadex
FlexFlow is not dialysis. It is short term and not performed 3-4
times each week for up to 12 hours each time. Aquadex FlexFlow patients
should not have End Stage Renal Disease (ESRD) or chronic renal
failure and should have functional kidneys that may be acutely compromised
due to the heavy fluid overload. Their kidneys can still process,
filter, and reduce the effects of this complex process. Patients
with ESRD or chronic renal failure cannot.
The Aquadex FlexFlow removes fluid only. If your
patient needs dialysis, they should be on dialysis. |
