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Detect Recirculation
Does your
patient have access recirculation? A single infusion of isotonic saline will tell you! No disposables are necessary, no blood samples to collect, no waiting for a BUN
report. Transonic Flow-QC gives you immediate answers so you can adjust the dialysis prescription before complications ensue.
... or no recirculation
Two-needle dialysis requires zero recirculation: any recirculation indicates unacceptably low access flow or incorrect needle placement. With Transonic Flow-QC, you
can confirm zero recirculation on-site during the dialysis treatment.
... or reversed hemodialysis lines
Case studies demonstrate that, in up to 4% of
hemodialysis patients, the arterial and venous lines are inadvertently reversed. Chronic morbidity may result. The Transonic Monitor catches inadvertent reversal of
lines in a patient's first Flow-QC session.
... FAQ: How can my monitor indicate 0% recirculation when vascular access flow is less than delivered blood flow?
See below or Click here for answer.
Monitor Actual Delivered Blood Flow
When a dialysis machine overstates blood flow by 20%, your KT/V prescription is not being administered. Our monitor tells you actual delivered blood flow! You can then
correct flow limiting causes such as small needle diameter, incorrect needle placement, or adjust the pump's RPM to correctly deliver your prescribed flow rate.
"Delivered blood flow during hemodialysis is often significantly less than prescribed QB. We believe that individualized prescriptions based on actually measured
QB will help to maximize the efficiency of delivered hemodialysis." Sands, JJ et al, ASAIO 42: 76, 1996.
- Prescribed Delivery of Dialysis
When a dialysis machine overstates blood flow by 20%, your KT/V prescription is not being administered. Our monitor tells you
actual pump (blood line) flow so you can correct flow limiting causes such as small needle diameter, incorrect needle placement, or you can adjust the pump's RPM to
deliver your prescribed flow rate.
- Case Report: Inadvertent Reversed Blood Lines Identified
A routine Transonic hemodialysis screening of a 41 year-old female patient reported a vascular
access recirculation of 22%. When the blood lines were reversed and another measurement was made no recirculation registered indicating that there had been an
inadvertent reversal of the hemodialysis lines. The lines were left in the now correct position and the patient received her prescribed dialysis delivery.
Cost Considerations
Transonic Flow-QC screening reduces patient
morbidity and the number of hospital tests for your patients. It allows more comprehensive diagnostics in your clinic. In a capitated cost environment, Transonic Flow-QC
reduces costs by eliminating more expensive procedures.
Transonic Flow-QC
The Transonic
Flow-QC Hemodialysis Monitor screens both for dilaysis delivery and vascular access flow during a patient's scheduled dialysis visits.
The screening takes only 10 minutes per patient. Quick, easy and painless this non-invasive technology can be used anytime during dialysis; with any type of
hemodialysis tubing; and with any hemodialysis machine."
FAQ
How can the HD01 Monitor indicate Zero
recirculation at a pump flow of 400 ml/min when access flow in reversed line position was only 350 ml/min?"
Indeed, as a rule of thumb you will find that access recirculation
(AR) exists when access flow (AF) is less than pump flow (Qb). Natural (baseline) access flow is the blood flow that is shunted between the access artery and vein. As
it withdraws blood, a hemodialysis pump produces a negative pressure which actually helps the natural flow through the access.
Therefore, a dialysis pump may increase baseline access flow. When
blood lines are reversed to measure access flow, the pump pushes flow against the natural access flow. This may decrease baseline access flow. Although rigorous
testing of HD01 access flow measurements in the reversed line position demonstrates that these minor differences between measured access flow and baseline access flow
have no clinical significance (see Transonic Hemodialysis Publications HD7T, HD40A, HD7A, HD27V, HD9A) , they are responsible for two exceptions to the recirculation
rule (AR exists when AF< Qb). These two exceptions show Zero recirculation even though access flow is less than pump flow. They are:
1. Significant narrowing (stenosis) between the needles.
This condition presents when measured access flow (AF) is significantly smaller (difference _ 200 ml/min) than pump flow (Qb) when Zero access recirculation (AR) is
detected:
Example: Zero AR at Qb = 400 ml/min, AF = 120 ml/min
When this relationship between pump flow and Zero access recirculation
exists, one can conclude that there is a significant narrowing (stenosis) between the needles. The stenosis causes considerable flow resistance. In normal line
position, the pump simply bypasses the stenosis because the arterial needle is located before the narrowing and the venous outflow needle is located after the
narrowing. A mid-access stenosis never produces access recirculation. There still can be adequate pump flow for hemodialysis, although baseline access flow is close to
zero and the access is in trouble.
2. Significant inflow and/or outflow narrowing (stenosis).
This condition exists when access flow is slightly smaller (difference _ 150 ml/min) than pump flow when Zero access recirculation is detected:
Example: Zero AR at Qb = 400 ml/min, AF = 350 ml/min
Here, one can conclude that there is an inflow (arterial) and/or
outflow (venous) stenosis creating the low access flow. This is also caused by the effect of the dialyzer pump on baseline access flow. Suppose the pump flow
prescription is 400 ml/min and baseline access flow is 380 ml/min. Suppose also, that the pump flow has a 10% (of pump flow) effect on baseline access flow. Then, with
dialysis lines in normal position, access flow becomes 380 + 40 = 420 ml/min. A recirculation measurement will indicate Zero recirculation because pump flow is less
than access flow (400<420). When the access lines are reversed with pump flow at 300 ml/min, access flow may decrease by 10% of pump flow (30 ml/min). The HD01
Monitor would thus register
AF = 380 - 30 = 350 ml/min.
Conclusion
Trust your access flow measurements! Do not rely on
an absence of recirculation. A vascular access may be severely compromised even when there is no sign of recirculation
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