I was going through a nephrology journal and I saw your advertisement for a new access measurement device. What is this measuring and how does it work? Thanks for any info

TQA is a revolutionary access monitoring device from In-Line Diagnostics that makes current flow monitors obsolete. Using transcutaneous (through the skin) technology, TQA directly measures the flow rate of blood in the access - without line reversal, without a laptop computer, and without the hassle of current methodology, and does all this in under one minute. Contact In-Line at 800 - 546- 5463 for additional information.

I saw this at NRAA. They said it did not have 510(k) clearance yet. Is that still the case ?

Charlotte,
We expect to have FDA approval within the next 30 days.

We are pleased to note that TQA approval from the FDA was received the week ending 24 December 2000. Contact Matt Haynie at In-Line for further details.

See press release from In Line regarding 510(k) approval for TQa in today's news section on Renalweb home page. Congratulations Nancy et. al.

Are there any independent validation studies published on the TQA method (that is, studies without In-Line Diagnostic staff members on the list of investigators)?

John,
We are in the process of doing that now with a group of independent physicians who are not associated with In-Line Diagnostics.

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Dear John Brown,

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[This message has been edited by Gary Peterson (edited 01-22-2001).]

Dear John Brown??
I would be more then happy to have a purposeful discussion with you regarding the TQa methodology. Please post your question again.
Thanks,
Nancy

That was interesting� Let me try once more.
I am disappointed that In-Line has not learned from its past experiences. The company has launched several access flow monitoring approaches before without reliance on the peer-review process: Saline Injection (1995), Go/No Go Saline Injection (1997), Delta-H (1988). The first peer-reviewed paper on saline injection came in Jan.�98 (Lindsay et al., ASAIO J.44:62-76); it reported that this method over-estimates access flow by a whopping 68% (w. zero offset of �170 ml/min). The first peer-reviewed paper on Delta-H (w. In-Line as co-author) came in Sept.�99 (Yarar et al., KI Vol.56 pp.1129-35), it reported that the Delta-H method reads 16% higher than the reference Transonic device. Per DOQI, clinics are advised to monitor patient for a critical access flow of 600 ml/min. With these Crit-Lines, such a flow would register, on the average, as 690 (Delta-H) and 838 (saline injection) ml/min. This will give the the clinic into a false sense of security and expose the patient to a higher access thrombosis rate with its related morbidity. Per the Crit-Line web site, all these methods have now been dropped.

With TQA, In-Line is back to direct saline injection. Again without independent peer review, but company officials are nevertheless promoting the device in ads, over the phone, and on this very bulletin board. Access disease accounts for half the morbidity and hospitalization of the ESRD patients.Why, In-Line Diagnostics, do you continue to experiment with patient�s access health?

Mr. Brown's comments reflect an interesting point of view. As correctly stated, In-Line has forwarded several methods of assessing access flow/condition - all of which are currently viable and in use. (The exception is ABF in the USA due to a court action by a competitor - which is still in process.) All of the In-Line methods are based on sound, mass balance mathematics and have been verified both in-vitro and in-vivo.

It seems a bit singular to conclude from the the cited peer review data that all In-Line methods "over-estimate". Rather, when multiple independent methods yield higher measurements than a single alternative device, would it not seem natural to ponder the possibility that the single alternate device just might be "under-estimating".

A bumper sticker in Wyoming once read, "Eat more lamb. 10,000 coyotes can't be wrong!" :-)

A major advantage of the TQA technology is that it frees the patient from the dialysis clinic environment for access management. This is clearly an advantage over any current alternate approaches in that it facilitates assessments of access condition in emergency rooms or even during a doctor visit. It's hard to imagine why this kind of forward thinking and capability would not be endorsed and embraced by anyone who has patient freedom, convenience and well being in mind.

[This message has been edited by lbarrett (edited 01-24-2001).]

My comments do not aim to discourage the development of new measurement devices with improved diagnostic features, and I commend In-Line for making several attempts in this area. My point is that a premature launch of such new technologies may well harm the patient. The primary task of a medical test such as TQA is, to diagnose the stage of stenotic disease. The capability to test for this disease during a doctors� visit is potentially harmful if the test produces data without established validity. Independent product verifications of previous Crit-Line access flow measurement approaches came years after product launch and they did not support In-Line�s device accuracy claims. I urge In-Line to follow, for patient�s sake, standard engineering validation practices for the new TQA device: in the long term you stand much to gain by proving that this device, in the hands of independent operators and over the full range of patient conditions, measures what you believe it does.

Mr. Barrett�s coyote logic to justify Crit-Line measurement deviations has several flaws:

1. He suggests that Transonic measurements may well be wrong, Crit-Line measurements be right. His logic has a fatal flaw. In line supports two separate measurement approaches: saline injection and Delta-H. In the example cited above, they differ by 20%. They cannot both be right at the same time.
(Nevertheless I encourage In-Line to shed light on the �Who�s right� question: it will require in vivo calibration studies with absolute calibration tools such as beaker stopwatch, magnetic resonance imaging. The end product would surely be: a validated measurement device with proven accuracy tolerance.)

2. All studies that resulted in the DOQI guideline: �test patients for a critical access flow of 600 ml/min� were done with Transonic devices as well. Assume for an instant that the Transonic device has a systematic measurement deviation. The DOQI guideline would then read: �test patients for a critical access flow of 600 Transonic units�. In this critical care environment, there is plenty of room for novel measurement approaches. With the calibration conversion factors produced by independent studies, In-Line Diagnostics could issue an urgent memorandum to its customers (�when doing the DOQI access flow study with a Crit-Line, test patients for a critical access flow of 838 Crit-Line saline injection units or 690 Crit-Line Delta-H units�) or do a full product recall to electronically adjust the measurements. Mr. Barrett�s comments indicate that In-Line is aware of this calibration discrepancy. Not acting on such knowledge puts patients at risk: clinics will not emergently act when Crit-Line indicates flow over 600 ml/min, and Transonic would have indicated 600 ml/min or less.