Comparative Analysis of 8 APAP Machines

[Sleeprider]

I found an article that may be worth reproducing or summarizing on the main forum. I thought I'd run it by you guys first. I don't think there is a commercial issue here. http://openres.ersjournals.com/content/1/1/00031-2015

Eight current machines were tested, AirSense 10 Autoset Standard and Response (ResMed), Dreamstar (Sefam), Icon (Fisher & Paykel), Resmart (BMC), Somnobalance (Weinmann), System One (Respironics) and XT-Auto (Apex). The differences in how the machines respond to obstructive apnea is pretty amazing. We have known for some time that the Resmed Airsense 10 responds fastest to OA, and this is confirmed in this study. The other reasonably fast responders were the F&P Icon and Somnobalance. In order of finish, Respironics, Resmart, Apex and Dreamstar failed to respond fast enough or strongly enough to normalize breathing when set to their minimum starting pressure of 4.0.

This reflects much of our advise in the forum to aggressively increase minimum pressure, particularly with the slower responding machines like Respironics. You can visulaize the pressure response of the machines in the figure below from the article (In order of best to worst finish):
A1 = Resmed Airsense 10 Autoset (purple)
A2 = Resmed Airsense 10 Autoset in Response Setting?? (Dark Blue)
C= F&P Icon (Yellow)
E = Sonomnobalance (Dark Grey)
F = PRS1 Remstar (Green)
D = Resmart (Light Blue)
G = Apex XT-Auto (Light Blue)
B = Dreamstar (Red)



Table 1 in the article has the best summary of quantitative results from the two test runs, but I'm not sure how to reproduce it here.

[KSMatthew]

Interesting.

I just read the article. The TL;DR version: different APAPs connected to a simulated patient. The measurements show how quickly the APAPs reached a pressure great enough to resume normal breathing. The dashed black line shows the pressure required to resume normal breathing.

I'm not sure how to interpret that graph. It seems that the two AirSense 10 and the Icon machine were the only ones to reach that pressure?

[justMongo]

Good article. (I don't see any commercial issues with it either)
There may be some bias since funding seems to have come from one of the manufacturers.

[Sleeprider]

Keep in mind the simulation is done with machines in auto mode starting at a pressure of 4.0. Your conclusion are correct insofar as the study criteria go. There may be a good reason for a machine to respond more slowly, or be better tuned to the patient's minimum pressure requirement, and that is not addressed by the study.

If an auto machine is to be dispensed without titration, I think the lesson here is that Resmed and Fisher Paykal are the best contenders. Also, if we see members struggling with their machines, or complaining of "hard to breath" when they use the Dreamstar, Apex, Resmart and Respironics auto machines, the answer has to be, increase minimum pressure because your machine takes too long to respond from the minimum auto setting.

[Sleeprider]

I want to add that there are not many comparative studies out there. This is kind of a Consumer Report thing, where awareness makes for a more empowered shopper. If a supplier is trying to foist a cheap Asian machine on an insured patient,and claiming the machines are all the same; this article disproves that. This empowers our members to complain and demand a top-quality machine. I'm a bit surprised by the Respironics results, but it is only marginally behind the F&P Icon based on Table 1. So I think it still belongs in the upper tier for auto CPAP. The study design definitely rewards speed of response, and I have not checked whether the study was sponsored by Resmed. Might have to do that.

In any event, the Discussion and Lessons for Clinicians sections of the report clearly suggest speed is not everything, and the algorithms may not be in error.

Lessons for clinicians

This bench test study assessed how currently available APAP devices respond to a simulated OSA patient. Regardless of the simplified experimental setting employed in this work, as compared with the complexity of events found in the clinical arena when treating OSA patients, the following practical lessons can be derived.

The way that each commercial APAP device modifies nasal pressure when subjected to disturbed breathing patterns is different.

These differences in response among APAP devices are not necessarily caused by incorrect performances. Instead, they are the result of the particular engineering solutions implemented in each device.

Knowing the specific functioning features of each APAP device (e.g. sensitivity in detecting the different obstructive events, tolerance to events before increasing pressure and speed of pressure changes) may help to understand treatment compliance in specific patient phenotypes.

Choosing the optimal APAP device for the needs/preferences of each individual patient may improve therapy compliance.

[KSMatthew]

Keep in mind the simulation is done with machines in auto mode starting at a pressure of 4.0. Your conclusion are correct insofar as the study criteria go. There may be a good reason for a machine to respond more slowly, or be better tuned to the patient's minimum pressure requirement, and that is not addressed by the study.

If an auto machine is to be dispensed without titration, I think the lesson here is that Resmed and Fisher Paykal are the best contenders. Also, if we see members struggling with their machines, or complaining of "hard to breath" when they use the Dreamstar, Apex, Resmart and Respironics auto machines, the answer has to be, increase minimum pressure because your machine takes too long to respond from the minimum auto setting.

I am, and always have been, on constant pressure so I have no personal experience with auto-PAPs.

I do see the point that this graph goes out only 10 minutes and the tests were 2 hours long. But the information from the report seems to say that the other machines never were able to reach the proper setting.

It's possible the internal algorithms on those systems will adjust up by a small percentage at a time and try to creep in and eventually reach a limit they won't go above. Where the ResMed makes a large jump, then backs off and re-corrects.

In either case, your comment above that the answer has to be "increase minumum pressure" seems like it is the best advice.

[KSMatthew]

Here is the sponsorship info from that report:

Footnotes

Support statement: This work was carried out within the framework of a ResMed–University of Barcelona contract aimed at bench testing automatic continuous positive airway pressure devices. ResMed provided financial support to carry out the study but did not intervene in the design or performance of the tests, or in the data analysis. ResMed also funded the assistance of a medical writer in preparing the manuscript. Funding information for this article has been deposited with FundRef.

Conflict of interest: Disclosures can be found alongside this article at openres.ersjournals.com

Received June 5, 2015.
Accepted July 26, 2015.

Copyright ©ERS 2015

This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial Licence 4.0.

[SuperSleeper]

As far as I can tell, the site's content isn't commercial in nature.

I'm moving the thread to the Main Forum if that's okay, Sleeprider.

[Sleeprider]

fine by me

[cands]

A2 = Resmed Airsense 10 Autoset in Response Setting?? (Dark Blue)

In the clinical menu:

Response: Options are Standard or Soft.
I assume 'Response' setting is 'Soft'?