Resmed S9 Autoset Vs S8 Autoset Spirit II

I have rented a Resmed S9 Autoset to compare it against my Resmed S8 Autoset Spirit II with a SleepZone heated hose with the intention to see if an upgrade is worth the expense.

Background
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Late 2009 I was diagnosed with moderate sleep apnea and put on a trial with a Resmed S8 Spirit II autoset. Got my life back! So I bought an S8 II autoset in early Feb 2010... and then the S9 came out. Yes, I was peeved, but I figured them's the breaks. I didn't know about it and hindsight's a wonderful thing.

My first experience with the H4i humidifier introduced me to "rain-out", where you wake up to water dribbling into your face because of condensation in the hose (and, to make matters worse, I had my hose lifted over the end of my bed, thereby making a classical condenser as you see in the chemistry labs). I bought the Resmed tube wrap and ran the hose from under my bed to underneath the blankets. This provided some relief.

My limiting factors are: 1. my wife hates a hot room (!?), so heating was turned down to 15 degrees Celsius); and 2. I need the humidifier, even at its lowest setting, otherwise my nose blocks. The problem was that, by the end of winter, I felt almost as bad as I had before the CPAP machine in summer (I live in Australia, so May-Sep are the winter months). A month ago I decided to buy the SleepZone heated tubing. Because I live near to where it is made, my SleepZone was delivered by the fellow who makes them (he was going shopping close to where I work). He's a great guy and really believes in his product. The heated tubing was a lifesaver. Not only did it fix, for me, the rain-out problem, I found it also warmed the air.

Last week I hired a Resmed S9 with the climate line to compare the two. Which would give me the better sleep - the S8 II with SleepZone or S9 with climate line? Luckily it's a cold October (nighttime temperatures at about 8-11 degrees Celsius), so I've been able to run a bit of a comparison.

Findings
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1. Noise

For me, while the S8 is barely audible, the S9 is inaudible. I didn't hear the slight whistle in the exhale. Mind you, I'm in my late 40s so my hearing's not the best. While the S9 is quieter, both are almost silent. To put it in perspective, the ducted heating system, when I'm allowed to have it on, makes more noise than either the S8 or the S9. However, the winner here is S9.

2. Build Quality

The S8 is a solid build. The S9, I believe, is layer(s) of chrome paint over plastic and I wonder if it's likely to peel off in the future. Also, the lever to open the H5 humidifier is plastic - again, something that I can see not lasting the distance. The knob and buttons on the S9 feel flimsy. I wonder if you can get a 5 year warranty on them as I could on my S8. In this category, the S8 is the clear winner.

3. Controls

The S9's interface should be easier to use with a colour screen and a press-able knob, but I've found it harder and somewhat unintuitive. It should be twist-knob-and-press to drill down menus and selections, with a button to escape. It's not that easy. There's an extra button.

However, the icons are nice and when you do get to where you want the information is there. The S8's controls seem primitive in comparison, but do work, although there are a number of buttons to press to get to where one wants. However, the buttons seem more consistent. Here - a tie.

4. Slimline Tube Vs Standard Tube

Slimline tube wins here for me, although I can see a climate line tube being more expensive to replace.

5. Rain-out

The S8 with the SleepZone heated tubing wins hands down here. The climate line still allowed, for me, repeated slight condensation in the mask. In fact, the night before last was so bad I had to disconnect the climate line (which, by the way, MUST be connected to the H5 humidifier) and attached the SleepZone tube sans humidifier.

6. Quality of Sleep

With similar conditions (SleepZone tube connected to APAP machine with no humidifier) I seem to feel less tired during the day with the S9, although it reports high AIs than the S8. Interestingly, I seem to be getting one or two central apneas during the night. Given the S9 detects them and, I presume, handles them by not increasing the pressure, it must win in this category. This also may be why the AI count is higher for the S9 than the S8. In contrast, the S8's HI count is way higher than the S9's count, so either the counting algorithm has been updated or the S9 handles HIs better -- maybe both.

Conclusion
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My ideal combination for sleep quality is the S9 with the SleepZone heated tube. If I didn't want, or couldn't get, the SleepZone tube, the S9 with the climate line is much better than the S8 without the heated tube. The quality of sleep for the S9 is better for me, probably due to the detection of central apneas, but only by a smidgen (or few percent).

Is this worth the upgrade? For me, probably. I would caveat this

For me, the cost of the upgrade is not a factor for me and alertness in my day-to-day job is a premium for me. So the benefits outweigh the costs. If cost was a factor -- and for many people it is -- then I would stick to the S8 with the SleepZone heated tubing. The S8 with a heated tube is pretty much identical to the S9 with a climate line.

If you run both under the bed rather than on the bedside table (and about a foot away from your head), then the difference in noise becomes negligible. Likewise, if you have zero central apneas, so all your apneas are obstructive, then I can't imagine there being any difference between the S8 or S9, so there'd be no point in upgrading. However, if rain-out's a real problem (as it was for me) and you can't, or won't, get a heated tube for the S8, then the S9 is with its climate line is the way to go.

Final Caveats and Waivers
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All this is one person's subjective view and not a scientific study. Your experience may well differ.

Good review, did you find the 95th percentile pressure any different between the two?

And a good question!

Embarrassingly, I haven't checked the 95th on the S9, but I will tomorrow. My 95th on the S8 is usually between 9.5-11.5. One thing I did notice, speaking about pressure, is that after the settling period the S8 tends to gently rise and there have been times when, after 20 or so mins of trying to fall asleep, I've found the pressure to be around 7 or so and have had to hit the button to switch it off and then back to settling in order to get to sleep. The S9 seems to remain on 4.6 longer, presumably rising after I fall asleep or if it needs to ramp up. On the falling-asleep factor, the S9 is a major improvement.

I have found no difference in the EPR, which I have set to 2.

One final thing - either machine is excellent and both are WAY BETTER than sleep apnea! I recall after my first week of using the S8 thinking how I got my life back.

There's another important difference. Since the S8 can't differentiate between obstructive and central apneas, it assumes that any apneas that occur at a pressure of 10 or higher are centrals, and these apneas do not result in pressure increases. The S8 will respond to flow limitations and snores at pressures at or above 10. But the S8 becomes much less aggressive at increasing pressure once the pressure has reached 10.

I happen to have the ResLink module, which allows me to see snores and flow limitations in ResScan. And while I can clearly see a pressure response to snores (quite aggressive responses, actually), I have been unable to see any relationship between the flow limitation graph and pressure changes. None at all.

Interesting. That means one should see pressures above 10 with more frequency on the S9 for obstructive apneas since it should be able to differentiate between the two and aggressively treat the obstruction; plus be able to ignore the central apnea.

I have the ResLink module on my old S7 Auto and the ResLink module for the S8 is quite hard for me to get.

Since the new S9 can now tell the differnce between central and obstructive apneas I would execpt that the 95th percentile pressure to be
little bit higher on the S9 but I am not sure what the S9 algorithm will tell the macnine to do.

Banjo,

On your S8 your stated that the pressure started to increase before you went to sleep as compared to the S9 which stays at the lower pressure longer.
Maybe the S9 sensitivity to flow limtations or HI events have changed and therefor the scoring is different as well?

I do find that on my S7 ResLink I do find that the flow limitation graph follows with pressure changes when the flow limitation get bad enough the pressure will jump and it is not a smooth transition.

Take a look at these ResScan graphs from an S9 that I found in another thread. The pressure is way above 10, and yet the response to obstructive apneas is aggressive. An S8 would not perform this way.

viewtopic.php?f=1&t=52063&st=0&sk=t&sd= ... 15#p480970

Well - checked the 95th for the last week on the S9 and it was at 9.6 -- which is about 1 lower than what the S8 usually gives. Also, last two days, the AI index has come down somewhat, but still getting about 1-2 central apneas a night. From the discussion above, it looks like they've really improved the algorithm. This, coupled with the climate line, means that as a choice between the two the S9 is probably worth the additional money if you can afford it; but as a complete upgrade from a new S8 -- if you're cost conscious -- then the incremental improvement is probably not worth the total outlay. I'm still going to purchase the S9 and use my S8 as a backup. For me, the additional alertness, however slight, is worth the cost.

Sorry about above post - didn't log in... maybe I'm not as alert as I think I am...

jdm2857 wrote:Take a look at these ResScan graphs from an S9 that I found in another thread. The pressure is way above 10, and yet the response to obstructive apneas is aggressive. An S8 would not perform this way.

viewtopic.php?f=1&t=52063&st=0&sk=t&sd= ... 15#p480970

Those charts are inconclusive because I noticed that the flow and the minute ventilation are going all over the place indicating a leak somewhere. Noticed that the snores also where high during that period. Most auto CPAP's will chase snores to the maximum if it has to. The obstructive apneas chart is not valid until other issues are resolved. This may have been a mouth leak that is confusing the S9.

Follow up:

Rang ResMed Australia (SleepVantage) and was told that, at least in Australia, for an additional $99 you can get the 5 year warranty on the S9

Final Update

OK, it's now been a month and I can add update some of my observations.

• Climateline - I found by bumping the temperature of the hose up, not down, I reduced the rain-out in the tube as much as the S8 II with heated hose;
• Sleep quality between the two is similar, although the S9 reports a higher AI count, typically, than the S8, and virtually no HI whereas the HI count on the S8 seems to be a random number between 0.2 and 2.2...

So, will I be buying the new S9?

I was so intent to buy it at the beginning of November (shiny and new), but now I'm not so sure. There have been more than a few nights on the S9 where the day after was terrible, as can happen on my S8. I've adjusted for leaks, looked at other mitigating factors, but the initial 'Wow - this is much better than my S8' has been toned down to a 'Well, maybe handles the one or two central apneas I get a night and that's about it.'

The rented S9 is marginally quieter, I believe, than my S8 II and doesn't have that slight chirp at the beginning/end of each breath that I sometimes get with the S8, particularly if the room is cold. But do we overstate the need for a xPAP to be completely quiet? A little while ago I undusted my old, old backup CPAP (an S8 Escape), changed the filter and used it for a night. Now, this is the 2006 model rated at a 'loud' 32 decibels which I bought as a backup. Because it's meant to be louder than both the S8 II (24-26) and the S9 (24) it shouldn't have worked so well and yet.... after an initial 1/2 hr of getting used to the sound, I slept through the night quite comfortably with it... indeed, soundly slept, to coin a phrase.

So maybe we (or I) overemphasized the need for quiet in the therapy side of it.

My final thoughts? I will analyze the numbers with my doctor on the 13 Dec, but unless they are quite convincing, I believe I will stick with my trusty S8 Spirit II and the heated hose for a few more years. As of today, I'm not seeing a compelling case to upgrade from it to the S9. **

** this is said, of course, with the great strength and resolve of one not surrounded by all the shiny and new equipment on display. Come the 13th, I could well be whistling a different tune, such is my 'fortitude'.