Interpreting data?

[131]

Thanks everyone, after a week of browsing I've learnt a heap, but I've got a couple of questions on data. From my sleep study my AHI was 95, the comment from the specialist was "Snoring and very severe predominantly OSA, which was associated with oxygen desaturation."

I can't display a graph because my kids have downloaded over 100Gb of data this month, exceeding our quota!

A quick glimpse of last nights' data:

Philips Respironics
System One 551P
RemStar Auto with A-Flex
Date Sleep Wake Hours
14/11/2011 22:51 05:47 06:55:49
AHI 11.69
Hypopnea 4.76
Obstructive 0.43
Clear Airway 6.49
RERA 1.88
FlowLimit 0.14
Vsnore 0.00
PB/CSR 5.40%
Min Avg 90% Max
Pressure 4.00 5.55 7.00 8.00
Leaks 15.00 17.98 21.00 32.00
Snore 0.00 0.00 0.00 0.00

What do all the numbers mean?
Leaks. What are the units and what does it mean? What's acceptable?
RERA? Couldn't find it in the definitions.
PB/CSR?
Flow limit?
After 2 weeks of APAP my average Obstructive apneas is 0.89 but my CA is 11.89 and Hypopnea 5.38, will these come down in time or does something need to be changed?

The "couple" of questions turned into quite a few, sorry about that.

[turbosnore]

RERA is there:

"RERAs: Respiratory effort related arousals. Episodes that are not apneas or hypopneas, often related to loud snoring, that generally do not cause a decrease in oxygen saturation."

I believe there is not much that can be done to CA.
They are mostly (I think) centrals.

[robysue]

My comments about the data are in RED

A quick glimpse of last nights' data:

Philips Respironics
System One 551P
RemStar Auto with A-Flex
Date Sleep Wake Hours
14/11/2011 22:51 05:47 06:55:49
You turned the machine on 10:51 pm, turned it off at 5:47 am, and the machine was running for 6:55 during that period
AHI 11.69
Overall, the machine was detecting an average of 11.69 apneas+hypopneas per hour. That is definitely lower than your diagnostic, but still much higher than the desired AHI < 5 with therapy. If this is just one isolated "bad" night, that's one thing, but if you are seeing AHI's that look like this night after night, then this is something to worry about.
Hypopnea 4.76
The machine was detecting an average of 4.76 hypopneas per hour. In my humble opinion, this is still high---if you are seeing this kind of number night after night.
Obstructive 0.43
The machine detected an average of .43 obstructive apneas per hour. This indicates that the machine was doing a good job of controlling the obstructive apneas.

One thing about the HI and OA together: It is worth looking at the ratio of H to OA on your diagnostic sleep study. One expectation on the titration study is that as the pressure increases, the OAs should turn into Hs and as the pressure is increased further, the Hs should be eliminated altogether (on a "great", perfect night).
Clear Airway 6.49
The machine detected an average of 6.49 CAs per hour. The machine believes your upper airway was open (clear) during these apneas and so the presumption is that they are central apneas---i.e. apneas caused by your brain forgetting to send the signal to breathe. While a few CAs are not uncommon (and even "normal") during the times we are transitioning to sleep, lots of CAs happening all night long are not. We really need a graph of the events to even begin to speculate on whether the pattern of your CAs is worrisome.

But in my humble opinion, if you believe you were asleep most of the time the machine was running and there's no clear pattern connecting the CAs to wakeful/transition periods of your sleep, then this is a potentially big problem and ought to be reported to your sleep doc. Did your sleep test mention anything about central apnea or complex apnea?
RERA 1.88
RERA stands for Respiratory Effort Related Arousal. Think of it as a wannabe hypopnea. The PR attempts to score these by looking at the wave form; but without the EEG evidence a sleep lab uses to score them, it's not that clear how accurate the RERA index is. However, you machine scored an average of 1.88 RERAs per hour.
FlowLimit 0.14
Flow limitations are changes in the inspriatory part of the wave flow that are known to be indicators that the airway is compromised
Vsnore 0.00
PB/CSR 5.40%
The machine detected period breathing during 5.40% of the night. Since the machine was running for almost 7 hours, that's almost 21 minutes of periodic breathing. Periodic breathing is a particular waxing/waning breathing pattern that can be associated with congestive heart failure. It's not uncommon to have a bit of this every now and then. But if you are seeing this kind of percentage night after night, it's an issue. Particularly if your CAs tend to be scored at the lowest parts of the waxing/waning cycle.
Min Avg 90% Max
Pressure 4.00 5.55 7.00 8.00
You're running in APAP mode. Your average pressure was 5.55 cm and your 90% was 7.00cm. At some point the pressure got as high as 8cm
Leaks 15.00 17.98 21.00 32.00
Leaks are measured in Liters/min. Your average TOTAL leak was 17.98 L/min; your 90% leak rate was 21.00 L/min. At some point the machine detected a leak of 32.00 L/min. My guess is that these leak numbers are very acceptable given your pressure range of 4--8 cm
Snore 0.00 0.00 0.00 0.00
No snoring, which is good
What do all the numbers mean?
Leaks. What are the units and what does it mean? What's acceptable?
RERA? Couldn't find it in the definitions.
PB/CSR?
Flow limit?
After 2 weeks of APAP my average Obstructive apneas is 0.89 but my CA is 11.89 and Hypopnea 5.38, will these come down in time or does something need to be changed?
If it's been two weeks and your CA is averaging close to 12, I think it is time to call the sleep doc and report the CA index is awfully high

The "couple" of questions turned into quite a few, sorry about that.

[rmeyer23]

Robysue

Wow, great information here on the data. Thanks for breaking all of this down. I was looking on how to read the data and this was very helpful

Ron M

[131]

G'day Robysue,
Thank you so much for your detailed reply. I've since done some homework, read some of your blog, very helpful, and organised a meeting with my sleep tech on Monday. From my sleep study report the findings were:

Patient exhibited fragmented sleep architecture throughout his home diagnostic sleep study. He had a sleep efficiency of 86% with a prolonged sleep latency of 60 mins. Rem proportion was reduced. Sleep was predominantly in the lateral positions and supine REM was not seen.
Severe respiratory disturbances were noted with an AHI of 95/hr, 97/hr whilst supine and 95/hr in REM. Central events were predominantly apnoeic in type, worse in NREM and whilst sleeping laterally. These events were associated with an average oxyhaemoglobin desaturation of 5% with a nadir saturation at 84%. Average saturation during the study was 93%. The desaturation index was elevated at 84 events/hr.
Mild snoring was observed throughout the night. ECG normal sinus rhythm was observed throughout the study with a baseline heart rate of 87bpm.

Sleep period 420 minutes.
Respiratory events.
Obstructive 169
Central 205
Mixed 253
Total apnea 627
Hypopnea 18
Total 645


Conclusion:
Given the severity of sleep apnea, treatment with CPAP is indicated. If there are residual central apneas despite CPAP, recommend sleep physician review.

17 days worth of data has my averaged AHI @ 16. 85, OAs are below 1, CA @ 10.7 and H @ 5.28. The lowest my AHI has been during treatment is 6.75, the highest 36.3.
When I rang my tech and said i was concerned about the number of Centrals, he asked me if I'd been looking at the daily data on the machine, he seemed surprised that I had software allowing me to see my data. Dealing with electronic instruments, dataloggers and software is my job, it now also includes my health, no way am I not going to find out what's going on. I want my reviewing physician to look at my data, if the tech won't refer it, I'll go back to my GP and ask him for a referral to a local sleep specialist.
I've purchased an S9 Autoset, but may have jumped the gun. Does the Autoset have the bells and whistles required to deal with the residual centrals I have, or do I require an ASV capable machine?

[jamiswolf]

131 wrote: Does the Autoset have the bells and whistles required to deal with the residual centrals I have, or do I require an ASV capable machine?

No. the autoset cannot deal with central apneas. That requires a machine with a timed back-up rate that will initiate a breath if you haven't breathed in a specific set period of time. ASV maqchines will do that (no such thing as asv capable...either asv or not) and BiPap ST and AVAPS machines also have that capability. I'm more familiar with Respironics machines but there are probably others.
Jamis

[131]

Okay, I've worked out how to post data up. After reading plenty of posts about centrals, hypopneas, cheynes stokes breathing, VPAP etc. I asked my sleep tech about the data I'm getting, because my OAs are below 1, he was happy with the treatment. The following is a sample of last nights data, it's fairly typical of sections of data from the last month.



I'll be in Melbourne in mid December and I have an appointment with a sleep specialist to review my data. Is this the sort of trace I should be showing him and voicing my concerns?



An overview of the last month.