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+--- Thread: Resmed A10 Pressure runup without apparent cause (/Thread-Resmed-A10-Pressure-runup-without-apparent-cause)
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Resmed A10 Pressure runup without apparent cause - Ed1101 - 04-02-2016
My A10 occasionally starts a pressure increase from my minimum of 15 to 20 in a matter of a few minutes. My usual 95% pressure is less than 16.5 cm and only increases from 15cm due to certain flagged events. Normally appears to increases by about 0.5 cm per event. Often this "run away" increase is after first startup at night or a restart after standby. The is no apparent events and the flow limit is below 0.25 with leaks ~10 L/min. Usually if I have gone to sleep, the mask blow-out will wake me and I will put the unit in standby monentarily and then restart and all will be ok. Occurred 4 times this past week - twice in one night. This is a new replacement unit. The first unit died but did not exhibit the pressure runaway as evidenced by review in Sleepyhead over first 30 days of use.
Anyone experienced pressure run away with their A10.
RE: Resmed A10 Pressure runup without apparent cause - sonicboom - 04-02-2016
Yes - but at pressure less than 10 with max settings less than 10 and the machine blowing past set maximums to 10. Determined to be caused most likely by rainout conditions. See this thread:
http://www.apneaboard.com/forums/Thread-airsense-10-autoset-malfunction
RE: Resmed A10 Pressure runup without apparent cause - zonk - 04-03-2016
(04-02-2016, 10:49 PM)Ed1101 Wrote: Anyone experienced pressure run away with their A10.My A10 tend to have this tendency, no leak or rain
Never had this issue with the S9
I had to lower the top number and only allow it to go as high as necessary for best results
RE: Resmed A10 Pressure runup without apparent cause - Ed1101 - 04-03-2016
Reviewed one of the graphs in Sleepyhead and in ResMed 5.5 that show ramp up of pressure.
The SH graph expanded:
![[Image: bIyYzfT.png]](http://i.imgur.com/bIyYzfT.png)
The ResMed 5.5 Graph expanded (same time range):
![[Image: 1GHdU4w.png]](http://i.imgur.com/1GHdU4w.png)
Initially, I only looked at SH detail graph. The SH flow limit graph does not seem to indicate a limit at first look, but I assume the flat tops mean that there is a flow limit. I had assumed that the graph would go to 1.0 or max out on the 0.0 -> 0.05 scale. The ResMed graph seems to show the flat top characteristic of a flow limitation.
Perhaps this explains the ramp-up. I use heated hose and loops above my head in "U" around bed post - rainout unlikely.
Can someone tell me how to interpret the SH flow limit graph?
RE: Resmed A10 Pressure runup without apparent cause - vsheline - 04-03-2016
Hi Ed1101,
Regarding terminology, there is no such thing as a Flow Limit graph. There is a Flow Limitation graph which plots how much the Flow graph is exhibiting the symptoms of Flow Limitation (FL).
The Flow graph shows the rate (volume per second) at which we are inhaling air into our lungs (positive Flow) or exhaling air (negative Flow).
FL is occurring when the positive portion (the inhalation portion) of the Flow graph shows flattening instead of a normal rounded hilltop shape.
FL indicates our airway is partially obstructed and the suction created by inhaling is causing the airway to narrow further, such that increased breathing effort yields the same or less Flow.
If FL does not lead to hypopnea FL can still lead to Respiration Effort Related Arousal (RERA) which is an awakening or arousal into a shallow stage of sleep caused by having to exert excessive breathing effort.
Increasing the inhalation pressure (IPAP) tends to prevent FL.
RE: Resmed A10 Pressure runup without apparent cause - green wings - 04-03-2016
Ed,
What does that SH graph look like for the time period ~0409-0412? Did you say that the flow rate waveforms have flattened tops?
RE: Resmed A10 Pressure runup without apparent cause - PaytonA - 04-03-2016
One additional note. The pressure increase does seem to follow the flow limitation graph both increase and decrease. Looks very much to me like the machine is responding to flow limitations.
Best regards,
PaytonA
RE: Resmed A10 Pressure runup without apparent cause - palerider - 04-03-2016
(04-03-2016, 02:55 PM)Ed1101 Wrote: Can someone tell me how to interpret the SH flow limit graph?
you interpret it the exact same way as the resscan graph. higher is worse.
the 'flat tops' you seemed to be referring to are in the *flow* graph, when you zoom in far enough to see the individual breaths.
RE: Resmed A10 Pressure runup without apparent cause - Ed1101 - 04-03-2016
(04-03-2016, 05:34 PM)green wings Wrote: Ed,
What does that SH graph look like for the time period ~0409-0412? Did you say that the flow rate waveforms have flattened tops?
Not sure what you are asking. Do you mean expanded further than shown? The flow limitation graph waveform has flattend tops to a degree. I'll look at the flow rate graph closer. Do not know if the flow rate waveform has flattened tops.This looks like my normal Flow rate waveform, flat tops on them normally:
![[Image: boe48iP.png?1]](http://i.imgur.com/boe48iP.png?1)
(04-03-2016, 05:50 PM)PaytonA Wrote: One additional note. The pressure increase does seem to follow the flow limitation graph both increase and decrease. Looks very much to me like the machine is responding to flow limitations.
Best regards,
PaytonA
I have used the SH software for about a month. As I stated I had assumed, apparently erroneously, that the flow limitation graph would expand to take the whole chart range if there was a flow limitation. Now I think I understand that any value above 0.0 indicates some degree of flow limitation that the machine is attempting to eliminate by increasing pressure if the limitation as great enough to trigger the pressure increase. Is my understanding correct?
(04-03-2016, 05:59 PM)palerider Wrote:(04-03-2016, 02:55 PM)Ed1101 Wrote: Can someone tell me how to interpret the SH flow limit graph?
you interpret it the exact same way as the resscan graph. higher is worse.
the 'flat tops' you seemed to be referring to are in the *flow* graph, when you zoom in far enough to see the individual breaths.
I understand that higher is worse. How high would one expect it go if no air is flowing and what is the meaning of the "flat tops" on the flow rate graph? I do not understand the scale on the flow limitation chart.
Thanks for the explanation Vsheline, but I do not see a positive and negative on the flow limitation graph only what appears to be positive?
RE: Resmed A10 Pressure runup without apparent cause - Ed1101 - 04-03-2016
Seems trying to add a chart , I inadvertently posted twice and I cannot delete. One should not be logged in on iPad and then add image on computer without logout on iPad first. See post #9 for chart and reply.