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+--- Thread: Do I have actual Flow Limitations based on the OSCAR Reports? (/Thread-Do-I-have-actual-Flow-Limitations-based-on-the-OSCAR-Reports)
Do I have actual Flow Limitations based on the OSCAR Reports? - Feelrefreshed - 02-07-2021
Hi. I was diagnosed with sleep apnea in 2006 and up until December 2019 I used a Respironics RemStar BiPAP Auto with Bi-Flex or a dental device, depending on whether I was congested. I've had Centrals, Obstructive Apneas. Without any PAP machine my apneas are 30 according to a home test in the summer of 2019. I am 68 years old. Starting December 2019 I was prescribed various devices including ResMed Aircurve 10 VAuto, ST, ST-A and a Dreamstation ASV. My apneas remained well above 5 AHI and I continued to have central apneas with all those devices. Finally at the end of December 2020 I received a ResMed Aircurve 10 ASV and my AHIs have been below 5 fairly consistently. One night it was even < 1. However, I sometimes still feel drowsy in the afternoon and do not feel refreshed in the morning (I don't think I have ever felt refreshed in the morning). Do I need to give it more time or is my problem Flow Limitation? I do feel noticeably better when I sleep 9 or 10 hours, even with Flow Limitations on OSCAR. Here are a couple recent OSCAR results. Thank you, Feelrefreshed.
RE: Do I have actual Flow Limitations based on the OSCAR Reports? - Sleeprider - 02-08-2021
You have a number of flow limitations indicated on your Oscar chart, however ASV presents a special case. Your ASV is currently setup at default settings and we can probably improve your results a bit, but let's explain the flow limitations first. With ASV, the respiration volume and rate are maintained by a combination of spontaneous effort and the machine's use of pressure support to supplement missing or low-volume breaths. When pressure support replaces spontaneous effort, that really means your lungs are being inflated by the positive air pressure from your ASV. This typically results in an inspiratory wave form that is flattened rather than a rounded form that is typical with spontaneous inspiration and a lack of inspiratory flow resistance. The flattening occurs because as your lungs inflate, resistance to inflation increases in a way ASV cannot overcome, so the flow rate slows down. If you look at the flow rate chart in a zoomed view where you can see individual breaths, and place the mask pressure and flow limit charts under it, you will see very clearly, that when you breathe spontaneously and pressure support is low, the respiratory wave will look normal. When the machine is supplying pressure support, you will see increasing flow limitation with increasing pressure support. This is normal on ASV, and we don't try to change it.
Your machine is setup at default values and my recommendation is to simply increase the EPAP min to 5.0 to clean up some of the hypopnea. This suggestion is consistent with the titration protocol recommended for your machine, and I'm sure your doctor would agree if you prefer to ask him or her about this change. See the decision tree below under "Obstructive events eliminated?" For hypopnea increase EPAP by 1-cm.
RE: Do I have actual Flow Limitations based on the OSCAR Reports? - Feelrefreshed - 02-08-2021
Thank you so much! I just sent a donation - you all are amazing.
RE: Do I have actual Flow Limitations based on the OSCAR Reports? - Sleeprider - 02-08-2021
Feelrefreshed, the donation is greatly appreciated. This site relies on donations to pay for the servers that allow us to help members, and without support from the membership, that would not be possible. We all volunteer our time and enjoy working with members, new and old. Again, Thank you very much.