6 hours ago
Acceptable AHI with worrying minute ventilation / tidal volume
Hi, new user of the forums, 3 months on CPAP.
Tested at 22 AHI when I was initially diagnosed, entirely obstructive. My obstructives completely disappeared with use of CPAP, but I did pick up about 2-3 central apneas per hour. I think my sleep quality is still lacking too - it's hard for me to judge, because it's better than it was previously, and I'm only 27 so I wouldn't be surprised if I've always had apnea, but I do find myself napping even after a solid nights sleep. Of course, that might just be because I need better sleep hygiene...
My doctor is not particularly attentive, so I did end up adjusting the clinical settings myself. I'm currently using EPR of 0, but have tried all levels of it, and have tried raising my pressure minimum a few times to 6/7/8, but have found that increasing my pressure only increases my centrals, not doing anything for the statistics I'm concerned about. We also did an overnight oximetry with CPAP a few weeks ago, but my doctor did not give me the detailed results for that, only that it was better than before I went on CPAP.
The statistics I'm concerned about are minute ventilation / tidal volume / respiratory rate. My respiratory rate concerned me prior to CPAP and actually was what drove me to initially ask my doctor about CPAP (along with both my parents having OSA and one of those cheap overnight pulse oximetry things measuring me with ). Basically, my smart watch was suggesting that when I went to sleep, my average respiratory rate jumped from around 12-13 brpm to ~16-17, though it doesn't have the resolution my data in Oscar does. This has not resolved with CPAP. My median respiratory rate while sleeping ranges from 17-19 brpm, where it's low when I'm awake, shoots up to a steady 18-ish when I'm asleep, and can hit 30 for extended periods of time at times when I'm sleeping and there are no flagged events. Meanwhile, my median tidal volume is 280-320, and during these hyperventilation periods can drop as low as 200. Starts high when I'm awake too then plummets for sleep. I did calculate what tidal volume I'm supposed to have based on height and ideal body weight and got 380. My minute ventilation is also a bit odd. I've read elsewhere on the forum that the expected range for sleep minute ventilation is 5-8 l/min. Mine is, by median, between 5-6, but again, there are a lot of times throughout the night where it dips down into the 3-4 l/min range, especially associated with the hyperventilation periods. Other than apnea, my only known conditions that could be influencing this are an anxiety disorder (though I don't ever hyperventilate from it when I'm awake), no lung disorders or anything.
Again, my doctor thinks this is all perfectly fine (Or, well, she's not interested in looking at the charts). Maybe it is? I've added a couple screenshots, one from a timepoint where I was breathing pretty steadily though still shallowly, and one from a timepoint where my breathing was a lot more erratic. Do you guys see breathing like this often?
Thinking about trying EERS - I've read the wiki entries on it, and it seems it does often have the effect of upping minute ventilation and tidal volume while dropping respiratory rate? Just nervous that it won't work and then I'll have ruined a mask elbow and bought the modification stuff for nothing.
Tested at 22 AHI when I was initially diagnosed, entirely obstructive. My obstructives completely disappeared with use of CPAP, but I did pick up about 2-3 central apneas per hour. I think my sleep quality is still lacking too - it's hard for me to judge, because it's better than it was previously, and I'm only 27 so I wouldn't be surprised if I've always had apnea, but I do find myself napping even after a solid nights sleep. Of course, that might just be because I need better sleep hygiene...
My doctor is not particularly attentive, so I did end up adjusting the clinical settings myself. I'm currently using EPR of 0, but have tried all levels of it, and have tried raising my pressure minimum a few times to 6/7/8, but have found that increasing my pressure only increases my centrals, not doing anything for the statistics I'm concerned about. We also did an overnight oximetry with CPAP a few weeks ago, but my doctor did not give me the detailed results for that, only that it was better than before I went on CPAP.
The statistics I'm concerned about are minute ventilation / tidal volume / respiratory rate. My respiratory rate concerned me prior to CPAP and actually was what drove me to initially ask my doctor about CPAP (along with both my parents having OSA and one of those cheap overnight pulse oximetry things measuring me with ). Basically, my smart watch was suggesting that when I went to sleep, my average respiratory rate jumped from around 12-13 brpm to ~16-17, though it doesn't have the resolution my data in Oscar does. This has not resolved with CPAP. My median respiratory rate while sleeping ranges from 17-19 brpm, where it's low when I'm awake, shoots up to a steady 18-ish when I'm asleep, and can hit 30 for extended periods of time at times when I'm sleeping and there are no flagged events. Meanwhile, my median tidal volume is 280-320, and during these hyperventilation periods can drop as low as 200. Starts high when I'm awake too then plummets for sleep. I did calculate what tidal volume I'm supposed to have based on height and ideal body weight and got 380. My minute ventilation is also a bit odd. I've read elsewhere on the forum that the expected range for sleep minute ventilation is 5-8 l/min. Mine is, by median, between 5-6, but again, there are a lot of times throughout the night where it dips down into the 3-4 l/min range, especially associated with the hyperventilation periods. Other than apnea, my only known conditions that could be influencing this are an anxiety disorder (though I don't ever hyperventilate from it when I'm awake), no lung disorders or anything.
Again, my doctor thinks this is all perfectly fine (Or, well, she's not interested in looking at the charts). Maybe it is? I've added a couple screenshots, one from a timepoint where I was breathing pretty steadily though still shallowly, and one from a timepoint where my breathing was a lot more erratic. Do you guys see breathing like this often?
Thinking about trying EERS - I've read the wiki entries on it, and it seems it does often have the effect of upping minute ventilation and tidal volume while dropping respiratory rate? Just nervous that it won't work and then I'll have ruined a mask elbow and bought the modification stuff for nothing.
But I did have it concurrently with CPAP for a while, and saw drops in O2. Not the greatest data quality which is what prompted the O2 test, but my doc didn't give me the actual results for that, just 'it's better than before you went on CPAP so don't worry about it.'
