Apnea Board Forum - CPAP | Sleep Apnea
[Symptoms] Low tidal volume (every night) - Printable Version

+- Apnea Board Forum - CPAP | Sleep Apnea (https://www.apneaboard.com/forums)
+-- Forum: Public Area (https://www.apneaboard.com/forums/Forum-Public-Area)
+--- Forum: Main Apnea Board Forum (https://www.apneaboard.com/forums/Forum-Main-Apnea-Board-Forum)
+--- Thread: [Symptoms] Low tidal volume (every night) (/Thread-Symptoms-Low-tidal-volume-every-night)



Low tidal volume (every night) - smfkdol9392 - 08-06-2022

My nightly median tidal volume hovers around 200 or less, which is apparently that of a 4 foot person (I am 6 feet tall).

My doctor is uninterested in this statistic when I have brought it up with him, but it worries me because I feel something is wrong. I also have an anxiety disorder, and I am not sure if this low tidal volume is contributing to this disorder or if there is a way to improve my anxiety by increasing my tidal volume. Also, I have found no information about low tidal volume other than in regards to people who are intubated.

Does anyone have some insight? I am basically just looking at a statistic I know nothing about and my doc isn't really offering any clues or even reassuring me that everything is fine. So I have turned to this community.

I have attached a typical night of sleep. I am not tired during the day, things are going well other than this possibly ominous statistic and my possibly related anxiety.


RE: Low tidal volume (every night) - car54 - 08-06-2022

Your low tidal volume is because you have low minute volume.
Minute volume is the amount of gas inhaled or exhaled from a person's lungs in one minute.
The tidal volume can be increased by extending you exhalation time but generally your minute volume will remain the same. This can be done by setting your PR to 3 on your machine.

Low minute volume is, I believe, determined by your age, sex, weight, medications and health issues like lung problems. I know when I use oxycodone my minute volume goes down.

I am sure other members will reply also.


RE: Low tidal volume (every night) - pholynyk - 08-06-2022

Tidal volume and minute vent are relate by a mathematical formula which includes breaths per minute.

Your respiratory rate is more or less normal, so we look at tidal volume and investigate why is is low.

Normally we might increase pressure support, but you are using EPR = 3, the maximum available. Short of moving to a bi-pap like the vAuto, I don't have any ideas. I think a referral to an ENT or pulmonologist would give you more information to work on.


RE: Low tidal volume (every night) - Crimson Nape - 08-06-2022

You might try a version of PEEP (positive end-expiratory pressure) to increase your tidal volume. The basic idea is to increase your exhale pressure above what is needed to address your apnea. Currently, your EPAP pressure is running between 7 and almost 9 cm. You might try setting your pressure range up to 15 to 18 cm. This will then give you an EPAP pressure range of 12 to 15 cm, with your EPR of 3. One night's data will tell if this has a positive effect.

Good luck!
- Red