Altitude problem with Resmed S9 VPAP Auto

Help! I travelled from sea level up here to an altitude of 7,000 feet (Bear Valley California) two days ago with my VPAP Auto. The first night I detected a whine in the machine portion of the VPAP. Last night (the second night) the whine seemed louder. It is rhythmic and occurs only with my expiration. However, it is not related to leaks at all, does not occur in the tubing or humidifier, but INSIDE the engine portion. This has never happened before with this machine. I have committed to stay here for six - eight weeks to help a family member. Please help me understand what is going on. I have diagnosed severe sleep apnea and cannot continue without my machine. (I also notice my centrals have worsened considerably, but first problems first!)

Perlina wrote:Help! I travelled from sea level up here to an altitude of 7,000 feet (Bear Valley California) two days ago with my VPAP Auto. The first night I detected a whine in the machine portion of the VPAP. Last night (the second night) the whine seemed louder. It is rhythmic and occurs only with my expiration. However, it is not related to leaks at all, does not occur in the tubing or humidifier, but INSIDE the engine portion. This has never happened before with this machine. I have committed to stay here for six - eight weeks to help a family member. Please help me understand what is going on. I have diagnosed severe sleep apnea and cannot continue without my machine. (I also notice my centrals have worsened considerably, but first problems first!)

some of the s9 machines have a bit of a whine/resonance, typically on exhale, it seems to vary with pressure and airflow, and the hose, I've had four of them and it's not consistent.

basically, I don't think that there's anything to worry about, with the machine, it does have to work harder to get to a pressure than when you're back home, so it may be moving into that noisy area, it'll probably go back to being quiet when you get back down where you're used to being.

Thank you for the reassurance, pale rider. Do you - or does anyone - know if centrals would go up in altitude?
Perlina

A couple of weeks ago I went camping at around 10,000 ft in Utah. I wondered about an increased chance of centrals too but my PR S1 machine didn't show any increase in centrals at all and in fact one night didn't have a single one. I almost always have a couple of centrals which are probably related to sleep onset or maybe tossing and turning a bit.
I think the chance of the CO2O and oxygen imbalance is likely greater at altitude but a lot of it is going to depend on a person's own body and how the balance happens to go. Some people might be more prone to having that imbalance than others and altitude could make it worse.
Though I don't think that it is a given that everyone always has problems with centrals at altitude. I sure didn't. YMMV though.

Thanks, Pugsy!

The whine is related to the fact that in the thinner air the blower impeller needs to spin faster to provide the pressure boost your therapy requires. So faster speed = more noise.

With all that goes on with your insufficient hemoglobin to handle the thinner air upon suddenly changing altitude, it's a wonder you slept normally at all. Altitude changes of over 5000' always leave me headachy and lethargic for about a day.