Posted by Chris M. on 3/18/2008, 12:07 am
72.251.73.155

I was a little disturbed by a suggestion recently that maintaining an oxygen level above low 90's was dangerous. First, I was addicted to oxygen at birth, with my first breath. Oxygen toxicity doesn't occur under normal conditions and I tend to maintain upper 90's for my own use and have done so under the care of my Pulmo who's been delighted I manage that. I use an oximeter. Without oxygen supplementation I drop rapidly into the 70's. I have severe emphysema with an asthmatic overlay. I have taken Pulmonary Rehab and learned pursed lip breathing and do it almost unconsiously now. I am on 3.5liter of oxygen and live at 4320' elevation with no trouble. At rest my PO2 level is 98% +-. When walking a treadmill or exercising I use 5 lpm of O2 and maintain around 92-94% oxygen levels. If I drop into 80's I call it short of breath and slow or stop to recover. Since my diagnosis of severe COPD and Secondary Pulmonary Hypertension (mild to moderate)almost 8yrs ago, little has changed , other than if I don't exercise each day, I get minor edema in my right foot. I use Spiriva, Foradil from ADC and 40 mg of furosemide if I experience any edema along with some Potassium Klor Con. I don't add sodium to anything. Sitting here my oxygen level is 99 with an 82 bpm. Everything I have heard about oxygen toxicity is that it occurs with pressurized oxygen on intubated patients and very small infants with under developed lungs, or to divers and potentially some astronaughts. Normal oxygen levels for normal air is 21%. When barometric pressures drop, oxygen levels drop too. But normally it's 21%. With increased liters per min. we might be increasing our oxygen levels to 30-35% I heard. But my lungs are 60% less functioning than a normal person because of my COPD. Oxygen, I understand, can become toxic for divers wearing special equipment to pressurised levels of .5 bar. Our oxygen is at .3bar. (no one has yet explain the "bar") In emergencies, we might be taken up with rebreathing masks and intubation techniques, closer to pure oxygen under pressure. THEN we hope someone is watching for toxicity. But that takes days of pressurised oxygen to reach problem levels. In all probability one is having severe cardiac problems as well. Naturally everyone jumps to the argument of building CO2 levels. Yes, if I am not breathing out CO2 adequately, I could be in trouble with normal oxygen levels. CO2 levels build dramatically when folks stop breathing, have cardiac problems, slow when folks stop moving and triggering normal breathing. It is important to discuss with your Doctor to know if you are retaining CO2 or have such a tendency. It also means you need to ensure you have no serious cardiac problems.Anyone who is bedridden may have different circumstances. Perhaps a secondary problem such as obesity, or an inability to exercise may obscure normal breathing. Inability to exhale is critical. Tom Petty who cheered for personal use of oxygen did not believe oxygen is toxic at any level under personal use of oxygen. I do not believe I wish to treat myself to lower levels of O2 under some question of toxicity, because I don't believe I am at risk. When I am walking around in my home at a normal pace I will stay at about 95sat. So far in 8yrs I haven't had to change this. If I go to Tucson, which is about 1000' lower elevation, I can drop .5 lpm (3lpm)and remain at 98+- oxygen sat while sitting...

Link: Anouther view of home oxygen