Scary

K looked over at Mandy last night, as she was getting just one more thing before sitting down on the couch for a casual dinner. K realized that the dog had gotten into the pile of pills she'd prepared, to take with dinner. Some of those pills could easily kill an 11 pound dog. K couldn't remember which pills she'd laid down, or which ones she'd already taken, so the situation quickly spun up into an emergency. We weren't yet fully prepared for a dog health emergency, so we wasted some time calling around to various poison centers for people and dogs, and a couple of emergency vet facilities. We finally got her to VRCC in Englewood, after what seemed like an eternity to me, but was really about an hour. They gave her a medication that caused her to empty her stomach, but they didn't find any pills. Still, they gave her some activated charcoal to soak up anything bad, and kept her overnight to watch for possible symptoms. They were ready for almost anything, with a catheter and various resuscitation equipment. She hadn't shown any symptoms by this morning, when we picked her up, so it's looking like she may not have actually eaten any pills. We had quite a scare of almost losing our "companion dog", who has rapidly become a new family member, and I really hope we don't repeat the experience.

Fall Walk

After having Mandy try on her new pumpkin theme fleece coat, we ventured out for a midday walk with the neighbors. The Fall colors are showing definite signs of fading, but there were still a few rich and colorful seasonal indicators to be found.

Airliner Pressurization

My good friend mentioned a recent incident where he, and some other passengers in an airliner, began "gulping for air" during their flight. He asserted that the airline was recirculating the air as a cost cutting measure, and wasn't providing enough oxygen for everyone to be able to breathe normally. We discussed airliner pressurization systems at some length, and I referenced some articles on Boeing 737 and 767 airliner pressurization, but still he wondered why they didn't provide oxygen masks for everyone, since his experience in the USAF taught him that supplemental oxygen was required above 10,000 feet.

This oxygen question has always been a subject of interest to me, especially since it so directly affects private pilots. When a pilot friend of mine showed me his miniature Nonin pulse oximeter, I realized I "had to have one", and aside from being helpful on long trips over the mountains, it's been invaluable with monitoring K's O2 levels over the past few years.

He's right that oxygen is the key concern, but of course there's oxygen in the air, and if you get enough in the air you're breathing, you're fine without a bottle and mask. The percent oxygen is about 21 in Earth's atmosphere, which works out to a partial pressure of about 3 PSI at sea level. Partial Pressure of oxygen is what the lungs use, and a PP of 3 results in a blood oxygen saturation of about 97% in most people. The experts say most people need about 87% to function normally. Up here in the mile-high city, I generally see my O2 saturation at about 95-97%.

At 10,000 ft, the atmospheric pressure is only 60% of sea level pressure. That results in an oxygen PP of about 1.8, and a blood saturation of about 87%, which is enough for most people to function normally, according to the experts. The USAF and others recommend going on supplemental oxygen at 10,000 feet, in an unpressurized plane, because it's the conservative thing to do. USAF pilots also have to worry about someone shooting a hole in their pressurized aircraft, so they always use bottled oxygen as a backup. Just for the record, the FAA doesn't require supplemental oxygen for private pilots in unpressurized aircraft until 14,000 feet, and oxygen doesn't have to be provided for passengers until 15,000 feet.

About the "gulping for air" symptom. When I lived in San Diego, I attended a course in "Physiological Training for Civilian Pilots" at Miramar Naval Air Station. One of the things we did, was sit in an "altitude chamber" while they ran the pressure down until it was the equivalent of 24,000 feet, and let us experience that high altitude without supplemental oxygen. There was a safety officer in the chamber with us, and his job was to force us back onto oxygen if we didn't do it when instructed. At that very high (simulated) altitude, I did notice some subtle symptomatic clues that hypoxia might be setting in, but they would have been easy to overlook, if I hadn't been watching for them. There was definitely no "gulping for air" symptom in any of the dozen people we had in the chamber. Then many years later, I was flying between Denver and Telluride several years ago, at 14,000 feet in an unpressurized Piper Turbo Arrow, and not using oxygen, although I had a bottle aboard just in case. I was carefully monitoring my blood oxygen with my portable oximeter. I saw my oxygen saturation level go as low as 77%, which is pretty low, but I never got short of breath or felt faint. I easily brought my oxygen level back up into the 90s, by inhaling deeply a few times, even though I didn't feel any need for it. There was no sense of a need to breathe differently, and definitely no "gulping" for air. All the articles I've read about pilots who fly higher than they should without supplemental oxygen, describe them as being unaware of their low oxygen situation. They just start acting stupid, then pass out after awhile. The Payne Stewart Learjet crash is a good example of this phenomena.

Modern day airliners are designed (and required by regulation) to be pressurized to an equivalent altitude of 8,000 feet or below, at their highest cruising altitude, without over stressing the pressure vessel that is the cabin. That leaves the partial pressure of oxygen at more than enough to sustain normal functioning, on all commercial flights, with no oxygen bottles involved. Airliners are also required to have an audible warning system in the cockpit, to warn when the cabin altitude exceeds 10,000 feet. Pilots are trained to act immediately, by descending the aircraft when that alarm goes off, although in practice it rarely does, partly because the systems don't fail very often, but mostly because the pilots are monitoring cabin pressure, and catch any anomalies before the alarm goes off.

I just couldn't accept the assertion that the airline was too cheap to fill the oxygen bottles, partly because I know there are no oxygen bottles involved, but mostly because the pressurization system is a mandatory item -- at the very least, it's required to keep the pilots awake.

I wondered if his shortness of breath might've been related to his asthma symptoms, combined with the likelihood that the cabin altitude was near 8,000 feet. I asked if he had difficulty breathing when he's in the mountains, and he said he does. Maybe the nearby passengers saw him having difficulty, and got nervous enough, that they started experiencing symptoms too. That kind of thing has happened before...

Or maybe the plane had a pressurization failure, and the cabin altitude alarm didn't go off, and the pilots didn't catch it. That's a lot of things to go wrong at the same time, but it's happened before too... in which case, they would have been dangerously close to having the pilots pass out along with the passengers. It's weird though, that more than one person experienced that gulping for air symptom. That's so unusual for that situation.

Snowdog

It's been getting more and more cool, as Fall settles in. With Mandy already showing a dislike for the chilly outdoors, we've had a scenario in our heads, of how this little desert dog would react to her first snow with us. We expected something on the order of, "Are you KIDDING?!", when we first tried to take her out in the stuff. Sure enough, we had our first decent amount of snow this morning, about 4 inches, with the temperature right around 34 degrees. It was a nice birthday present for K! Mandy saw me dressing for a walk, and got all excited about going. She was twirling in circles, doing excited little push ups with her forepaws, and generally trying to get me moving out the door as quickly as possible. I put on my boots, coat, and hat, filled my pockets with dog-walk paraphernalia, got her nice new waterproof coat on, and clipped on the leash. I could barely hold her back, as she dragged me to the front door. I swung the door open, and a blast of cold air hit her. She stopped in her tracks, leaned forward and examined the layer of white on the steps and across the yard, watched the flakes drifting down, and sniffed a little. She spun around, and ran upstairs as far as the leash would let her, and looked down at me, with a look that said, "Are you KIDDING?!" K activated the fallback plan, and took her down through the basement, to a covered spot in the back yard under the deck stairs. We figured this was a great opportunity to try letting her off leash, but that backfired, and she used her freedom to sneak up the snowy deck stairs to the (usually nice warm sunny) deck. That didn't work, so she scooted past us, and back indoors without doing anything. K led her with the leash to the desired spot, and she finally was successful, if somewhat miffed.

I tried getting her out for a walk again later in the day, after it had stopped snowing and the sun was out. She wasn't all that interested, but I persisted, and soon we were on our way down the wet street. She didn't find much of interest at first, with all the grass covered in snow. Something changed when we got to the bottom of the street, and her favorite trail was also covered in snow, except for the flagstones, which had been warm enough to melt the falling snow. She pressed on, hopping from stone to stone, in a cheery and springy kind of way. Halfway down the path, she started exploring out into the belly-deep (for her) snow, looking for a place to go. Not finding her ideal spot, she returned to the path, and we ventured on, down into Lee Gulch. She boldly struck out into the layer of snow on the boardwalk, and onto the bridge across the creek, which was already burbling loudly with runoff, and headed up onto the main trail, where there were only patches of snow. This she loved. I expected her to stick to the dry spots, but it seemed that now that she knew she had dry spots to come back to, she got her usual sense of adventure back. She explored out into the deeper snow on a regular basis, sniffing around and pushing snow around with her nose, and dragged me onward with great enthusiasm, for a fairly long walk. It looks like we have a snow dog! Of course I couldn't resist taking pictures.

Fall Walks

Mandy got to see some really nice Fall colors this weekend. Well, being colorblind, I suppose her big thrill was with all the colorful smells she got to experience. Ken and I took her with us Friday for lunch at Panera Bread in Aspen Grove. The colors along Lee Gulch and the Platte River were very vivid. This was Mandy's longest walk so far, around 5 miles, and she did just fine. On Saturday morning when I woke up, I noticed Mandy watching me closely every minute, and it was clear that she was hoping for another long walk. As it turns out, we had one in the plan. Ken and Freddie and I took her down to the King Soopers at Broadway and Mineral, and then back by way of the Highline Canal trail, maybe 5.5 miles, and she did fine on that one too. Then this morning, Ken and I walked down to the Post Office, and on for a cup of coffee, and of course she breezed through that teeny little 4 mile walk.

We made a trip to Office Liquidators on Saturday afternoon, and came home with a few file cabinets. We have great hopes of using them to get just a little more organized. Then we went back today and ordered a couple of office chairs. We're looking forward to having comfortable places to sit while doing paperwork, email, and such. Mandy got a little chilly in the car, as a cold front blew through while we were in the store. I went out to check on her, and she was shivering up a storm, so I bundled her up in her warm fleece dog coat, and wrapped her in a nice wool blanket that I carry in the car for just such an occasion. She was snug as a bug in a rug. The next time we came out, she was so comfortable she didn't want to move out of her seat. It felt like it was going to snow, and I did see a few flakes, but then it just turned into a short rain shower. So it's official - Fall is definitely here!