I am not commenting much on John's condition. He now in the hospital in San Diego, and improving daily. I just talked with Grayle.
I agree that the ranger was a great deal of help, but some "medical information" was given to casual requests from members of our group, which was not correct when he was encountered at Dangling Rope.
Because of the high number of deaths on Lake Powell in the past from Carbon Monoxide poisoning, pulse CO-oximeters available which have made it possible to estimate carboxyhemoglobin with non-invasive technology similar to a pulse oximeter. The "cherry red" color of the skin, in CO poisoning is very visible. The CO-oximeter, uses different wave lengths to determine the CO level vs the O level.
I had checked the O2 level on John, and it appeared to be normal. Apparently the ranger/flight medic had used the CO-oximeter, and determined that he had a moderate elevation of CO. and P 02 was low
There is no way of knowing if this is acute, or chronic (such as in cig. smokers!). The elevated level might have been a contributing factor in John's illness. It was not entirely clear, but it appeared that John did run the generator on the aft seat of the C Dory 25, and may have run it on the floor of the cockpit. There was a CO detector in the boat. But it had an expiration date of 2014. The back door was closed, but we must all remember that these doors are not air tight, and CO moves just like oxygen.
The CO oximiter which the emergency crew had cost about $800. (Rad-57 Pulse CO-Oximetry) I carry a pulse oximeter for oxygen, which cost about $100---and had checked John's level, which was normal. The ranger, found a lower level, and it may have been using the more sophisticated unit.
There is a very accurate ambient CO meter, which is sold by Aero Medix: "Ultra Low Level Carbon Monoxide Detector | CO - Experts 2015" for $199. This is often used in air plane cockpits, but is equally valid in a boat; especially in an enclosed cabin. Station Wagon effect can be an issue in our boats.
Treatment of CO poisoning is by breathing 100 % oxygen, and correcting any metabolic abnormalities. But in severe cases hyperbaric chamber may be indicated.
The blood tests are more accurate than the field CO pulse oximeter, but time is also very important, so that the field test is valid at Lake Powell, especially with the history up there of at least 8 deaths a year (one year) form CO!.
For the record, there is nothing which suggested that Propane entered into the medical issues which John had. However this was a question asked by the flight medic.
Be safe!
