Some of the reason for my delayed TR was due to one of the guys in my summit hiking group was suffering with HAPE/HPO. He was in the hospital for a few days. He's home now and doing well. (I must admit to having very mixed emotions after finding out he was in the ICU.)
Here's some of the info that he has allowed me to share:
Mike, Chris, & Jim (all in the group this year) had done the exact same hike on Whitney 2 years ago with no problems. Mike happened to have a physical the day before the group left for Mt Whitney. (He was given a clean bill of health) Knowing they needed some time to acclimate, they stayed at the portal campground Wed (8/31). They took 4 hours to hike to Outpost Camp on Thurs (9/1). Stopping several times for snacks/fluids/pictures. They left Outpost Camp at 5am on Fri (9/2) with daypacks for the summit. They arrived at Trail Crest about 9:30am. I join them at Trail Crest. Mike is behind me, and every time we stop, he is taking in some fluids and or snacking. I do not hear any heavy breathing from him. He was not complaining of a headache or difficulty breathing. We arrive at the summit at noon. That's a 7 hr hike from Outpost Camp for Mike. (about 7.5 miles and 4k elevation gain)
On the return from the summit, Mike & Jenny were showing signs of fatigue, but neither were stumbling or having trouble speaking. On the few uphill sections, we had to stop a couple of times, especially that last section up to Trail Crest. However, I think a lot of people have a little struggle up that incline.
On the downhill switchbacks, Mike & Jenny were slowing down, but nothing to indicate Mike was in serious trouble. They made it down to Outpost Camp about 7pm. (about a 6 hr descent) I saw them the next morning (Sat) around 8:30am. Chris mentions Mike had spent most of the night coughing. Chris also mentions Mike probably had some fluid in his lungs. Mike is standing up and we talk. He looks a little tired, but his breathing was fine and he stated he was feeling better after having some breakfast.
I continue on down to the portal store. As I'm eating my burger out in front of the store, I see Chris, Jenny, and Mike come down sometime around noon. They find a place in the shade to sit with the gear and Chris goes to get their car. As we are chatting, Mike appears to be breathing without any problems and is not coughing or gives any appearance of distress.
I found out on Sun, they had lunch in Lone Pine before a 3hr drive home. (Mike had a 1/2 lb ortega burger) By 6:30pm on Sat, Mike was in Loma Linda University Hospital ICU. (I don't have the details as to what symptoms arose that had Mike go to the hospital) Mike's potassium, magnesium, and phosphorous levels were out of whack. Along with an enzyme that was rising that indicates a possible heart attack. He was diagnosed with High Altitude Pulmonary Odema (HPO). From an email from Chris "It appears that he exerted a tremendous amount of energy with insufficient oxygen. Physical fitness is not a factor with AMS/HPO, but rather how well your body acclimates to low pressure and low oxygen levels that are found above 8,000 ft."
After many tests and appropriate treatment, Mike was discharged on Wed (9/7) afternoon and is home recovering. Mike was not rushing up or down the trail, was eating & drinking appropriately, had previous experience at high altitude with no problems. But he still got hit with a bad case of AMS.