Acetazolamide

Okay, so after my last experience with altitude I thought I would get prepared for the next time I went that high. I recently took a trip around Tibet, where the majority of the travel was above 4000m and the highest point was at Mt Quomolonga (Mt Everest) base camp at 5200m.

Before leaving Lhasa I thought I would try to track down some Acetazolamide (trade name Diamox), which works to lessen the severity of AMS through allowing hyperventilation and hence increasing the oxygenation of the blood. I checked many pharmacies all over Lhasa before being directed to the Peoples Hospital, where I managed to purchase a bottle of 100 tablets for 14 RMB. The reason I made the effort to get the tablets was that there was a nights sleep planned at the Rhongphu Monastery guesthouse, Wikipedia says that its at 5200m, however while we were there someones altimeter watch said it was around 5000m. Either way, its damn high. Sleeping at altitude is very difficult, and I didn't want a repeat of my last altitude experience.

I should mention that I have actually tried Diamox before, while I was sick up at Namtso. I didn't mention it in the last post, but one of the people I was with gave me a few tablets which I swallowed with no immediate effect. This makes sense of course, as Diamox takes 6 - 12 hours to become effective. The one thing I did notice was the side effects the next day, my face tingled intensely for half a day.

The first half of the trip involved sleeping around 4000 meters, and that all seemed to be okay. I was a little short of breath while exerting myself, but nothing too serious. Then we got to Shigar.

Shigar is a picturesque Tibetan town in the shadow of a monastery and ruined hill fort, after leaving our bags at a guesthouse we decided to check out said monastery and ruined hill fort. (see left for monastery and right for hill fort)

The town is at 4400 meters, and the top of the fort was about 300 meters above the town. It was very hard work getting to the top, out of 8 of us that attempted it, me and 2 others made it. It was probably a bad idea but the view was fantastic.

In the evening I started to feel a little ill, a familiar altitude headache was coming on. I think I made the same mistake as I did at Lake Karakul, by going up high then climbing higher. Given that the day after we had planned to go to Everest base camp, I decided to start taking the Diamox. I felt pretty average in the night, and at one point my oxygen starved brain thought there was a small Tibetan child hanging from the roof of our dormitory (it was a jacket).

I expected to wake up with a tingling face, as that was a side effect I had experienced before. I also expected to wake up with my vision intact. That was not the case. As soon as I woke I found that the whole room was blurry. I rubbed my eyes a few times to no avail, I couldn't see more than a foot in front of me clearly. I could only read text if it was a few inches from my eyes and as for seeing into the distance, forget it. I had read somewhere that blurred vision was a possible side effect of Diamox so I wasn't totally freaking out, however since I had hoped to see Everest that afternoon I was a little concerned. We had a 5 hour bus trip up to Rhongphu Monastery and Everest base camp, in which I spent the beginning vainly attempting to discern the scenery we were passing through. One of the women on the bus offered me her prescription glasses saying they were a 3.5 correction factor, whatever that means. I tried the glasses, and to my amazement everything suddenly regained sharp focus. Praise the lord, I could see!

The mountains and valleys that had been just coloured shapes now had texture and contours, and I didn't have to guess who people were by their general body shape and clothing colour.

The woman in question was wearing contact lenses, so I borrowed her glasses for the day. It would have looked quite amusing, me wearing narrow euro-style women's glasses, but for clear vision it was worth the price. I used the glasses several times during the bus trip to see various sights of merit, but I didn't keep them on continuously as I didn't know if they would adversely affect my vision in the long term.

My vision slowly recovered over the day, to the point where I could see Everest without the glasses in the afternoon. (Everest image below)

The real proof my vision had returned was that in the evening wearing the glasses made everything blurred. I had a decent nights sleep, and the next day stopped taking the Diamox.

It was a very interesting experience having impaired vision, especially as it seemed to mimic the common sight disorder of myopia. It only lasted 6 hours or so, however I really noticed how much lack of sight affected my life. I couldn't read signs or tell the time. It would have been interesting (albeit annoying) if the side effects had lasted for longer, so I could have seen how I adapted to blurred living.

Too high

The first time I had altitude sickness was up in the mountains between China and Pakistan. We had driven from Kashgar up the Karakorum highway to Lake Karakul. Lake Karakul is at 3600 meters high, the highest I had ever been on land (at the time). Kelly and I were were staying in a Kyrgyz family yurt on the edge of the lake, and after leaving our bags we set off for to circumambulate the lake. I was feeling pretty good at this point, the air seemed a little thin and it was harder than normal to walk, but I didn't have any symptoms of sickness at that point. As I was feeling fine I decided to climb a mountain overlooking the lake to get a better view. It was very difficult to climb as the thin air meant that I had to rest every couple of hundred meters, but I finally reached the top. Exercise at altitude is unwise as it greatly increases your chances of suffering from the altitude, by the time I was near the top I was defiantly affected. I had climbed another 800-1000 meters and my mental faculties had diminished significantly, I was talking to myself and felt rather dizzy. To the right is a photo of Lake Karakul taken from the top of the mountain I climbed. Below is a photo of me at the top of a survey marker tower on the top of the mountain





After getting to the bottom of the mountain, a headache set in that was to get progressively worse all night. Even though I was very tired I couldn't sleep, and was too mentally tired to read a book or conduct much of a conversation. When I arose to use the bathroom (a ditch near the Yurt) I got lost in the dark and nearly stumbled into the wrong Yurt. The stars were fantastic however, probably the best I have ever seen. Too bad I wasn't really in a state to appreciate them. In the morning we drove back down to Kashgar and after a few hours sleep I felt much better.

My second experience with altitude sickness happened recently in Tibet. I had been in Lhasa for 3 nights and had been experiencing mild discomfort due to the altitude. Lhasa is at 3650 meters, and at that height there is only 65% oxygen available, compared to sea level. It was not so bad, I had a slight headache in the evening and interrupted sleep. On the 3rd day in Lhasa, some people I had been travelling with were planning on going up to Lake Namtso and spend the night, so as to see the sunset and sunrise. I arranged for them to buy me a ticket without really thinking about acclimatisation. Namtso is the highest saltwater lake in the world at 4720 meters, at this height the oxygen is down to 56%. The night before going I still had a headache and was beginning to think that an extra kilometer of altitude was a poor idea. The next morning I had resolved to only go to Namtso if I could get back the same day. Altitude sickness is always worse at night, and by being up high for only half a day I would avoid the worst of the sickness without wasting my ticket. The driver of our vehicle indicated that it would be possible for me to return the same day, so I boarded the bus and we departed Lhasa. I wasn't sure that I would be able to return, as the driver didn't speak English and our discussion was mainly conducted with the Chinese word for today, and hand motions.




On the way up to the lake, the highest pass we crossed was at 5190. The air was very thin and I didn't feel totally normal but when we got down to the lake I was feeling fine, out of breath and tired, but that is pretty normal for the height. We walked a kora circuit around a rocky hill near the lake and checked out the Buddhist trappings of this holy lake, there were the ubiquitous prayer flags strung from every possible place and carvings and devotional objects in the caves.

A headache was coming on, so I returned to our guesthouse and lay down for a few hours. The pain in my head was getting stronger and stronger as the afternoon ended, however I really wanted to see the sunset and the rest of my companions were on top of the hill watching, so I slowly tried to walk up to the top. As soon as I started walking up the stairs I knew it was a bad idea, I was so out of breath and dizzy I had to go back down. I still wanted to see the sunset, so I staggered round the base of the hill to sit by the lake. I made it halfway round before collapsing down behind a rock out of the wind. By this time I realised that I wasn't in any fit state to make it any further. I decided to try and get back to the cabins, and with difficulty stood up. My head felt like it had been pierced by an ice pick and any movement I made twisted the pick, sending debilitating waves of pain through my brain. After standing I took a few steps before intense nausea resulted in me throwing up my lunch of instant noodles and yak cheese. I threw up a few more times on the long painful trip back to the cabin, there was no one around when I got there so I crawled onto my bed and waited till the others came back to the cabin. Mark, one of my companions at that point had some Diamox with him and had left it on the table in the cabin. Diamox is an altitude sickness medication and I had heard it would alleviate some of the symptoms of altitude. I messaged Kelly and asked her to find out what dosage I should take. She was naturally alarmed to hear I was sick, and did some research on the Internet. She reviewed my symptoms and found that they fit the description of Moderate Acute Mountain Sickness. According to http://www.princeton.edu/~oa/safety/altitude.html "At this stage, only advanced medications or descent can reverse the problem. Descending even a few hundred feet (70-100 meters) may help and definite improvement will be seen in descents of 1,000-2,000 feet (305-610 meters)". Without descent my symptoms would only get worse, and would eventually progress to Severe AMS (Acute Mountain Sickness) and the potential fatal conditions of High Altitude Pulmonary Edema and High Altitude Cerebral Edema (HAPE and HACE respectively, basically meaning water on the lungs and water swelling the brain).

My mental faculties were severally diminished, and the massive pain in my head distracted me from taking any definitive action on my own. Luckily Kelly insisted that I find a way to descend immediately, otherwise I may have sat in pain as I became sicker and sicker. Once the rest of the group I was travelling with arrived, they helped by finding our driver and insisting that he take me down. He was very reluctant to drive down through the mountains in the night, and charged me 600 RMB to take me to a lower town. To get down to a lower altitude however, we had to go back up to the 5190 meter pass. Mikko, a Finish man bought a small bottle of oxygen from a woman at the guesthouse and gave it to me for the trip. I lay in the back of the van and breathed the oxygen as we left. I had an agonising headache at the lake, and that only got worse with the ascent to the pass. Every bump of the road was an agonising jolt to my head, and the twisting of the road exacerbated my nausea to the point I had to stop the van and throw up several times. After an hour and a half we reached a town at around 4200 meters and the driver checked me into a hotel. I went to sleep despite my headache and slept for 10 hours.

When I woke up it took me a while to realise where I was, but when I did I also realised that my headache was gone. I still felt lethargic and slightly nauseous, but the improvement over last night was dramatic. Returning to Lhasa, I slept for the rest of the day and awoke feeling better than I had when I had left for Namtso.

It was foolish of me to have gone up to the lake so not as to waste my 120 RMB ticket, when it ended up costing me much more than that in the end. I now think I have more of a healthy fear of altitude sickness. I am glad I spent the money to get down lower, when I returned I met someone whose friend is still in a coma in a chinese military hospital with HAPE and HACE. That could have been me if I hadn't of got down when I did.

I am still in Tibet at the moment, and have started to upload some new photos to flickr. Click the link to the right to check them out.

Kashgar

This man tried to pick my pocket.

I was on a local bus in Kashgar, going from the city to the outskirts to check out the Apak Khoja tomb. Like usual in China, I stuck out something hefty. I couldn't stand straight up on the bus, and when I boarded, every single person looked at me like I was Godzilla.The bus was crowded, and I was watching the rural scenery pass by. It was quite interesting to see blacksmiths making shovels and turners carving wood right on the main street out of town.

I turned to the right, and saw that the man in question had a bag pressed against my hip. Noticing his hand withdrawing quickly from the general area, I checked my pocket to find my wallet half out. The felon was looking forward nonchalantly, but I was sure there was no way that my wallet could have found itself in such a position naturally. I asked Kelly how I would say "thief" in Chinese. The man looked Uighur, but still I pointed at him and proclaimed him "Sha To" I am sure he understood me but he continued playing it cool, everyone else in the vicinity looked at me and I mimed a hand going into my pocket while saying "Sha To, Sha To" and pointing to him. The locals seemed quite shocked, and the man got up and was trying to leave the bus. I pulled out my camera and snapped the above shot while he was fleeing.

It was interesting to have the attempt made. It will sure make me more careful in future, but the man wouldn't have been too ecstatic even if he was successful, i had only 15 RMB ($2.5 AUS) and an expired drivers license in the wallet. I keep all my valuables in a money belt around my waist while I am travelling, I always thought it kind of dorky, but now I feel vindicated.

It was quite amazing as I didn't feel a thing. I would never be able to put my hand inside someones pocket without them feeling it. If I hadn't have glanced to the side, I would now be sans-wallet.