r/hiking_Nepal

Based on my years of guiding across the Himalayas, I have come across a blanket behavior of Diamox being recommended by anyone and everyone to the ailments of Altitude Sickness and trekkers/climbers treating this as a miracle drug. While Diamox does aid in Altitude Sickness, it is not a one-stop solution against Altitude Sickness and even worse, sometimes mask the initial symptoms of Altitude Sickness to let the situation unfold into severe forms of AMS to HACE (High Altitude Cerebral Edema) or HAPE (High Altitude Pulmonary Edema). 

 Acetazolamide (Diamox), is a very popular choice of medication for trekkers or climbers venturing into high altitude and empirical/clinical studies have shown that it is a very effective tool to prevent and aid against Acute Mountain Sickness (AMS). However, every once in a while, I have come across trekkers/climbers who followed the dosage to the tee and yet, had to be evacuated due to HACE or HAPE. I understand the science behind the Diamox but this intriguing factor is what lead me to dive deeper into this topic. 

 In simple terms, Diamox works by forcing Respiratory Adaptation i.e., your kidneys accelerate excretion of bi-carbonates, resulting in hyperventilation and oxygenation of your blood. While this is effective to prevent AMS, serious conditions like HACE and HAPE works on a completely different pathological pathway. More often than not, this might work dangerously for trekkers and climbers giving them a false sense of security whilst their body requires more time to adapt to the change in barometric pressure and hypoxic conditions. This exact false sense of respiratory adaptability is what makes the onset of HACE and HAPE unpredictable. Localized vascular pressure, severe fluid shifts and inflammation that causes these conditions are not addressed by Diamox. 

Below are the summarised versions of why Diamox is not effective against HACE and HAPE.

https://preview.redd.it/f8t8fx60hsah1.png?width=1414&format=png&auto=webp&s=5f9c1bb74d726a19614da5b66d09e19310fb8daa

https://preview.redd.it/ms3ijy60hsah1.png?width=1414&format=png&auto=webp&s=e77f6406fde6a16195e6ab20bafc20ed1962cfea

To summarize the above,

https://preview.redd.it/00soi2gzhsah1.png?width=1438&format=png&auto=webp&s=a639b8c4d57c7b40ff83c5de2f8ee974df2d3f89

We come back to the foundation, the age old guidelines of slow ascent, dedicated rest days, adequate hydration. I have observed countless threads in Reddit where climbers and trekkers swear-by Diamox for the courtesy of following a shorter itinerary or quicker bag to the summit. I hope this helps you to take more informed decision on why slow acclimatization and hydration is paramount for your expeditions. My curiosity drove me further to dig deeper into the reasons behind these recommendations; 

https://preview.redd.it/z260m6zuhsah1.png?width=1444&format=png&auto=webp&s=17190a2f1d32e8560fc516c4f40d876a45ab4ed3

https://preview.redd.it/nhuo55zuhsah1.png?width=1390&format=png&auto=webp&s=26d303f2c9901bd8522b112551c60b8fbe208ca2

Now finally onto, why halting your ascent or descending to lower elevations is one of the quickest and most-effective against any conditions of Altitude Sickness. Throughout my tenure of Guiding, I have made the uncomfortable decisions to descend as soon as possible even though its 11 pm in the night or 3 am in the morning. I knew it helped immensely but I never knew the reasons of how it helped. This has further solidified my intuition to ‘Descend’ whenever possible when things don’t seem right. 

https://preview.redd.it/hshwui15jsah1.png?width=1406&format=png&auto=webp&s=30150ac51144ee1879acbbdc8b20f83d5cc92acc

https://preview.redd.it/wwuxij15jsah1.png?width=1400&format=png&auto=webp&s=80d94a397e78ad8ae38ae635b8ead6066537db83

https://preview.redd.it/rqn5fk15jsah1.png?width=1372&format=png&auto=webp&s=8d89dbbcdfc08f8685d2bdcdac070d0b8f16410d

I have had moments when I called for immediate descent at 3 am or descent till the next village at least a 1000m lower, even though we had hiked for 6-7 hours already. It is not uncomfortable but it is my responsibility to ensure that we survive this onset of ordeals to experience the mountains without fighting for survival.

Thus, if you have heard it, you have heard it right, the only miracle treatment to the onset of Altitude Sickness, HACE and HAPE is Descend, Descend and Descend.

Upon further research, various sources recommended the following prophylactic dosages for AMS, HACE and HAPE. However, I am not a medical professional neither have the licesing to advocate any medication but here is a summarised version, if you wish to discuss this with your travel doctor;

Use in caution with your Doctor's advice

As a Climbing and Trek Guide, one needs to be observant and perhaps more than others as you look for minute indicators that things are not going on the way that’s meant to be. I have had instances where I have descended trekkers and climbers who were already on full dosage of Diamox, recommended and administered Dexamethasone to buy more time but fortunately haven’t had to use Nifedipine. There are things that I pay attention to which might seem a bit ridiculous but there are reasons to it, 

Checking on Hydration: I always check with my clients sometimes a bit more rigorously if I know that someone doesn’t drink a lot of water. Those who have trekked with me before know that I am known to be quite firm with my demands of having adequate hydration both for myself and for the team that I am leading the climb or trek with. With enough familiarity I even make it a point to remark in funny or satirical ways of the hydration intake.

Checking on Sleep Quality and Appetite: Once you are on the trails for a number of days, you begin to have a baseline understanding of your client’s natural appetite. A seemingly mundane question, ‘How was your sleep?’ or your client’s significant loss of appetite are the early signs of Altitude Sickness. 

Overall Mood, Slower Pace: This might seem surprising but a smiling, talkative person, suddenly going silent for periods, falling behind even in slow pace and having to hyperventilate even in rest periods are many of the tale tell signs of unfolding crisis. As an independent climber/trekker, if you are observing these signs with your friends or climbing partners, it is time to descend and/or access cautionary approaches. 

Refusing to push further than required: There are instances where I have refused to lead the clients through the option of trails that is more demanding or exhausting or took them to that view point that they saw in Instagram unless they allocate rest days in their time commitment.  Physical exhaustion and consistent stress on your body overlaps with the exact bio-chemical markers on your body that accelerates the onset of Altitude Sickness or HACE or HAPE. We discuss the side trails and the side hikes before the trek so that I can build that into the itinerary without compromising the safety of my clients.

Note: There are direct bio-chemical changes that improves your High Altitude Adapatibility with Hydration, preventing Physical Exhaustion, Dedicated Rest Days and Active Acclimmatisation Days, which are the foundations of successful high altitude endeavours. I will attempt to discuss all of this in the next chapter of this article. These attributes are even more paramount if you are looking to summit your next peak or participate in high altitude adventure, than a blanket approach of relying just on Diamox.

Conclusion

As always, I am not a medical professional neither a Researcher but a curious individual making an attempt to correlate my experiences with scientific reasonings. I am Kiran, a Trek and Climbing Guide based in Nepal and a big part of my academic studies focuses on the Mountain Safety and Prevention/Management of its related ailments. For those of you who are curious, I am in near proximity to completing my Masters of Adventure Tourism Studies and thus, it helps immensely to be able to correlate my field experience with clinical understanding.

Lastly, I want to hear your stories of when and how relying on Diamox alone and speeding your ascent failed you. Your stories of survival and management might be a learning lesson for everyone in this wonderful community. I hope this helps for your future adventures and if you are seeking to connect with me, you can find my contact details in my profile info.

Kiran