This is a handout distributed by Dr. Christine Ebert-Santos, MD, MPS, at Ebert Family Clinic, Frisco, Colorado.
Living at high altitude is a challenge for our bodies. The amount of oxygen in the air we breathe is less the higher you go. Since we all need oxygen to live, this can cause problems.
There are three times when oxygen may be needed by children living at altitude:
During the newborn period;
When a child has a respiratory illness, even a mild cold;
During the first 48 hours after returning/arriving from sea level.
When a baby takes their first breath, the higher oxygen level in the air sets off many changes in the heart, lungs and blood vessels around the lungs that convert the child’s respiratory system from transferring oxygen from the placenta to the lungs. Exposure to a low oxygen environment during the first few weeks can interfere with the normal fall in the pressures of the blood vessels in the lungs and closing of the vessels that shunted blood away from the lungs in the womb.
In babies and children, we are not worried about brain damage from lack of oxygen due to the altitude. Don’t panic if the oxygen cannula falls off during the night or the tank runs out. The problems caused by the low oxygen saturations (usually running between 78 – 88%) seen at altitude develop over days, weeks or years, due to changes in the heart and lung. Hypoxia, the term for low oxygen in the blood, causes constriction, or narrowing, of the blood vessels in the lungs. This can lead to back pressure on the lungs and heart, which may cause fluid to leak into the air sacs in the short term or abnormal increases in the heart muscle in the long ter.
Rarely do babies or children with low oxygen levels at altitude show symptoms. The normal oxygen saturation levels at 9000′ are about 92 – 93%, and can be 89 – 90% in healthy people. We start treating with oxygen below 89%, even though symptoms like trouble breathing, fast breathing, poor sleep, or poor color are unusual until the saturation level is in the 70’s.
It is important to understand that oxygen is prescribed by your doctor to treat symptoms of altitude sickness such as headache, vomiting and trouble breathing, and to prevent more severe symptoms from developing. A small percent of persons with mildly low oxygen levels will suddenly, over a few hours, go into full-blown pulmonary edema where their lungs fill with fluid, they have much more trouble breathing, and turn blue. This is a life threatening emergency.
When you arrive home with your child on oxygen, be sure and call the respiratory therapist at the phone number on the tank so they can come to your house and teach you about the equipment. Don’t feel discouraged if your toddler or young child is fighting the oxygen at first. They will usually adjust and accept the cannula in about 30 minutes.
After a horrendous Autumn of forest fires in Colorado, we’ve received well over a foot of snow in a series of storms, and it’s safe to say Winter has arrived. Hiking season is never truly over in the Rockies, but Colorado’s famed Fourteeners are now blanketed in snow, increasing the risk of any attempted ascent exponentially. But through the fire and ice, the Summer yielded ample opportunity for at least one enthusiast to check off more of her bucket list adventures.
Since leaving her home in Paraguay, mountaineer and hiking expert Clarissa Acevedo Santos has spent over a decade ascending Colorado and Hawai’i’s highest peaks. In addition to her excursions in the Ko’olau and Kahalawai ranges including Maui’s Haleakalā crater, she has summited well over half the 58 peaks in Colorado over 14,000 feet, making her the first from her country of record to do so.
She was invited on her first Fourteener years ago when friends took her up Quandary outside of Breckenridge, CO, at 14,271′ (4350 m).
“When I hiked that first mountain, it was hard, because I wasn’t used to gaining that much elevation. I didn’t really enjoy it so much because of how cold it was on the summit. Even though I made it to the top, I wasn’t really having fun with not feeling my lips and not feeling my fingers because it was really, really cold. I could barely smile, and we couldn’t even enjoy the summit because of how windy it was!
“After that hike, I didn’t hike for a while, and I got invited again to climb Mt. Elbert in 2012. It was actually much more enjoyable because it was with a big group of college kids from Summit and the weather was just perfect. We were able to summit it and enjoy the day and have lunch up there. So that’s what started to change my mind about hiking Fourteeners because I enjoyed my time up top. That’s when I realized it’s not always difficult to be up there. I think I got what all the hikers call ‘Peak Fever’. So after that is when I feel like I started going non-stop, and I met more friends that were into hiking, and researched more about the mountain before I go.
“I always go with people who knew more about it, so I started learning more with other friends and other hikers. And I started feeling actually great when I got higher. It was always harder to get started close to the beginning [of the trail], just to gain all that elevation. But then when I was getting close to the summit, I just got more energy. I just got more excited to be at the top. That’s the goal. It’s a great feeling.”
Clarissa has an app that she uses to record all her summits called Colorado 14ers that allows her to keep record of and upload photos from every Fourteener she’s hiked. She pulls it up as she recounts year after year of more and more summits, some she’s even done more than once.
There is a class system rating every trail by level of difficulty, Class 1 being the easiest and Class 4 being the most difficult. The most difficult peak Clarissa recounts climbing is Long’s Peak, as well as the most dangerous weather she’s climbed in.
“It was a little bit late to summit it. It was not a good idea. If the rocks got wet, it could be very dangerous. There were people turning around. We decided to wait on a ridge. There were three [of us], and one turned around. He wasn’t feeling good, he was getting tired, he wasn’t used to hiking that many hours.
“We decided to wait for the clouds to go away. After that we just kept going. It did not rain on us, thankfully.”
Clarissa has seen her share of altitude sickness as well. One of her frequent hiking companions repeatedly gets stomachaches and headaches everytime they hike, in spite of being an experienced hiker as well.
“I always ask [one of my friends in particular] if she wants to stop or if she wants something. She normally doesn’t eat before she starts a hike. No breakfast. But I also carry ginger candy … I learned that from other hikers telling me it can help settle your stomach a little bit. It’s everywhere, in all the stores. Now they’ve created gums. I’ve started chewing them on my hikes just in case. You never know. I’ve seen people who hike all the time, and they ate something that didn’t digest well, and they feel sick and get a little dizzy.
“I’ve never experienced any headaches on the way up. The only time I remember having a headache is when I ran out of water. I hiked Oxford and Belford in the Saguache range in the same day. My head hurt and it lasted for that night. Now I take a filter with me so I can fill my [Camelbak] bladder. And I also take electrolytes. And I’ve started hiking with poles more as well, just because you put alot of weight on your knees when you’re hiking down. It’s very smart to start using poles.”
When it comes to preparing such demanding ascents, Clarissa recommends spending some time at an intermediate altitude before hitting the trail, and staying well-hydrated. Caffeine and alcohol the night before doesn’t typically help.
“It doesn’t matter how fit you are … you can still get really sick. I’ve heard of people who get headaches for several days because [they’re] not used to [the elevation here].”
She also says it’s important that you start any hiking at all to build the strength in your lungs.
“It does hurt,” she says about the stress on your respiratory system. “I remember when I was hiking Quandary, my chest was so pressed, my heart was [beating] so fast, my stomach was feeling weird, like I had to pee or I had to do number two or something. It was such a difficult part of … gaining all that elevation.”
“You’ve gotta find a good pace for yourself. I see many of my friends going really fast ahead of me, then they’re very tired and they have a hard time getting to the top. I’ve waited for many people because they are struggling so much at the end. Take as many breaks as you think [you need]. Carry enough water!“
Clarissa keeps seeing a lot of hikers running out of water. “They just bring a tiny plastic bottle. That’s a huge mistake. And bring food, too. You will get hungry after a mountain. It’s so funny how many people are unprepared. If I’m hiking with newbies, I make sure they have everything, and they’re always thankful.”
When it comes to clothes and shoes, Clarissa recommends really good traction. She’s tried some more affordable brands, but says the durability is worth paying more for.
Don’t ever hike in new hiking shoes before you’ve broken them in. Good hiking socks also have more padding at the heels and toes and help prevent blisters. She also will double-up on socks, or even bring an extra pair to help mitigate possible cold.
“I reapply sunscreen on my hikes two to three times. Many times my nose will burn. I always carry sunglasses. You’re so close to the sun, you don’t realize. You don’t want to burn your eyes or your face. Even with the sunglasses, having a hat on top of it doesn’t hurt. Even in the Summer in the mountains, carry additional gloves or layers, because you don’t know what the weather could be. Temperature changes quick.
“I just recently purchased a nice puffy Northface that helped me. I will always have a thin layer underneath because you get hot and cold. You’re gaining elevation, you get hot, then you get cold in the middle …”
When it comes to navigation, Clarissa’s main resource is 14ers.com, which allows you to download offline maps, so you aren’t relying completely on having cell service.
“Even though I have hiked many of them, I want to be sure I’m going the right direction … I just love reading everything I can beforehand. I read about the class, how much exposure, how long it’s going to take, then I download the maps, look at the maps, what kind of road it’s going to be, if my car can make it up higher or if I have to hike longer.”
Clarissa has heard of other Paraguayans hiking around the world, but has never met another one on a Fourteener personally. But she does meet a lot of people from around the world on these ascents who ask if there are mountains in Paraguay. The highest is Cerro Peró at 2762′ (842 m) in this landlocked country known more for its rivers and the hydroelectricity they provide for Paraguay and its neighboring countries, including Brazil and Argentina.
Clarissa says she’s learning more and more each year about mountaineering and advocates learning as much as possible about each ascent before you go. The weather may be different every single time.
Bring the layers, whether you think you’ll need them or not. And leave no trace.
Thank you, Clarissa, for sharing your continuing legacy, and be safe up there!
Roberto Santos is from the remote island of Saipan, in the Commonwealth of the Northern Mariana Islands. He has since lived in Japan and the Hawaiian Islands, and has made Colorado his current home, where he is a web developer, musician, avid outdoorsman and prolific reader. When he is not developing applications and graphics, you can find him performing with the Denver Philharmonic Orchestra, snowboarding Vail or Keystone, soaking in hot springs, or reading non-fiction at a brewery. Clarissa is his wife who is increasingly a much faster, more experienced mountaineer than he is, but he will occasionally feel ambitious enough to join her on a Fourteener, at the top of which they both enjoy a delicious cider, weather permitting.
Typical symptoms of acute mountain sickness (AMS) are headache, loss of appetite, disturbed sleep, nausea, vomiting, fatigue, and dizziness. However, more serious conditions such as high altitude pulmonary edema (HAPE) or cerebral edema (HACE) can present with this illness. Avoiding these unpleasant symptoms while at elevatione is possible through gradual pre-acclimatization when possible (what science recommends!), or there are specific medications that can potentially prevent the development of AMS, such as acetazolamide. This article will address how acetazolamide (also known as Diamox) can help prevent AMS, discuss the physiological effects of the medication, some side effects, and whether or not this drug can enhance physical performance.
How does it work?
Acetazolamide is a carbonic anhydrase inhibitor. Carbonic anhydrase regulates kidney absorption of sodium bicarb and chloride. Acetazolamide works by inhibiting carbonic anhydrase, preventing the reabsorption of sodium bicarb and chloride, causing acidosis in the blood. When experiencing AMS, the body is in a state of respiratory alkalosis. By taking acetazolamide, which causes metabolic acidosis it drives receptors in the body to increase the patient’s minute ventilation by as much as 50%, improving arterial PO2 and increasing oxygen saturation.
How can I obtain acetazolamide and when should I start taking it?
Acetazolamide requires a doctor’s prescription, and the typical dose for the prevention of AMS is 125 mg twice daily. The typical recommendation is to start taking acetazolamide one day before your exposure to high altitude and continue usage throughout your trip. When taken one day before exposure, studies show that acetazolamide reduced AMS incidence and enhanced tolerance to submaximal exercise on the first day at high altitude versus starting administration the day of arrival.2 However, if, for some reason, the medication isn’t started a day before arrival to high altitude, then the medication should be started upon arrival, which still shows a decreased incidence in the development of AMS.
Allergies & Side Effects
Acetazolamide belongs to a classification of drugs known as sulfonamides, which is broken down further into two categories: antibiotics and nonantibiotics. Acetazolamide is considered a nonantibiotic sulfonamide, which varies significantly from sulfonamide antibiotics because these antibiotics contain what is known as an arylamine group in their chemical structure. This arylamine group is a key component of the allergic response to sulfonamide antibiotics (sulfamethoxazole, sulfasalazine, sulfadiazine, and the anti-retrovirals amprenavir and fosamprenavir); however, this structure is not present in other sulfonamide drugs like acetazolamide.1 There is available evidence that suggests patients who are allergic to arylamine sulfonamides do not cross-react to sulfonamides that lack the arylamine group and so may safely take non-arylamine sulfonamides.1 Patients with known allergies to sulfonamide drugs should consult with their healthcare provider before taking acetazolamide.
Like all other medications, there are risks that side effects will occur with acetazolamide’s administration. The common side effects are fatigue, malaise, changes in taste, paresthesia, diarrhea, electrolyte disorders, polyuria, and tinnitus. While conducting research, I found 3 – 4 people from my hometown, located at 69 feet above sea level, who have taken acetazolamide while rapidly ascending to 8,000+ feet to ski or hunt. When asked how their experience was taking acetazolamide, the common response was that they stopped using it within the first two days due to the change in the taste of their beer! The pleasurable “fizz” in our carbonated drinks is attributed to chemical excitation of nociceptors in the oral cavity via the conversion of CO2 to the carbonic acid in a reaction catalyzed by carbonic anhydrase. So administering a carbonic anhydrase inhibitor like acetazolamide results in flat-tasting carbonated drinks, or, as described by the aforementioned subjects, a “nasty beer”!4 While a bad tasting beer is no fun, AMS is a lot less fun, and one would be best advised to continue taking acetazolamide while at high altitude.
Can taking acetazolamide increase physical performance and endurance at high altitudes?
Though enticing, it doesn’t seem to work out that way. There are multiple studies on exercise endurance in hypoxic conditions with the administration of acetazolamide, but the produced results are confounding. The majority of the studies show that for a non-acclimated person taking acetazolamide in hypoxic conditions, endurance and exhaustion time were increased with submaximal and maximal exercise. A few reasons this may be true are the induction of metabolic acidosis and its effects on muscle cells, the diuretic effect of the drug inducing dehydration, and additional increases in work of breathing cause vasoconstriction in locomotor muscles, which can impair exercise performance.3 Regardless, this medication’s proven science in the prevention of AMS should not be mistaken with the multiple confounding studies on exercise endurance.
From Opelousas, Louisiana, Scott Rogers is currently a Family Nurse Practitioner student at Walden University after having practiced five years as an RN following his BSN from the University of Louisiana at Lafayette. He has lived in Colorado for the past four years where he enjoys hiking with his wife and dog, snowboarding all the resorts in Summit County, and basketball, and hopes to pursue more work with acute physical rehabilitation, orthopedics, and sports medicine.
1. American Academy of Allergy Asthma & Immunology. (2019, June 23). Acetazolamide and sulfonamide allergy: AAAAI. Retrieved November 13, 2020, from https://www.aaaai.org/ask-the-expert/acetazolamide
2. Burtscher, M., Gatterer, H., Faulhaber, M., & Burtscher, J. (2014). Acetazolamide pre-treatment before ascending to high altitudes: when to start?. International journal of clinical and experimental medicine, 7(11), 4378–4383.
3. Garske, L., Medicine, 1., Brown, M., Morrison, S., Y, B., G., B., . . . Zoll, J. (2003, March 01). Acetazolamide reduces exercise capacity and increases leg fatigue under hypoxic conditions. Retrieved November 13, 2020, from https://journals.physiology.org/doi/full/10.1152/japplphysiol.00746.2001
4. Jean-Marc Dessirier, Christopher T. Simons, Mirela Iodi Carstens, Michael O’Mahony, E. Carstens, Psychophysical and Neurobiological Evidence that the Oral Sensation Elicited by Carbonated Water is of Chemogenic Origin, Chemical Senses, Volume 25, Issue 3, June 2000, Pages 277–284, https://doi.org/10.1093/chemse/25.3.277