Cornfields to mountains: altitude awareness
By Derek Meyer
I’m from a cornfield south of Chicago – about 600 feet above sea level. Like many of our patients, I felt the altitude at Big Sky my first week. Altitude related illnesses were very rarely discussed in my Midwestern medical education.
But it’s different story at 6,000 feet above sea level, where altitude can wreak havoc on unsuspecting tourists.
In late June, a patient on a road trip from a California coastal city came to the clinic complaining he couldn’t catch his breath. He said this started a few days earlier and at lower altitude. He’d been on a strenuous hike in Yellowstone when he began to feel nauseated, dizzy and short of breath. At a local hospital, the patient’s blood oxygen level was found to be severely low. After close observation, with oxygen provided, the patient recovered and was discharged.
Unfortunately, his travel plans for the next day sent him 2,000 feet higher, to Big Sky. In the clinic here, his blood oxygen was again low, and he was huffing and puffing up a storm. We provided oxygen, ran a few tests, and recommended he either take an oxygen machine back to the condo and rest, or descend to Bozeman – wisely, he chose the latter.
Altitude sickness commonly occurs in people ascending more than 8,200 feet and is a result of the body’s faulty response to low blood oxygen. The three main altitude sickness syndromes include:
• Acute mountain sickness (AMS)
• High-altitude cerebral edema (HACE)
• High-altitude pulmonary edema (HAPE)
In most cases, a mild form of AMS occurs 6-12 hours after reaching high altitude, and one may experience headache, nausea or vomiting. Fortunately, AMS will usually resolve by stopping further ascent and taking an ibuprofen for the headache.
HACE and HAPE are much more severe and can lead to coma and death if left untreated. In HACE (which typically follows AMS), the brain begins to swell, leading to changes in a person’s level of consciousness. In HAPE (which may occur after two to four days at altitude), the lungs become leaky, causing coughing and shortness of breath. For both of these conditions, immediate descent with oxygen and drug therapy is lifesaving. Luckily, Dr. Daniels only sees a case of HAPE about every two years around here.
So what advice can you give your visiting cousin from Miami who has ambitions to hike the Spanish Peaks this summer? Tell him to take it easy! The best strategy for avoiding altitude sickness is gradual ascent with plenty of rest. For someone with a history of mild AMS, a physician may recommend taking a medication called Diamox. Avoiding alcohol isn’t a bad idea, either.
Derek Meyer is a forth year medical student at the University of Illinois College of Medicine. He did a rotation at the Medical Clinic of Big Sky in 2011.