Oxygen at High Altitude

How can we tell if your body has enough oxygen at high altitude? For your safety, we use a pulse oximeter to check your blood oxygen saturation regularly throughout your climb. This medical instrument allows your guide to accurately determine how your body is adapting to the reduced amount of oxygen at higher altitudes. If your guide determines you need oxygen at any time, we carry extra oxygen on each climb for your safety.

Most companies do not use an oximeter to track the condition of their clients. Nor do they carry extra oxygen. Without an oximeter, certain decisions regarding your safety are just a guess! We feel that the use of a pulse oximeter is essential to ensure the safety of any climber at high altitude. If the company with which you hope to climb Kilimanjaro does not know what a pulse oximeter is, you’ve narrowed your search!

What is Oxygen Saturation?
When you breath oxygen, it binds to the hemoglobin in your red blood cells and is then transported throughout your body. Oxygen saturation is the percent of hemoglobin that is fully saturated with oxygen. A healthy person, breathing air at sea level, would have a saturation rate of 96 to 98 percent.

What Does Oxygen Saturation Tell You?
Oxygen saturation tells you exactly how much oxygen is available for your body to use. Healthy people function at oxygen saturation levels in the high nineties. As saturation falls to the low nineties, most of us would be aware of “feeling different”, as the first symptoms of hypoxia appear. These sensations vary from person to person but include lightheadedness, lip tingling, deterioration of night vision, increased heart and respiratory rate, and mild memory impairment.

What Determines Your Oxygen Saturation?
There are several variables that will determine oxygen saturation, but the most important is oxygen partial pressure, which drives the oxygen into your body and onto the red blood cells. This is a function of the atmospheric pressure and the concentration of oxygen contained at pressure (such as 21 percent in room air). But individual factors also play a huge role in your saturation level, such as age, condition of the lungs, and smoking history. There are many variables, so the only way to know your saturation level at any time is to use a pulse oximeter regularly.

How is Oxygen Saturation Measured?
The technology is called “pulse oximetry”. It was first developed for pilots in the 1940s but the development of microprocessors has now made it practical and more available. The pulse oximeter shines two different light sources (red and infrared) through the finger. Each light has a different absorption characteristic for oxyhemoglobin (the red, saturated blood) and deoxyhemoglobin (the blue, unsaturated blood). The oximeter measures the ratio (percent) of saturated to unsaturated hemoglobin.