Hypoxemia - Deficient Oxygen in The Inspired Air

Deficient Oxygen in The Inspired Air

The oxygen contained in the alveolar air is directly proportional to its fractional composition in air. The oxygen content also depends on the barometric pressure, so altitude reduces alveolar oxygen. For calculations, the barometric pressure of the atmosphere is reduced by the vapor pressure of the water that comes to saturate the air in the lung, since the airways humidify the inhaled air:

.

and at sea level:.

and in Denver, Colorado: .

and on the top of Pikes Peak, Colorado:.

and on the top of Mount Everest, Nepal:.

• Flying does too, since cabin pressure is maintained at 7,000 to 8,000 feet, which is greater than Denver and almost that of Vail, Colorado. The effects of altitude can be reversed by pressurizing the cabin or by supplementing inhaled air with 100% oxygen.

• Air depleted of oxygen has also proven fatal. In the past, anesthesia machines have malfunctioned, delivering low-oxygen gas mixtures to patients. Additionally, oxygen in a confined space can be consumed if carbon dioxide scrubbers are used without sufficient attention to supplementing the oxygen which has been consumed.