Why in News?

• Medical practitioners have reported a condition called silent or happy hypoxia in the ongoing Covid pandemic

What is Hypoxia?

• Hypoxia is a condition in which the body or a region of the body is deprived of adequate oxygen supply at the tissue level. 
• Hypoxia may be classified as either generalized, affecting the whole body, or local, affecting a region of the body.
• The normal oxygen saturation in the bloodstream of a healthy person is above 95%, but COVID-19 patients display dangerous declines of as less as 40%. When levels fall below 90%, patients could begin experiencing lethargy, confusion or mental disruptions because of insufficient quantities of oxygen reaching the brain. Levels below 80% can result in damage to vital organs.

What is happy hypoxia?

• Low oxygen saturation in the blood without any visible manifestation of distress is called happy hypoxia.
• While hypoxia is a warning signal for imminent failure of vital body organs like the kidneys, brain, heart and is usually accompanied by prominent breathlessness, happy hypoxia does not prompt any such obvious external signs
• A medical device called a pulse oximeter can be used in the early detection of silent hypoxia.

Related information

Oxygen concentrator

• An oxygen concentrator takes in air and separates the oxygen and delivers it into a person via a nasal cannula.
• Air is 79% nitrogen and 21% oxygen and a concentrator that works by plugging into a source of electricity delivers air that is upto 95% oxygen.
• In respiratory infections that causes oxygen saturation levels to dip below 90%, having an external device supply pure oxygen eases the burden on the lungs.
• However in cases of severe respiratory distress, it may be necessary to provide oxygen that is almost 99% pure and an oxygen concentrator is not up to that job. 
• A concentrator consists of a compressor and sieve bed filter. The former squeezes atmospheric air and also adjusts the pressure at which is delivered.
• A sieve bed in the concentrator is made of a material called Zeolite. It separates the nitrogen.