Why we can’t give 100% Oxygen for People with Chronic Lung Diseases?

Some people suffer from chronic lung diseases like bronchiactasis, chronic obstructive pulmonary disease (COPD) etc. As the lung functions are compromised in these patients, there oxygen saturation of blood is decreased. Most of these people face acute exacerbations of the disease where the respiration becomes hard. 

IF you have chronic lung disease and face such situation, you may crave for oxygen. Some people ask for oxygen, sometimes the physician may not let you have any oxygen. Many patients become irritated when they face such problem. But, they should understand that it is the best way to manage. 

Why?

Now you must be wondering why. To understand it you should have a clear understanding about the physiology of respiration and how it is controlled. 

How the respiratory rate is maintained. 

The respiration is controlled by the respiratory centre situated in the brain stem. There are several inputs to this respiratory centre. They are,

• Inputs from the higher centers enabling voluntary control over respiration.
• Information from the peripheral circulation indicating the amounts of oxygen and Carbon Dioxide.
• Inputs from the chemoreceptor area situated near the respiratory centre which detects the amount of CO₂ present in the brain.

Out of above the inputs from the chemoreceptor area plays a major role. As the CO₂ in the brain increased the respiratory centre increases the respiratory rate to get rid of the excess CO₂. 

In chronic lung diseases they are persistently high amount of CO₂ in the brain making the respiratory centre insensitive to its presence. At this time the respiratory rate is maintained by the peripheral oxygen concentrations. If the peripheral oxygen content reduces the massage is sent to the respiratory centre to increase the respiratory rate.

So, if we give 100% oxygen for such person once the peripheral oxygen content raises the stimulation of the respiratory centre reduces. As a result the respiratory rate reduces. This ultimately leads to reduction of oxygen. Therefore, 100% oxygen is not given for patients with chronic lung diseases. 

Oxygen Therapies [VHS]