Oxygen saturation level

[martin1945]

Is the oxygen saturation level indicative of the damage or destruction of the alveolar, (meaning that a low level indicates the inability of the lungs to exchange gas and thus the damage to alveoli?

[Hidden]

I am not sure - I understand that low oxygen levels were an indication that other organs were at risk. I would imagine you are right - although it may just be the inability to expel enough air and therefore the inability to inhale enough "fresh" air to enable good gaseous exchange. I know that exhalation is a major problem for my husband which will relate to the damage and lack of elasticity in the alveoli which in turn means that as he never expels as much stale air as he should, he can never inhale an adequate amount of fresh air. TAD xx

[Suzy6 in reply to Hidden]

That is how it was explained to me TADAW. Which seemed to make sense.

[Offcut]

Not sure if this helps?

Effects of decreased oxygen saturation

SaO2 Effect:

85% and aboveNo evidence of impairment

65% and lessImpaired mental function on average

55% and lessLoss of consciousness on average

Healthy individuals at sea level usually exhibit oxygen saturation values between 96% and 99%. An SaO2 (arterial oxygen saturation) value below 90% causes hypoxemia (which can also be caused by anemia). Hypoxemia due to low SaO is indicated by cyanosis, but oxygen saturation does not directly reflect tissue oxygenation. The affinity of hemoglobin to oxygen may impair or enhance oxygen release at the tissue level. Oxygen is more readily released to the tissues (ie, hemoglobin has a lower affinity for oxygen) when pH is decreased, body temperature is increased, arterial partial pressure of carbon dioxide (PaCO2) is increased, and 2,3-DPG levels (a byproduct of glucose metabolism also found in stored blood products) are increased. When the hemoglobin has greater affinity for oxygen, less is available to the tissues. Conditions such as increased pH, decreased temperature, decreased PaCO2, and decreased 2,3-DPG will increase oxygen binding to the hemoglobin and limit its release to the tissue.

Example pulse oximeter

Pulse oximetry is a method used to measure the concentration of oxygen in the blood. A small device that clips to the body (typically a finger but may be other areas), called a pulse oximeter, uses a special light to estimate the amount of oxygen in the blood. The clip attaches to a reading meter by a wire to collect the data. Oxygen levels may also be checked through an arterial blood gas test (ABG), where blood taken from an artery is analysed for oxygen level, carbon dioxide level and acidity.

[happyfeet59 in reply to Offcut]

When testing for oxygen need my nurse takes arterial blood gas as this gives a more accurate reading than capillary gasses (oxymeter on finger, ear blood). She also said that she doesn't use the eg 86% reading but looks at different measurements for pressure and at the co2 readings too. The oximeter gives a quck indication of what is happening but not the full picture.

Other than that I know very little about why I am desaturating

[Hidden]

That's a hard one, I would say no I don't think low oxygen levels are an accurate indication of the extent of lung damage. I say this because I know of people with severe lung damage who don't use oxygen and others who have moderate lung damage who do require it.

Oxygen only is prescribed if arterial blood gas indicates blood oxygen levels are below the norm.

It sort of makes sense that the more damage to the alveoli the more difficult it would be to achieve a good gas exchange, it may be the situation in some cases.

Not sure if I have entirely understood what you are saying, I don't think low oxygen levels would cause more alveoli damage. Probably we would each have to study more extensively the way the lungs work and the gas exchanges. But I am sure the respiratory consultant could advise on this query and the BLf helpline also

Best wishes BC