What are the causes of low o2 sats in asthma?

Updated July 19, 2017

Low Sa02 sats, or low oxygen saturations, in asthma patients are due to a process by which inflamed and constricted airways prevent adequate perfusion (oxygenation) of the bloodstream.

Understanding Asthma

Asthma is a condition in which the air pipes, or bronchi, suddenly begin to narrow as a result of inflammation. Smooth muscle tissue inside the bronchi contract during what is termed brochoconstriction, leading to breathing irregularities.

The Asthma Attack

During an asthma attack, the narrowing of the airways leads to increased breathing exertion in an attempt to force air in and out of the lungs.

Development of Hypoventilation

The struggle to breathe, which is characterised in asthmatics by chest tightness, coughing and wheezing, can lead to a condition of “underbreathing” or respiratory depression known as hypoventilation.

Inadequate Gas Exchange

Poor ventilation causes increased carbon dioxide retention and decreased oxygen saturation, as the lungs are incapable of performing properly.

Measurement and Terminology

Sa02 stands for arterial oxygen saturation. This measurement is captured by a pulse oximeter (probe on the finger), which will indicate lower oxygen levels in these asthma patients.

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About the Author

Nathan Schwartz holds a master's degree and works in the health care field as a technologist. Schwartz has five years of freelance writing experience, and has written reference material on a range of health and wellness topics.