Resting blood oxygen levels. When not suffering from an exacerbation mine can be as high as 92% when sitting here at my computer typing. But rise and walk to another part of my home, or take part in any activity without oxygen and my levels may well fall into the low 80's, sometimes to 79%. Saturation levels that low is dangerous. At PaO 2 values greater than 60 mm Hg, the slope of the curve is reduced and becomes flat at values in the range of 80 mm Hg, which correlates with SaO 2 values of approximately 93% 3,4. Normal SaO 2 and SpO 2 values in healthy dogs and cats breathing room air (FiO 2 =21%) are approximately 97%. If you are very sick, your doctor may need to measure your blood oxygen levels using a blood sample from an artery, usually in your wrist. This is called an arterial blood gas test. Your doctor may test a sample of sputum (spit) or mucus from your cough to find out what germ is causing your pneumonia.
The Takeaway
- The Apnea Hypopnea Index (AHI) and oxygen desaturation levels are used to indicate the severity of obstructive sleep apnea.
Apnea Hypopnea Index (AHI)
The AHI is the number of apneas or hypopneas recorded during the study per hour of sleep. It is generally expressed as the number of events per hour. Based on the AHI, the severity of OSA is classified as follows:
- None/Minimal: AHI < 5 per hour
- Mild: AHI ≥ 5, but < 15 per hour
- Moderate: AHI ≥ 15, but < 30 per hour
- Severe: AHI ≥ 30 per hour
Sometimes the Respiratory Disturbance Index (RDI) is used. This can be confusing because the RDI includes not only apneas and hypopneas, but may also include other, more subtle, breathing irregularities. This means a person's RDI can be higher than his or her AHI.
Oxygen Levels Chart
Oxygen Desaturation
Reductions in blood oxygen levels (desaturation) are recorded during polysomnography or limited channel monitoring. At sea level, a normal blood oxygen level (saturation) is usually 96 - 97%. Although there are no generally accepted classifications for severity of oxygen desaturation, reductions to not less than 90% usually are considered mild. Dips into the 80 - 89% range can be considered moderate, and those below 80% are severe.
Normal Blood Oxygen Level
This content was last reviewed on February 11, 2011