What oxygen saturation level is a relative indication to stop exercise testing?

What oxygen saturation level is a relative indication to stop exercise testing?

• A. Peripheral oxygen saturation ≤90%.
• B. Peripheral oxygen saturation ≤80% is a relative indication to stop the test due to potential hypoxaemia.
• C. Peripheral oxygen saturation ≤85%.
• D. No oxygen saturation cutoff is used.

Answer: (B)

Monitoring oxygen saturation during exercise tests helps protect safety by catching hypoxaemia early. If the saturation falls to 80% or lower, that signals a substantial desaturation, indicating the body's oxygen delivery is struggling to meet the increased demand. Continuing the test at that level could increase the risk of adverse events, so it’s treated as a relative indication to stop or modify the test rather than proceeding unchecked. This threshold is used as a safety signal because it reflects meaningful oxygen deprivation to tissues during exertion. Other levels, like 85% or 90%, may indicate milder desaturation and aren’t the cutoff described in this guideline, and having no cutoff would remove an important safety check.

Monitoring oxygen saturation during exercise tests helps protect safety by catching hypoxaemia early. If the saturation falls to 80% or lower, that signals a substantial desaturation, indicating the body's oxygen delivery is struggling to meet the increased demand. Continuing the test at that level could increase the risk of adverse events, so it’s treated as a relative indication to stop or modify the test rather than proceeding unchecked. This threshold is used as a safety signal because it reflects meaningful oxygen deprivation to tissues during exertion. Other levels, like 85% or 90%, may indicate milder desaturation and aren’t the cutoff described in this guideline, and having no cutoff would remove an important safety check.