Which device is commonly used by therapists to assess activity tolerance by monitoring oxygen saturation during exercise and position changes?

• A. Swan-Ganz catheter
• B. Oximeter
• C. Arterial line
• D. Intracranial pressure monitor

Answer: (B)

Monitoring oxygen saturation during exercise and position changes is best done with a pulse oximeter. This noninvasive device attaches to a finger, toe, or earlobe and provides real-time values of SpO2 along with heart rate. In rehabilitation, watching SpO2 as a patient changes position (lie to sit to stand) or increases activity helps gauge how well the body is delivering oxygen to tissues under increased demand. If SpO2 stays within a safe range (typically above about 90% for many patients, with tighter thresholds for certain conditions), you can safely progress activity. If it desaturates—drops toward or below the threshold—you adjust the exercise intensity or duration or consider supplemental oxygen. Other options like Swan-Ganz catheters, arterial lines, or intracranial pressure monitors are invasive monitoring tools used in critical care or neurosurgical settings; they don’t provide the quick, noninvasive oxygen saturation feedback needed to assess activity tolerance during typical PT sessions.