These include exercise, sleep, and during procedures such as surgery. Contraindications for exercise may be found in the section on cardiopulmonary exercise testing. Permanent or disposable sensors should be applied according to the manufacturer's instructions. When finger probes are used, the patient should be instructed not to grip treadmill rail or handlebars tightly to avoid reduction of circulation to the digits.
Preparation depends on the type of test being performed.
Exercise patients should wear loose comfortable clothing. Patients should refrain from smoking 24 hours prior to test to avoid functional versus fractional O 2 saturation discrepancy that occurs with elevated carboxyhemoglobin levels. Draw the heparinized arterial blood sample while the pulse oximetry sensor is in place and is stable. This adjustment should also be made to determine the therapeutic endpoint when titrating supplemental oxygen therapy at rest, during sleep, or exercise. Monitor ECG, blood pressure, and patient status frequently during the first 5 minutes after a maximum exercise test.