While trying to use a finger probe to assess a patient's oxygenation status,

the respiratory therapist finds that the pulse rate and the ECG monitor heart rate are not con-sistent and the oxygen saturation measured by pulse oximeter (SpO2) reading is blank. The patient is awake, alert, and in no obvious respiratory distress. The respiratory therapist should first take which of the following actions?
1. Change the probe site.
2. Draw an arterial blood gas.
3. Adjust the probe position on the finger.
4. Remove the probe, and perform a capillary refill test.
a. 1 and 2 only
b. 2 and 3 only
c. 3 and 4 only
d. 1 and 4 only

ANS: C
The fact that the patient is awake, alert, and in no respiratory distress decreases the likelihood that the problem is with the patient. Therefore, the first action in this case should not be to draw an arterial blood gas (ABG). In cases where the pulse oximeter cannot identify a pulsatile signal, the oxygen saturation measured by pulse oximeter (SpO2) reading may not be present. This could be alleviated by adjusting the probe position on the finger. Absent SpO2 readings could also be due to low perfusion states. Performing a capillary refill test on the finger being used for the probe would show whether or not the finger has adequate blood flow. If this is true, the next step would be to change the site.