Final answer:
The radial pulse is assessed to establish a baseline for the patient's vital signs, which includes monitoring heart rate and rhythm.
Step-by-step explanation:
The nurse initially assesses the patient's radial pulse during the admissions process primarily for the establishment of a baseline as part of the patient's vital signs. This assessment allows healthcare providers to monitor changes in the patient's condition and respond accordingly. The radial pulse provides information about heart rate and rhythm which are critical elements of the circulatory system's functioning. It is not specific to the assessment of peripheral blood perfusion, cardiovascular disease risk, or determination of oxygen saturation—though these can be indirectly affected by pulse characteristics.