Final answer:
The nurse should prioritize and first assess the 70-year-old female with an irregular fast pulse, as it indicates a potential cardiac arrhythmia, which could be life-threatening.
Step-by-step explanation:
After receiving change-of-shift report about four patients, the nurse should assess the 70-year-old female taking levothyroxine (Synthroid) who has an irregular pulse of 134 first. An irregular pulse coupled with a fast heart rate could indicate atrial fibrillation or another form of tachyarrhythmia, which could be life-threatening and requires immediate assessment and intervention.
A 31-year-old female with Cushing syndrome and a blood glucose level of 244 mg/dL may require prompt attention, but the situation is not as immediately critical as that of the patient with the irregular, fast pulse rate. A 53-year-old male with Addison's disease needing a dose of hydrocortisone and a 22-year-old male with SIADH with a low sodium level also require assessments, but these situations generally do not pose the same acute risk as a potential cardiac arrhythmia.