Final answer:
The nurse should assess the client who is postoperative following a total knee arthroplasty with a capillary refill of 4 seconds first, as this could indicate a serious complication like a clot.
Step-by-step explanation:
A nurse has just received a report on four clients on a medical-surgical unit and needs to decide which client to assess first. The clients are: a) a client postoperative following a total knee arthroplasty with a capillary refill of 4 seconds, b) a client with a history of hypertension with a blood pressure of 150/90 mm Hg, c) a client admitted for pneumonia with a temperature of 38.2°C, and d) a client with diabetes mellitus who is due for a scheduled insulin injection in 30 minutes. The first client to be assessed should be the one with the potential for the most immediate life-threatening complication. A capillary refill time of more than 3 seconds can indicate poor circulation, which, after a surgery like a total knee arthroplasty, could mean a complication such as a clot. This requires prompt assessment and intervention if necessary. The other clients have issues that are concerning but not immediately life-threatening.