Which client should the nurse assess first based on potential instability?

The client with new-onset atrial fibrillation receiving IV diltiazem should be assessed first due to the immediate potential for hemodynamic instability associated with this condition. Atrial fibrillation can lead to rapid ventricular rates, which may result in decreased cardiac output, hypotension, and increased risk for thromboembolic events such as stroke. The use of IV diltiazem indicates an acute management of the arrhythmia, reinforcing the need for continuous assessment to monitor for response to treatment and any signs of instability.

In contrast, other clients presented, such as those with end-stage heart failure on hospice care, may have complex needs but are typically in a more stable phase of their care where immediate life-threatening changes are less likely. The clients admitted one and two days ago with thrombophlebitis and heart failure may require ongoing monitoring and care, but they do not present the same acute risk of instability as a patient experiencing new-onset atrial fibrillation. Therefore, the focus on the client receiving IV diltiazem is warranted to ensure timely intervention if complications arise.