Final answer:
The highest priority nursing assessment for a client with ulcerative colitis and severe diarrhea is monitoring blood pressure due to the risk of dehydration-induced hypotension.
Step-by-step explanation:
The priority nursing assessment for a client with ulcerative colitis and severe diarrhea should focus on blood pressure. This is because severe diarrhea can lead to dehydration, which can cause a drop in blood pressure and may lead to hypovolemic shock, a life-threatening condition. While skin integrity, heart rate and rhythm, and abdominal percussion are important assessments, the immediate risk associated with severe diarrhea is the potential for dehydration and subsequent hypotension.
Ulcerative colitis is an inflammatory bowel disease that can lead to significant fluid loss, making blood pressure a critical sign to monitor in these patients. Consistent diarrhea, as seen in the case study where a patient experienced watery diarrhea, loss of appetite, and signs of dehydration, underscores the need for vigilant monitoring of blood pressure. Should a significant drop in blood pressure be observed, it may indicate hemorrhage or dehydration, which requires prompt intervention.