In an emergency department, which client should the triage nurse assess first?

The client with sudden-onset chest pain and a heart rate of 110 beats per minute should be assessed first due to the potential for a life-threatening condition. Chest pain can indicate serious issues such as myocardial infarction or other cardiac events, especially when accompanied by a tachycardic heart rate. This presentation necessitates immediate evaluation and intervention, as time is crucial in preventing complications associated with cardiac problems.

In contrast, while the other clients may present with concerning symptoms, they do not typically pose an immediate risk of life-threatening conditions requiring urgent intervention. The client with type 2 diabetes who lost insulin should be monitored and managed, but while this situation is important, it is not as acute as the risk posed by chest pain. The client with pain and swelling in the right leg may be assessed for conditions such as deep vein thrombosis, which is serious but does not bear the same urgency as chest pain. Lastly, the client with left lower abdominal pain and diarrhea may be experiencing gastrointestinal issues, but these conditions generally are not as urgent as those associated with acute chest pain. Thus, the triage nurse's priority should focus on the client presenting with the most critical symptoms.