Final answer:
The priority finding to report is the capillary refill time of 3 seconds, as it could indicate serious circulatory or cardiac issues that may require urgent medical attention.
Step-by-step explanation:
When a nurse in an emergency department is performing an admission assessment on a 2-week-old male newborn, the priority finding to report to the provider would be B) Capillary refill time of 3 seconds. The capillary refill time is an important indicator of circulatory efficacy and perfusion; a time above 2 seconds is typically considered abnormal and could signal circulatory or cardiac issues that may require urgent attention.
Other findings such as the presence of a single umbilical artery or weight loss might be significant but do not overrule immediate concerns related to perfusion, which can indicate severe health problems. Thus, the provider should be informed promptly about the prolonged capillary refill time to assess and manage potential emergencies.