What could cause a prolonged capillary refill time?

A prolonged capillary refill time can indicate impaired perfusion and is often associated with decreased blood flow resulting from low cardiac output. In children, capillary refill time is an important indicator of cardiovascular status; it reflects the effectiveness of the circulation and the ability of the heart to pump blood adequately to the peripheral tissues. Situations that reduce blood flow or oxygen delivery, such as low cardiac output, can lead to delayed capillary refill, as the blood may not be reaching the extremities efficiently.

In contrast, adequate hydration supports vascular volume and blood flow, while high blood pressure is generally indicative of efficient circulation, not a cause of prolonged capillary refill. Similarly, normal body temperature would not contribute to a prolonged capillary refill since hypothermia or other temperature extremes are associated with changes in perfusion. Therefore, low cardiac output is the appropriate answer because it directly impacts the ability to maintain normal capillary refill times in pediatric patients.