A 2-year-old arrives with a 2-day history of vomiting and diarrhea. The patient has a fever of 38.4oC (101.2°F), resting HR of 152 beats/minute, RR of 34 breaths/minute, and blood pressure of 94/ 56 mm Hg. Assessment reveals a capillary refill time of > 5 seconds. Which of the following would be most indicative of the need for intravenous rehydration therapy for this patient?
