Final answer:
The school-age child with acute epiglottitis (C) should receive immediate care due to the life-threatening nature of the condition, which can rapidly lead to airway obstruction.
Step-by-step explanation:
When triaging clients in an emergency department, a nurse must prioritize care based on the severity and acuity of patients' conditions. Among the clients listed, the one who should receive immediate care is the school-age child who has acute epiglottitis, is drooling, and has an absence of spontaneous cough (option C). Acute epiglottitis is a life-threatening condition as it can lead to rapid airway obstruction. Prompt evaluation and treatment by a provider are critical to prevent respiratory arrest.
While the other conditions listed are concerning and require medical attention, they present with less immediate threat to life compared to acute epiglottitis which requires immediate intervention. The toddler with asthma (option A) and the one with otitis media (option B) may have distressing symptoms, but they are less likely to lead to immediate airway compromise. The adolescent with sickle cell disease (option D) is experiencing pain, which needs to be managed expeditiously, but pain management does not typically represent an immediate life-threatening situation compared to acute airway obstruction.