A nurse in an emergency department is caring for an infant who has a 2-day history of vomiting and an elevated temperature. Which of the following should the nurse recognize as the most reliable indicator of fluid loss?

During a sickle cell crisis, the child experiences severe pain due to the sickled red blood cells blocking blood flow in the vessels, leading to tissue ischemia and infarction. Pain is the hallmark symptom of sickle cell crisis and can occur in various parts of the body, such as the abdomen, chest, back, joints, and extremities.

A. Constipation is not a common symptom of sickle cell crisis. It may be associated with other conditions but is not directly related to sickle cell crisis.
C. High fever is not a typical finding in sickle cell crisis. Fever may occur due to infections, which individuals with sickle cell disease are at increased risk of developing, but it is not a direct symptom of the crisis itself.
D. Bradycardia (slow heart rate) is not commonly associated with sickle cell crisis. Tachycardia (rapid heart rate) may occur in response to pain, but bradycardia is not a typical finding.

For a child with hemophilia experiencing a joint injury, the best home treatment and therapy would be elevation and the application of ice to the affected joint. This approach helps reduce swelling and minimize bleeding in the joint.
Option A (factor VIII concentrates) is a treatment for hemophilia but is typically administered intravenously to replace the deficient clotting factor in the blood. It is not a home treatment for joint injuries.
Option C (nonsteroidal anti-inflammatory drugs - NSAIDs) may be used to manage pain and inflammation, but they do not address the underlying bleeding disorder in hemophilia or directly treat joint injuries.
Option D (DDAVP - synthetic vasopressin) is used in some types of hemophilia to temporarily raise factor VIII levels, but it is not typically used for joint injuries or as a home treatment.