What should be given to treat hypotension in a child experiencing anaphylaxis?

The use of isotonic crystalloid solution is the appropriate treatment for hypotension in a child experiencing anaphylaxis because it helps to rapidly expand the intravascular volume and improve blood pressure. Anaphylaxis leads to severe allergic reactions that can cause widespread vasodilation and increased capillary permeability, resulting in significant fluid loss into the interstitial space. Administering isotonic crystalloid solutions, such as normal saline or lactated Ringer's solution, helps to counteract this fluid loss and restore circulating blood volume, thereby stabilizing the child's hemodynamic status.

Other options, while they may have their own applications in different contexts, are not indicated for the treatment of hypotension due to anaphylaxis. Oral rehydration salts are typically used for treating mild to moderate dehydration from conditions like diarrhea, not for acute hypotension in a severe allergic reaction. Continuous morphine infusion is unrelated to the management of anaphylaxis and could complicate the clinical scenario by depressing respiratory function. Hypertonic saline may be used in specific situations, particularly in cases of severe hyponatremia or traumatic brain injury, but it is not the first line for addressing hypotension in anaphylactic shock due to the risk of hypernatremia and