Final answer:
The correct answer is 'patients with hypovolemia'. Intraosseous lines are used for emergency access when intravenous access is not possible, particularly useful for patients with significantly low blood and fluid levels, known as hypovolemia.
Step-by-step explanation:
Placing an intraosseous line is appropriate for patients with hypovolemia when rapid intravenous access cannot be obtained. Hypovolemia is defined as abnormally low levels of fluid and blood within the body, which can lead to hypovolemic shock, a type of circulatory shock caused by excessive loss of blood volume due to hemorrhage or possibly dehydration. In such emergency situations where intravenous access is challenging, intraosseous infusion is a reliable method that allows for the delivery of fluids directly into the bone marrow where they can then enter the systemic circulation.
When a dehydrated human patient needs to be given fluids intravenously, it is common practice to provide isotonic saline, which is at a concentration that is isotonic with respect to body fluids, to ensure the safe and effective restoration of fluid balance without causing harm to the body's cells.