A nurse is reading a journal article about adolescents and major causes of unintentional injuries in this age group.

The nurse demonstrates understanding of this information by identifying which situation as the major cause of adolescent unintentional injuries?

Choice A rationale

An X-ray is a form of imaging used to visualize bones and soft tissues, which would be ordered to assess for structural problems or infection in organs like the lungs, but it is not the primary initial test for evaluating the overall function of the immune system.

Choice B rationale

An Electrocardiogram (EKG) is a diagnostic test that records the electrical activity of the heart, used to assess cardiac rhythm and function, and it would not be the initial test to investigate a suspected disorder of the body's immune defenses.

Choice C rationale

A urine analysis is a test that examines the physical, chemical, and microscopic properties of urine, primarily used to detect conditions like urinary tract infections or renal disease, and does not provide comprehensive information on immune status.

Choice D rationale

A Complete Blood Count (CBC) is anticipated because it provides a quantitative measure of white blood cells (WBCs), red blood cells (RBCs), and platelets, offering critical initial insights into the number and differential count of leukocytes, which are the main components of the immune system.

Choice A rationale

Administering furosemide, a loop diuretic, is often utilized in the management of patent ductus arteriosus (PDA) to decrease pulmonary congestion. This medication works by inhibiting sodium and chloride reabsorption in the ascending limb of the loop of Henle, which promotes diuresis and reduces the fluid volume overload contributing to respiratory distress, but it is not the primary mechanism to close the defect. The newborn's vital signs, especially the tachypnea and mild desaturation, suggest significant pulmonary overflow that needs corrective intervention.

Choice B rationale

Indomethacin, a nonsteroidal anti-inflammatory drug (NSAID), is a prostaglandin synthesis inhibitor which is the primary pharmacological treatment for closing a hemodynamically significant PDA in a premature infant. Prostaglandins, particularly PGE_2, maintain ductal patency, so blocking their production allows the ductus arteriosus to constrict and eventually close. The elevated pulse and respiratory rate in this newborn indicate a large left-to-right shunt requiring this specific closure therapy.

Choice C rationale

Initiating intravenous access is a necessary procedural step for administering medications like indomethacin or furosemide, but it is not the therapeutic "order" that directly addresses the pathophysiology of the PDA. Securing IV access is a prerequisite action for treatment, but Choice B represents the most critical therapeutic order to question for a patient presenting with symptomatic PDA and signs of pulmonary overcirculation.

Choice D rationale

While newborns with PDA often have increased caloric needs due to the work of breathing and potential heart failure, feeding a high-calorie formula every two hours is a supportive measure, not the urgent primary treatment. Furthermore, frequent, large feeds may exacerbate respiratory distress or necrotizing enterocolitis due to gut hypoperfusion in a severely compromised infant. The priority is to close the PDA and stabilize the cardiorespiratory status.