A nurse is monitoring an older adult female client who had a myocardial infarction (MI) for the development of an acute kidney injury (AKI). Which of the following findings should the nurse identify as indicating an increased risk of AKI?

Choice A Reason: Urine output is not a finding that should decrease with adequate fluid replacement. On the contrary, urine output should increase as the fluid therapy restores the renal perfusion and function. The nurse should monitor the urine output and ensure that it is at least 0.5 mL/kg/hr for adults and 1 mL/kg/hr for children.

Choice B Reason: Heart rate is a finding that should decrease with adequate fluid replacement. A high heart rate is a sign of hypovolemia, which occurs when the burn injury causes fluid loss from the intravascular space. The nurse should monitor the heart rate and expect it to decrease as the fluid therapy replenishes the blood volume and improves the cardiac output.

Choice C Reason: Weight is not a finding that should decrease with adequate fluid replacement. On the contrary, weight may increase as the fluid therapy restores the hydration status and corrects the fluid deficit. The nurse should monitor the weight and compare it with the pre-burn weight to evaluate the fluid balance.

Choice D Reason: Blood pressure is not a finding that should decrease with adequate fluid replacement. On the contrary, blood pressure may increase as the fluid therapy restores the vascular tone and improves the tissue perfusion. The nurse should monitor the blood pressure and expect it to increase as the fluid therapy compensates for the fluid loss.

Choice A Reason: This choice is incorrect because flatened neck veins are not a sign of cardiac tamponade. Cardiac tamponade is a condition in which fluid accumulates in the pericardial sac that surrounds the heart, causing compression and impaired filling of the heart chambers. This leads to reduced cardiac output and hypotension. One of the manifestations of cardiac tamponade is distended neck veins due to increased venous pressure and impaired venous return.

Choice B Reason: This choice is incorrect because bradycardia is not a sign of cardiac tamponade. Bradycardia is a condition in which the heart rate is slower than normal (less than 60 beats per minute). It may be caused by various factors such as vagal stimulation, medication side effects, hypothyroidism, or sinus node dysfunction. It may cause symptoms such as fatigue, dizziness, or syncope, but it does not indicate cardiac tamponade.

Choice C Reason: This choice is incorrect because sudden lethargy is not a specific sign of cardiac tamponade. Lethargy is a condition in which the person feels tired, sluggish, or drowsy. It may be caused by various factors such as sleep deprivation, depression, infection, anemia, or hypoglycemia. It may affect the person's mental and physical performance, but it does not indicate cardiac tamponade.

Choice D Reason: This choice is correct because muffled heart sounds are a sign of cardiac tamponade. Muffled heart sounds are heart sounds that are fainter or softer than normal due to reduced transmission of sound waves through fluid-filled pericardial sac. They may indicate that the heart function is compromised by cardiac tamponade and require immediate intervention such as pericardiocentesis (removal of fluid from pericardial sac).