An 18-month-old child returned from the cardiac cath lab 1/2 hour ago. The child wakes up and begins crying. The nurse notices that the pressure dressing is becoming saturated with blood. The nurse's first action should be to:

Choice A reason: This is not a good choice. Watching for signs of cyanosis and administering high dose steroids are not the first steps in managing infective endocarditis. Cyanosis is a late sign of hypoxia and steroids are not indicated for this condition.

Choice B reason: This is the correct choice. Obtaining blood cultures, administering high dose antibiotics, and assessing for cardiac decompensation are the priority interventions for a child with infective endocarditis. Blood cultures are needed to identify the causative organism and guide antibiotic therapy. High dose antibiotics are needed to eradicate the infection and prevent further damage to the heart valves. Cardiac decompensation is a serious complication of infective endocarditis that can lead to heart failure and shock.

Choice C reason: This is not a good choice. Starting high dose antibiotics, obtaining serial blood cultures, and putting the child on high flow oxygen are not the best order of management for infective endocarditis. Blood cultures should be obtained before starting antibiotics to avoid false negative results. High flow oxygen may not be necessary unless the child has signs of hypoxia or respiratory distress.

Choice D reason: This is not a good choice. Obtaining CBC, CXR and starting child on high dose aspirin are not the first steps in managing infective endocarditis. CBC and CXR are useful tests to monitor the infection and the cardiac function, but they are not as urgent as blood cultures. High dose aspirin is not recommended for infective endocarditis as it can increase the risk of bleeding.

Choice A reason: Slowing the heart rate does not increase diastolic filling time. Diastolic filling time is the time during which the ventricles are relaxed and filling with blood. Slowing the heart rate would decrease the cardiac output and worsen the heart failure.

Choice B reason: Increasing urine output does decrease pulmonary congestion, but it is not the primary effect of Captopril. Captopril is an angiotensin-converting enzyme (ACE) inhibitor, which blocks the conversion of angiotensin I to angiotensin II, a potent vasoconstrictor. This reduces the blood pressure and the afterload on the heart. Diuretics are the drugs that increase urine output and reduce fluid overload.

Choice C reason: This is the correct choice. Decreasing the afterload means reducing the resistance that the heart has to overcome to pump blood to the body. This lowers the blood pressure and the workload on the heart, which improves the cardiac function and reduces the symptoms of heart failure.

Choice D reason: Increasing serum potassium does not improve cardiac performance. In fact, high levels of potassium can cause cardiac arrhythmias and cardiac arrest. Captopril can cause hyperkalemia (high potassium) as a side effect, which is why patients on this drug need to monitor their potassium levels and avoid potassium supplements or salt substitutes.