Tailored MgSO4 Supplementation to Reduce Complications in Pediatric Heart Surgery

Lay Summary This study tests two ways of measuring blood magnesium after heart surgery. Children who need heart surgery may have heart and kidney problems after surgery. The right amount of magnesium in blood reduces this risk. This study will test the best way to measure magnesium. This will let doctors choose the right dose of MgSO4. MgSO4 is a magnesium supplement. Taking MgSO4 after heart surgery helps children. For each child, it is best to personalize MgSO4 dose. This is based on the amount of magnesium in blood. This study will test two ways of personalizing MgSO4 dose. In the blood, there are two kinds of magnesium. Usually, blood magnesium tests measure both forms together. This does not say anything about active magnesium. This study will measure the two forms separately. Then, MgSO4 will be given based on either the active or whole magnesium. Measuring active magnesium is good. Active magnesium levels change faster than total. That means active magnesium tests may better protect children. Also, active magnesium has more of an impact on heart and kidney function. Focusing on the active form will help these organs stay healthy. To test how well the MgSO4 is working, heart and kidneys will be examined. After surgery, certain harmful heart rhythms can occur. The types and number of harmful rhythms will be studied. Kidney problems can also happen after heart surgery. Kidney health will be studied. To help understand how active magnesium works, further tests will be done. These tests will look for evidence of poor health in the cells that make up the heart, kidney, and blood.