Blood Tests

Many blood tests may be needed before and after heart surgery, or at other times. They may include blood counts to detect anaemia or infection, or chemical analysis to detect an imbalance in the blood or build up of harmful acid or waste products. During the early days after surgery and while patients are having drug treatment for congestive heart failure, chemical imbalances in the blood are frequent and may require medications to be altered. Some medicines need to be checked to see how much of it is in the child’s blood in order to assess whether the dose needs to be increased or decreased. Other tests may measure the effectiveness of a medication (e.g. anticoagulants). The presence of fever or other indications of possible infection will also need investigation with blood counts or blood cultures.