Pharmacokinetics of Post Operative Cefuroxime in Infants Undergoing Cardiac Surgery

Congenital heart defects are structural or functional anomalies in the heart that occur during fetal development and are present at birth. Congenital heart disease is the most common congenital structural malformation. The survival of children born with congenital heart disease has improved dramatically over the past thirty years, improvements in diagnosis, medical and surgical management as well as anaesthetic care has improved survival rates from 20% to 80%.

Paediatric cardiac surgery Children with congenital heart disease may undergo either closed or open heart surgery. In a closed operation, the heart and main blood vessels can be operated on while the heart is still beating. In open procedures, the heart is opened and the blood flow to the child's vital organs is supported by a heart-lung bypass machine (Cardio-pulmonary bypass - CBP). In light of improving outcomes recent years has seen a worldwide shift towards neonatal biventricular repair where possible. For those where repair is not possible then the majority will be offered surgical univentricular palliation typically requiring 'high-risk' surgery in the first few weeks. 'High risk' neonates undergoing cardiac surgery often spend prolonged periods on the intensive care requiring maximal support.

These patients on the intensive care unit can suffer from multi-organ failure due to a variety of reasons and may require cardiovascular and respiratory support, and also renal replacement therapy in the form of peritoneal dialysis or haemodialysis/filtration. As a result of organ failure/support and different cardiac anatomy and physiology, the pharmacokinetics of drugs used in this post-operative period could potentially vary greatly.

Post-operative surgical site infections Post operative wound infections in paediatric patients undergoing cardiothoracic surgery occurs in 2.3% to 8% of patients. This complication results in increased morbidity, longer hospitalisations and increased cost. A major strategy in reducing postoperative surgical site infections has been the use of perioperative antibiotics to reduce primarily gram-positive skin flora that colonises the skin and can potentially infect an open wound.

Of particular concern for patients undergoing cardiac surgery are deep sternal wound infections or mediastinitis. Associated mortality is significant and has been reported to be as high as 60% in adults although there is little comparable data for children.