Phrenic nerve injury during cardiac surgery: mechanisms, management and prevention.

Phrenic nerve injury is a well-recognised complication of cardiac surgery that can lead to disabling effects from diaphragmatic dysfunction, especially in children and patients with a history of chronic obstructive airway disease. Various mechanisms of injury have been recognised including hypothermia, mechanical trauma and possibly ischaemia. A clear understanding of these mechanisms is important in order to modify surgical techniques to prevent this serious complication of cardiac surgery.