Eisenmenger Syndrome

A patient with Eisenmenger syndrome may have chronic cyanosis and a low oxygen saturation that is usual for them while remaining clinically stable. The danger is not the number alone; it is a change from the patient’s baseline or a loss of the conditions that support forward systemic blood flow. A large congenital left-to-right shunt exposes the pulmonary circulation to excessive flow and pressure. Progressive pulmonary vascular remodelling raises pulmonary vascular resistance until the shunt becomes bidirectional or right-to-left, allowing deoxygenated blood to enter the systemic circulation. This model explains cyanosis, secondary erythrocytosis, exercise limitation, paradoxical emboli, and poor tolerance of dehydration, systemic vasodilatation, and anaesthesia. This is advanced pulmonary arterial hypertension associated with congenital heart disease. Assessment and treatment are shared with an adult congenital heart disease (ACHD) and pulmonary-hypertension centre. The RN recognizes deterioration, protects preload and systemic vascular resistance, prevents intravenous air entry, administers prescribed therapy, monitors response and adverse effects, and urgently notifies the ACHD/pulmonary-hypertension team or most responsible physician/NP about deterioration; the RN does not independently determine operability, prescribe therapy, or close the defect.