Glenn Shunt:Anaesthetic Concerns for a Non Cardiac Surgery

Patients with single ventricle physiology have single chamber for pulmonary and systemic venous return that is supplied in parallel leading to cyanosis and ventricular volume overload. Palliative surgeries in the form of superior cavo-pulmonary anastomosis, also known as Bidirectional Glenn shunt (BDG) and complete cavo-pulmonary anastomosis, also known as Fontan procedure are done to divert blood from superior vena cava and inferior vena cava respectively into pulmonary circulation. As a result systemic and pulmonary blood flow run in series and forward flow is dependent on the relationship of systemic vascular resistance and pulmonary vascular resistance. Patients who have undergone Glenn shunt usually have peripheral oxygen saturation in the range of 75-85 % as a consequence of non-diversion of blood from inferior vena cava into pulmonary circulation. Fontan procedure is done in a staged manner to avoid sudden unloading of ventricle leading to failure. Anaesthesiologists encounter patients with Glenn shunt for non-cardiac surgery before they have undergone completion Fontan. A thorough understanding of Glenn and single ventricle physiology is required to deal with such patients and meticulous approach to anesthesia management is required after discussing with the surgeons and cardiologist, regarding the type of non-cardiac surgery, and to know the functional status of Glenn shunt. The present review article aims to discuss the anaesthesia concerns, and search of terms such as 'anaesthetic management', 'Glenn shunt', 'cavopulmonary anastomosis', 'Fontan procedure' was carried out in KKH eLibrary, Medline, PubMed, and Google scholar focusing on current research, randomized control trials, review articles and editorials.