1 Intensive Care Medicine and Anaesthesia, Southmead Hospital, Bristol BS10 5NB, United Kingdom. Electronic address: Alex.Manara@nbt.nhs.uk.
2 Organización Nacional de Trasplantes, C/Sinesio Delgado 6, pabellón 3, 28029 Madrid, Spain.
3 Division of Critical Care Medicine, Neurocritical Care Unit, Complejo Hospitalario, Universitario de Granada, Avenida del Conocimiento 33, 18016 Granada, Spain.
4 Intensive Care Medicine and Anaesthesia, Southmead Hospital, Bristol BS10 5NB, United Kingdom.