1Perioperative, Acute, Critical Care and Emergency Medicine (PACE) Section, Department of Medicine, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK. andrea.lavinio1@nhs.net.
2Departments of Intensive Care Medicine & Anaesthesia, Cambridge University Hospitals NHS Foundation Trust, Cambridge Biomedical Campus, Cambridge, CB2 0QQ, UK. andrea.lavinio1@nhs.net.
3Department of Health Sciences, University of Florence, Florence, Italy.
4Department of Anaesthesia and Intensive Care, Azienda Ospedaliero-Universitaria Careggi, Florence, Italy.
5Perioperative, Acute, Critical Care and Emergency Medicine (PACE) Section, Department of Medicine, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK.
6Departments of Intensive Care Medicine & Anaesthesia, Cambridge University Hospitals NHS Foundation Trust, Cambridge Biomedical Campus, Cambridge, CB2 0QQ, UK.
7Masimo Corporation, Irvine, CA, USA.