About the Author John Kellum is a Professor of Critical Care at the University of Pittsburgh School of Medicine. Scott Gunn is an Assistant Professor of Critical Care at the University of Pittsgurgh School of Medicine. Mervyn Singer is a Senior Lecturer in Intensive Care Medicine, Director, Bloomsbury Institute of Intensive Care Medicine at the University College London Medical School. Andrew Webb is Clinical Director and Consultant Physician in the Department of Intensive Care at the University College London Hospitals.