1. Department of Anesthesia and Intensive Care Region VästraGötaland Sahlgrenska University Hospital Gothenburg Sweden
2. Department of Anesthesiology and Intensive Care Institute of Clinical Sciences Sahlgrenska Academy University of Gothenburg Gothenburg Sweden
3. Department of Neurosurgery Region VästraGötaland Sahlgrenska University Hospital Gothenburg Sweden
4. Department of Clinical Neurosciences Institute of Neuroscience and Physiology Sahlgrenska Academy University of Gothenburg Gothenburg Sweden