1 Anesthesia and Intensive Care, Fondazione IRCCS Policlinico S. Matteo, Pavia, Italy. Electronic address: silvia.mongodi@libero.it.
2 Anesthesia and Intensive Care, Fondazione IRCCS Policlinico S. Matteo, Pavia, Italy; Department of Clinical-Surgical, Diagnostic and Pediatric Sciences, Unit of Anesthesia and Intensive care, University of Pavia, Pavia, Italy.