Patient monitoring will include electrocardiographic lead II, intra-arterial pressure (+/- cardiac index with PICCO plus, Pulsion Medical Systems, Munich, Germany)], and peripheral oxygen saturation (SaO2). Anesthesia will be maintained with midazolam and/or propofol, and fentanyl or remifentanil. Nrutomuscular blockade will be accomplished with cisatracurium, which will be used in concordance with current recommendations and as part of the attending physician-prescribed medical treatment. During the study period, all patients will be receiving a continuous infusion of cisatracurium.