Cardiac Output and Recovery Time

Inclusion Criteria: * Age \> or = 18 years old. * Patients willing to participate and provide an informed consent. * Patients undergoing an elective surgical procedure requiring administration of rocuronium, and the use of a pulmonary artery catheter intraoperatively. Exclusion Criteria: * Patients with unilateral disorders, such as stroke, carpal tunnel syndrome, broken wrist with nerve damage, Dupuytren contracture. * Patients with systemic neuromuscular diseases such as myasthenia gravis. * Patients with significant organ dysfunction that can significantly affect pharmacokinetics of neuromuscular blocking and reversal agents, i.e., severe renal impairment or end-stage liver disease. * Patients having surgery that would involve prepping the arm or leg into the sterile field.