Dose-Response of Adenosine for Perioperative Pain

Inclusion Criteria: * Female gender; age 18 to 65 years; * American Society of Anesthesiology (ASA) physical classification I to III; * scheduled for non-emergent abdominal hysterectomy (with or without salpingo-oophorectomy) or myomectomy under general anesthesia; Exclusion Criteria: * ASA physical classification of IV or V; * documented history of cardiovascular disease including coronary artery disease, uncontrolled hypertension, aortic stenosis, congestive heart failure, cardiac arrhythmias or conduction defects greater that first degree atrioventricular (AV) block, sinoatrial (SA) or AV node disease including sick sinus syndrome or symptomatic bradycardia, presence of devices including pacemakers or internal defibrillators, or history of symptoms consistent with any of the aforementioned conditions (e.g., angina, dyspnea on exertion, paroxysmal nocturnal dyspnea); * history of asthma, bronchospastic lung disease, or hyper-reactive airway disease; * history of gout;