The goal of this study is to use electromyography-based train-of-four monitoring (TetraGraph™ Neuromuscular Transmission Monitor) as a means of evaluating differences in neuromuscular transmission between infants ≤ 3 months of age and adolescent and older patients (≥ 12 years of age).

Inclusion Criteria:

• ASA 1-3 patients
• Aged 28 days - 3 months or ≥ 12 years
• Undergoing a surgical procedure with a volatile-agent based anesthetic that does not require administration of a neuromuscular blocking agent

Exclusion Criteria:

• Patients with history of a peripheral neurologic or neuropathic disorder
• Patients in whom the upper extremity cannot be used for TOF monitoring
• Patients undergoing a surgical procedure in which neuromuscular blockade is required
• Edematous patients
• Patients receiving total intravenous anesthesia (TIVA)