The effect of muscle relaxants need to be followed during surgery and before waking up the patient, the anesthesiologist has to make sure that the effect of muscle relaxants is gone. For this purpose, anesthesiologists use so called objective neurlmuscular monitors. These monitors stimulate the ulnar nerve in the wrist and examine the evoked muscle response. The aim of this study is to examine the usability of another nerve in the wrist, the median nerve.

Inclusion Criteria:

• ASA I-III physical status
• elective surgery requiring muscle relaxation
• both arms are available during surgery in the same position for neuromuscular blockade monitoring
• signed informed consent form

Exclusion Criteria:

• neruomuscular disorder in patient history (eg. stroke, myasthenia)
• innervation problem in either arms (eg. carpal tunnel syndrome)
• deformity to either arms (eg. Dupyurten contracture, severe arthritis)
• Severe hepatic or renal insufficiency that affects muscle relaxant pharmacokinetics
• skin lesions at the site of electrode placement
• implanted pacemaker jelenléte
• gravidity
• muscle relaxant needs to be repeated during surgery

Adult patients undergoing elective surgery that requires one dose of non-depolarising neuromuscular blocking agent, whose arms are accessible for intraoperative neuromuscular blockade monitoring.