Effects of Zero- and 90-Degree Abduction of Glenohumeral Joint on the Upper Extremity Nerve Conduction Velocity (NCV) in Patients with Diabetes Undergoing Coronary Artery Bypass Graft Surgery

Abstract

Background: The aim of this study was to evaluate the effect of arm position during coronary artery bypass surgery on neuropathic symptoms and nerve conduction velocity (NCV) of the upper extremity nerves in patients with diabetes. Methods: In this clinical trial, 20 patients with diabetes, who were candidates for open-heart surgery, were divided randomly into control and experimental group. During the operation, patient’s arm was positioned at 90 degree abduction and at the sides of the body in the experimental and control group, respectively. Electrodiagnostic tests including assessing amplitude and conduction velocity of sensory and motor nerves of radial, median and ulnar of left hand was performed. Physical examination was also done for checking the numbness and Paresthesia in both hands. Findings: The Comparison of the changes for mean of amplitude and NCV of radial, median and ulnar nerves showed significant change in the control group after operation (P < 0.050). The Comparison of the changes for mean of amplitude and NCV of radial, median and ulnar nerves showed significant change except in radial motor NCV and sensory amplitude of ulnar nerve in the test group after operation (P < 0.050). The comparison of mean values after operation between groups showed no significant changes except in sensory amplitude of ulnar nerve. Conclusion: Arm abduction at 90 degrees reduces the axonal injury of the ulnar sensory fibers during coronary artery bypass graft surgery.

Keywords

• Diabetes
• Nerve conduction velocity (NCV)
• Coronary artery bypass