A comparison of the accuracy of ulnar versus median nerve stimulation for neuromuscular monitoring
نویسندگان
چکیده
BACKGROUND Inexperienced anesthesiologists are frequently unclear as to whether to stimulate the ulnar or median nerve to monitor the adductor pollicis. The primary purpose of this study was to determine whether monitoring the adductor pollicis by positioning the stimulating electrodes over the median nerve is an acceptable alternative to applying electrodes over the ulnar nerve. METHODS In 20 patients anesthetized with propofol and remifentanil, one pair of stimulating electrodes was positioned over the ulnar nerve. A second pair was placed over the median nerve on the other hand. The acceleromyographic response was monitored on both hands. Rocuronium 0.6 mg/kg was administered. Single twitch (ST) and train-of-four (TOF) stimulations were applied alternatively to both sites. RESULTS None of the patients showed a twitch response at either site after injection of rocuronium. There were no differences in the mean supramaximal threshold, mean initial TOF ratio, or mean initial ST ratio between the two sites. Bland-Altman analysis revealed a bias (limit of agreement) in the TOF and ST ratios over the median nerve of 7% (± 31%) and 26% (± 73%), respectively, as compared with the ulnar nerve. The median nerve TOF ratio was overestimated by 16.2%, as compared with that of the ulnar nerve value, and the median nerve ST ratio was overestimated by 72.9%, as compared to that of the ulnar nerve. CONCLUSIONS The ulnar and median nerves cannot be used interchangeably for accurate neuromuscular monitoring.
منابع مشابه
Prevalence of ulnar-to-median nerve motor fiber anastomosis (Riché-Cannieu communicating branch) in hand: An electrophysiological study
Background: Two main muscles studied in the hand for evaluation of median nerve injuries are opponens pollicis (OP) and abductor pollicis brevis (APB). However, Riché-Cannieu communicating branch (RCCB) may limit the use of these muscles in electrodiagnosis. This condition is confusing in the case of median nerve injuries. This study was conducted to evaluate the prevalence of RCCB. &...
متن کاملReliability of Upper Limb Neurodynamic Tests: Median, Radial and Ulnar Nerves
Objective: in the evaluation of peripheral nerves, upper limb neurodynamic tests are used to assess the mechanical sensitivity of the nerve. However, very little is known about the reliability of upper limb neurodynamic tests, especially for the radial and ulnar nerves. The aim of this study was to evaluate the reliability of neurodynamic tests of the upper extremities including median, radial ...
متن کاملBackground: Two main muscles studied in the hand for evaluation of median nerve injuries are opponens pollicis (OP) and abductor pollicis brevis (APB). However, Riché-Cannieu communicating branch (RCCB) may limit the use of these muscles in electrodiagnosis. This condition is confusing in the case of median nerve injuries. This study was conducted to evaluate the prevalence of RCCB. &...
متن کاملTWITCHER: a device to stimulate thumb twitch response to ulnar nerve stimulation.
OBJECTIVE To design and fabricate a device to simulate evoked thumb adduction in response to ulnar nerve stimulation. METHODS We implemented a computer-controlled, motorized thumb (TWITCHER) that responds to ulnar nerve stimulation by an unmodified peripheral nerve stimulator. Clinically realistic response patterns are generated for both depolarizing and non-depolarizing muscle relaxants and ...
متن کاملUlnar Nerve Changes Associated with Carpal Tunnel Syndrome Not Affecting Median Versus Ulnar Comparative Studies
Objective: The present study was conducted to assess the involvement of ulnar sensory and/or motor nerve fibers in patients with carpal tunnel syndrome (CTS) and whether this affects the accuracy of the median versus ulnar comparative tests. Patients and methods: The present study included 145 CTS hands and 71 asymptomatic control hands. Clinical examination was done. The following tests were d...
متن کامل