A Prospective Look at the Prevalence of Setup Electrode-Swap Errors Across Over 450 Intraoperative Neuromonitoring Cases

ABSTRACT

Intraoperative neurophysiological monitoring (IONM) is shown to be useful in surgeries when the nervous system is at risk. Its success in part relies upon proper setup of often dozens of electrodes correctly placed and secured upon patients and inserted in specific stimulating and recording receptacles. Given the complicated setups and the demanding operating room environment, errors in setup are bound to occur. These have led to false negatives associated with new patient morbidities including, at times, paralysis. No studies quantify the prevalence of these types of setup errors. Approximately 800,000 operations annually utilize intraoperative neuromonitoring in the US alone, so even a small percentage of errors suggests clinical significance. In addition, these types of errors hinder the overall effectiveness of IONM and may result in lower reported sensitivities and lower cost-effectiveness of this important service. We sought to discover through a prospective study and verification through chart review the prevalence of “electrode-swap” errors (when recording and/or stimulating electrodes are incorrectly placed on the patient or in the IONM equipment during setup) across all procedures monitored. We found recording and/or stimulating electrode set up errors in 24 of 454 cases (5.3%). These data and examples of how errors were discovered intraoperatively are reported. We also offer techniques to help reduce this error rate. This study demonstrates a significant potential avoidable error in IONM diagnostic utility, patient outcome, and sensitivity/specificity of alert criteria. The value of identifying and correcting these errors is consequential, multifaceted, and far-reaching.

KEY WORDS:

• Electromyography (EMG)
• false negative
• intraoperative neurophysiological monitoring (IONM)
• somatosensory-evoked potentials (SSEP)
• transcranial electrical motor-evoked potentials (MEP)

ACKNOWLEDGMENTS

The authors wish to thank Gene Balzer, Ph.D., FASNM, FAAA, for his kind time, advice and comments for this submission.

DISCLOSURE STATEMENT

No potential conflict of interest was reported by the author(s).

Additional information

Funding

 The author(s) reported there is no funding associated with the work featured in this article.