NEUROANESTHESIA (D SHARMA, SECTION EDITOR)
Optimizing Intraoperative Neuromonitoring: Anesthetic Considerations
Christoph N. Seubert
Springer Science+Business Media, LLC, part of Springer Nature 2018
Purpose of Review Intraoperative neuromonitoring (IONM) offers near-real-time assessment of neuronal pathways during
surgery. Anesthetic regimens and derangements in homeostasis may render IONM ineffective and challenge its clinical utility.
We review important anesthetic considerations for optimizing IONM modalities sensitive to these factors including sensory- and
Recent Findings Anesthetic management during IONM requires consideration and the balance of multiple competing goals
related to depth of anesthesia, patient comorbidities, and surgical requirements. Inhalational anesthetics in higher concentrations
unequivocally depress IONM signals and should be used judiciously or avoided altogether in specific cases. The addition of
adjuncts such as dexmedetomidine and lidocaine to carefully composed and titrated intravenous anesthetic regimens allows for
propofol dose reduction and the optimization of IONM. Hypothermia, cerebral/spinal cord hypoperfusion, and reduced oxygen
delivery should be avoided and corrected to maintain homeostasis for optimized neuronal functioning and IONM.
Summary Optimization of anesthetic management contributes to successful integration of IONM into perioperative care.
Keywords Intraoperative neuromonitoring
Intraoperative neuromonitoring (IONM) is dependent on reli-
able acquisition of electrophysiologic (EP) recordings of the
small electrical signals generated by the neuronal pathways
being monitored. EP signals may thus be regarded as surro-
gate markers of neuronal function and can be thought of as a
repeated but limited neurological examination under general
anesthesia [1•]. The primary purpose of IONM is to promptly
detect a decline in neuronal function and to immediately trig-
ger appropriate interventions to treat reversible causes, which
would otherwise lead to permanent neurological injury .
Outcomes such as stroke or paraplegia, targeted for prevention
through integrating IONM into perioperative care, are typical-
ly rare but are devastating and associated with significant
downstream costs . For IONM to add value, it is therefore
important to consistently achieve high-quality integration of
IONM into perioperative care.
Optimal IONM requires a good real-time communication
between the neuromonitorists, the anesthesiologist, and the sur-
geon. Such teamwork is best achieved when everyone who
participates in the care of a specific patient has a detailed mental
model of the operative procedure as it affects that patient. Such
a model should be the basis for planning the surgical approach,
the IONM modalities, as well as the anesthetic and should be
followed by open communication among all team members
throughout the phases of the procedure. No individual team
member can make neuromonitoring work by him/herself, but
each has the capacity to render neuromonitoring ineffective.
The term IONM has a broader definition encompassing a wide
variety of monitoring strategies in the operating room including
electrophysiologic, Doppler ultrasonography, and near-infrared
modalities to name a few. However, the term IONM is com-
monly used in a narrower context referring to electrophysiolog-
ic monitoring (EPM) and these terms will be used interchange-
ably in our review.
This review will focus on aspects of perioperative anesthet-
ic management that contribute to optimal integration of IONM
This article is part of the Topical Collection on Neuroanesthesia
* Christoph N. Seubert
Department of Anesthesiology, University of Florida College of
Medicine, 1600 SWArcher Road, Gainesville, FL 32610-0254, USA
Current Anesthesiology Reports