Intraoperative neurophysiological monitoring during spine surgery with total intravenous anesthesia or balanced anesthesia with 3 % desflurane

Abstract

Total intravenous anesthesia (TIVA) with propofol and opioids is frequently utilized for spinal surgery when somatosensory evoked potentials (SSEPs) and transcranial motor evoked potentials (tcMEPs) are monitored. Many anesthesiologists would prefer to utilize low dose halogenated anesthetics (e.g. 1/2 MAC). We examined our recent experience using 3% desflurane or TIVA during spine surgery to determine the impact on propofol usage and on the evoked potential responses. After institutional review board approval we conducted a retrospective review of a 6 month period for adult spine patients who were monitored with SSEPs and tcMEPs. Cases were included for the study if anesthesia was conducted with propofol-opioid TIVA or 3% desflurane supplemented with propofol or opioid infusions as needed. We evaluated the propofol infusion rate, cortical amplitudes of the SSEPs (median nerve, posterior tibial nerve), amplitudes and stimulation voltage for eliciting the tcMEPs (adductor pollicis brevis, tibialis anterior) and the amplitude variability of the SSEP and tcMEP responses as assessed by the average percentage trial to trial change. Of the 156 spine cases included in the study, 95 had TIVA with propofol-opioid (TIVA) and 61 had 3% expired desflurane (INHAL). Three INHAL cases were excluded because the desflurane was eliminated because of inadequate responses and 26 cases (16 TIVA and 10 INHAL) were excluded due to significant changes during monitoring. Propofol infusion rates in the INHAL group were reduced from the TIVA group (average 115-45 μg/kg/min) (p<0.00001) with 21 cases where propofol was not used. No statistically significant differences in cortical SSEP or tcMEP amplitudes, tcMEP stimulation voltages nor in the average trial to trial amplitude variability were seen. The data from these cases indicates that 1/2 MAC (3%) desflurane can be used in conjunction with SSEP and tcMEP monitoring for some adult patients undergoing spine surgery. Further studies are needed to confirm the relative benefits versus negative effects of the use of desflurane and other halogenated agents for anesthesia during procedures on neurophysiological monitoring involving tcMEPs. Further studies are also needed to characterize which patients may or may not be candidates for supplementation such as those with neural dysfunction or who are opioid tolerant from chronic use.

Impact of inhalation vs. intravenous anaesthesia on autonomic nerves and internal anal sphincter tone

“…An additional limitation of our study refers to a potential bias against volatile agents. Some authors recommend 0.5 MAC in combination with narcotics and propofol infusion to facilitate MEP monitoring . In our study BIS guidance led to higher MAC values (i.e.…”

“…As evoked potentials such as SSEPs and MEPs are affected by inhalational agents, this may also count for monitoring of the IAS. In connection with these procedures, depressing effects were not linear, but had a sharp effect above concentrations of 0.5 MAC . However, our endeavours targeted at autonomic nerves and smooth muscles.…”

A comparison of the effects of desflurane and total intravenous anaesthesia on the motor evoked responses in scoliosis surgery

“…tcMEPs were followed-up in a retrospective study of Sloan et al and they formed two groups of cases, as the TIVA (propofol-opioid) and desflurane (3%) (with 50% air) groups; additionally, opioid or propofol was administered in these groups. 10 When the groups were compared regarding the tcMEP and SSEP responses, no statistically significant differences were detected. The retrospective nature of the study, and non-randomized sampling of the patients may be considered as limitations to this study.…”

“…tcMEP monitorization, applied for decreasing intraoperative and post-operative neurological deficits in the course of high-risk and long-lasting scoliosis surgery, requires an appropriately developed method of anaesthesia, to achieve good consequences. 10 tcMEP responses are affected and inhibited by anaesthetic agents like neuromuscular blockers, inhalation anaesthetics, and nitrous oxide; however, these responses are known not to be affected by the TIVA method. 11,12 When inhalation anaesthetics were investigated, studies demonstrated that sevoflurane and isoflurane in particular depress the amplitudes of tcMEPs in a dose-dependent manner.…”

Anesthetic experience of Benedikt syndrome complicating lumbar spine involved multiple myeloma -A case report-

“…Furthermore, data regarding the relation between galantamine and motor evoked potential is scarce, but a previous clinical study demonstrated that motor evoked potential monitoring is reliable if T2/Tcontrol twitch height is ＞ 0.5 or train of four count is ＞ 2 [10]. Although it has also been reported that balanced desflurane anesthesia and total intravenous anesthesia provided similar hemodynamic responses and recovery profiles [11,12], total intravenous anesthesia is considered to have favorable pharmacokinetic and neurophysiological properties, to enhance the quality of intraoperative motor evoked potentials, and reduce the risk of procedure-related morbidity [13]. After considering the effects of inhalation agents on motor evoked potentials and train of four monitoring, we selected target controlled propofol and remifentanil infusion.…”