1.
Posterior spinal instrumentation and fusion (PSIF) is a surgical procedure to correct adolescent idiopathic scoliosis [1]. In these procedures, intraoperative neurophysiological monitoring (IONM) is standard practice to detect and prevent potential neurological damage [1]. Anesthetic agents can have significant effects on IONM measurements by suppressing neural activity, resulting in potential IONM inconsistencies [2]. It is important to establish that anesthetic agents can be used safely during PSIF procedures without compromising IONM measurements. Intravenous lidocaine infusion therapy (IVLT) is a component of multimodal analgesia in PSIF that has been shown to decrease opioid requirements and improve postoperative pain outcomes in patients following spine surgery [3, 4]. Preliminary work published by our team found no evidence that IVLT had a negative impact on IONM during PSIF [5]. However, that was a retrospective study, in which the anesthetic regimen was not standardized, and the intervention was not randomly allocated. In the present work, we have applied the same analysis to a prospectively collected dataset, with randomized allocation, a standardized anesthetic regimen, and standardized IVLT dosing, to provide more robust evidence for the impact of IVLT on IONM.
Following approval from the University of British Columbia Children's and Women's Research Ethics Board (H18‐03103, 2019‐08‐22) and written informed parental consent and adolescent assent, a prospective randomized controlled trial was conducted to investigate the effects of IVLT as an adjunct to multimodal analgesia on 44 adolescents undergoing PSIF between December 2019 and May 2024 [6]. Participants were aged 10–19 years with an American Society of Anesthesiologists physical status of I to III who underwent single‐stage PSIF and received propofol‐opioid total intravenous anesthesia at BC Children's Hospital (Vancouver, Canada) (Table 1). Participants in the IVLT group received a 1 mg/kg bolus of preservative‐free lidocaine at the induction of anesthesia, then 2 mg/kg/h infusion for the next 8 h followed by a 1 mg/kg/h infusion for 40 h giving a total of 48 h of IVLT. Control participants received a 0.9% sodium chloride placebo with matching infusion rates. All other anesthetic agents and components of multimodal analgesia were standardized. Intraoperative data included timing and dose of IVLT and all other anesthetic agents, amplitude of motor evoked potentials, and amplitude and latency of somatosensory evoked potentials. Motor evoked potentials were reported for upper limbs, including bilateral adductor pollicis brevis and brachioradialis muscles, and lower limbs, including bilateral adductor hallucis and tibialis anterior muscles. Somatosensory evoked potentials were also reported for upper limbs, including bilateral ulnar nerves, and lower limbs, including bilateral posterior tibial nerves. Motor and somatosensory evoked potentials were captured at hourly snapshots and at the time of any reportable IONM event. A reportable event was defined as a reduction in amplitude of motor or somatosensory evoked potentials by ≥ 50% or an increase in the latency of somatosensory evoked potential by ≥ 10%. Data were analyzed using linear mixed‐effects modeling.
TABLE 1.
Participant details.
| Lidocaine (n = 23) | No lidocaine (n = 21) | |
|---|---|---|
| Age, years | 15 (14, 16.5) | 16 (15, 17) |
| Sex (female) | 21 (91%) | 15 (71%) |
| Weight (kg) | 53.0 (48.3, 58.4) | 54.6 (52.0, 59.6) |
| Surgery duration (min) | 282 (240, 372) | 294 (264, 312) |
| Curve magnitude (Cobb Angle), ° | 61.0 (54.5, 72.5) | 61.0 (56.0, 65.0) |
Note: Data presented as median (IQR) or n (%).
We analyzed data from 44 participants; demographic details are shown in Table 1. There was no difference in the occurrence of reportable IONM events, which were reported in 8/23 (35%) IVLT cases and 7/21 (33%) control cases; the total count of reportable IONM events was 10 in the IVLT group and 6 in the control group. Based on hourly snapshots, there was no evidence that IVLT had a detrimental effect on the measured change from baseline for motor evoked potential amplitudes in lower limbs (mean difference [MD] −10.8; 95% CI −143.4 to 121.9; p = 0.874; Figure 1) or upper limbs (MD −21.5; 95% CI −133.9 to 90.9; p = 0.708) or for somatosensory evoked potential amplitudes in lower limbs (MD −6.7; 95% CI −16.6 to 3.3; p = 0.188; Figure 1) or upper limbs (MD −6.7; 95% CI −23.5 to 10.1; p = 0.434). The confidence intervals do not suggest a clinically meaningful reduction in neurophysiological signals between IVLT and control groups.
FIGURE 1.
Change from baseline amplitude in motor evoked potentials (MEPs) and somatosensory evoked potentials (SSEPs) of lower limbs per hour of posterior spinal instrumentation and fusion surgery for adolescent idiopathic scoliosis in the no lidocaine (control) group and lidocaine (intervention) group.
This supplemental analysis addressed many of the limitations of our previous retrospective study and confirms that under more controlled conditions, a standardized regime of IVLT did not impact IONM in adolescents undergoing PSIF for idiopathic scoliosis. Further research is needed to corroborate these findings. This study highlights the importance of incorporating collection and analysis of neurophysiological monitoring data into any trial investigating the effect of anesthetic and analgesic drug interventions during PSIF surgery.
Funding
This work was supported by BC Children's Hospital Evidence to Innovation seed grant, BC Children's Hospital Clinical Research Support Development Award and BioTalent Canada student funding.
Data Availability Statement
Data are available on request from the authors.
References
- 1. Halsey M. F., Myung K. S., Ghag A., Vitale M. G., Newton P. O., and de Kleuver M., “Neurophysiological Monitoring of Spinal Cord Function During Spinal Deformity Surgery: 2020 SRS Neuromonitoring Information Statement,” Spine Deformity 8 (2020): 591–596, 10.1007/s43390-020-00140-2. [DOI] [PubMed] [Google Scholar]
- 2. Sloan T., “Anesthesia and Intraoperative Neurophysiological Monitoring in Children,” Child's Nervous System 26 (2010): 227–235, 10.1007/s00381-009-1023-3. [DOI] [PubMed] [Google Scholar]
- 3. Batko I., Kościelniak‐Merak B., Tomasik P. J., Kobylarz K., and Wordliczek J., “Lidocaine as an Element of Multimodal Analgesic Therapy in Major Spine Surgical Procedures in Children: A Prospective, Randomized, Double‐Blind Study,” Pharmacological Reports 72 (2020): 744–755, 10.1007/s43440-020-00100-7. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4. Lauder G. R., “A Review of Intravenous Lidocaine Infusion Therapy for Paediatric Acute and Chronic Pain Management,” in Pain Relief—From Analgesics to Alternative Therapies, ed. Maldonado C. (InTech, 2017), 10.5772/66771. [DOI] [Google Scholar]
- 5. Bates R., Cave F., West N., et al., “Intravenous Lidocaine Infusion Therapy and Intraoperative Neurophysiological Monitoring in Adolescents Undergoing Idiopathic Scoliosis Correction: A Retrospective Study,” Pediatric Anesthesia 35 (2025): 47–56, 10.1111/pan.15019. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 6. Luo J., West N., Pang S., et al., “Perioperative Intravenous Lidocaine Infusion Therapy as an Adjunct to Multimodal Analgesia for Adolescent Idiopathic Scoliosis Surgical Correction: A Double‐Blind Randomized Controlled Trial,” Pediatric Anesthesia 35 (2025): 552–561, 10.1111/pan.15124. [DOI] [PMC free article] [PubMed] [Google Scholar]
Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Data Availability Statement
Data are available on request from the authors.