The protective role of lidocaine in surgeries involving trigeminal nerve manipulation: a meta-analysis of trigeminocardiac reflex prevention.

The trigeminocardiac reflex (TCR) is activated when the trigeminal nerve is manipulated through mechanical pressure, traction, or irritation. This leads to a rapid increase in parasympathetic activity, resulting in a decrease in heart rate (HR) and blood pressure, which can potentially lead to bradycardia, and cardiac arrest, with a prevalence of 14.5% during neurointerventional procedures (8). The aim of this study was to assess the effect of lidocaine injection on preventing TCR during cranial surgeries. We conducted a comprehensive search of PubMed, Web of Science, and Cochrane CENTRAL electronic databases for clinical trials comparing the use of lidocaine versus placebo, or no intervention for TCR prevention during cranial surgeries up until 20 May 2024. Meta-analyses were performed using fixed-effects models, and heterogeneity was assessed using I-squared and Chi-square tests. A total of five studies involving 421 patients were included in this meta-analysis. The incidence of TCR was significantly lower in the lidocaine group compared to the control group, with a risk ratio of 0.05 (95% CI 0.01 to 0.37, P = 0.003). Additionally, the lidocaine group had a relatively small change in HR, with a mean difference of -10.56 (95% CI -13.30 to -7.83 beat per minute, P = 0.00001). No statistically significant difference in mean arterial pressure was observed between the two groups (MD -5.15, 95% CI [-10.38 to 0.08 mmHg], P = 0.09). Our results suggest that lidocaine may be effective in preventing TCR and stabilizing HR. The use of lidocaine could be considered a prophylactic measure during cranial surgeries. Further studies are needed to investigate the optimal dose and timing of lidocaine administration.