Influence of Local Anesthesia on Autonomic Nervous Activity in Healthy Young Adults: Evaluation of Heart Rate Variability

Abstract

Objective: Proper understanding of the systemic effects of various dental therapies is essential for dental professionals to safely treat their patients. In the present study, we used a novel autonomic nervous activity (ANA) monitoring system to investigate the ANA changes that occur in healthy young adult volunteers while receiving local anesthesia. Methods: Twenty volunteers (27.0 ± 2.9 years) participated in the study. First, subject anxiety about dental treatment was evaluated using Corah’s Dental Anxiety Scale (DAS). Next, the monitoring system was used to assess blood pressure (BP), heart rate (HR), and ANA for 3 minutes prior to anesthesia (pre-anesthesia) in sitting and supine positions, 2 minutes during administration of local anesthesia in the supine position, and 3 minutes after anesthesia (post-anesthesia) in the supine and sitting positions. Subject anxiety and psychological stress experienced pre- and post-anesthesia were evaluated using visual analog scale (VAS) and salivary α-amylase activity (Aml). ANA was evaluated by analyzing the low-frequency and high-frequency spectral components of ECG R-R intervals. Parasympathetic nervous activity was indicated by HF, and Sympathetic Nervous Activity (SNA) was indicated by LF/HF. Results: BP, HR, VAS, and Aml did not differ significantly at any of the measurement intervals. SNA was significantly lower during local anesthesia (1.42 ± 0.24) than in the pre-anesthesia sitting position (3.43 ± 0.71) (p = 0.034). The study findings suggest that systemic effects of invasive stimuli during administration of local anesthesia to healthy young adults may be minimal compared to the effects of psychological stress and changes in body position. Conclusion: In healthy young adults, SNA at the time of local anesthesia administration in the supine position is lower than it is in the sitting position before anesthesia.