Transcutaneous auricular vagus nerve stimulation effects on inflammatory markers and clinical evolution of patients with COVID-19: a pilot randomized clinical trial

Objective: To evaluate the effects of transcutaneous auricular vagus nerve stimulation (taVNS) on inflammatory markers and clinical outcomes in patients with COVID‐19. Methods: A randomized blinded pilot study was carried out with 21 individuals hospitalized with COVID‐19 who received 14 sessions of active (a‐taVNS) or sham taVNS (s‐taVNS). The level of interleukin‐6 (IL‐6), interleukin‐10 (IL‐10), cortisol, and C‐reactive protein (CRP) in plasma and clinical evolution pre‐ and post‐intervention were evaluated. The memory and attention levels were evaluated 14 days after the end of the treatment. Results: After treatment, significant intragroup differences were found in the CRP (p = 0.01), IL‐6 (p = 0.01), and cortisol (p = 0.01) levels; however, in the comparison between the groups, only the CRP level was statistically lower for the a‐taVNS (p = 0.04). The impression of improvement in memory and attention was greater in the a‐taVNS than in the s‐taVNS (p = 0.01, p = 0.04, respectively). There was no difference between the other clinical outcomes. Conclusions: taVNS is a viable and safe intervention in the acute care of patients with COVID‐19, which can modulate their inflammatory profile and improve cognitive symptoms. However, improvements in overall clinical outcomes were not detected. Larger sample sizes and longer follow‐ups are needed to confirm the anti‐inflammatory and clinical effects of taVNS in patients with COVID‐19. Trials Registry: The Brazilian Registry of Clinical Trials (RBR–399t4g5).