Vagus Nerve Stimulation ARDS Prevention Trial for COVID-19 Hospitalized Patients

Patients hospitalized with COVID-19 predominantly die of organ failure due to a surge of pro-inflammatory cytokines triggering the need for mechanical ventilation, often due to acute respiratory distress syndrome (ARDS). Known as a cytokine storm, the surge in cytokines is similar to the excessive inflammatory reaction associated with septic shock. Anti-viral agents will most likely be required to reduce the molecular viral burden in COVID-19 patients, but an additional approach to control the damaging cytokine release is required to alter the course of disease in hospitalized patients and improve chances of survival. Immunosuppressant drugs may reduce inflammation and the tissue damaging cytokines, but they could also be detrimental by inhibiting natural anti-viral immune responses (i.e., suppression of interferons), thereby delaying viral clearance and increasing the risk of secondary infections and death. The reason for the severity of the disease course in some individuals may lie in the regulation of the immune system by the vagus nerve. The vagus nerve is involved in an inflammation controlling reflex similar to the blood pressure regulating baroreflex. The vagus inflammatory reflex is triggered when the afferent vagus nerve senses inflammatory products through peripheral receptors. Vagus nerve activity is relayed through the central nervous system to the efferent vagus nerve. This pathway involves the splenic nerve, which when activated releases norepinephrine and results in suppression of pro-inflammatory cytokine production by macrophages and alleviates inflammation in many pathological settings (e.g., endotoxemia, peritonitis, or acute kidney injury). Electrical stimulation of the vagus nerve using VNS can improve the body's natural ability to regulate the inflammatory response and may be potent enough to suppress pro-inflammatory cytokines and prevent death from COVID-19, especially if used early enough in the course of hospitalization. In rat models of sepsis, VNS attenuates the release of pro-inflammatory cytokines, prevents hypotension, modulates coagulation, and prevents fibrinolysis activation, decreasing organ dysfunction, and improving survival. Human studies also demonstrate that VNS suppresses the production of pro-inflammatory cytokines and improves clinical symptoms in rheumatoid arthritis, intractable epilepsy, atrial fibrillation, and Crohn's Disease. This suggests that VNS may be effective in treating disorders characterized by cytokine dysregulation and that it has the potential to prevent hospitalized patients with COVID-19 from progressing to respiratory failure and death.