NCT06055270

Stellate Ganglion Block With Lidocaine for the Treatment of COVID-19-Induced Parosmia

Stellate Ganglion Block With Lidocaine for the Treatment of COVID-19-Induced Parosmia: Double-Blinded, Placebo-Controlled Randomized Clinical Trial

• Status: Recruiting
• Phase: Phase 3
• Study type: Interventional
• Enrollment: 44 (estimated)
• Sponsor: London Health Sciences Centre Research Institute OR Lawson Research Institute of St. Joseph's · Academic / Other
• Sex: All
• Age: 18 Years – 70 Years
• Healthy volunteers: Not accepted

Summary

Chronic olfactory dysfunction, both hyposmia and parosmia, from the COVID-19 pandemic is a growing public health crisis, affecting up to 1.2 million people in the United States. Olfactory dysfunction significantly impacts one's quality of life by decreasing the enjoyment of foods, creating environmental safety concerns, and affecting one's ability to perform specific jobs. Olfactory loss is also an independent predictor of anxiety, depression, and mortality. Recent research suggests that parosmia, more so than hyposmia, can increase anxiety, depression, and even suicidal ideation. While the pandemic has advanced the scientific community's interest in combating the burgeoning health crisis, few effective treatments currently exist for olfactory dysfunction. Persistent symptoms after an acute COVID-19 infection, or "Long COVID" symptoms, have been hypothesized to result from sympathetic nervous system dysfunction. Stellate ganglion blocks have been proposed to treat this hyper-sympathetic activation by blocking the sympathetic neuronal firing and resetting the balance of the autonomic nervous system. Studies before the COVID-19 pandemic have supported a beneficial effect of stellate ganglion blocks on olfactory dysfunction, and recent news reports and a published case series have described a dramatic benefit in both olfactory function and other long COVID symptoms in patients receiving stellate ganglion blocks. A previous pilot study using stellate ganglion blocks of 20 participants with persistent COVID-19 olfactory dysfunction resulted in modest improvements in subjective olfactory function, smell identification, and olfactory-specific quality of life, but it lacked a control group. Therefore, we propose a double-blinded, placebo-controlled, randomized clinical trial assessing the efficacy of a stellate ganglion block with Lidocaine versus saline injection in up to 50 participants with persistent COVID-19-associated olfactory dysfunction.

Detailed description

This will be a double-blinded, placebo-controlled, randomized clinical to assess the efficacy of Stellate Ganglion Block with Lidocaine 1% (8mL). Participants with parosmia will be randomly assigned to SGB with Lidocaine 1% (8mL) or Placebo (saline solution). Baseline assessment will happen in person and will consist on demographic information, Parosmia Olfactory Dysfunction Outcomes Rating (DisODOR), Clinical Global Impression: Severity Scale (CGI-S), University of Pennsylvania Smell Identification Test (UPSIT), Long-COVID Questionnaire (LCQ), Olfaction Catastrophizing Scale (OCS), Hospital Anxiety and Depression Scale (HADS), Pre-Intervention Expectations. Then, after the assigned interventional procedures are performed three remote visits will be performed as follow-ups (1, 3, and 12 months), in which the variables above will be reassessed.

Conditions

• Parosmia

Interventions

Type	Name	Description
PROCEDURE	Stellate Ganglion Block	All SGBs will be performed by a board-certified anesthesiologist and pain management specialist with extensive experience performing SGBs. The laterality of the SGB will be randomized between the left and right sides of the neck. Participants will be asked to abstain from eating and drinking for 8 hours prior to the SGB. Using ultrasound guidance, the transverse process of the C6 vertebra is identified. Color-doppler is used to identify blood vessels. A 27-gauge needle is used to anesthetize the superficial skin with 1% lidocaine. Then, a 21-gauge ultrasound needle is advanced using an in-plane technique from lateral to medial with careful avoidance of neurovascular structures. After negative aspiration, 8 mL of 1% Lidocaine is deposited beneath the prevertebral fascia and above the Longus coli muscle into the stellate ganglion.
OTHER	Placebo	The placebo sham injection will be performed in an identical fashion as the stellate ganglion block, with the exception of using 8 mL of 0.9% saline injection instead of Lidocaine

Timeline

• Start date: 2024-02-15
• Primary completion: 2025-12-24
• Completion: 2026-05-15
• First posted: 2023-09-26
• Last updated: 2024-10-23

Locations

1 site across 1 country: Canada