Recruiting
Phase 3

Stellate Ganglion Block with Lidocaine

Sponsor:

London Health Sciences Centre Research Institute OR Lawson Research Institute of St. Joseph's

Code:

NCT06055270

Conditions

Parosmia

Eligibility Criteria

Sex: All

Age: 18 - 70

Healthy Volunteers: Not accepted

Interventions

Stellate Ganglion Block

Placebo

Study Details

Brief 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.

Conditions

Parosmia

Study ID

NCT06055270

Start date

Feb 15, 2024

Status verified date

Apr, 2024

Completion date

May 15, 2026

Anticipated

Primary completion date

Dec 24, 2025

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18 - 70

Healthy Volunteers: Not accepted

Inclusion Criteria:

1. Adults age 18 to 70
2. Diagnosis of COVID-19 at least 6 months prior to study enrollment with self-reported parosmia
3. Ability to read, write, and understand English
4. Score of at least 15 on DiSODOR

Exclusion Criteria:

1. History of smell loss or change prior to COVID-19 infection
2. History of conditions known to impact olfactory function:

1. Chronic rhinosinusitis
2. History of prior sinonasal or skull base surgery
3. Neurodegenerative disorders (Parkinson's disease, Huntington's disease, Amyotrophic lateral sclerosis, Lewy body dementia, frontotemporal dementia)
3. Currently using concomitant therapies specifically for the treatment of olfactory dysfunction
4. Inability to tolerate a needle injection into the neck
5. History of coexisting conditions that make SGB contraindicated:

1. Unilateral vocal cord paralysis
2. Severe chronic obstructive pulmonary disease (FEV1 between 30-50% of predicted)
3. Recent myocardial infarction within the last year
4. Glaucoma
5. Cardiac conduction block of any degree
6. Currently taking blood thinners or antiplatelet agents
7. Allergy to local anesthetic
8. Inability to extend the neck for any reason (e.g., severe arthritis)

Study Design

Enrollment

44 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

placebo comparator: Placebo Group

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.

experimental: Stellate Ganglion Block

The ultrasound-guided stellate ganglion blocks will be performed by a pain management specialist with extensive experience performing these blocks. The first SGB at the initial visit will be performed on the right side, and the second SGB will be on the left side 5-10 days after the first SGB, given that the patient tolerated the first SGB.

Interventions

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.

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

Primary outcome measure

  • Parosmia Olfactory Dysfunction Outcomes Rating (DisODOR) [ Time Frame: Baseline, 1, 3, and 12 months after SGB ]

Central Contacts and Locations

Central contacts

Lanette Friesen-Waldner, Ph.D

5196466100lanette.friesen-waldner@sjhc.london.on.ca

Cristian Dihel, MD

cristian.dihel@sjhc.london.on.ca

Locations

St. Joseph's Hospital London

Recruiting

London, Ontario, Canada, N6A 4V2

Contacts

Michal Kahanovitch, MsC

5196466100michal.kahanovitch@sjhc.london.on.ca

More Information

Sponsor

London Health Sciences Centre Research Institute OR Lawson Research Institute of St. Joseph's

Last update posted

Oct 23, 2024

Last verified

Apr, 2024

Keywords

  • Long-COVID
  • Olfactory disfunction
  • smell
  • olfaction
  • anosmia
  • bad smell

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-09. This information was provided to ClinicalTrials.gov by London Health Sciences Centre Research Institute OR Lawson Research Institute of St. Joseph's on 2024-10-23.