Cervicothoracic Sympathetic Block Evaluation for Post COVID Condition

NCT07468604 · tracked via the Priya Life Science Canada tracker

Sponsor

University Health Network, Toronto

Phase

Phase 4

Started

2026-05-19

Last updated

2026-09-29

Condition(s) studied

Autonomic Dysfunction

Investigational drug(s) / intervention(s)

5 mL of 0.25% bupivacaine with epinephrine (1:200,000)Placebo (Saline) Control

5 mL of 0.25% bupivacaine with epinephrine (1:200,000): The active group will have cervical sympathetic block (CSB) on both the left and right sides using up to 5 mL of 0.25% bupivacaine with epinephrine (1:200,000). After the injection, all patients will be monitored for a minimum of 30 minutes to check for expected effects of the block and to watch for any side effects or complications.

Placebo (Saline) Control: Participants will receive cervicothoracic sympathetic chain block (CSB) on both the left and right sides using up to 5 mL of normal saline (0.9% NaCl), by an identical ultrasound-guided approach to the active arm. After the injection, all participants will be monitored for a minimum of 30 minutes for expected effects of the block and for side effects or complications.

Study summary

Post-COVID Condition (PCC) affects roughly 2.1 million Canadians, carrying an annual economic burden of CAD $7.8-50.6 billion. It presents across multiple organ systems with symptoms including fatigue, brain fog, palpitations, and orthostatic intolerance, at an annual cost of CAD $1,675-$7,340 per case.

A key mechanism underlying many treatment-resistant PCC symptoms appears to be dysautonomia abnormal autonomic nervous system function driven by immune-mediated sympathetic overactivity. Persistent inflammation (cytokine storms, T/B-cell dysfunction, microclots) sustains sympathetic hyperactivity, which in turn perpetuates systemic inflammation and "sickness behaviors" resembling PCC symptoms.

Current treatments including beta blockers, ivabradine, fludrocortisone, and rehabilitation are limited by variable responses, side effects, and the complication of post-exertional symptom exacerbation. Emerging therapies (SSRIs, low-dose naltrexone, antihistamines, HBOT) show promise but lack robust trial evidence.

Cervicothoracic sympathetic chain block (CSB) a local anesthetic block of the cervical and upper thoracic sympathetic ganglia is a promising intervention that reduces sympathetic outflow, improves cerebral blood supply, and lowers pro-inflammatory cytokines. Small observational studies (16 studies, 224 patients) show benefit for PCC symptoms, but all lack placebo controls and have significant methodological heterogeneity.

The proposed study aims to fill this gap with a double-blind, placebo-controlled RCT to rigorously evaluate CSB's efficacy, magnitude of benefit, and durability in PCC patients.

Eligibility

Sex

ALL

Min age

18 Years

Max age

—

Healthy volunteers

Inclusion criteria 1. Age 18 years or older 2. PCC following COVID-19 infection with symptoms lasting for at least three months 3. Ability to read, write, and understand English 4. Quantified autonomic symptoms from at least one domain as reported by the patient on the screener Composite Autonomic Symptom Score (COMPASS-31), i.e. a COMPASS-31 score greater than 0. COMPASS-31 assesses 6 domains of autonomic symptoms: Orthostatic Intolerance, Vasomotor, Secretomotor, Gastrointestinal, Bladder, and Pupillomotor. 5. Patients should be stable on any PCC-related medications for at least four weeks. Exclusion criteria 1. History of co-existing conditions that are a contraindication for CSB: 1. Unilateral vocal cord paralysis; Severe chronic obstructive pulmonary disease (FEV1 between 30-50% of predicted value) 2. Recent myocardial infarction (within the last one year), Cardiac conduction block of any degree 3. Glaucoma 4. Infection or mass at injection site, bleeding disorders 2. Comorbid conditions that could confound study results, such as: 1. Active autoimmune disorders 2. Pre-existing autonomic dysfunction (e.g. POTS, IST, and CRPS) prior to COVID-19 3. Untreated psychiatric conditions (e.g. severe anxiety or PTSD requiring medication adjustments during the study period) 3. Recent history of major surgery or cerebrovascular events within the last three months 4. Allergy to local anesthetic; Inability to extend the neck for any reason (e.g. severe arthritis) 5. History of prior stellate ganglion block

Primary outcome measure(s)

Change from baseline in the Modified COVID-19 Yorkshire Rehabilitation Scale (C19-YRSm) Symptom Severity subscale score — Three months after the final injection.
Description: The C19-YRSm Symptom Severity subscale is scored from 0 to 30, with higher scores indicating greater symptom burden. The outcome is the change from baseline in this score.

Trial sites (2)

Facility	City	Region	Status
Women's College Hospital	Toronto	Ontario	Not Yet Recruiting
Toronto Western Hospital	Toronto	Ontario	Recruiting

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Official registry record

This page summarises publicly available registry data for informational purposes — not medical advice. Eligibility is determined by each study team; patients should discuss participation with their clinician.

View NCT07468604 on ClinicalTrials.gov ↗ ← All trials in Canada