Overview

This single-center, randomized, controlled, single-blind clinical trial evaluates whether a stellate ganglion block (SGB) using bupivacaine can improve persistent symptoms in adults with long COVID. Participants are assigned in a 1:1 ratio to receive either an ultrasound-guided right-sided SGB or a placebo saline injection delivered to the sternocleidomastoid muscle. After the intervention, participants are followed for 26 weeks with scheduled evaluations that include symptom questionnaires and functional tests.

The study assesses changes in functional status, fatigue, cognitive complaints, quality of life, dyspnea, lower-limb endurance, and orthostatic tolerance over time. Safety is monitored throughout all follow-up visits. Approximately 40 participants meeting predefined eligibility criteria will be enrolled. This trial seeks to determine whether a single stellate ganglion block has an effect on persistent long-COVID symptoms compared with placebo.The results will help determine the therapeutic value of SGB in the management of long COVID and inform future research and clinical practice.

Eligibility

Inclusion Criteria:

• Adults aged 18 years and older
• Positive COVID-19 test confirmed by RT-PCR, antibody test, or antigen test at least 3 months prior to randomization, OR presumed COVID-19 evaluated by the site investigator (no positive test required) with an acute illness occurring after October 15, 2019 and at least 3 months prior to randomization.
• Persistent symptoms ≥12 weeks after onset of acute COVID-19 AND symptoms lasting at least 2 months. The onset date is defined as the earliest of: date of first positive test, date of first symptoms
• Post-COVID Functional Status Scale score ≥2.
• Persistent dyspnea ≥2/4 on the mMRC scale at least 12 weeks post-infection.
• Persistent COVID-19-related symptoms at the time of randomization.
• If taking medications for fatigue or cognition (e.g., sildenafil, modafinil, armodafinil, guanfacine, N-acetylcysteine, stimulants for ADHD), these must have been initiated and stable for ≥4 weeks prior to randomization. Participants are asked not to stop or alter these medications during the study if possible.
• Able and willing to provide written informed consent.
• Able to read and understand French.

Exclusion Criteria:

• Prior diagnosis of myalgic encephalomyelitis (ME) or fibromyalgia
• Being on sick leave or disability at the time of the original acute COVID-19 infection.
• Pregnancy or breastfeeding.
• Myocardial infarction within the last 12 weeks.
• Use of anticoagulant therapy.
• Glaucoma.
• Emphysema requiring home oxygen.
• Cardiac conduction abnormalities.
• Known hypersensitivity to bupivacaine.
• Previous stellate ganglion block (SGB) procedure.
• Any condition that, in the judgment of the medical investigator, makes the patient not a candidate for the proposed treatment.