Farrell Nyssa Fox, Crock Lara W, Islam Aseeyah, Adkins Dean, Peterson Andrew M, Kallogjeri Dorina, Piccirillo Jay F
Department of Otolaryngology-Head and Neck Surgery, Washington University School of Medicine, St Louis, Missouri.
Department of Anesthesiology, Washington University School of Medicine, St Louis, Missouri.
JAMA Otolaryngol Head Neck Surg. 2025 Jun 12. doi: 10.1001/jamaoto.2025.1304.
Smell distortion (parosmia) is a symptom of post-COVID-19 condition that persists and has immeasurable detriments on quality of life. To date, a standard criterion for treatment of this bothersome condition has not been identified.
To determine whether stellate ganglion block (SGB) is effective and safe in improving olfactory dysfunction in patients with persistent COVID-19-induced parosmia.
DESIGN, SETTING, AND PARTICIPANTS: This was a randomized, double-blinded, placebo-controlled clinical trial conducted from October 2023 to September 2024 at a single center study (the Washington University in St Louis/Barnes Jewish Hospital). A volunteer sample of 192 individuals were screened; 57 were enrolled after meeting eligibility criteria (age 18-70 years with self-reported parosmia of ≥6 months since COVID-19 infection, and a screening score of ≥40 on the Parosmia Olfactory Dysfunction Outcomes Rating [DisODOR] scale). Of 135 excluded, the most common reasons were prior SGB (n = 42) and parosmia resolution or non-COVID-19-induced parosmia (n = 28). Data were analyzed from September to October 2024.
Ultrasonography-guided injection of 6 to 8 mL of active mepivacaine, 1%, or saline, 0.9%, at the right or left (randomized 1:1) stellate ganglion was performed by a board-certified anesthesiologist and pain medicine specialist.
Between-subject difference of 25% in proportion of responders (defined by a 15-point decrease in DisODOR score) from baseline.
The study evaluated 48 participants, 32 randomized to SGB (median [range] age, 45 [19-64] y; 25 [81%] female), and 16 to placebo (median [SD] age, 45 [26-64] y; 13 [81%] female). Time since COVID-19 infection was similar between groups (SGB, 35.3 vs placebo, 30.6 months; MD = -3.1 months; 95% CI, -10.9 to 3.7). Three-month response rate was 43% (n = 13) for SGB and 38% (n = 6) for placebo (difference, -5%; 95% CI, -32% to 33%). There was no between-group difference in clinical global impression of improvement.
This randomized clinical trial found that SGB is not superior to placebo in treating COVID-19-induced parosmia, and thus, should not be recommended as treatment.
ClinicalTrials.gov Identifier: NCT06253806.
嗅觉扭曲（嗅觉异常）是新冠后状况的一种症状，会持续存在并对生活质量造成难以估量的损害。迄今为止，尚未确定治疗这种令人困扰状况的标准准则。
确定星状神经节阻滞（SGB）在改善持续性新冠病毒诱发嗅觉异常患者嗅觉功能障碍方面是否有效且安全。
设计、地点和参与者：这是一项于2023年10月至2024年9月在单一中心研究（圣路易斯华盛顿大学/巴恩斯犹太医院）进行的随机、双盲、安慰剂对照临床试验。对192名个体的志愿者样本进行了筛查；57名符合资格标准（年龄18 - 70岁，自新冠病毒感染后自我报告嗅觉异常≥6个月，且在嗅觉异常嗅觉功能障碍结果评定[DisODOR]量表上筛查得分≥40）的个体被纳入研究。在被排除的135名个体中，最常见的原因是既往接受过星状神经节阻滞（n = 42）以及嗅觉异常缓解或非新冠病毒诱发的嗅觉异常（n = 28）。于2024年9月至10月对数据进行分析。
由一名获得委员会认证的麻醉医生和疼痛医学专家在右侧或左侧（随机分配，比例为1:1）星状神经节进行超声引导下注射6至8毫升1%的活性甲哌卡因或0.9%的生理盐水。
应答者比例（定义为DisODOR评分降低15分）相对于基线的组间差异达到25%。
该研究评估了48名参与者，32名被随机分配至星状神经节阻滞组（年龄中位数[范围]为45[19 - 64]岁；女性占25[81%]）以及16名被分配至安慰剂组（年龄中位数[标准差]为45[26 - 64]岁；女性占13[81%]）。两组自新冠病毒感染后的时间相似（星状神经节阻滞组为35.3个月，安慰剂组为30.6个月；平均差 = -3.1个月；95%置信区间为 -10.9至3.7）。星状神经节阻滞组的三个月应答率为43%（n = 13）,安慰剂组为38%（n = 6）（差异为 -5%；95%置信区间为 -32%至33%）。在改善的临床总体印象方面两组之间没有差异。
这项随机临床试验发现，星状神经节阻滞在治疗新冠病毒诱发的嗅觉异常方面并不优于安慰剂,因此，不应推荐将其作为治疗方法。
ClinicalTrials.gov标识符：NCT06253806。
