Xijing Hospital of Digestive Diseases, Air Force Medical University (Fourth Military Medical University), Xian, China.
Gastrointest Endosc. 2022 Feb;95(2):249-257. doi: 10.1016/j.gie.2021.07.025. Epub 2021 Aug 8.
Lugol's iodine chromoendoscopy is an important method to detect esophageal squamous cell carcinoma. Sodium thiosulfate solution (STS) has been used to neutralize iodine after Lugol's chromoendoscopy; however, it is not available in many medical centers. The aim of the current study was to assess the efficacy of N-acetylcysteine solution (NAC) for relieving symptoms caused by Lugol's iodine chromoendoscopy.
Patients were randomized to receive either STS or NAC after spraying Lugol's iodine solution on the esophagus. The neutralizing effects for residual iodine in the esophagus and gastric mucous pool were observed. The primary endpoint was the intensity of retrosternal pain and/or heartburn measured by a visual analog scale (VAS) score 30 minutes after chromoendoscopy. Secondary endpoints were the rate of patients with any adverse symptom, rate of moderate to severe retrosternal discomfort occurring, and heart rate variability between time points before and after chromoendoscopy.
The neutralization rates for residual iodine between the NAC and STS groups were not significantly different (P > .999). The difference of median VAS scores between the NAC and STS groups 30 minutes after chromoendoscopy was .0 (P = .719; 95% confidence interval, .0-.0), and the 95% confidence interval higher limit was .0, which was less than our prespecified margin of .5, concluding an noninferiority of NAC with regard to STS. There was no significant difference between the 2 groups regarding the rate of patients with any adverse symptom, rate of moderate to severe retrosternal discomfort, or heart rate variability at 5 minutes or 30 minutes after chromoendoscopy.
As a very easily accessible reagent in clinical circumstances, NAC can also alleviate mucosal irritation symptoms induced by Lugol's chromoendoscopy at similar efficacy as STS and can be routinely recommended. (Clinical trial registration number: NCT04764643.).
卢戈氏碘染色内镜检查是发现食管鳞状细胞癌的重要方法。硫代硫酸钠溶液（STS）已被用于中和卢戈氏染色内镜检查后的碘；然而，许多医疗中心都没有这种药物。本研究的目的是评估 N-乙酰半胱氨酸溶液（NAC）缓解卢戈氏碘染色内镜检查后碘引起的症状的疗效。
患者随机接受 STS 或 NAC 治疗，方法是在食管喷洒卢戈氏碘溶液后。观察食管和胃黏膜池内残留碘的中和效果。主要终点是染色内镜检查后 30 分钟时胸骨后疼痛和/或烧心的视觉模拟量表（VAS）评分强度。次要终点是有任何不良反应症状的患者比例、发生中度至重度胸骨后不适的比例以及染色内镜检查前后心率变异性。
NAC 和 STS 组之间残留碘的中和率无显著差异（P>.999）。染色内镜检查后 30 分钟时，NAC 和 STS 组的 VAS 评分中位数差值为 0（P=.719；95%置信区间，0.0-0.0），95%置信区间上限为 0.0，小于我们预设的 0.5 界限，这表明 NAC 与 STS 相比具有非劣效性。两组之间在有任何不良反应症状的患者比例、中度至重度胸骨后不适的发生率或染色内镜检查后 5 分钟或 30 分钟时的心率变异性方面无显著差异。
NAC 作为一种在临床环境中非常容易获得的试剂，其缓解卢戈氏染色内镜检查引起的黏膜刺激症状的效果与 STS 相似，可常规推荐使用。（临床试验注册号：NCT04764643）。
