Department of Otolaryngology, Faculty of Medicine, Al-Azhar University, Damietta, Egypt.
Department of Otolaryngology, Alexandria University, Alexandria, Egypt.
Am J Rhinol Allergy. 2023 Nov;37(6):630-637. doi: 10.1177/19458924231184055. Epub 2023 Jun 25.
COVID-19 has been associated with olfactory dysfunction in many infected patients. The rise of calcium levels in the nasal secretions plays an essential role in the olfaction process with a desensitization effect on the olfactory receptor neurons and a negative impact on the olfaction transmission. Ethylene diamine tetra acetic acid (EDTA) is a chelating agent that can bind free calcium in the nasal secretions, thereby reducing the adverse effects of calcium on olfactory function.
The objective of this work is to demonstrate the effect of intranasal EDTA on improving olfactory dysfunction following COVID-19.
Fifty patients with a history of COVID-19 and olfactory dysfunction that persisted for more than 6 months were enrolled in the current prospective randomized clinical trial. Participants were randomized into 2 equal groups. Twenty-five patients were treated with olfactory training only, while the remaining 25 patients received treatment with olfactory training and a topical nasal spray of ethylene diamine tetra acetic acid. The olfactory function was assessed before treatment and 3 months later using the Sniffin' Sticks test. Additionally, the determination of calcium level in the nasal secretions was performed using an ion-selective electrode before treatment and 3 months later.
Eighty-eight percent of the patients treated with olfactory training in addition to EDTA exhibited clinical improvement, while 60% showed improvement in patients treated with olfactory training only. Furthermore, a significant decrease in the measured calcium level in the nasal secretions was demonstrated after the use of ethylene diamine tetra compared to patients treated with olfactory training only.
Ethylene diamine tetra acetic acid may be associated with an improvement of the olfactory function post-COVID-19.
COVID-19 与许多感染患者的嗅觉功能障碍有关。鼻分泌物中钙水平的升高在嗅觉过程中起着至关重要的作用，对嗅觉受体神经元产生脱敏作用，并对嗅觉传递产生负面影响。乙二胺四乙酸（EDTA）是一种螯合剂，可与鼻分泌物中的游离钙结合，从而减少钙对嗅觉功能的不良影响。
本研究旨在证明鼻内 EDTA 对改善 COVID-19 后嗅觉功能障碍的作用。
本前瞻性随机临床试验纳入了 50 例有 COVID-19 病史且持续超过 6 个月的嗅觉功能障碍患者。将参与者随机分为两组，每组 25 例。一组仅接受嗅觉训练治疗，另一组则接受嗅觉训练和乙二胺四乙酸局部鼻喷雾剂治疗。使用 Sniffin' Sticks 测试在治疗前和 3 个月后评估嗅觉功能，并用离子选择性电极在治疗前和 3 个月后测定鼻分泌物中的钙水平。
在接受嗅觉训练加 EDTA 治疗的患者中，88%的患者表现出临床改善，而仅接受嗅觉训练治疗的患者中，60%的患者表现出改善。此外，与仅接受嗅觉训练治疗的患者相比，使用乙二胺四乙酸后鼻分泌物中的钙水平显著降低。
乙二胺四乙酸可能与 COVID-19 后嗅觉功能的改善有关。
