The Effects of Eugenol Nanoemulsion on Pain Caused by Arteriovenous Fistula Cannulation in Hemodialysis Patients: A Randomized Double-blinded Controlled Cross-over Trial

Objectives: Local anesthetic and antinociceptive activity of eugenol, as the main ingredient of clove, was determined in previous researches. This study aimed to assess the efficacy of its topical nanoemulsion gel vs. placebo in controlling pain caused by arteriovenous fistula (AVF) needling in patients undergoing hemodialysis (HD).

Design: In this double-blinded cross-over trial, the patients were randomly allocated to eugenol gel 4% (n = 34) and placebo gel (n  = 34) groups. For each patient, a tip of finger unit of gel was applied 2 cm around the insertion site of hemodialysis needles. After 10 min, AVF needling was done. AVF needling-related pain was assessed using visual analogue scale (VAS) immediately after the puncture. All patients were tested at three different states: (1) before using any intervention; (2) after using either the eugenol or placebo gel; and (3) after crossing over the groups.

Results: There was a significant difference between the mean of patients' pain severity score in the three states (p = 0.001). It was reported as low as 3.29 ± 0.67 in patients who received eugenol nanoemulsion. Also, the highest pain severity score (5.03 ± 0.57) was reported at the no-intervention state.

Conclusions: It seems that topical application of eugenol nanoemulsion may significantly decrease AVF cannulation related pain intensity score in patients undergoing HD. However, further studies with larger sample size and longer intervention period should be done for better judgment on its efficiency and safety.