Clinical impact of bicarbonate-buffered lidocaine on pain during tunneled catheter placement

Aims: Numerous studies have reported the efficacy of bicarbonate-buffered lidocaine solutions in reducing injection pain. In our study, we aimed to examine the difference in injection pain scores between buffered and unbuffered lidocaine solutions during subcutaneous injection, perivascular injection, and injection along the tunnel line during the tunneling dialysis catheter placement procedure. Methods: This retrospective observational study included 101 patients who underwent tunneled central venous hemodialysis catheter placement between January 2023 and June 2024. Clinical data were obtained through retrospective review of patient medical records.The patients included in the study were divided into two groups based on the content of the local anesthetic solution used during the procedure. The first group (n=53) consisted of patients who received local anesthesia with a 1% lidocaine solution only, while the second group (n=48) consisted of patients who received a solution of 1% lidocaine buffered with 8.4% sodium bicarbonate at a 9:1 ratio. Pain levels were recorded using a visual analog scale (VAS). Age, gender, and VAS scores were compared between groups. Results: The age range of the 101 patients included in the study was between 19 and 84 years, and there was no significant difference in the mean age between the two groups. The gender distribution also did not show any statistically significant differences. In the comparison of VAS scores, the subcutaneous, perivascular, and tunnel region VAS scores for patients in group 1 (unbuffered) were 4.7±1.3, 4.4±1.2, and 4.2±1.5, respectively, while those in group 2 (buffered) were 2.6±1.1, 2.9±1.4, and 3.1±1.2, respectively. The difference between the groups was significant for all three injection sites, with p-values of