Prospective, randomized and controlled trial to investigate the effect of two application methods for local anesthesia on the patients

Abstract

Local infiltration anesthesia (LIA) plays a key role in routine dermatological surgery. The smooth process of surgery and the high satisfaction from patient depend on greatly on the qualified and pain-relieved LIA.

In our study, by using a painless mixture of Lidocaine and Ropivacaine highly diluted with an isoionic solution, the comparison of slowly performed (0.5 ml / second) hand-actuated local anesthesia (HA) and subcutaneous infusion local anesthesia (SIA) was performed. We found very low pain scores, but in contrast to our expectations, no statistical significant difference of pain scores at the needling, injection/infusion, during and after operations. This means HA can be applied with low pain. This study is limited to these both infiltration methods and the use of the special solution of local anesthetics. However, comparison to other local anesthetic drugs is not possible in this study.

By using SIA, one person could offer anesthesia to several patients at the same time. Furthermore, many patients preferred this kind of semi-automatic anesthesia. SIA is able to develop as an effective anesthetic method. The limitations of SIA consisted of requirement for constant supervision and the experience of operators’ experience, which still need further improvements and standardizations in the future. We believe SIA is a promising local anesthesia method in dermatological surgery with a broad application area.

In another aspect, the impact of 6 factors (age, gender, defect size, dose of anesthetic solution, duration of the procedure, the severity of anxiety/nervousness) on the analgesia effect in both HA and SIA group were investigated. Results showed age, gender and defect size did have certain influence on the analgesia effect in HA group. Particularly duration of the procedure and the severity of anxiety/nervousness had significant impact on the analgesia effect in both two groups at all four timings. The results proved the importance of shortening the anesthetic procedure and relieving the anxiety before surgery.