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Comparison of topical ethyl chloride spray and subcutaneous 1% mepivacaine for local anesthesia in single-rod etonogestrel implant insertion: an observational study

Year: 2026

Type: article

Abstract: Introduction This observational study examined the association between two local anesthetic techniques—topical ethyl chloride spray and subcutaneous 1% mepivacaine injection—and pain perception during the insertion of the single-rod etonogestrel contraceptive implant (Implanon NXT ® ). The study also compared the immediate procedural resources required for each technique, including application time and material use. Methods A total of 144 women were randomly allocated to receive ethyl chloride or mepivacaine solely to minimize selection bias within an observational design. All procedures were performed by experienced midwives in a primary care reproductive health setting. Overall pain was assessed using a 10-cm Visual Analogue Scale (VAS) at the end of the procedure. Procedural cost, anesthetic application time and adverse events were recorded. Pre-procedural anxiety and nervousness were assessed using validated VAS measures. Results No statistically significant differences in overall pain scores were observed between groups. Ethyl chloride required significantly less time to achieve adequate anesthesia (22.1 s vs. 64.6 s; p < 0.01) and had lower procedural cost estimates (€ 0.11 vs. € 0.21; p < 0.01). One needlestick injury occurred in the mepivacaine group. Pre-procedural nervousness was the only variable showing a significant, though weak, association with higher pain levels (rho = 0.23; p < 0.01). Conclusion Ethyl chloride spray was associated with shorter anesthetic application time and lower procedural resource use without increasing perceived pain, suggesting that it may enhance procedural efficiency and support workflow optimization in high-demand reproductive healthcare settings.

Source: Frontiers in Medicine

DOI: 10.3389/fmed.2026.1729384