Department of Orthopedics, General Hospital of Chinese People's Liberation Army, Beijing, China (mainland).
Department of Clinical Microbiology, General Hospital of Chinese People's Liberation Army, Beijing, China (mainland).
Med Sci Monit. 2018 Jan 23;24:448-452. doi: 10.12659/msm.908585.
BACKGROUND Synovial fluid culture (SFC) is recommended as one of the major diagnostic criteria by the Musculoskeletal Infection Society (MSIS) for diagnosing periprosthetic joint infection (PJI). Local anesthetic agents are used for anesthesia and analgesia in some clinical settings to relieve pain. As a local anesthetic, lidocaine is safely used in arthrocentesis to obtain synovial fluid. The goal of this study was to determine if infiltration anesthesia with additive-free lidocaine 2% has antibacterial effects that might interfere with subsequent SFC. MATERIAL AND METHODS Eight isolates of reference strains of Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus hominis, Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii, Streptococcus pyogenes, and Candida albicans were incubated on the plates. Each bacterial suspension was formed by 50-fold dilution before the test lidocaine 2% was added. For each strain, bacterial suspension was divided into 2 groups (5 samples each) exposed either lidocaine 2% or sterile non-bacteriostatic 0.45% saline. The antimicrobial property of lidocaine 2% was determined by measuring the bacterial density on agar plates incubated for 24 h and comparing it with controls unexposed to lidocaine 2%. RESULTS Exposure to lidocaine 2% negatively affected microbial viability in vitro. Of the lidocaine 2% exposure, reference strains but no Streptococcus pyogenes strain resulted in fewer colony-forming units compared with the sterile saline control. The antibacterial property of lidocaine 2% appears to affect the ability to culture the organism in synovial fluid. CONCLUSIONS Lidocaine 2% has strong antimicrobial activities against some commonly encountered bacterial strains in PJI. As a result, infiltration anesthesia with additive-free lidocaine 2% before the arthrocentesis procedure may affect the results of SFC. To further evaluate its potential antibacterial usefulness in clinical applications, studies are needed to assess the ability of lidocaine to reduce the risk of iatrogenic infections.
滑液培养（SFC）被肌肉骨骼感染学会（MSIS）推荐为诊断人工关节假体周围感染（PJI）的主要诊断标准之一。在某些临床情况下，局部麻醉剂被用于麻醉和镇痛以缓解疼痛。作为局部麻醉剂，利多卡因安全地用于关节穿刺术以获得滑液。本研究的目的是确定不含添加剂的 2%利多卡因浸润麻醉是否具有抗菌作用，从而可能干扰随后的 SFC。
将金黄色葡萄球菌、表皮葡萄球菌、人葡萄球菌、大肠杆菌、肺炎克雷伯菌、鲍曼不动杆菌、化脓性链球菌和白色念珠菌的 8 株参考菌株接种在平板上。在测试前，用 50 倍稀释的方法制备每种细菌悬液，然后加入 2%利多卡因。对于每种菌株，将细菌悬液分为两组（每组 5 个样本），一组暴露于 2%利多卡因，另一组暴露于无菌非抑菌性 0.45%生理盐水。通过测量孵育 24 小时后的琼脂平板上的细菌密度并与未暴露于 2%利多卡因的对照相比，来确定 2%利多卡因的抗菌特性。
暴露于 2%利多卡因会对微生物的体外活力产生负面影响。与无菌生理盐水对照组相比，2%利多卡因暴露组的参考菌株但不是化脓性链球菌菌株导致的菌落形成单位减少。2%利多卡因的抗菌特性似乎会影响在滑液中培养生物体的能力。
2%利多卡因对 PJI 中常见的一些细菌菌株具有很强的抗菌活性。因此，关节穿刺术前使用不含添加剂的 2%利多卡因浸润麻醉可能会影响 SFC 的结果。为了进一步评估其在临床应用中的潜在抗菌作用，需要研究评估利多卡因降低医源性感染风险的能力。
