Metcalf Daniel, Parsons David, Bowler I Philip
Acta Med Croatica. 2016 Mar;70(1):49-56.
Delayed wound healing due to infection is a burden on healthcare systems, and the patient and caregiver alike. An emerging factor in infection and delayed healing is the presence development of biofilm in wounds. Biofilm is communities of microorganisms, protected by an extracellular matrix of slime in the wound, which can tolerate host defences and applied antimicrobials such as antibiotics or antimicrobial dressings. A growing evidence base exists suggesting that biofilm exists in a majority of chronic wounds, and can be a precursor to infection while causing delayed healing itself. In vivo models have demonstrated that the inflammatory, granulation and epithelialization processes of normal wound healing are impaired by biofilm presence. The challenge in the development of a new antimicrobial wound dressing was to make standard antimicrobial agents more effective against biofilm, and this was answered following extensive biofilm research and testing. A combination of metal chelator, surfactant and pH control displayed highly synergistic anti-biofilm action with 1.2% ionic silver in a carboxymethylcellulose dressing. Its effectiveness was challenged and proven in complex in vitro and in vivo wound biofilm models, followed by clinical safety and performance demonstrations in a 42-patient study and 113 clinical evaluations. Post-market surveillance was conducted on the commercially available dressing, and in a 112-case evaluation, the dressing was shown to effectively manage exudate and suspected biofilm while shifting difficult-to-heal wounds onto healing trajectories, after an average of 4 weeks of new dressing use in otherwise standard wound care protocols. This was accompanied by a low frequency of dressing related adverse events. In a second evaluation, clinical signs of infection and wound dimension data, before and after the evaluations, were also available. Following an average of 5.4 weeks of dressing use, all signs of clinical infection were reduced, from an average frequency of 36% to 21%. An average of 62% wound size reduction was achieved, with 90% of wounds reducing in size and 10 wounds healing completely. The new clinical evidence for this next-generation antimicrobial wound dressing suggests it is safe and effective at managing exudate, infection and biofilm, while it can shift established, stubborn wounds onto healing trajectories. The scientific rationale for this new dressing technology is supported by in vitro and in vivo evidence, so now further comparative, randomized and outcome-based clinical studies are required to fully understand the clinical and economic benefits this new dressing technology can bring.
感染导致的伤口愈合延迟对医疗系统以及患者和护理人员来说都是一种负担。感染和愈合延迟中一个新出现的因素是伤口中生物膜的形成。生物膜是微生物群落,被伤口中的黏液细胞外基质所保护,能够耐受宿主防御以及诸如抗生素或抗菌敷料等外用抗菌剂。越来越多的证据表明,大多数慢性伤口中都存在生物膜,它可能是感染的先兆,同时本身也会导致愈合延迟。体内模型表明,生物膜的存在会损害正常伤口愈合的炎症、肉芽形成和上皮形成过程。开发新型抗菌伤口敷料面临的挑战是使标准抗菌剂对生物膜更有效,经过广泛的生物膜研究和测试后这一问题得到了解决。在羧甲基纤维素敷料中,金属螯合剂、表面活性剂和pH控制与1.2%的离子银表现出高度协同的抗生物膜作用。其有效性在复杂的体外和体内伤口生物膜模型中得到了验证,随后在一项针对42名患者的研究和113次临床评估中进行了临床安全性和性能验证。对市售敷料进行了上市后监测,在一项112例的评估中,结果显示该敷料在按标准伤口护理方案使用新敷料平均4周后,能够有效处理渗出液和疑似生物膜,同时将难以愈合的伤口转向愈合轨道。这伴随着较低频率的与敷料相关的不良事件。在第二项评估中,还获得了评估前后感染的临床体征和伤口尺寸数据。在平均使用敷料5.4周后,所有临床感染体征均有所减少,从平均发生率36%降至21%。伤口大小平均减少了62%,90%的伤口尺寸缩小,10个伤口完全愈合。这种新一代抗菌伤口敷料的新临床证据表明,它在处理渗出液、感染和生物膜方面安全有效,同时能够将已形成的顽固性伤口转向愈合轨道。这种新敷料技术的科学原理得到了体外和体内证据的支持,因此现在需要进一步开展比较、随机和基于结果的临床研究,以充分了解这种新敷料技术所能带来的临床和经济效益。