The practice of wound cleansing has become a basic principle in modern wound management, where it forms part of the process of wound bed preparation. Cleansing, debridement and disinfection help to reduce bacterial load in the wound and gently remove debris and exudate to prepare the wound bed for closure. This article focuses on the use of polyhexamethylene biguanide (polihexanide, PHMB) in combination with advanced wound dressings as a topical approach to wound cleansing and disinfection.

INTRODUCTION

The number of patients with chronic wounds is increasing rapidly due to an ageing population. This has a considerable impact on diagnostic, therapeutic and socio-economic resources. To support wound healing in these secondary healing wounds, both systemic and local factors need to be addressed [1-3]. Antiseptics can provide a useful alternative to antibiotics, are easy to use and widely available. Topical antiseptic agents in common use in wound dressings include silver, iodine and honey. In addition, PHMB has been widely used in Europe and in the US, although is a relative newcomer to the UK market


TOPICAL ANTISEPTICS FOR WOUND INFECTION

Most open chronic wounds will be heavily colonised with bacterial or fungal organisms [3]. Infection can cause a delay or failure in wound closure if not treated promptly using good hygiene, debridement and wound cleansing. When the problems caused by bacteria remain localised to a wound (critical colonisation), treatment with topical antiseptics may be indicated and is usually sufficient [4].

When providing a topical approach to treatment, it is important to differentiate between inflammation, increased bacterial burden, and superficial and deep infection [1,2]. Microbiological management is aimed at achieving an optimal organism loading within the wound that does not only focus on infected wounds, but also on critically colonised (locally infected) and non-healing wounds [1-3].

The presence of bacteria in a wound does not necessarily impede wound healing. This is dependent on the quantity and pathogenicity as well as patient immunity (host response) [1]. Bacteria may stimulate a persisting inflammation, which can lead to the production of inflammatory mediators and proteolytic enzymes, extracellular matrix (ECM) degradation and inhibition of re-epithelialisation [2]. Controlling the bacterial burden will therefore facilitate wound healing.
 
Contaminated trauma wounds as well as stagnating wounds and those that show general signs and symptoms of clinically manifest infection can be treated using topical antiseptics for the following reasons:

• Colonised wounds have the potential to develop infection, which can cause a delay or a failure in wound closure
• Infection may spread and, in some cases, leads to sepsis
• Colonisation or infection caused by multi-resistant pathogens (for example, Methicillin-resistant Staphylococcus aureus; MRSA) should be treated to prevent spreading of the infection.

STRATEGIES FOR MICROBIAL MANAGEMENT

Topical agents are used primarily when there are local signs of infection and when a wound is not healing[4]. Systemic agents such as antibiotics are used when clinical signs of infection are present such as spreading cellulitis. A further distinction is made between primary and secondary infection [1,5] (Fig 1). When a wound infection is detected, the following principles apply:

• Localised infections should be treated with antiseptics
• Wound infections that exhibit signs of spreading or systemic infection as well as sepsis should be treated with systemic antibiotics in combination with an appropriate antiseptic agent.

Fig 1 (click image to enlarge)