Polyhexamethylene Biguanide Dressing – Another Promising Tool to Reduce Catheter-related Bloodstream Infection

C atheter-related bloodstream infection (CRBSI) continues to be a significant problem in our healthcare system. The current prevailing thought is that these infections are preventable when the insertion and care of catheters meet published guidelines. These documents use two approacheswork practice controls, which requires a change in human behavior, and engineering controls, which employs product and process changes. The skin is a primary source of organisms producing CRBSI in percutaneously inserted central venous catheters, especially those used for a short period. One engineering control to reduce the burden of organisms on the skin is to place an antimicrobial dressing directly over and around the insertion site. The most common antimicrobial agent currently used is chlorhexidine gluconate. Recently a foam dressing with a new antimicrobial agent has been introduced for this purpose – polyhexamethylene biguanide or PHMB. What is PHMB? PHMB is a member of the family of cationic biocides, which are antiseptic agents. Quaternary ammonium compounds (e.g. benzalkonium chloride) and bisbiguanides (e.g., chlorhexidine) and polymeric biguanides (e.g., PHMB) are included in this family. For more than five decades, biguanides have been manufactured in a broad range of drugs including anti-malarial, anti-protozoal and blood glucose-reducing agents. Distinct anti-bacterial properties were found in this family with chlorhexidine being the first one to be synthesized. Early work with PHMB demonstrated that its antimicrobial effect was superior to other cationic biocides, however its chemical action could not be easily explained until recently. This limitation prevented the early use of PHMB in pharmaceutical products. (Gilbert & Moore, 2005) Biguanides work by attacking the cell wall. Bacterial cell walls are composed of peptidoglycan, a mixture of hexose sugars and amino acids. Gram positive bacteria have a thick layer while gram negative bacteria have a thin layer that has an outer membrane containing lipopolysaccharides and lipoprotein.(Goering, et al., 2008) The external cell layer for both gram positive and Polyhexamethylene Biguanide Dressing – Another Promising Tool to Reduce Catheter-related Bloodstream Infection