Science and technology have truly made great strides in the past century in almost every field. Modern medicine is one such field that has been revolutionized in the past century, specifically in the surgical applications being used today. Many new surgical techniques have been introduced that greatly improve safety, effectiveness, and types of surgeries available. The most important of these improvements is safety. When describing surgery, safety is usually thought of as how life threatening or dangerous a surgery can become, especially through possible complications that may occur; however, there is one vital factor that is often overlooked: antiseptics. If you would like to learn a little bit about the history of antiseptics and antiseptic surgery its creator Joseph Lister, watch this video by the British Medical Journal.
Prior to surgery there are many procedures that must be followed regarding antiseptics. The main goal of these procedures, especially the procedures that directly involve the patient’s skin, is to remove transient and pathogenic microorganisms on the skin surface and to reduce the resident flora to a low level. Iodophors are used to achieve this goal. Iodophors are substances that consist of iodine and a solubilizing agent that allow for free iodines to be released in solution. Iodine causes the amino acids in the outer cell membrane of pathogens and other unicellular organisms to denature, effectively killing the organism instantaneously. The amino acids found in these membranes that denature when in contact with iodine are tyrosine and histidine. This property of denaturing amino acids makes iodophors extremely useful for antiseptic purposes and makes it one of the most commonly used antiseptics. However, there are many other ways antiseptics. If you would like to learn more, check out this podcast from the British Journal of Surgery.
Common Surgical Antiseptics
Betadine Microbicides have been in existence for almost half a century and have been used worldwide as a first-line of defense against topical infections. Betadine is the well-known brand name for povidone-iodine antiseptics. This iodophor is of a stable chemical complex of polyvinylpyrrolidone (the solubilizing agent) and elemental iodine. Betadine has many uses. One form of Betadine is an over the counter solution used to clean small wounds as well as for pre-surgery use in hospitals. Another form of this povidone-iodine solution is a liquid mixed with detergent used to disinfect hands prior to surgery. In general, Betadine and other povidone-iodine products use its characteristics regarding iodine to work to prevent infection and disease both before and after surgery.
Another common antiseptic is Chlorhexidine, which is also known as Hibitane. Chlorhexidine is also used in hospital settings as well as at home. It is used to disinfect skin or areas, whether necessary for a major surgery or a small cut that requires only a bandaid. Specifically, this antiseptic effects both gram negative and gram positive bacteria, being less effective on gram negative bacteria though. One should also take caution with this solution for it is very dangerous at high concentrations.
Benzalkonium chloride, or alkyldimethylbenzylammonium chloride (ADBAC or BAK), is a chemical compound included in solutions commonly used as topical antiseptics. The formula for benzalkonium chloride is [C6H5CH2N(CH3)2R]Cl where “R” represents a mixture of alkyls. ADBAC has the structure of ammonium chloride, NH4Cl, but has a carbonaceous chain for each of the hydrogen atoms. Benzalkonium chloride are used to fight against bacteria and some viruses. BAK works by disrupting the intermolecular interactions of the bacteria or virus. The cell membrane is broken down so the cellular permeability can not be controlled and the cellular contents can exit the bacteria. Also, the bacteria is exposed to the environment so external forces can destroy the bacteria or virus. Gram positive bacteria are more susceptible than gram negative bacteria and ADBAC’s activity
increases at higher temperatures and longer exposure time. BAK is now mixed with different kinds of quaternary ammonium derivatives to treat infectious diseases such as hepatitis and HIV. Solutions and disinfectants that include benzalkonium chloride are now used by hospitals. Not only is benzalkonium chloride used as a disinfectant, but it can be used to externally treat cuts, burns, and scrapes, but because some people are allergic to this antiseptic, it is not usable for everyone. ADBAC is especially used on surgical and dental instruments to disinfect the tools before surgery. Also, ADBAC is frequently used as a preservative in ophthalmic solutions such as in eye drops and contact lens solutions. There are many other applications of benzalkonium chloride such as in water treatment and timber protection.