Aseptic technique is used to prevent the access of micro-organisms to a sterile field where a procedure or operation is being performed. The word “antisepsis” derives from the Greek and means “against putrefaction.” The concept of antisepsis was recognized in the mid-19th century by Oliver Wendell Holmes when he observed that a physician performing an autopsy was infected and subsequently killed by the same disease as the patient being autopsied. This knowledge resulted in improved handwashing and changing of clothing during some procedures. In 1867, Lister published his first description of “antiseptic principles,” coincident with the discovery of bacteria and their role in wound infection.

Aseptic technique employs several methods: the use of sterile instruments and antiseptic hand scrubs; the wearing of sterile gowns, gloves, caps, and masks by personnel; and the cleansing of the patient’s skin with antiseptics. Other modalities are included in aseptic technique. Sterilization is the ultimate in disinfection, for it is defined as the process of killing all micro-organisms by either physical or chemical agents. Steam under pressure is the most commonly used method of sterilizing instruments for pediatric procedures. An antiseptic is a chemical agent applied to the body that kills or inhibits the growth of pathogenic organisms. A disinfectant is a chemical substance used on inanimate objects, such as floors and countertops, to eliminate bacteria.

Aseptic technique is an important prelude to many of the other procedures described in this text. Proper aseptic technique should be used by physicians, nurses, and other health professionals performing pediatric procedures to eliminate potentially serious infectious complications.

The anatomy of the skin and its microbial inhabitants must be understood in order to properly perform aseptic technique. Two types of micro-organisms are causative in both skin and wound infections and have been termed “resident flora” and “transient flora.” Resident flora are those bacteria that live and grow in the skin and can be repetitively cultured from it. These micro-organisms live in the cracks and dead cells of the horny layer of the skin. Most organisms are of low virulence and include Staphylococcus epidermidis, micrococci, and diphtheroids such as Propionibacterium acnes. Transient skin flora coexist with the resident flora in the horny skin layer and are barred from deeper skin invasion by the cells of the tightly packed stratum corneum. The transient organisms are acquired by contact with colonized or infected materials, often in the hospital environment. Subsequently these organisms are more likely to be resistant to many antibiotics and responsible for nosocomial infections. Staphylococcus aureus and Gram-negative enterobacteria are frequently identified as transient flora. The goal of cleansing and preparing the skin with antiseptics is to remove the transient bacteria and reduce the levels of resident flora to a low level.

These potentially infectious micro-organisms must be removed from both the patient and the health care provider. It is important to understand the bacterial load of various areas of the body, for it has been determined that when organism counts exceed 10⁵ per square centimeter, infection is more likely (1). Organisms are actually sparse on the palms and dorsa of the hands. However, most hand flora are harbored under the nails and around the lateral nail folds, achieving counts of 10⁴ to 10⁶ per square centimeter. Most of the body surface, including the trunk, arms, and legs, are colonized with
only a few thousand organisms per square centimeter. Other moist places, such as the perineum, axilla, and intertriginous areas, harbor millions of bacteria per square centimeter. These bacterial counts must be considered in the preparation of a field during aseptic technique.

The physiology of the body and its relation to aseptic technique has been reviewed. The physical characteristics of barriers used in aseptic technique are also important. Various barrier methods are used in aseptic technique to eliminate the passage of micro-organisms onto the sterile field, including caps, masks, gloves, and gowns worn by the health care providers as well as sterile drapes to define and preserve the boundaries of the sterile field. Masks should be worn, especially by those with upper respiratory tract infections, to decrease the transmission of respiratory flora to the sterile field. Speaking while wearing a mask promotes leaking of respiratory flora from the sides of the mask and so should be kept at a minimum during procedures. Gowns and gloves are worn to provide a barrier to the transfer of the physicians’ bacterial flora to patients. Gowns impermeable to moisture prevent the wicklike effect of transferring bacteria from one side of a gown to the other. Latex gloves, and to a lesser extent vinyl gloves, serve as protective barriers to the transmission of bacteria from health care workers’ hands. However, bacteria multiply under moist gloves, and hand contamination can occur even when gloves are worn, so handwashing is recommended routinely after gloves are removed (2).

Aseptic technique is indicated to minimize the risk of infectious complications from various invasive procedures. Such procedures in the pediatric emergency setting typically include lumbar puncture, urethral catheterization, suprapubic bladder aspiration, central venous and arterial access procedures, thoracentesis, chest tube placement, paracentesis, joint aspiration, tapping of a cerebrospinal fluid (CSF) shunt, and wound repair. The need for aseptic technique in laceration repair has never been proven, and one randomized trial found similar wound infection rates whether sterile or nonsterile gloves were used (3).

Good judgment, as well as specific institutional guidelines, should be used in determining the level of aseptic technique necessary for a given procedure. The following list details what level of aseptic technique is recommended for various procedures:

There are no true contraindications to aseptic technique. Latex sensitivity must be considered in patients at risk, especially those with spina bifida. Although allergies to the various antiseptic solutions are rare, a history of sensitivity to povidone-iodine or other antiseptics must be elicited.

Sterile gowns and drapes may be purchased in disposable, single-use types, which are often made of waterproof material that is nonwoven and therefore not likely to be penetrated by bacteria. More traditional woven cloth can also be used. Woven gowns and drapes may be reused after laundering but should be washed no more than 75 times to maintain their barrier integrity (4).

If disposable sponges are not available, fine-pore (90 pores per inch) 4″ × 4″ gauze pads may be soaked in a disinfectant and used to cleanse the field.

Any type of sterile glove may be used, although studies have shown that latex gloves are more protective and resistant to organism penetration than vinyl gloves (2). The use of double gloving has been shown to improve barrier protection in the operating room and reduce occupational exposure to patients’ bloodborne pathogens (5). Although it has not been studied in the emergency department, double gloving should be considered for full aseptic procedures and when trying to maximize protection against potential exposures.