The American Society of Anesthesiologists (ASA) Committee on Occupational Health (COOH) is charged with periodically reviewing current scientific evidence and expert opinion on matters related to infectious outcomes associated with anesthesia care. Anesthesiologists serving on the COOH developed the following expert consensus statement pertaining to surgical attire. The objective of these surgical attire recommendations is to limit infectious spread in surgical and procedural settings. In addition to these recommendations, the ASA Committee on Quality Management & Departmental Administration includes important guidance for establishing and implementing local policies regarding surgical attire.
Recommendations
Process Recommendations
Regulations Governing Infection Control and Prevention Policies
The Centers for Medicare & Medicaid Services (CMS) Conditions of Participation (under Federal regulation §482.42) 1 requires that facility level programs for prevention, control, and investigation of infections and communicable diseases be conducted in accordance with nationally recognized infection control practices or guidelines, as well as applicable regulations of other federal and state agencies.
Local policy should consider: 1) applicable state and federal regulatory and accrediting organization statutory requirements; 2) the care environments of individual facilities and health systems; and 3) requirements of other healthcare organizations.
Once a policy is established and agreed to by relevant stakeholders, all perioperative and procedure team members should comply with the attire policies in facilities where they practice. Auditing and compliance with infection control and surgical attire policies should be handled in accordance with other nationally established best practices.
Discussion
The most common pathogen source for surgical site infection is the patient’s endogenous microbial flora, particularly that which colonizes the skin, mucous membranes, or hollow viscera. 2,3
Pathogens causing surgical site infection may also originate from an airborne exogenous source (i.e., outside of the patient). Shed skin cells and hair from individuals other than the patient have long been recognized as potential reservoirs for airborne infectious particles in the operating room setting. 4-10 These particles may settle directly into the surgical wound or contact the wound indirectly by settling onto gloves, sterile sponges, and instruments.
Airborne infectious particles play a greater role as a source for surgical infections for procedures classified as “clean,” especially those during which implants are placed (e.g., total joint replacement, vascular graft insertion, cardiac valve replacement, and spine surgery with instrumentation). 6-9 Surgical procedures involving implants are most vulnerable to infection from intraoperative settling of bacteria-laden airborne particles because a smaller inoculum is required to cause infectious complications. In the operating room environment, the potential pathogen most frequently cultured from air samples is coagulase-negative Staphylococcal spp. (e.g., Staph. epidermidis). 4
All humans shed dead skin cells and hair. About ten percent of shed skin cells carry bacteria. 4 During low level activity such as walking, each person sheds about 10,000 enucleated keratinocytes per minute (600,000 per hour) from the outermost layer of the epidermis. Humans also shed between 50-100 hairs per day.
Healthy human skin and hair is colonized by bacteria which are generally not harmful and may be beneficial to the host. In healthy adults, skin microbiology is stable over time, despite a changing environment. Bacteria are firmly attached and generally are not eliminated by routine bathing or shampooing. 11
Shed skin particles that measure approximately 10 to 25 microns in the greatest diameter have the greatest potential to carry bacteria as compared to smaller particles. 5 For particles larger than 10 micrometers, factors such as turbulence and particle velocity have far less affect upon settling as compared to gravitational factors; therefore, settling occurs at distances closer to the source. Therefore, measures to prevent dispersion of shed squames are of greatest importance to individuals who are over or near the surgical field.
The recommendation to wear scrub attire made from “fabrics … that are tightly woven and low linting” 12 stems from a theoretical concept that material impermeable to shed skin scales would prevent their dispersion by “containing” or “holding them in.”
Some investigations found that ambient airborne infectious particles in the operating room were reduced when occlusive or semi-occlusive scrubs and/or surgical gowns were worn as compared to conventional weave cotton attire. 13,14 However, the results of these studies were often conflicting, and the investigations were conducted in settings with varying air flow and filtration systems (e.g., conventional turbulent air flow, laminar air flow, ultrafiltration).
Total body exhaust gowns are currently used during high-risk orthopedic procedures; they represent the most extreme barrier precaution to reduce surgical site infections. Not all studies demonstrate their superiority over other forms of surgical garb. Polyester gowns were found to contain infectious particles at least as well as total body exhaust gowns. 15
Wearing head gear during surgical procedures is also recommended to prevent dispersion of infectious particles shed from the scalp and hair. Hair may entrap and sequester shed skin particles, and these may be released into the ambient air, especially when contacted by hands or inanimate objects.
Ritter et al. 16 studied the airborne infectious particles sampled during the use of various head covers. These investigators found no significant difference during the use of a cloth cap, a cloth hood tucked into gown, and no head cover. However, the use of hair spray diminished bacterial counts with or without a head cover.
In contrast, Friberg et al. 17 found that the omission of mask and skull cap head covering resulted in 3- to 5-fold increase in bacterial air counts and an almost 60-fold increase in bacterial sedimentation rate. This study took place in a laminar flow operating room environment. Sterile helmet respirators provided no benefit beyond wearing head coverings and masks.
If containment of shed infectious particles is the goal, then, in theory, impermeable coverings that completely cover the hair would most effectively prevent dispersion. However, no studies have demonstrated an association between the material from which scrubs, head gear, and beard covers are constructed and surgical infectious outcomes (e.g., the incidence of surgical site infection). Similarly, no studies show that the extent to which these articles cover the hair or scalp affects infectious outcomes in surgical patients.
Markel et al. 18 compared disposable bouffant-style caps and skull caps to home-laundered cloth caps to determine permeability, particle transmission, and pore size. All three types of caps were evaluated twice at two different institutions for a total of four one-hour long mock surgeries for each. In addition, all cap types underwent permeability and porosity testing. The researchers found that the material of the disposable bouffant cap was more permeable as compared to the material of the disposable skull cap and the cloth cap. By using settle plates, the investigators observed greater bacterial shed when bouffant caps were worn than when cloth skull caps were worn.
Kothari et al. 19 conducted a retrospective study to compare SSI rates following procedures performed when the surgeon wore a bouffant cap versus a skullcap. A total of 1,543 patients were included in the trial. Factors pre-disposing to infection (e.g., smoking, diabetes mellitus) were similar between groups. When adjusting for the type of surgery (e.g., clean, contaminated, clean-contaminated), SSI rates were not significantly different for procedures performed wearing skullcaps compared to those performed wearing bouffant caps. Three additional retrospective studies 20-22 found that strict implementation of a policy to substitute bouffant caps or surgical hoods in place of skull caps had no effect on the incidence of postoperative surgical infections.
Facial hair coverings are also recommended to contain infectious particles shed by health care workers during surgical procedures. Wakeam et al. 23 compared facial bacterial colonization among 408 male health care workers with and without facial hair. Male hospital workers with facial hair did not harbor more potentially concerning bacteria than clean shaven workers. Clean shaven workers were significantly more likely to be colonized with Staph. aureus including MRSA. Both groups shed bacteria at high rates.
Parry et al. 24 studied the infectious particles shed by bearded and clean-shaven men during standardized facial motions. The researchers concluded that, while wearing surgical masks, bearded surgeons and non-bearded surgeons had similar rates of bacterial shedding. The addition of surgical hoods did not decrease the amount of shedding in either group.
In contrast to these results, McLure et al. 25 found that bearded men had significantly more bacterial shedding than women or clean-shaven men, even when wearing a mask. Workers with facial hair were more likely to shed bacteria after rubbing their faces; however, both men (whether bearded or clean shaven) and women shed bacteria at high rates with facial manipulation. The investigators concluded that facial manipulation leads to bacterial shedding in both male and female HCWs, and that facial hair can increase bacterial shedding in male HCWs even when they wear surgical masks.
Clothing itself may increase skin scale shedding by friction. Researchers have demonstrated that naked men shed approximately a third to a half as many bacteria as the same men wearing street clothes or scrub suits. 26 Others demonstrated that women wearing stockings shed more bacteria than women with bare legs. 27
Surgical attire that is too tight promotes friction. Prolonged friction may cause chafing. In addition, less porous fabrics promote sweating, and hyperhydrated skin from sweating promotes bacterial colonization. Moisture promotes skin maceration, which causes further skin damage.
Prolonged chaffing and moisture can lead to skin damage. Damaged skin often harbors more pathogens than normal skin. Washing damaged skin is less effective at reducing the number of bacteria, and the number of organisms shed from damaged skin are often higher than from healthy skin. 28 When inflammatory and/or desquamating skin conditions such as eczema and atopic dermatitis are present, the skin affected by these conditions is more likely than normal skin to be colonized by pathogenic bacteria (e.g., Staph. aureus and gram negatives). 28 Moreover, skin affected by these conditions sheds more squames than normal skin and the shed squames are more likely to contain pathogenic bacteria. 28 Because of the effects of friction and the potential for less “breathable” materials to evoke skin damage and inflammatory skin conditions, comfort and fit are important considerations for surgical attire beyond the containment of shed skin particles.
There are case reports describing infectious outbreaks associated with airborne particles shed by a health care worker. One published case report describes an outbreak of surgical infections associated with an individual who carried Staph. aureus in his hair. 29 Even though he wore a head covering and a mask during procedures, eleven infections were linked to this carrier. After abatement measures were taken, the infections ceased temporarily. However, the carrier again became colonized and he was subsequently linked to five more infections. After the carrier left the facility, no further outbreaks were observed.
Another case report described a series of surgical wound infections linked to a skin carrier of Group A beta-hemolytic Streptococcus. 30 Settle plates were used to detect airborne infectious particles shed by this carrier. The carrier was identified as a woman with a history of psoriasis and seborrhea, and multiple skin and hair sites were found to be colonized with the specific Streptococcal strain. Interestingly, the carrier consistently wore paper head gear when in the operating room.
Ultraclean air filtration and laminar air flow have each been shown to significantly impact microbiologic air quality. However, improved air quality with these systems has not translated into reductions in surgical site infections following joint implantation procedures. 31 Importantly, several studies indicate that operating room air quality is affected by the number of people in the operating room and their behavior (e.g., activity level and traffic in and out of doorways). Published data about the impact of operating-room behaviors on the risk of infection are limited and heterogeneous; some have indicated that the “studies exhibit major methodological flaws.” 32
The 2017 CDC recommendations for prevention of Surgical Site Infections (SSI), 33 based upon information available through April 2014, did not address surgical attire. The supplemental material (eAppendix 1) states “that many of the 1999 strong recommendations should be re-emphasized as accepted practice for preventing surgical site infections.”
The 1999 CDC Guideline for the Prevention of Surgical Site Infection 33 reads as follows:
References
Curated by: Governance
Last updated by: Governance
Date of last update: October 26, 2022