aseptic technique chapter 2

Question 1

In dermatologic surgery, gloves become perforated in approximately 11% of procedures, and the wearer recognizes that a perforation has occurred in only 17% of those cases.

Answer 1

T

Question 2

Double-gloving reduces perforations of the innermost glove nine-fold compared with single surgical gloves.

Answer 2

T

Double-gloving with special darkly-colored “indicator” undergloves (Biogel®, Mölnlycke Health Care, Norcross, GA) can further facilitate rapid identification of punctures.

Question 3

Many Mohs surgeons no longer use sterile gloves for the acquisition of layers and a growing number eschew them for the final reconstruction. Three studies provide evidentiary support for these practices.

Answer 3

T

The first was a retrospective study in 2006, which compared infection rates between two Mohs surgeons in the same practice, one of whom used clean gloves and the other sterile for Mohs layers. Both used sterile gloves for reconstructions. 17 Their infection rates were statistically similar (1.8% vs 1.7%, respectively). A 2010 prospective, but uncontrolled, study reported an SSI rate of 0.91% when using clean gloves for all steps of Mohs surgery, including reconstruction. 18 Similarly, a randomized controlled trial of 60 patients that compared clean versus sterile gloves for all aspects of Mohs surgery showed SSI rate equivalency. 19 However, this pilot study was underpowered and cannot support definitive conclusions. Given the low baseline SSI rate, a properly powered study would require at least 1000 patients depending on one’s assumptions. A prospective randomized study of that magnitude is needed to substantiate consensus evidence-based recommendations for the exclusive use of clean gloves.

Question 4

Patients in street clothes disperse the same amount of bacteria as those dressed in a clean cotton gown, covered with a cotton sheet.

Answer 4

T

Infection rates for same-day surgery are not significantly affected when patients remain fully dressed. Aside from causing embarrassment, removal of underwear and putting on a minimally secured gown allows for increased bacterial shedding from the perineum into the environment. Therefore, unless a gown facilitates exposure of the surgical site, or body fluid spillage is expected, the scientific literature does not support the need for patients to remove their street clothes before dermatologic surgery.

Question 5

Shaving with a razor in particular should be avoided, because it causes abrasions which compromise skin integrity and allow bacteria to flourish.

Answer 5

T

Question 6

The time lapse between shaving and surgery plays a key role in the risk for infection. Seropian and Reynolds found a wound infection rate of 3.1% in patients shaved immediately before surgery that was significantly higher than the rate of 0.6% that occurred in those who were not shaved.

Answer 6

T

Question 7

The time lapse between shaving and surgery plays a key role in the risk for infection. This infection rate rose to 7.1% when shaving was done the day before surgery, and to as much as 20% when performed more than 24 h before surgery.

Answer 7

T

Question 8

From an infection standpoint, it is generally agreed that hair should be left intact within the surgical field.

Answer 8

T
If these methods do not prove sufficient, and removal is required, the hair should be judiciously clipped at the skin with a pair of scissors or electric clippers before establishing a sterile field.

Question 9

Frustration of attempting to suture on the scalp when hair is caught with each throw of the knot is well known to surgeons who work in this area. If care is not taken, the entangled hair can decrease knot security and increase the risk of a foreign-body reaction

Secure the hair away from the field with sterile hair clips, rubber bands, or a water-soluble gel, such as E-Z Lubricating Jelly (Chester Labs, Cincinnati, OH). This sterile lubricant is also a useful replacement for mineral oil when harvesting grafts with a dermatome. Petrolatum-based ointments can be difficult to cleanse from the hair and are generally not recommended.

Answer 9

T

Question 10

On the night before surgery, a preoperative shower with CHG or PI has been shown to decrease bacterial colonization and wound infection rates, particularly those from S. aureus , in some studies.A large meta-analysis and a Cochrane review, however, concluded that current evidence does not support this as routine practice. It may be considered for procedures with large surgical fields such as liposuction or for surgical sites with increased risk for infection, like on the lower extremity.

Answer 10

T

Question 11

CHG and alcohol-containing preparations should be avoided in the periocular area, as they may cause corneal and conjunctival irritation.

Answer 11

T

Question 12

ocular CHG exposure has caused severe keratitis even leading to blindness.

Answer 12

T

Question 13

If there is accidental conjunctival exposure to CHG, immediate and copious flushing of the eye is recommended until the patient reports no more pain or irritation.

Answer 13

T

Question 14

PI solution at half strength (5%) is a safe and effective alternative preparation to use in the eye area. If the surgical site is near the eye but will not involve the lids themselves, then prepping the eyelids can be omitted and the eye covered with a sterile eye pad or gauze

Answer 14

T
Widely accepted as safe and effective for disinfection of the conjunctiva; commonly diluted to 5% with saline to reduce potential for irritation

Question 16

5% povidone iodine is approved for ophthalmic use

Answer 16

T

Question 17

Iodine povacrylex and 74% isopropyl alcohol is a moderate eye irritant due to alcohol

Answer 17

T

Question 18

3% chloroxylenol and 3% cocamidopropyl PG-dimonium chloride phosphate is safe and effective for mucous membranes and around ears and eyes

Answer 18

T

Question 19

Tightly woven cotton surgical drapes are softer and arguably more comfortable for patients than disposable impermeable drapes, but they may absorb fluid during surgery and “wick” bacteria into the sterile field

Answer 19

T

Question 20

To limit the risk for contamination, woven drapes should be chemically treated to retard water, inspected frequently for wear, and changed immediately if they should become wet.

Answer 20

T
Alternatives to woven drapes are disposable plastic and plastic-lined paper drapes, which are impermeable to moisture and bacteria. The drawback is that they may be stiff and have a tendency to shift during surgery.

Question 21

To limit potential contamination, doors should be kept closed, the passage of non-essential personnel should be minimized, and cleaning and disinfection of surgical rooms should be performed on a scheduled basis with a quaternary ammonium sanitizer.

Answer 21

T
Microorganisms from both the patient and surgical personnel are continually shed into the operating room environment via desquamated skin cells. Once dispersed, they eventually settle onto horizontal surfaces such as the surgical field, floor, or counter tops. This reservoir can be re-aerosolized from the passage of feet across the floor and by the breeze generated from opening the surgical room door

Question 22

Most guidelines recommend visible inspection of the room in between procedures, and prompt clean-up of any visible soiling or discarded surgical items that may have fallen onto the floor. A thorough terminal cleaning is recommended at the end of each day of use.

Answer 22

T

Question 23

the goal of preoperative skin cleansing is to decrease resident flora to its lowest possible level, with the realization that it cannot be completely eradicated

Answer 23

T

Question 24

The most common resident organisms are the coagulase-negative staphylococci, with Staphylococcus epidermidis accounting for more than 90% of resident aerobes. 4 Anaerobic diphtheroids such as Propionibacterium acnes are common in lipid-rich locations, such as the pilosebaceous unit. Gram-negative bacteria represent a small portion of the resident flora. They are mostly limited to the humid intertriginous areas with Enterobacter , Klebsiella , Escherichia coli , and Proteus spp. being the predominant organisms

Answer 24

T

Question 25

Transient flora are acquired through contact with people, objects, or the environment. They are loosely attached to the surface of the skin and are amenable to removal by washing. The majority of postoperative wound infections are due to transient microorganisms that contaminate the wound during surgery. In most cases, the source is the endogenous flora of the patient's nose, throat, or skin

Answer 25

T

Question 26

Based on the Centers for Disease Control and Prevention (CDC) data examining all types of SSIs, Staphylococcus aureus ( S. aureus ) is the most frequent organism isolated, followed by coagulase-negative staphylococci, Enterococcus spp., E. coli , group A streptococci and Pseudomonas aeruginosa .

Answer 26

T

Question 27

For surgical procedures, the contact and air-borne routes are the most likely means of contamination. Contact transmission may be indirect where organisms are transferred via fomites (e.g., if a suture touches contaminated skin and is then placed into the wound) or direct (if contaminated skin of the patient or surgeon touches the wound). During air-borne transmission, microorganisms are not suspended freely but carried on desquamated skin cells, aerosolized water droplets, or dust particles. 8 In this way, the gowns, linens, surgical tables, and operating room floors are easily contaminated, particularly with staphylococci and enterococci, which are resistant to desiccation.

Answer 27

T

Question 28

The predominant pathogen responsible for infection in clean skin surgery is S. aureus and its source is most frequently the patient's anterior nares. Of the US population, 31.6% are nasal carriers of S. aureus at any given time, 9 and nasal carriers have a 3–9.6-fold increased risk of SSIs. 10 11 Furthermore, among patients who develop staphylococcal SSIs and are also nasal carriers, 85% of isolates are genetically identical between the two sites, confirming the endogenous nature of the SSI

Answer 28

T

Question 29

The CDC defines SSI as any surgical wound that produces pus (suppurates) within 30 days of the procedure, even in the absence of a positive culture.

Answer 29

T

Question 30

A positive culture does not necessarily confirm a wound infection, because chronic wounds may be colonized but not infected. In this case, it is the quantity of bacteria per gram of tissue (usually >10 5 ) that determines whether infection is present.

Answer 30

T

Question 31

If there are minor breaks in aseptic technique, or entry into the gastrointestinal, respiratory, or genitourinary tracts, the wound is considered to be clean-contaminated.

Answer 31

T

Question 32

Contaminated wounds include those where major breaks in aseptic technique have occurred, or there is inflammation, but no frank purulence encountered. A dirty wound contains frank purulent fluid such as an abscess. It may also involve the perforation of a viscus or fecal contamination.

Answer 32

T

Question 33

In addition to the local condition of the wound, patient and operative characteristics may influence the risk for developing an SSI. For example, biopsies performed in a hospital ward, as opposed to an outpatient setting, have a higher risk for infection. A comprehensive method, such as that proposed by the CDC, incorporates additional factors such as the patient's age, malnutrition, obesity, hypothermia, use of immunosuppressants (including alcohol), and the length of the procedure.

Answer 33

T

Question 34

The ideal antiseptic agent should be broad-spectrum, non-irritating, fast-acting, and provide continued antimicrobial action within the moist environment of the surgical glove.

Answer 34

T

Question 35

chlorhexidine does not have much activity against tuberculosis

Answer 35

True

Question 36

PCMX has poor coverage as a single agent

Answer 36

Parachlorometaxylenol (PCMX), also known as chloroxylenol, has good Gram-positive bacteria coverage but notably poor activity against P. aeruginosa . To address this limitation, several PCMX formulations have either an added chelator, such as ethylenediaminetetraacetic acid (EDTA) or a quaternary compound, which markedly increase the anti- Pseudomonas activity of the mixture

Question 37

Re: iodine The scrub contains a detergent, which should not be allowed to make contact with the eyes. Prolonged skin contact with wet PI solution can induce irritant and rarely allergic contact dermatitis but once dried, it is generally non-irritating and can be left on the skin and covered with a dressing.

Answer 37

T

Question 38

It works within minutes but must be left on the skin to have a persistent effect. It is quickly inactivated in the presence of blood or sputum, and chronic maternal use has been associated with hypothyroidism in newborns

Answer 38

T

Question 39

# RE: iodine While approved for use on other mucous membranes, the label for PI 10% aqueous solution states “Do not use in the eyes.” Consequently, Alcon (Fort Worth, TX) markets a specific ophthalmic preparation of PI (Betadine® 5% Ophthalmic Prep Solution). However, 10% PI solution diluted 1: 1 with normal saline is commonly used off-label for surgical antisepsis of the conjunctiva and periocular skin. This approach is based on extensive safety and efficacy data for bacterial endophthalmitis prophylaxis in cataract surgery. 22 It is felt that the full strength 10% PI solution causes conjunctival irritation but direct comparative data is lacking.

Answer 39

T

Question 40

Chlorhexidine gluconate (CHG) has a similar antimicrobial spectrum as PI. CHG binds to the stratum corneum and maintains residual activity in excess of 6 h, even when wiped from the field. Its action is not affected by the presence of organic matter, but it should be used with caution around the eyes, as it can cause conjunctivitis and severe corneal ulceration

Answer 40

T

Question 41

Chlorhexidien can also induce ototoxicity if allowed to reach the middle ear through a perforated tympanic membrane. Animal studies and human case reports describe resultant deafness from prolonged exposure of CHG to the middle ear. Application to the pinna and even the external auditory meatus does not pose a risk to patients with an intact tympanic membrane but, as the status of the membrane is generally unknown, it is prudent to avoid dripping the solution into the auditory canal. CHG comes in a wide variety of strengths and formulations, the full menu of which is beyond the scope of this chapter. The most common formulation in dermatologic use is the 4% scrub solution (Hibiclens®, Mölnlycke Health Care, Norcross, GA or generic equivalents), which is used for surgical hand scrub as well as skin preparation.

Answer 41

T

Question 42

ChloraPrep®, approved in 2000, contains 2% Chlorhexidine in 70% isopropyl alcohol. The addition of alcohol, a broad-spectrum antiseptic in its own right, greatly increases the speed of action, while maintaining the residual activity of the antiseptic. These one-step agents are only available packaged in single use applicators, which has limited their routine use in dermatologic surgery, but they are widely used in hospitals. Alcohol is irritating to mucous membranes and therefore these agents must be used cautiously around the eyes or mouth.

Answer 42

T

Question 43

When applied as a single agent, alcohol is rapidly germicidal, but once evaporated, it does not have significant residual activity. For this reason, alcohol as a single agent is not commonly used for preoperative skin preparation for sterile procedures, although it is an excellent option for surgical hand antisepsis.

Answer 43

T

Question 44

A typical protocol involves removing any visible debris with a single 1 min handwash with non-antiseptic soap at the beginning of the day. This is followed with two applications of an alcohol solution (~4 mL total) to the forearms and hands prior to every procedure or whenever changing gloves. The solution should be allowed to air dry for about a minute before donning gloves.

Answer 44

T

Question 45

Since the outer surfaces of a hand pump are easily contaminated, many surgeons prefer single-use packets or a foot-operated dispensing system.

Answer 45

T

Question 46

The perineum is heavily colonized and the friction generated by walking can liberate bacteria-laden skin cells into the operating room environment. A scrub shirt tucked into pants that are constricted at the waist and ankles is an efficient means of reducing perineal dispersal.

Answer 46

T

Question 47

There are conflicting data regarding nail polish and its effect on the surgical hand scrub. It is generally agreed that nail polish may be worn as long as it is not chipped or dark in color, potentially obscuring the presence of subungual debris. Jewelry is known to harbor bacteria beneath it and to decrease the effectiveness of the hand scrub, but it is not known whether this sequestration leads to increased risk for SSI. Despite the lack of consensus or scientific data, jewelry and long fingernails (natural or artificial) limit dexterity, increase the risk for glove perforation, and are therefore best avoided during surgery.

Answer 47

T

Question 48

Wearing a long-sleeved scrub jacket that snaps closed in the front can decrease bacterial shedding from the forearms. However, there are no scientific data to show that wearing scrub suits rather than street clothes affects the incidence of SSI.

Answer 48

T

Question 49

The effectiveness of a face mask is defined by its shape, the materials from which it is made, and the way in which it is worn. Loose-fitting masks allow up to 40% of expired air to escape backward past the cheeks and ears, particularly when sneezing or coughing, and must be tied snuggly to be effective.

Answer 49

T

Question 50

At the end of each surgery, face masks should be discarded. They should not be placed in the pocket for future use or left dangling around the neck, as the inner surface of the mask becomes contaminated with expired microorganisms. Once removed, it should be handled only by the ties.

Answer 50

T

Question 51

Speaking in a normal tone for up to 30 min without a face mask projects relatively few bacteria. Conversely, speaking in a loud tone, even briefly, liberates significantly more bacteria– up to 1 meter away– and coughing or sneezing can propel bacteria up to 3 meters. Given these findings, it is possible that operating in silence without a mask may provide the least risk for surgical site contamination

Answer 51

T

Question 52

Footwear worn during surgery should be fluid resistant and have impervious soles. It should be cleaned regularly and restricted to use in the operating room environment.

Answer 52

T If such footwear is not available, paper booties with elastic at the ankles can be worn over street shoes. These disposable covers protect the shoes from exposure to blood-borne pathogens and add to the overall hygiene of the operating room environment. However, there is little evidence that their use directly affects wound infection rates