The presence of a susceptible host is an important element in the chain of infection that paradoxically results from advances in current medical therapies and technology (e.g., children undergoing organ transplantation or chemotherapy, or extremely premature neonates) and the presence of children with diseases that compromise their immune systems (e.g., AIDS, tuberculosis, malnutrition, or burns). The organism may enter the host through the skin, mucous membranes, lungs, gastrointestinal tract, genitourinary tract, or the bloodstream via IV solutions, after laryngoscopy, or from surgical wounds. Organisms may also infect the individual because of work accidents with cutting or piercing devices. The development of THE RABBIT HOLE THAT IS THE PERIOPERATIVE ENVIRONMENT is not well understood by the majority of our general pediatric colleagues. Similarly, the rabbit hole of the primary care clinic or the pediatric inpatient ward is not well understood by the majority of our anesthesiology colleagues. A pediatric patient may repeatedly enter the rabbit hole over the course of a hospital admission, a journey fraught with dangers of airway mishaps, respiratory and/or cardiac arrests, hemorrhage, profound anxiety and stress experienced by the young patient and his or her family, as well as infection risks. 1 Anesthesiologists have long been patient safety advocates. It is not surprising that anesthesia providers in the 21st century have taken on increasing responsibility for preventing health careassociated infections (HAIs), including surgical site infections (SSIs). Anesthesia providers practice in a nonsterile environment within the operating room (OR) and frequently contact areas of the patient known to have a high rate of contamination such as the axilla, nares, and pharynx. There are two recognized but poorly implemented interventions: preoperative patient skin and other bacterial reservoir decontamination and hand hygiene by anesthesia providers. 2 Anesthesia providers have an impact on bacterial transmission and infection rates. Specifically, anesthesiologists are known to contaminate their work environment within the OR. Contamination of the work environment includes contamination of intravenous (IV) access ports. Without encouragement, anesthesiologists perform hand hygiene less frequently than once per hour during a case, but with reminders, the rate of hand hygiene is more frequent. Improved hand hygiene reduces contamination of the work area and IV access ports from 32% to 8%, which in turn significantly reduces HAIs. 3, 4 The transmission of infection depends on the presence of three interconnected elements: a causative agent, a source, and a mode of transmission ( Fig. 50.1 ). Understanding the characteristics of each element provides the practicing anesthesiologist with methods to protect susceptible patients and themselves to avoid spreading infection.
There has always been concern about the transmission of infectious agents to the patient from the anesthesiologist and vice versa. 5 In addition, there are many sites within the hospital environment where moist or desiccated organic material with the membranes. Droplets remain suspended for only a short duration and distance from the source, but this may be affected by temperature, humidity, force of expulsion, and air currents. Larger particle sizes contact the mucosa of the upper airway, whereas aerosols are capable of penetrating into the lower respiratory tract. Infectious agents vary in their affinity for receptors in different regions of the respiratory tract. 9,10 When a person coughs, the exhaled air may reach a speed of up to 965 km/hour (600 mph). 11 However, because the droplets are relatively large, they tend to descend quickly and remain suspended in the air for a very brief period, thus obviating the need for special handling procedures for the OR air. Examples of droplet-borne diseases include influenza, respiratory syncytial virus (RSV), severe acute respiratory syndrome (SARS), diphtheria, Haemophilus influenzae, Neisseria meningitidis, mumps, pertussis, rhinovirus, rubella, and Ebola. Droplet precautions include communication of infectious risk infection is influenced by the host defense mechanisms that may be classified as either nonspecific or specific: ■ Nonspecific defense mechanisms include the skin, mucous membranes, secretions, excretions, enzymes, inflammatory responses, genetic factors, hormonal responses, nutritional status, behavior patterns, and the presence of other diseases. ■ Specific defense mechanisms or immunity may occur because of exposure to an infectious agent (antibody formation) or through placental transfer of antibodies; artificial defenses may be acquired through vaccines, toxoids, or exogenously administered immunoglobulins.
Microorganisms are transmitted in the hospital environment through a number of different routes; the same microorganism may also be transmitted via more than one route. In the OR, the three main routes of transmission are through the air and by direct and indirect contact.
Airborne infections that may infect susceptible hosts are transmitted via two mechanisms: droplets and droplet nuclei.
Droplet contamination is considered a direct transmission of organisms because there is a direct transfer of microorganisms from the colonized or infected person to the host. This generally occurs with particles whose diameters are greater than 5 µm that are expelled from an individual's mouth or nose, mainly during sneezing, coughing, talking, or during procedures such as suction, laryngoscopy, and bronchoscopy ( Fig. 50.2 ). Transmission occurs when the microorganism-containing droplets, expelled or shed by the infected person (source), are propelled a short distance (usually not exceeding 60 cm or about 2 feet through the air) and deposited on the host's conjunctivae or oral or nasal mucous 
Droplet nuclei result from the evaporation of droplets while suspended in the air. Unlike droplets, the nuclei have an outer layer of desiccated organic material and a very small diameter (1-5 µm) and remain suspended in air indefinitely. The microorganisms contained within these nuclei may be spread by air drafts over great distances, depending on the environmental conditions (dry and cold atmosphere, with limited or no exposure to sunlight favoring the spread). 12 In contrast to droplets, which are deposited on mucous membranes, droplet nuclei may enter the susceptible host by inhalation; examples of droplet nuclei-borne diseases include tuberculosis, varicella, and measles, zoster, smallpox, SARS, and Middle Eastern respiratory syndrome. 10 
Direct and indirect contacts are the most significant and frequent methods of hospital infection transmission.
This type of disease transmission involves direct physical contact between two individuals. The physical transfer of microorganisms from an infected or colonized person to a susceptible host may occur from child to health care provider or from health care provider to child during professional practice (e.g., venous cannulation, laryngoscopy, burn care, or suction of secretions). Health care providers working in the OR may be exposed to skin contamination by body fluids. This is an issue of grave concern because of the potential exposure of health care providers to patients with unrecognized infections, especially hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV). Hepatitis B is a highly infectious virus that requires a small amount of blood (10 −7 -10 −9 mL) to transmit the disease. The incidence of skin contamination of anesthesiologists and related personnel by blood and saliva is substantial. One study examined 270 anesthetic procedures during 7 consecutive days. The blood of 35 patients (14%) contaminated the skin of 65 anesthesiologists in 46 incidents. Of these contamination events, 28 (61%) occurred during venous cannulation. Of anesthesiologists who had been contaminated by blood, 5 of 65 (8%) had cuts in the skin of their hands. 13 The importance of this observation is that seroconversion of health care providers has been reported after skin contamination by infected blood from HIV carriers 14 and HBV infection after blood splashing into health care workers' (HCWs') eyes. 15 Scabies, pediculosis, and herpes simplex are among the diseases most frequently transmitted by direct contact. [16] [17] [18] [19] [20] [21] [22] [23] Meticulous hand washing before and after every patient contact and routine use of barriers such as gloves and eye protection are essential basic methods for protecting ourselves even during routine procedures such as starting an IV line or performing laryngoscopy. 4
Indirect contact involves the transmission of microorganisms from a source (animate or inanimate) to a susceptible host by means of a vehicle (e.g., an intermediary object) contaminated by body fluids. Tables 50.2 and 50. 3 provide examples of diseases associated with bodily fluids to which HCWs may be exposed. The vehicle for transmission may be the hands of a health care provider who is not wearing gloves or a provider who fails to wash his or her hands after providing care to a child. 3, [24] [25] [26] This type of contact can also come from health care providers who touch (with or without gloves) contaminated monitoring or other patient care devices (e.g., blood pressure cuffs, stethoscopes, electrocardiographic cables, or ventilation systems [respirators, corrugated tubes, Y-pieces, valves]) that are used without proper cleaning or disinfection between each use. [27] [28] [29] Knowledge about the transmission of the spread of bacteria from patients to HCWs' hands and to the hospital environment ( Fig. 50 .3) has driven many interventions that have reduced patient risks for developing HAIs. 30 
Disease Transmitted   Blood  HBV, HIV, HCV, CMV, EBV, NANBH   Seminal fluid  HIV, HBV, CMV   Vaginal discharge  HIV, HBV, CMV   Saliva and sputum  HSV, TB, CMV, respiratory diseases   Cerebrospinal fluid  Encephalopathic organisms (see  Table 50 30 Characterization of the transmission dynamics of frequently encountered gram-negative bacteria in the anesthesia work area environment 32 demonstrates that the spread follows an epidemiologic pattern similar to that seen in ICUs and inpatient wards: from patient, to environment and HCWs' hands, and to other patients ( Fig. 50.4) . In this report, provider hands were less likely to serve as a transmitter of infection than contaminated environmental or patient skin surfaces. These findings have clinical implications for the risk of colonization and subsequent HCIs-for example, SSIs. This calls attention to the need to develop and enforce strict hand hygiene guidelines for personnel who are providing anesthesia care, but more importantly the need to increase compliance with environmental disinfection of the OR (between cases and terminal cleaning), and to study further the directions of the spread of pathogens in the OR and anesthesia work areas. This study unequivocally underscores our need to improve cleaning procedures in the OR and equipment surfaces to reduce infection risk.
There are also reports of equipment, fomites, and drugs (mainly propofol) that have resulted in hospital-acquired infections. 20, [33] [34] [35] [36] [37] [38] [39] [40] [41] [42] [43] [44] [45] [46] [47] [48] [49] [50] [51] Propofol is widely used for both inpatient and outpatient anesthesia. This hypnotic agent is a nutrient-rich drug. It is hypothesized that propofol increases bacterial contamination of IV stopcocks and may compromise safety of IV tubing sets when continued to be used after propofol anesthesia. There is a covert incidence of IV stopcock bacterial contamination during anesthesia that is aggravated by the prior presence of propofol. Propofol may increase the risk for postoperative infection because of bacterial growth in IV stopcock dead spaces. 52 Other facets that may also contribute to infection include the following: ■ Up to 40% of anesthetic equipment in direct or indirect contact with a child (blood pressure cuffs, cables, oximeters, laryngoscopes, monitors, respirator settings, and horizontal and vertical surfaces) may be contaminated with blood because of inadequate cleansing procedures between uses. 6,7,27,53,54 ■ In some institutions, up to 8% of the Bain circuits that were reused without previous sterilization were contaminated. 55 ■ Contamination of syringe contents has occurred with glass particles during ampule opening, which in turn may compromise the sterility of the contents, presumably because of the passage of bacteria contained on glass particles into the solution. 56-58 ■ IV tubing has both blood contamination as well as contamination by blood from syringes used to inject medications. This can occur with the absence of visible blood reflux in the tubing or syringe. Simply replacing the needle on a syringe that will be reused is ineffective in preventing cross-infection; it is essential to not use the same syringe in multiple patients. 59 ■ Refilling both glass and plastic syringes several times has also been shown to result in contamination of the contents; single use is therefore recommended. 59 Studies on vancomycin-resistant enterococci established the importance of a domino effect of contamination in intensive care units (ICUs) and inpatient wards: spread of vancomycin-resistant enterococci that colonize patients' gastrointestinal tracts ("rectal carriage"), to patients' skin, to the hospital environment, to hands of HCWs, and then to other patients. The skin contamination of patients with enteric organisms inspired the rather graphic description, the patient's "fecal patina." 31 Also referred to as a "stool veneer," this coating with enteric organisms is limited not only to patients' skin but also extends to surfaces in the surrounding environment that are touched, and thereby contaminated, by patients and by HCWs. The environmental contamination spreads out from the patient in a target-like concentric pattern, with the densest contamination closest to the rectum of patients who have rectal carriage of the problem bacteria. This interplay among the blood of a patient in an advanced disease stage or with a higher HIV viral load; a deep percutaneous injury; a procedure wherein the sharp was in the vein or artery of an infected source patient; an injury with a hollow-bore, blood-filled needle; and limited or delayed access to postexposure prophylaxis. After exposure, the risk of infection varies for specific bloodborne pathogens. For HBV, if the source patient has active HBV and the HCP do not already have immunity, the risk for infection after percutaneous injury is between 1% and 30%. If the source patient has active HCV, the risk of hepatitis C transmission is approximately 1.8% (range 0%-7%) after a percutaneous injury. If the source patient has HIV infection, the risk of HIV transmission is approximately 0.3% after a percutaneous exposure and 0.09% after a mucous membrane exposure. The risk of HIV transmission for an exposure with nonintact skin has not been determined and is estimated to be less than the risk after a mucous membrane exposure. 78 Anesthesia staff lacking HBV protective antibodies are at great risk for acquiring the disease. 79, 80 These infection rates underscore the need for the use of "safe" needles and the need to advocate the use of "needleless" systems even though they are significantly more expensive. 81, 82 This also emphasizes the need for meticulous handling and disposal of needles and other sharp instruments, as well as the use of special "sharps boxes" designed to minimize accidental needlesticks (e.g., "mailbox"-type boxes that do not allow the hand to enter the disposal area). [83] [84] [85] [86] [87] [88] [89] [90] [91] [92] [93] [94] [95] [96] [97] [98] The U.S. Centers for Disease Control and Prevention (CDC) has estimated that in the United States there are approximately 385,000 cutting and piercing accidents annually among HCP in hospitals; 25% of these occur in the OR. 77 However, the actual prevalence is thought to be much greater, because many of these events are unreported. The distribution of these accidents among anesthesiologists is shown in Fig. 50 .5A; the distribution of the items most frequently associated with cutting and piercing injuries in health care providers is shown in Fig. 50 .5B. Should such an accident occur (e.g., needle puncture, exposure to nonintact skin, or mucous membrane ■ Needles that have been used for spinal or epidural anesthesia were contaminated with coagulase-negative staphylococci (15.7%), yeasts (1.5%), enterococci (0.8%), pneumococci (0.8%), and micrococci (0.8%), suggesting that there may be needle contamination despite standard skin preparation and cleansing. 68 It is unclear whether these skin organisms can be transmitted and cause an infection during administration of a neuraxial block. ■ Blood and saliva frequently contaminate the skin of anesthetic personnel during routine anesthetic practice. 13 ■ Violations of contemporary guidelines for preventing infections (e.g., hand washing, wearing gloves, surgical masks, ocular protection, scrubs, or syringe reuse) by anesthesiologists are frequent. 4 Anesthesia staff are aware that they work in a potentially infectious environment, but they commonly do not adopt appropriate protective measures to reduce infections in both themselves and their patients (11%-99%). 27,69-71
Percutaneous contamination from a cutting or piercing accident is the most effective means to transmit bloodborne pathogens. Evidence suggests that this is the main route of HIV, HBV, and HCV infection, [72] [73] [74] especially if the injury is caused by hollow-bore needles that were used to draw blood or establish IV access. 75, 76 Over 20 other bloodborne pathogens have been transmitted by this means, including those causing herpes, malaria, and tuberculosis. 77 The risk of exposure to blood and bloodborne pathogens is greater for health care personnel (HCP) than for people who do not work around blood. An exposure to infected blood, tissue, or other potentially infectious body fluids can occur by percutaneous injury or contact with mucous membrane or nonintact skin. The risk of infection after an exposure depends on a number of variables and appears to be greater with exposure to a larger quantity of blood or other infectious fluid; prolonged or extensive exposure of nonintact skin or mucous membrane to blood or other infectious fluid or concentrated virus in a laboratory setting; exposure to 
Institutional administrative measures aimed at developing, implementing, and monitoring specifically designed accident prevention policies and procedures are important for reducing and preventing transmission of infectious agents in health care centers. To this end, centers should consider the following: 77,99,100 ■ Include infection control as a major goal in the organizational mission statement and implement safety programs, both for patients and HCWs. ■ Provide sufficient administrative and financial support to carry out this mission. ■ Provide sufficient administrative and financial support for the microbiology laboratory and implement an infection surveillance plan, especially for postsurgical infections. ■ Establish a multidiscipline cross-functional team (e.g., a team manager, an epidemiologist, a representative from industrial health, and a person trained in quality control) to identify health and safety issues within the institution, analyze trends, assess outcomes, implement interventions, and make recommendations to other members of the organization. ■ Provide sufficient administrative and financial support to develop and implement education programs for health care providers, patients, and their families. One positive example of such education is that anesthesiologists who have read the CDC's Universal Precaution Guidelines for the Prevention of Occupational Transmission of HIV and HBV have developed better hygienic practices. 69 ■ Provide HCWs with hepatitis A and B vaccine and document that an appropriate immunologic response was achieved. Provide hepatitis A and B immune globulins (HAIG, HBIG) for those exposed who do not have established immunity. 8 ■ Provide a health care service for employees for counseling and postexposure prophylaxis should an exposure to HIV occur. 101 , there are now specific recommendations regarding immediate assessment of risk, assessment of the exposure source (chart review, inform the patient that an accident has occurred and ask permission to determine HBV, HCV, and HIV serologic status), and rapid initiation of appropriate antiviral treatment of the HCW. 82 It is advised to obtain as much information regarding the patient as possible-if the patient is known-to (1) obtain a sample of blood from the patient for determination of potential carrier state (Table 50 .4) and (2) report to the health service for immediate institution of prophylaxis and follow-up ( Air is delivered to each OR from the ceiling, with downward movement toward several exhaust or return ducts near the floor. This design helps provide steady movement of clean air through the breathing and working zones. The AIA has specific guidelines for the location of outside fresh air inlets to minimize contamination from exhaust systems and noxious fumes. A greater air inflow rate and a larger air-inlet area are desirable for contaminant control, but these approaches are detrimental to the thermal comfort of the staff and patient. 108 The AIA recommends an air-change rate in an OR of 20 to 25 air changes per hour (ACH) for ceiling heights between 9 feet wound contamination in the OR is the result of the patient's skin flora and bacteria shed on airborne particles from the OR personnel. Room ventilation affects the distribution of these airborne particles in four ways: total ventilation (dilution), air distribution (directional airflow), room pressurization (filtration barrier), and filtration (contaminant removal). As the air flows of the room increase, the greater the dilutional effect on airborne particles. Balancing this phenomenon is important because while increased flow increases the effectiveness of air exchange, the resultant turbulent flow increases microbial distribution throughout the room. Low-velocity unidirectional flow minimizes the spread of microbes in the room. Directional flow can be inward, from the outside into the OR (negative pressure), or outward, from the OR to the outside (positive pressure). Negative-pressure ventilation is used for highly infective rooms in the hospital (e.g., isolation rooms for tuberculosis patients), and positive-pressure ventilation is used for protective environments (e.g., ORs and PEP Step 1: Treat Exposure Site
• Use soap and water to wash areas exposed to potentially infectious fluids as soon as possible after exposure. • Flush exposed mucous membranes with water. • Flush exposed eyes with water or saline solution.
• Do NOT apply caustic agents, or inject antiseptics or disinfectants into the wound.
Step 2: Report and Document 
Standard precautions 117 assume that any person or patient is potentially infected or colonized by microorganisms that could be transmitted and cause an infectious process. Standard precautions must be implemented with all patients and include the following: ■ Universal precautions-blood and body fluid precautions, developed to reduce bloodborne pathogen transmission ■ Body substance isolation, designed to reduce the risk of pathogen transmission by moist body substances Standard precautions are used to reduce the transmission of all infectious agents from one person to another, thus protecting health care providers and children against exposure to the most common microorganisms. Standard precautions are implemented for any contact with blood and body fluids, secretions, and excretions (except sweat), whether or not they contain visible blood, as well as for any contact with nonintact skin, mucous membranes, and intact skin that is visibly soiled with blood and/ or body fluids. Prevention is primary. All HCPs should be familiar with standard precautions: wash hands frequently and thoroughly before and after patient care; use personal protective equipment: gloves, gowns, boots, shoe covers, eyewear, masks, and shields, as appropriate for the patient care situation; gloves must be worn when any kind of venous or arterial access is being performed; use sharps with caution: plan ahead (use sharps in a safe environment with a sharps container nearby), dispose of used sharps in puncture-proof receptacles immediately after use, do not recap needles, and use safety devices if available. All HCPs should be vaccinated with the hepatitis B vaccine series and should undergo testing for HBsAb response after completion of the series to document adequate protection. Employees who have not gone through the vaccination series previously should be offered the hepatitis B series through their employer at no cost. 118 Summaries of standard precautions, droplet precautions, airborne precautions, and contact precautions are available on line. 100, [119] [120] [121] Hand Washing Overall hand hygiene compliance across health care providers remains less than 50%, with anesthesia providers identified as a particularly noncompliant group (one study found a compliance rate of only 23%). 122 Bacterial contamination of anesthesia providers has been directly linked to high-risk bacterial transmission events to IV stopcocks and 30-day postoperative infections. 24 The vast majority of SSIs are caused by Staphylococcus aureus. Transmission of specific staphylococcal phenotypes within and between patients is a major contributor to SSIs and HAIs. 3, 4, 123 The role of anesthesia-provider hand contamination in transmission of Enterococcus to the workstation and patient biome is concerning, even though it was not associated with actual infection, because of rising rates of antibiotic-resistant organisms and the observation that Enterococcus is becoming a more prevalent pathogen. 3, 124 Two approaches are indicated: improved methods of patient reservoir decontamination and more effective and frequent decontamination of provider hands. Hand hygiene is a well-known and effective solution to the problem of bacterial transmission within and across patients. Compliance with the current "5 moments" World Health Organization guidelines could make a major inroad into reducing provider hand and workspace contamination. One study found that only 20% of anesthesia providers demonstrated complete knowledge regarding WHO hand hygiene guidelines. 125 Failure of providers to recognize prior contact with the environment and prior contact with the patient as hand hygiene opportunities contributed to this low percentage. Several cognitive factors were associated (2.74 meters) and 12 feet (3.66 meters). Some controversy exists between engineers and clinicians over the need for laminar airflow ventilation in the OR to further minimize airborne infection. Careful mathematical analyses of airflow suggest that laminar airflow is not necessary. Clinical studies are confirmatory. Similarly, the use of ultraviolet light to cleanse the room air is no longer recommended. 109 Table 50 .8 shows the 2003 Healthcare Infection Control Practices Advisory Committee and CDC general recommendations for ventilation system specifications for the OR. 12 Children with tuberculosis require special consideration because of the high risk of occupational transmission of Mycobacterium tuberculosis, 110, 111 especially after the emergence of multidrug-resistant strains (Table 50.9 ). An easy preventive measure is to screen all children before coming to the OR to determine recent exposure to infectious disease such as measles, mumps, rubella, and chickenpox because these infections can pose a significant risk to HCWs and patients, especially those who are immunocompromised. 73, 106 Another potential source for airborne spread of pathogens is through the anesthesia circuit; this may be reduced by the use of circuit filters. However, at present there are no regulatory requirements to use such devices, and performance characteristics vary widely. 28 
• PEP should be initiated within 2 hours of the exposure.
• The eficacy of PEP initiation is thought to diminish after 24 to 36 hours following an exposure.
• If the fourth-generation combination HIV Ag/Ab assay is used to test the source patient, HIV follow-up testing can be completed 4 months after exposure. Hand washing is considered the most important and costeffective individual intervention in the prevention of HAIs in children and health care providers. 126 Its importance in medical practice had not been universally accepted, despite the pioneering work by Oliver Wendell Holmes 127 (1843) and Ignaz Semmelweis 128 with a reduced risk of incomplete knowledge, including providers responding positively to washing their hands after contact with the environment, disinfecting their environment during patient care, believing that they can influence their colleagues, and intending to adhere to guidelines. These results suggest that anesthesia providers have knowledge deficits pertaining to opportunity-based hand hygiene in the intraoperative arena 125 HIV-positive class 1: asymptomatic HIV infection or known low viral load (e.g., <1500 ribonucleic acid copies/mL). HIV-positive class 2: symptomatic HIV infection, acquired immunodeficiency syndrome, acute seroconversion, or known high viral load. If drug resistance is a concern, obtain expert consultation. Initiation of PEP should be delayed pending expert consultation, and because expert consultation alone cannot substitute for face-to-face counseling, resources should be available to provide immediate evaluation and follow-up care for all exposures. The recommendation "consider PEP" indicates that PEP is optional; a decision to initiate PEP should be based on a discussion between the exposed person and the treating clinician regarding the risks versus benefits of PEP. g If PEP is offered and administered and the source is later determined to be HIV-negative, PEP should be discontinued. Recommendations for surgical hand preparation are as follows: remove rings, wristwatch, and bracelets before beginning surgical hand preparation (II); artificial nails are prohibited (IB); sinks should be designed to reduce the risk of splashes (II); if hands are visibly soiled, wash hands with plain soap before surgical hand preparation (II); remove debris from underneath fingernails using a nail cleaner, preferably under running water (II); brushes are not recommended for surgical hand preparation (IB); surgical hand antisepsis should be performed using either a suitable antimicrobial soap or suitable alcohol-based handrub, preferably with a product ensuring sustained activity, before donning sterile gloves (IB); if the quality of water is not assured in the operating theatre, surgical hand antisepsis using an alcohol-based handrub is recommended before donning sterile gloves when performing surgical procedures (II); when performing surgical hand antisepsis using an antimicrobial soap, scrub hands and forearms for the length of time recommended by the manufacturer, typically 2-5 minutes. Long scrub times (e.g., 10 minutes) are not necessary (IB); when using an alcohol-based surgical handrub product with sustained activity, follow the manufacturer's instructions for application times. Apply the product to dry hands only (IB); do not combine surgical hand scrub and surgical handrub with alcohol-based products sequentially (II); when using an alcoholbased handrub, use sufficient product to keep hands and forearms wet with the handrub throughout the surgical hand preparation procedure (IB); after application of the alcohol-based handrub as recommended, allow hands and forearms to dry thoroughly before donning sterile gloves (IB).
At present, alcohol-based handrubs are the only known means for rapidly and effectively inactivating a wide array of potentially harmful microorganisms on hands. The WHO recommends alcohol-based handrubs based on the following factors: evidencebased, intrinsic advantages of fast-acting and broad-spectrum microbicidal activity with a minimal risk of generating resistance to antimicrobial agents; suitability for use in resource-limited or remote areas with lack of accessibility to sinks or other facilities for hand hygiene (including clean water, towels, and so on); capacity to promote improved compliance with hand hygiene by making the process faster and more convenient; economic benefit by reducing annual costs for hand hygiene, representing approximately 1% of extra costs generated by an HCI; minimization of risks from adverse events because of increased safety associated with better acceptability and tolerance than other products. 118 After hand washing, it is very important to dry the hands properly with appropriate paper towels, hot air flow, or both, because the level of pathogen transmission from a HCW's hands to a patient is greatly increased if the hands are wet. 141 Sterile cloth towels are most frequently used in ORs to dry wet hands after surgical hand antisepsis. Several methods of drying have been tested without significant differences between techniques. 118 Transmission may also occur from patients' wet sites, such as groins or armpits, or when a HCW gets his or her hands wet when opening parenteral solutions. It is critical for health institutions to establish written procedures and protocols to support adherence to the recommended hand hygiene practices.
Wearing clean or sterile gloves while caring for children is an effective means of reducing HAIs. Gloves remain a supplementary barrier to infection that should not replace proper hand hygiene. more frequent (on average, 22 opportunities per patient-hour). The greatest adherence rate (59%) was observed in pediatrics, where the average intensity of patient care was smaller than elsewhere (on average, 8 opportunities per patient-hour). The results suggest that full adherence to guidelines is unrealistic and that easy access to hand hygiene at the point of patient care, (i.e., in particular, alcohol-based handrubbing) could help improve adherence to hand hygiene.
Perceived barriers to adherence with hand hygiene practice recommendations include skin irritation caused by hand hygiene agents, inaccessible hand hygiene supplies, interference with HCW-patient relationships, patient needs perceived as a priority over hand hygiene, wearing of gloves, forgetfulness, lack of knowledge of guidelines, insufficient time for hand hygiene, high workload and understaffing, and the lack of scientific information showing a definitive impact of improved hand hygiene on HAI rates. Lack of knowledge of guidelines for hand hygiene, lack of recognition of hand hygiene opportunities during patient care, and lack of awareness of the risk of cross-transmission of pathogens are barriers to good hand hygiene practices. Furthermore, some HCWs believed that they washed their hands when necessary even when observations indicated that they did not. The risk of pathogen transmission via the hands is proportional to the power of the number of times a child is touched. 140 Table 50 .10 presents 1. Wash hands with soap and water when visibly dirty or visibly soiled with blood or other body fluids (IB) or after using the toilet (II).
2. If exposure to potencial spore-forming pathogens is strongly suspected or proven, including outbreaks of Clostridium difficile, hand washing with soap and water is the preferred means (IB).
3. Use an alcohol-based handrub as the preferred means for routine hand antisepsis in all other clinical situations described in terms 4(a) to 4(f) listed below, if hands are not visibly soiled (IA). IF alcohol-based handrub is not obtainable, wash hands with soap and water (IB).
4. Perform hand hygiene: a. before and after touching the patient (IB); b. before handling an invasive device for patient care regardless of whether or not gloves are used (IB); c. after contact with body fluids or excretions, mucous membranes, non-intact skin, or wound dressings (IA); d. if moving from a contaminated body site to another body site during care of the same patient (IB); e. after contact with inanimate surfaces and objects (including medical equipment) in the immediate vicinity of the patient (IB); f. after removing sterile (II) or nonsterile gloves (IB). 5. Before handling medication or preparing food, perform hand hygiene using an alcohol-based handrub or wash hands with either plain or antimicrobial soap and water (IB).
6. Soap and alcohol-based handrub should not be used concomitantly (II). Gloves protect patients by reducing health care provider hand contamination and the subsequent transmission of pathogens to other children, provided the gloves are changed after providing care to each child. Additionally, when the use of gloves is combined with CDC standard precautions, they protect the health care provider against exposure to bloodborne infections or infections transmitted by any other body fluids, such as excretions, secretions (except sweat), mucous membranes, and nonintact skin. Examination gloves are single-use and usually nonsterile. Sterile surgical gloves are required for surgical interventions. Some nonsurgical care procedures, such as central vascular catheter insertion, also require surgical glove use. In addition to their sterile properties, these gloves have characteristics of thickness, elasticity, and strength that differ from other medical gloves. The use of gloves in situations when their use is not indicated represents a waste of resources without necessarily reducing crosstransmission. The wide-ranging recommendations for glove use have led to very frequent and inappropriate use. Indications for gloving and glove removal are shown in Table 50 .11. Situations that require and that do not require glove use are presented in Fig. 50 .6.
Ranked consensus recommendations for the use of gloves, categorized according to the CDC/HICPAC system, include the following 118, 142, 143 : ■ Wear gloves in case of contact with blood or any other potentially infecting body fluid, such as excretions, secretions (except sweat), mucous membranes, and nonintact skin (IC). ■ Remove the gloves immediately after providing care to a child.
Staff should not wear the same pair of gloves to take care of more than one child, nor should they touch the surfaces of any equipment, monitoring devices, or even light switches. ■ Alcohol-based handrub dispensers and clean glove boxes (at least two sizes) should be in place near every patient care site (e.g., on top of every anesthesia cart, medication cart, or in the nursing station). ■ Disposable gloves should not be washed, resterilized, or disinfected (IB). If gloves are reused, appropriate reprocessing methods should be in place to ensure the physical integrity of the gloves and their full decontamination (II). ■ Sterile gloves are much more expensive than clean, disposable gloves and should be used only for certain procedures, such as when hands are in contact with normally sterile body areas or when inserting intravascular or urinary catheters. Clean gloves should be used during any other procedure, including wound dressing. ■ Latex-free gloves should be worn when caring for children at risk for latex allergy.
Surgical antimicrobial prophylaxis is an essential tool to reduce the risk of postoperative infections, and the anesthesia team plays a central role in ensuring the proper timing of drug administration. 147, 148 The aim of the perioperative administration of antibiotics is to obtain plasma and tissue drug concentrations exceeding the minimal inhibitory concentration of those organisms most likely to cause an infection. This will reduce the microbial load of the intraoperative contamination; it is not the intent to cover all possible pathogens, because this can lead to the selection of drug-resistant bacteria.
There have been few studies regarding the effectiveness of prophylactic guidelines for prevention of SSIs in children. Currently, prophylactic antibiotic guidelines exist for certain subsets of the pediatric surgical population, but there are no global recommendations, and the guidelines that exist are mostly based on studies from adults or from expert opinion. A retrospective study suggested that the appropriate use of antibiotic prophylaxis was a vital modifiable risk factor and may be the easiest factor to influence. Primary failure to administer the correct dose of antibiotics at the appropriate time resulted in an almost 2-fold increase in the risk of developing an SSI. The importance of correct antibiotic usage and dosing plays a major role in decreasing risk of SSIs in children. Recommendations are provided for adult (age ≥19 years) and pediatric (age 1-18 years) patients. The guidelines do not specifically address newborn (premature and full-term) infants (Table 50. 
Although pediatric-specific prophylaxis data are sparse, available data have been evaluated for specific procedures. Selection of antimicrobial prophylactic agents mirrors that in adult guidelines, with the agents of choice being first-and second-generation cephalosporins, reserving the use of vancomycin for patients with documented β-lactam allergies. While the use of a penicillin with a β-lactamase inhibitor in combination with cefazolin or vancomycin and gentamicin has also been studied in pediatric patients, the number of patients included in these evaluations remains small. As with adults, there is little evidence supporting the use of vancomycin, alone or in combination with other antimicrobials, for routine perioperative antimicrobial prophylaxis in institutions that have a high prevalence of methicillin-resistant S. aureus (MRSA). Vancomycin may be considered in children known to be colonized with MRSA and decreases MRSA infections. 150 Mupirocin is effective in children colonized with MRSA, but choice, alternative antibiotics should be administered to those children at risk of anaphylaxis to β-lactams, based on their history or diagnostic tests (e.g., skin testing). However, the incidence of severe allergic reactions to first-generation cephalosporins in children with reported allergy to penicillin is rare (but not zero) 158, 159 ; furthermore, skin testing does not reliably predict the likelihood of adverse reactions to cephalosporins in those with reported allergy to penicillin. [160] [161] [162] There is no evidence of any risk of cross-reactivity between penicillin and second-and thirdgeneration cephalosporins. For the most part, "allergies" to oral antibiotics that appear on children's charts (rash, vomiting, gastrointestinal disturbances) are reactions to the additives in the antibiotic formulation, including food dyes, fillers, and other compounds, or a manifestation of the underlying infection. IV administration of small test doses of the pure antibiotic in a fully monitored (and anesthetized) child will determine whether the child is at risk for an allergic reaction to the antibiotic. In the case of surgical procedures where antibiotic prophylaxis is mainly directed at gram-positive cocci, children who are truly allergic to β-lactams (cephalosporins) should receive either vancomycin or clindamycin. 163 However, in those children where the history is consistent with either an IgE-mediated penicillin allergy (urticaria, angioedema, anaphylaxis, bronchospasm) or a severe non-IgEmediated reaction (interstitial nephritis, toxic epidermal necrolysis, hemolytic anemia, or Stevens-Johnson syndrome) it is advisable to switch out the cefazolin. Cross-sensitivity occurs when the R1 side chains of the penicillins and cephalosporins are similar, which perhaps surprisingly is not the case with cefazolin. Cephalosporins with R1 side chains similar to penicillins include cephalexin, cefaclor, and cefadroxil. The risk associated with use of first-or second-generation cephalosporins with dissimilar side chains, or third-or fourth-generation cephalosporins, "appears to be very low in patients with mild-to-moderate reactions to penicillin G, ampicillin, or amoxicillin. Dismissing cefazolin use when there is a vague history of any penicillin allergy should be reconsidered." 155 Indications for Prophylactic Antibiotics Surgical wounds are classified into four categories (Table 50 .13). The use of antibiotic prophylaxis for postoperative infections is well established for clean-contaminated procedures. Within the clean category, prophylaxis has been traditionally reserved for surgical procedures involving a foreign body implantation or for any surgical procedure where an SSI would be catastrophic (e.g., cardiac surgery or neurosurgical procedures). However, there is evidence that postoperative infections resulting from procedures not involving prosthetic elements are underreported; estimates show that more than 50% of all complications occur after the patient is discharged and are thus unrecognized by the surgical team. Therefore antibiotic prophylaxis is also recommended for certain procedures, such as herniorrhaphy. 164, 165 The direct and indirect costs of these complications may not affect the hospital budget; however, they represent a substantial cost for the community at large. In the case of contaminated or dirty procedures, bacterial contamination or infection is established before the procedure begins. Accordingly, the perioperative administration of antibiotics is a therapeutic, not a prophylactic, measure. The use of antibiotics in children has implications not only for the response to the current treatment but also to future treatments. Thus all medical professionals are jointly responsible for the rational use of antibiotics. Protocols, although effective, require continuous feedback on their acceptance and SSI results. 166 No surgical protocol can replace there are limited data supporting its use perioperatively. 151, 152 Most recommendations for adults are the same for pediatric patients. Dosing recommendations in pediatric patients are limited and have been extrapolated from adult data; therefore nearly all pediatric recommendations are based on expert opinion. Pediatric efficacy data are few. Fluoroquinolones should not be routinely used for surgical prophylaxis in pediatric patients because of the potential for toxicity in this population. The same principle of preoperative dosing within 60 minutes before incision has been applied to pediatric patients. Additional intraoperative dosing may be needed if the duration of the procedure exceeds two half-lives of the antimicrobial agent or there is excessive blood loss during the procedure. As with adult patients, single-dose prophylaxis is usually sufficient. If antimicrobial prophylaxis is continued postoperatively, the duration should be less than 24 hours, regardless of the presence of intravascular catheters or indwelling drains. There are sufficient pharmacokinetic studies of most agents to recommend pediatric dosages that provide adequate systemic exposure and, presumably, efficacy comparable to that demonstrated in adults. Therefore the pediatric doses recommended in guidelines are based largely on pharmacokinetic data and the extrapolation of adult efficacy data to pediatric patients. Because few clinical trials have been conducted in pediatric surgical patients, strength of evidence criteria have not been applied to these recommendations. With few exceptions (e.g., aminoglycoside dosages), pediatric doses should not exceed the maximum adult recommended dosages. Generally, if a dose is calculated on a milligram-per-kilogram basis for children weighing more than 40 kg, the calculated dosage will likely exceed the maximum recommended dose for adults; adult dosages should therefore be used for larger children. 153 The Timing of Antibiotic Prophylaxis The 2013 revised policy paper on prophylactic antibiotics developed jointly by the American Society of Health-System Pharmacists (ASHP), the Infectious Disease Society of America, the Surgical Infection Society, and the Society for Healthcare Epidemiology of America states:
Successful prophylaxis requires the delivery of the antimicrobial to the operative site before contamination occurs. Thus, the antimicrobial agent should be administered at such a time to provide serum and tissue concentrations exceeding the minimum inhibitory concentration (MIC) for the probable organisms associated with the procedure, at the time of incision, and for the duration of the procedure. 154 Current evidence suggests that for most β-lactams, a bolus dose at 15 to 45 minutes before incision is ideal and provides maximum interstitial fluid concentrations at the time of initial bacterial seeding (see Table 50 .12). Because diffusion distances from capillary to pathogen are greater in obese patients, for this patient subset initiating antibiotic infusion 30 minutes or longer before incision is warranted on theoretical grounds. 155 The initial β-lactam bolus dose should be followed by additional doses at every 1 to 2 half-lives per the ASHP guidelines. 154 The use of a SSI prevention bundle in pediatric patients improves compliance with preincision antibiotic administration and decreases the SSI infection rate. 156 Allergy to β-Lactams Several studies have shown that the true incidence of allergy to antibiotics is less than that reflected in medical charts. 157 For surgical procedures where cephalosporins are the prophylaxis of the judgment of the medical professional; clinical reasoning must be tailored to the individual circumstances. Finally, children with congenital heart disease and a subgroup of those with repaired congenital heart disease may require bacterial endocarditis prophylaxis (see also Tables 16.2 and 16. 3). 167 