I. INFECTION CONTROL

Infection control in the hospital setting encompasses the surveillance of epidemiologically important organisms and the prevention of transmission of healthcare-associated infections. Patients coming through the operating room can be colonized or infected with a variety of pathogens, which are often multidrug resistant and easily communicable. Infections caused by antibiotic-resistant pathogens lead to prolonged hospital stays and higher costs, as well as increased morbidity and mortality. Therefore, strict adherence to infection control practices is imperative throughout the perioperative course.

II. INFECTION CONTROL PROGRAMS

Infection control programs in the hospital became a requirement in the United States because of mandates from the Joint Commission for Accreditation of Hospitals (JCAHO) and guidelines set forth by the Centers for Disease Control (CDC). Infection control teams are responsible for ensuring proper adherence to standard and transmission-based precautions and for the surveillance of multidrug-resistant organisms (MDROs) and outbreaks. In addition, the hospital infection control team should provide education to both clinical and nonclinical staff regarding the harms of MDROs; the prevention of hospital-acquired infections; the proper cleaning, disinfection, sterilization of equipment; and the proper disposal of infectious wastes. Finally, it is the responsibility of the infection control committee to provide oversight from pharmacists and infectious disease specialists to promote appropriate antimicrobial use and encourage the preferred use of narrow-spectrum antibiotics to prevent the development of antimicrobial resistance. Antimicrobial stewardship teams should ensure the proper doses and durations of antibiotics are prescribed because an inadequate dose, duration, or both may make the evolution of a resistant organism more likely. An effective infection control program will be cost-effective while decreasing the incidence of hospital-acquired infections.

III. TRANSMISSION OF INFECTION

The transmission of infection requires three components: a source or reservoir of infection, a susceptible host, and a mode of transmission.

A. Sources of Infectious Agents

Pathogens transmitted during healthcare practices generally emanate from human sources (patients, healthcare workers [HCWs], family, and visitors), although inanimate objects and the environment can also be implicated. Source individuals may not show signs of active infection; they may be chronically colonized carriers or in the asymptomatic/incubation phase.

B. Host

Most of the factors that influence the development of infection are related to the host. Some persons exposed to a potential pathogen never
become infected, whereas others can become chronic carriers of the pathogen, and others develop clinically significant infections. Unique host factors that influence the development of infection once exposed include age, comorbidity, immunodeficiency, certain medications (immune modulators, drugs that interrupt the normal flora such as gastric acid inhibitors, other antimicrobial agents), surgical procedures and irradiation that can interrupt the skin’s line of defense, indwelling catheters and lines, and permanently implanted devices.

C. Mode of Transmission

The three principal modes of transmission are by contact (direct or indirect), by droplet, or by the airborne route.

1. Contact transmission is the most common mode of transmission of pathogens. Direct contact occurs when microorganisms are transferred from one infected person to another, without an intermediate object or person. This generally requires blood or other bodily fluids from an infected patient directly entering the body of another person through mucous membranes or breaks in the skin. In addition, this includes infections or infestations that can occur from direct skin to skin contact (i.e., scabies infestations or herpes infection). Indirect contact involves transmission of an infectious agent through a contaminated intermediate object (i.e., electronic thermometers, glucose monitors) or person (i.e., HCW).

2. Droplet transmission from the source person occurs primarily during coughing, sneezing, talking and during certain procedures such as suctioning and bronchoscopy. Large-particle droplets, defined as those that are greater than 5 µm, must come into contact with the conjunctivae or mucous membranes of a susceptible person in order for the infection to be passed. Transmission of droplets generally requires close contact, because they cannot stay suspended in the air for more than about 3 feet. Given the inability for prolonged suspension, special air handling and ventilation are not necessary.

3. Airborne transmission occurs by dissemination of small particles in the respirable size range (less than 5 µm) containing the infectious agent, which can remain suspended in the air for long periods of time and distance. Pathogens carried in this manner can be easily dispersed by air currents in hospital ventilation systems and can be inhaled by a susceptible person in the same room. Special ventilation systems are required to prevent airborne transmission.

IV. STANDARD PRECAUTIONS

Standard precautions are the minimum practices of infection control to be followed when dealing with all patients, without knowledge of the patient’s infection status, and in any healthcare environment. The components of standard precautions are listed below.

A. Hand Hygiene

Hand hygiene is the single most important measure for controlling the spread of MDROs and the most effective component of an infection prevention and control program. Wearing gloves does not replace the need for hand hygiene, because gloves may have small, not readily apparent defects or tears that may occur during wear, and contamination of hands may occur when gloves are removed. Diligent hand hygiene must occur prior to touching any patient and after contact with a patient or a patient’s environment, even if gloves are worn. In addition, hand hygiene must be performed prior to donning sterile gloves to insert a catheter or device, before handling medications, and prior to manipulating respiratory devices, urinary catheters, and intravascular catheters.

1. Hand hygiene includes both hand washing with antimicrobial soap and water and the use of an alcohol-based hand rub (ABHR). In
2002, the CDC recommended that ABHR be the primary choice for hand hygiene (except in specific cases outlined later), because it has better in vivo and in vitro efficacy against drug-resistant bacteria. Additionally, the ABHRs have improved the ability for clinicians to easily and comfortably sanitize hands at frequent intervals, hence increasing compliance. Compared to soap and water, the ABHRs have superior microbiocidal activity against gram-positive and gram-negative organisms and viral pathogens, and have shown to decrease the incidence of nosocomially acquired methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE). Frequent hand washing can cause drying of the hands, with potential skin damage and irritation, leading to changes in skin flora, increased skin shedding, and increased risk of transmission of microorganisms. However, in the case of certain pathogens such as Clostridium difficile and norovirus, hand washing with soap and water must be employed first, prior to using an ABHR. Furthermore, hands must be washed with soap and water prior to the use of an ABHR in the case of visibly soiled hands.

2. There has been a correlation between the use of artificial fingernails and more pathogenic organisms, especially bacilli and yeast. Artificial fingernails should not be worn by healthcare personnel in contact with high-risk patients (i.e., those in the ICU, OR, PACU). In addition, natural nails should be well maintained and kept less than 1/4 inch in length.

B. Personal Protective Equipment

Personal protective equipment (PPE) is used to protect the HCW from exposure to or contact with infectious materials. The choice of PPE depends on the pathogen and possible modes of transmission. Hand hygiene is always the first step prior to donning PPE and final step after the removal and disposal of PPE.

1. Gloves: should be used when there may be contact with blood or bodily fluid, mucous membranes, nonintact skin, or potentially infectious material. They should also be worn if there is any contact with a patient or patient’s environment in the setting of pathogens transmitted via the contact route in the case of isolation precautions. Finally, gloves are necessary when having any contact with visibly contaminated patient equipment or environmental surfaces. When interacting with an individual patient, it is important to remember the practice of working from “clean” to “dirty,” and it often may be necessary to change gloves when working with the same patient to reduce cross-contamination of body sites. When gloves are used with other PPE, they should be put on last.

2. Gowns are used as part of standard precautions if there is a chance of contamination of the HCW’s arms or clothing with blood, bodily fluid, and other infectious material. In addition, gowns should be used as part of isolation precautions in the case of transmission via the contact route. Many studies have demonstrated the contamination of HCW’s clothing with MDROs, and a decrease in transmission of MDROs when gowns are worn in addition to gloves compared to the use of gloves alone. Gowns should be donned first, prior to other PPE, and when patient care is complete, remove gowns before leaving a patient care area. The gown should be removed in such a way that the outer, contaminated side of the gown is turned inward and rolled into a bundle prior to discarding.

3. The use of mouth, nose, and eye PPE is considered standard precautions in situations where splash of blood or bodily fluid may occur and come in contact with the mucous membranes of the HCW.
Masks are required in the case of a sterile procedure, to protect the patient from pathogens carried in the HCW’s mouth or nose. Lastly, masks and respirators are to be used in the case of droplet and airborne precautions, as detailed below.

C. Safe Injection and Sharps Practices

Safe injection and sharps practices aim to prevent transmission of infection between one patient and another and between patient and healthcare provider. Injuries due to sharps have been linked to the transmission of HIV, HBV, and HCV to HCWs. The principles of safe injection and sharps practices include:

1. Never recap used needles or manipulate them using more than one hand, instead using the one-handed “scoop” method to reapply the cap onto the needle;

2. Do not remove used needles from syringes by hand, and do not bend or break used needles by hand;

3. Place all used needles and sharps into the appropriate puncture-resistant containers; and

4. Whenever possible, use single-dose vials (SDVs) of medication, and if multidose vials (MDVs) are necessary, a new needle and syringe must be used for each patient.

a. The American Society of Anesthesiologists (ASA) recommends using SDVs for parenteral medications whenever possible. SDVs should be used only once and for only one patient. Both the CDC and JCAHO warn against using SDVs in multiple patients because these vials typically lack antimicrobial preservatives and can serve as a source of infection when contaminated. Misuse of SDVs has been associated with outbreaks of blood-borne pathogen, bacterial bloodstream infections, meningitis, and epidural abscesses. If the SDV needs to be reaccessed for another dose in the same patient, a new needle/cannula/syringe must be used each time the vial is accessed. The SDV should be discarded at the end of the case.

b. MDVs are approved by the Federal Food and Drug Administration for use on multiple persons. Prior to each entry, the vial’s rubber septum should be disinfected by wiping with an antiseptic swab (e.g., sterile 70% isopropyl alcohol) and the septum should be allowed to dry before inserting a new needle and syringe. CDC guidelines require that MDVs be stored outside immediate patient treatment areas including surgery/procedure rooms where anesthesia is administered and any anesthesia medication carts used in or for those rooms. Thus the ASA recommends that if a medication (or other solution) is not available as a SDV and a MDV must be used (e.g., neostigmine, succinylcholine), discard the MDV after single-patient use.

c. Propofol is formulated in a lipid emulsion that can support bacterial growth and has been associated with postoperative infections and sepsis. Though current propofol formulations contain a bacteriostatic agent (e.g., sodium metabisulfite or benzyl alcohol), these only slow the rate of growth of microorganisms. Propofol should be drawn up just prior to administration using strict aseptic technique including hand hygiene. The syringe containing propofol should be labeled with the date and time the vial was opened, and any unused propofol should be discarded at the end of the case or within 6 hours after the vial was opened. If propofol is administered as an infusion from a bottle (e.g., for ICU sedation), the tubing and any unused portion must be discarded within 12 hours after the vial has been entered.

D. Environmental Cleaning

The proper cleaning and disinfection of surfaces in the patient environment is part of standard precautions. Studies have shown that both MRSA and VRE can persist on dry environmental surfaces for weeks to months. Hospital infection control programs should provide rigorous policies and procedures for routine cleaning, disinfection, and sterilization of devices and environmental surfaces in between patient uses. These protocols should also address the prompt cleaning and removal of spills of blood, bodily fluid, and other infectious materials. Certain pathogens may be resistant to routinely used hospital disinfectants; it has been suggested that a 1:10 dilution of 5.25% household bleach be used in the case of C. difficile.

E. Medical Equipment

In order to prevent patient-to-patient transmission of infectious agents, reusable medical equipment and devices must be properly cleaned, disinfected, and sterilized. Whenever possible, patients on transmission-based precautions should be provided with dedicated noncritical equipment such as thermometers, stethoscopes, and blood pressure cuffs.

1. The Spaulding classification categorizes instruments and items for patient care according to the degree of risk for infection involved in use of the items.

a. Critical items are objects that enter sterile tissues and, thus, confer a high risk of infection if they are contaminated with any microorganism. Critical items must be sterile at the time of use and include surgical instruments, vascular needles and catheters, regional needles and catheters, urinary catheters, syringes, stopcocks, etc. Most of these items are single-use items. Those that are not single use need to be sterilized.