How Can VRE Infections Be Prevented in Surgery?
By Pamela S. Falk, MPH
This article discusses strategies for preventing and controlling VRE.
Photo courtesy of Surgery at NW Community Hospital (Arlington Heights, Ill).
The first infections due to vancomycin-resistant enterococci (VRE) were identified in Europe in 1986.1 Since that time, VRE have been identified in many countries around the world including the UK, France, Canada, and the US.1-3 Based on data from the Centers for Disease Control and Prevention's (CDC) National Nosocomial Infection Surveillance (NNIS) system, the percentage of nosocomial infections caused by VRE between 1989 and 1993 increased from 0.3% to 7.9%.4 Most of the reported cases were from intensive care units. In the past few years, VRE have also been isolated from patients in general medical and surgical units and long-term care facilities.
Patient Colonization and Infection
Enterococci are part of the normal flora of the intestinal tract. Some species of enterococci are relatively resistant to many commonly used antibiotics but until recent times have been sensitive to vancomycin. When enterococcal species with relative resistance to other antimicrobial agents acquire vancomycin resistance, they have a selective advantage over other species in the normal flora, permitting them to replicate in the intestinal tract as the other species are eradicated by antimicrobial therapy. Of the patients who become colonized by VRE, only 1 in 10 will develop a clinical infection. VRE cause endocarditis, intravascular catheter-related infections, bacteremia, and urinary tract infections.
Reservoirs and Sources
Photo courtesy of Surgery at NW Community Hospital (Arlington Heights, Ill).
The colonized gastrointestinal tracts of hospitalized patients make up the most important reservoir of VRE. To identify patients colonized by VRE, many healthcare facilities have developed a surveillance program using cultures of perianal swabs on selective culture media. It has been noted that patients may remain colonized for weeks, months, or years after discharge from the hospital and may still be colonized at the time of readmission to the hospital.
The hospital environment has been identified as a source of VRE. Surfaces such as bedrails, cardiac monitors, and bedside tables in the rooms of VRE patients are frequently contaminated by VRE. Environmental contamination occurs commonly in rooms of patients who have VRE. It is particularly prevalent in rooms of patients who are incontinent of stool or have diarrhea. Many VRE remain viable on surfaces from days to weeks because the organism seems to be resistant to desiccation and extreme temperatures.
Contaminated hands of healthcare workers may transmit VRE directly between patients. Medical equipment and inanimate surfaces in the hospital environment are frequently contaminated with VRE. VRE may be transmitted between patients by the contaminated surfaces of medical equipment or when healthcare workers contaminate their hands by touching environmental surfaces before they provide patient care.
Most patients colonized by VRE have been in intensive care units, transplant units, and oncology units. Risk factors for VRE acquisition identified in the literature include duration of hospitalization, enteric feeding, and treatment with vancomycin, third generation cephalosporins, and sucralfate.5-7 We have recently identified diarrhea and administration of antacids as risk factors for acquisition of VRE in burn patients.8
Prevention and Control
Based on the epidemiology of VRE in the healthcare setting, the Hospital Infection Control Practices Advisory Committee (HICPAC) published control recommendations for VRE.
The infection control measures are as follows:
- Place VRE-infected or colonized patients in a single room or in the same room as another patient with VRE.
- Wear a clean non-sterile gown when entering the room of a VRE infected or colonized patient if substantial contact with the patient or environmental surfaces in the patient's room is anticipated or if the patient is incontinent, or has diarrhea, an ileostomy, a colostomy, or wound drainage not contained by a dressing.
- Wear clean non-sterile gloves when entering the room of a VRE-infected or colonized patient. During the course of caring for the patient, a change of gloves may be necessary after contact with materials that may contain high concentrations of VRE (i.e., stool).
- Remove gown and gloves before leaving the room and wash hands immediately with an antiseptic soap or decontaminate hands with a waterless disinfection agent.
- Dedicate non-critical items such as a stethoscope, sphygmomanometer, or rectal thermometer to each patient.
- Obtain stool cultures of roommates of patients newly discovered to have VRE colonization or infection to determine whether the roommates may also be colonized. Perform additional screening of patients on the ward at the discretion of the infection control staff.
- Develop a policy that defines when patients with VRE may be removed from isolation precautions.
- Establish a system of highlighting records/computer files of VRE patients so that they can be identified and immediately isolated when they re-access the healthcare system.
- Develop a communication plan between the acute care hospital and nursing homes and other healthcare facilities regarding the transfer of a VRE colonized patient from the hospital to their facility.
In addition to following the HICPAC guidelines it is essential that the environment of a VRE patient be cleaned and disinfected daily. Items such as stethoscopes, sphygmomanometers, and rectal thermometers should be dedicated to each VRE patient. A variety of healthcare workers, such as housekeepers, nurses, and respiratory therapists must share the responsibility for cleaning the patient's environment. A checklist may be used to ensure that all environmental surfaces and medical equipment are cleaned daily. The responsibilities for cleaning should be delineated clearly (Table 1).
VRE in the Emergency Department
If a patient is presented to the Emergency Department (ED) and is known to have VRE, control measures depend on the type of care to be rendered. If the patient presents with significant diarrhea, gown and gloves are recommended. However, this is no different than following the Standard Precautions that have been instituted at all healthcare institutions.
Since patients do not ordinarily spend as much time in an ED treatment room as they would in an inpatient room, the environment does not have as much time to become heavily contaminated with VRE. Timely and thorough cleaning and disinfection of environmental surfaces contaminated with stool is important for controlling VRE.
VRE in the Operating Room
Patients should be at low risk for acquiring VRE from the OR. Healthcare workers routinely wear gowns and gloves during the surgical procedure and work in a sterile field. Circulating personnel should wear gloves as necessary and wash their hands frequently. The environment of the surgical suite should be cleaned between all cases.
While the floor of the OR, operating table, instrument tables, and mayo stands are usually cleaned between cases, items infrequently cleaned include the anesthesia cart and gas machine surfaces, monitor cables, bolsters, and the electrocautery unit. Management should assure that all the items that are used during a case are cleaned before the next case.
Medication carts with drawers with small partitions (commonly used by anesthesia) may pose a unique problem for VRE control. The medication cart should be cleaned and disinfected between cases. It is recommended that the medications needed for a VRE case be removed from the drawer prior to the procedure. Thus, the healthcare worker does not need to enter the drawer during the procedure and risk contaminating its contents with VRE. If a medication is needed that was not anticipated prior to the case, the healthcare worker should wash hands prior to entering the drawer (a waterless hand disinfection agent is acceptable). Therefore, with appropriate cleaning and handwashing, and the use of gowns and gloves, transmission should not occur in the OR.
At the University of Texas Medical Branch Hospital (Galveston, Tex), a patient with VRE or any resistant organism is taken directly to the OR, recovered in the OR, and returned directly to the patient's room. While the post-anesthesia recovery room (PACU) is not a high-risk area for transmission of the organism, emergency situations do occur that may require an invasive procedure. An invasive procedure on a VRE patient in the PACU may increase the risk of VRE transmission to another patient. If a VRE patient is recovered in the PACU, a private room is recommended. The room should be cleaned thoroughly on discharge of the patient.
VRE in Outpatient Clinics and Surgical Centers Skeptical
Like the Emergency Room, patients with VRE need little special attention in the outpatient clinic and surgical center, except following Standard Precautions. If a patient requires procedures, such as endoscopy, hemorrhoidectomy, or perirectal abscess drainage, risk for transmission for VRE may be increased. However, if Standard Precautions are followed (wearing gowns and gloves for contact with patient body fluids) and the medical equipment and environment are cleaned and disinfected thoroughly after use, additional precautions are not required for VRE patients.
Transport of VRE Patients through the Hospital
Personnel who transport patients from place to place in the hospital have frequent contact with many patients during the day. Good handwashing is essential for control of nosocomial infections. Barriers are also important because transporters have close physical contact with patients as they lift them from stretchers and wheelchairs into beds and onto procedure tables. Therefore, the person transporting a VRE patient should wear a gown and gloves. A sheet should be placed between the patient and the stretcher or the wheelchair. After transporting the patient, gowns and gloves should be removed and hands washed. The wheelchair or stretcher should be disinfected. The patient does not need to wear a gown and gloves for transport.
Colonization of a patient by VRE is not a contraindication for discharge from the hospital. Once medically ready to be discharged, the patient may go home to a nursing home or rehabilitation center. Prior to discharge of a VRE patient to another institution, hospital staff should inform personnel at the receiving facility that the patient is colonized by VRE. Most facilities have programs to control VRE in their unique setting.
Other Important Reasons to Control VRE
Many healthcare workers have become familiar with methicillin-resistant Staphylococcus aureus (MRSA). Patients infected or colonized with this organism are placed in isolation and treated with vancomycin as needed. Epidemiologists are concerned that the genes that control antibiotic resistance in VRE will be transferred to MRSA. Infections caused by vancomycin-resistant Staphylococcus aureus (VRSA) would be very difficult to treat. Unlike enterococci, Staphylococcus aureus is a highly pathogenic bacterium, which is moderately contagious and causes infections such as endocarditis, bacteremia, surgical site infections, intra-abdominal abscesses, and pneumonia. It will be a public health nightmare if MRSA develop resistance to vancomycin.
VRE is a bacterium that is becoming more prevalent in patient populations. Patients in transplant units, oncology units, and intensive care units are at a higher risk of acquiring VRE due to prolonged length of stay and treatment with multiple antibiotics. They are also frequently subjected to invasive procedures that place them at risk for colonization with VRE. Healthcare workers in inpatient settings should care for VRE patients using barrier precautions, which includes use of gowns and gloves and handwashing before and after each patient contact. It is essential that all equipment used on VRE patients be cleaned daily to decrease microbial load. Equipment that is no longer needed for a VRE patient must be decontaminated prior to use on the next patient. Standard Precautions are appropriate for the ED, OR, PACU, and outpatient facilities.
Pamela S. Falk, MPH, is the Director of Healthcare Epidemiology at the University of Texas Medical Branch (Galveston, Tex). The author would like to thank Janice Winnike, BSN, and the staff of the Department of Healthcare Epidemiology for their assistance with the development of Table 1 and C. Glen Mayhall, MD, for his overall guidance with this article.
For references, access the ICT Web site.
Table 1: Routine Departmental Equipment Cleaning Responsiblities
|Items||Nursing||Pulmonary Care||Environmental Services||Monitoring* Services|
|Cardiac Monitors (leads, cables)||x|
|High-Pressure Infusion Bags||x|
|Portable Patient Scales||x|
|Vital Signs Monitors (rolling)||x|
|Airway Management Packs||x|
|Code Carts (after each use, daily)||x|
|Nitric Oxide Set Ups||x|
|Portable Pulse Oximeters||x|
|Respiratory Supply Carts||x|
|Oxygen and Air Flowmeters (wall mount)||x|
|IV Poles (hanging and rolling)||x|
|Sphygmomanometer (wall mount)||x|
|Suction Bottles/Suction Control Units||x|
|Enteral Feeding Pumps||x|
|IV Infusion Pumps||x|
|Over-bed Cradle/Traction Equipment||x|
|Portable Suction Machines||x|
|Sequential Compression Devices||x|
- Monitoring services: Monitoring Services, at the author's hospital, services and distributes portable medical equipment.
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