Infection Control PDF

Infection Control Dental personnel and patients are at increased risk for acquiring tuberculosis, herpes viruses, upper respiratory infections, and hepatitis strains A through E. After the recognition of acquired immunodeficiency syndrome (AIDS) in the 1980s, rigorous hygienic procedures were intro...

Infection Control Dental personnel and patients are at increased risk for acquiring tuberculosis, herpes viruses, upper respiratory infections, and hepatitis strains A through E. After the recognition of acquired immunodeficiency syndrome (AIDS) in the 1980s, rigorous hygienic procedures were introduced in dental offices. The primary goal of infection control procedures is to prevent cross-contamination and disease transmission from patient to staff, from staff to patient, and from patient to patient. The potential for cross- contamination in dental radiography is great. In the course of making radiographs, an operator's hands become contaminated by contact with a patient's mouth and saliva- contaminated films and film holders. The operator also must adjust the x-ray tube head and x-ray machine control panel settings to make the exposure. These actions lead to the possibility of cross-contamination. Cross-contamination also may occur when an operator handles digital sensors or opens film packets to process the films in the darkroom. The procedures described in the following sections minimize or eliminate such cross- contamination (Box 16.1). Each dental office or practice should have a written policy describing its infection control practices. It is best if one individual in a practice, usually the dentist, assumes responsibility for implementing these procedures. This person also educates other members of the practice. 1|Page Standard Precautions Standard precautions (also called universal precautions) are infection control practices designed to protect workers from exposure to diseases spread by blood and certain body fluids, including saliva. Under standard precautions, all human blood and saliva are treated as if known to be infectious for human immunodeficiency virus (HIV) and hepatitis B virus. Accordingly, the means used to protect against cross-contamination are used for all individuals. The ADA and the U.S. Centers for Disease Control and Prevention (CDC) stress the use of standard precautions because many patients are unaware that they are carriers of infectious disease or choose not to reveal this information. Wear Personal Protective Equipment During All Radiographic Procedures Personal protective equipment is an effective means to shield the operator from exposure to potentially infectious material, including blood and saliva. Hand hygiene is most important to prevent spread of infections. After the patient is seated, the practitioner should wash his or her hands using plain or antimicrobial soap, specific for health care settings. Alcohol-based hand rubs are also effective. Disposable gloves should be worn in sight of the patient if the operatory arrangement permits. The operator should always wear gloves when making radiographs or handling contaminated receptor barriers or associated materials such as cotton rolls and receptor- holding instruments or when removing barrier protections from surfaces and radiographic equipment. Operators should wear protective clothing (e.g., disposable gown or laboratory coat) that covers clothes and skin to protect against potential contamination. Eyewear, a mask, or a face shield must be worn if splash exposure to bodily fluids is anticipated. 2|Page Disinfect and Cover Clinical Contact Surfaces Clinical contact surfaces are surfaces that might be touched by gloved hands or instruments that go into the mouth. These include the x-ray machine and control panel, chair-side computer, beam alignment device, dental chair and headrest, protective apron, thyroid collar, and surfaces on which the receptor is placed. The CDC classifies these as noncritical items. These are objects that may come in contact with saliva, blood, or intact skin but not oral mucous membranes. The goal of preventing cross-contamination is addressed by disinfecting all such surfaces and by using barriers to isolate equipment from direct contact. Barriers made of clear plastic wrap should cover working surfaces that were previously cleaned and disinfected. Barriers protect the underlying surface from becoming contaminated and should be changed when damaged and routinely after each patient. Although barriers greatly aid infection control, they do not replace the need for effective surface cleaning and disinfection. Experience has demonstrated that failure of mechanical barriers is common during the daily activity of treatment. Whenever this happens, surfaces that become accidentally exposed must be cleaned and disinfected. Operators should avoid touching walls and other surfaces with contaminated gloves. Any clinical contact surface that is contaminated or potentially contaminated should be disinfected. Table 16.2 lists intermediate- and low- level activity disinfectants recommended for use on clinical contact surfaces. Intermediate-level disinfectants are Environmental Protection Agency (EPA)- registered agents and are tuberculocidal—an effective killer of tuberculosis— and capable of preventing other infectious diseases, including hepatitis B virus and HIV. Low-level disinfectants are EPA registered without tuberculocidal activity but inactivate hepatitis B virus and HIV. High-level disinfectants are used for chemical sterilization and should never be used on clinical contact surfaces. 3|Page TABLE 16.2 Countertops and the x-ray control console should be covered with a plastic barrier. When covering the x-ray control console, the operator should be sure to include the exposure switch and the exposure time control, if they are integral parts of the unit (Fig. 16.6). An x-ray exposure switch that is separate from the console should be covered with a plastic barrier. FIG. 16.6 The exposure control console should be covered with a clean barrier and changed after every patient. The dental chair headrest, headrest adjustments, and chair back may be easily covered with a plastic bag (Fig. 16.7). The x-ray tube head, PID, and yoke should be covered while they are still wet with disinfectant with a barrier to stop any dripping (Fig. 16.8). The bag should be cured by tying a knot in the open end or by placing a heavy rubber band over the x-ray tube head just proximal to the swivel. FIG. 16.7 A new plastic bag is placed over the chair and headrest for each patient. 4|Page FIG. 16.8 A plastic bag is slipped over the x-ray tube head with a large rubber band just proximal to the swivel or tie ends, as shown here. The plastic is pulled tight over the position-indicating device (PID) and secured with a light rubber band slipped over the PID and placed next to the head. The protective apron should be cleaned, disinfected, and covered between patients because it is frequently contaminated with saliva as the result of handling (readjusting its position) during a radiographic procedure. The apron should be suspended on a heavy coat hanger to permit turning front to back. It should be sprayed with a low-level disinfectant and then wiped (Fig. 16.9). FIG. 16.9 Hanging apron is sprayed with disinfectant and then dried and covered with a garment bag. Exposure charts should be kept away from sources of contamination and not handled during the radiographic examination. Panoramic chin rest and patient handgrips should be cleaned with a low-level disinfectant. Disposable bite- blocks may be used. The head-positioning guides, control panel, and exposure switch should be carefully wiped with a paper towel that is well moistened with disinfectant. The radiographer should wear disposable gloves while positioning and exposing the patient. The gloves should be removed before the cassette is removed from the machine for processing because the cassette and film remain extraoral and should not be handled with contaminated disposable gloves. Cephalostat ear posts, ear post brackets, and forehead support or nasion pointer should be cleaned and disinfected. These may then also be covered with a plastic barrier. 5|Page  After patient exposures are completed, the barriers should be removed, and contaminated working surfaces (including surfaces in the darkroom) and the apron should be sprayed with disinfectant and wiped as described previously. The barriers should be replaced in preparation for the next patient. Sterilize Nondisposable Instruments Receptor-holding instruments are classified by the CDC as semicritical items — instruments that are not used to penetrate soft tissue or bone but do come in contact with the oral mucous membrane. It is best to use receptor-holding instruments that can be sterilized, preferably by steam under pressure (autoclave). After using these instruments, disassemble the aiming ring, support arm, and bite-block. Each instrument should be cleaned with hot water and soap to remove saliva and debris. The cleaned components are then loaded into plastic or paper pouches and sterilized in an autoclave. After sterilization, the instruments should be kept in pouches for storage and subsequent transport to the radiography area. When the instruments are taken to the radiography area, it is good practice to keep them in the pouch until immediately before use. After use, instruments should be replaced in the pouch to reinforce cleanliness in the area. The same sterilization pouch should be used to transport the contaminated instruments back to the cleaning and sterilizing areas. Use Barriers With Digital Sensors Sensors for digital imaging cannot be sterilized by heat, so it is important to use a barrier to protect them from contamination when placed in the patient's mouth (Fig. 16.10). Typically, the manufacturers of these sensors recommend the use of plastic barrier sheaths that extend a few inches along the sensor cord. However, such barriers fail approximately 40% of the time. The supplemental use of latex finger cots provides significant added protection and is recommended for routine use when using digital sensors. Because such barriers may fail, the sensors should be cleaned and disinfected with an EPA- registered, intermediate-level hospital disinfectant after every patient. The manufacturer of such 6|Page equipment should be consulted for the proper disinfectant. Some manufacturers have designed solid-state sensors that can be immersed into a cold sterilant (a high-level EPA- registered disinfectant). FIG. 16.10 Film-holding instrument with barrier wrapping to protect sensor and cord from saliva. PSP sensors are placed in disposable plastic bags with a folded seal for use in the mouth. Because the entire plastic bag goes into the mouth with PSP sensors, these plates possibly can become contaminated with saliva when removed from the plastic bags for processing. This contamination could lead to cross-contamination of other plates and the processing equipment. To minimize this problem, PSP plates should be disinfected between patients, using a method recommended by the manufacturer. PSP plates may be gas sterilized with ethylene oxide. Use Barrier-Protected Film (Sensor) or Disposable Container To prevent contamination of bulk supplies of film, they should be dispensed in procedure quantities. The required number of films for a full-mouth or interproximal series should be prepackaged in coin envelopes or paper cups in the central preparation room. These envelopes of films should be dispensed with the film-holding instruments. For unanticipated occasions in which an unusual number of films are required, a small container of films can be on hand in the central preparation and sterilizing room. No one wearing contaminated gloves should retrieve a film from this supply. Films should be dispensed only by staff members with clean hands or wearing clean gloves. Film packets may be prepackaged in a plastic envelope (Fig. 16.11), which protects the film from contact with saliva and blood during exposure. Barrier- 7|Page protected film fits in most film-holding instruments. An attractive feature of the protective envelopes is the ease with which they may be opened and the film extracted. For best results, the packet should be immersed in a disinfectant after the films have been exposed in the patient's mouth. Then the packet should be dried and opened, allowing the film to drop out. The barrier envelopes can be conveniently opened in a lighted area, the film can be dropped onto a clean work area or into a clean paper or plastic cup, and the film can be transferred to the daylight loader or darkroom for processing. FIG. 16.11 Dental film with a plastic barrier to protect film from contact with saliva. During opening, the plastic is removed and the clean film is allowed to drop into a container. If barrier-protected film is not used, the exposed film should be placed in a disposable container for later transport to the darkroom for processing. Paper film packets are exposed to saliva and possibly blood during exposure in the patient's mouth. To prevent saliva from seeping into a paper film packet, a paper towel should be placed beside the container for exposed films. The practitioner should use this towel to wipe each film as it is removed from the patient's mouth and before it is placed with the other exposed films. This problem may also be avoided by using film packaged in vinyl. Prevent Contamination of Processing Equipment After all film exposures are made, the operator should remove his or her gloves and take the container of contaminated films to the darkroom. The goal in the darkroom is to break the infection chain so that only clean films are placed into processing solutions. Two towels should be placed on the darkroom working surface. The container of contaminated films should be placed on one of these towels. After the exposed film is removed from its packet, it should be placed on the second towel. The film packaging is discarded on the first towel with the container. 8|Page The procedure to remove film from a packet without touching (contaminating) is simple. Fig. 16.12 illustrates the method for opening a contaminated film packet while wearing contaminated gloves without touching the film. The practitioner dons a clean pair of gloves, picks up the film packet by the color-coded end, and pulls the tab upward and away from the packet to reveal the black paper tab wrapped over the end of the film. Holding the film over a cup, the practitioner carefully grasps the black paper tab that wraps the film and pulls the film from the packet. When the film is pulled from the packet, it falls from the paper wrapping into the cup. The paper wrapper may need to be shaken lightly to cause the film to fall free. The packaging materials should be placed on the first paper towel. After all films are opened, the practitioner gathers the contaminated packaging and container and discards them along with the contaminated gloves. The clean films are processed in the usual manner. It is not necessary to wear gloves when handling processed films, film mounts, or patient charts. FIG. 16.12 Method for removing films from packet without touching them with contaminated gloves. (A) Packet tab is opened, and lead foil and black interleaf paper are slid from wrapping. (B) Foil is rotated away from black paper and discarded. (C) Paper wrapping is opened. (D) Film is allowed to fall into a clean cup. An alternative procedure when exposing films in vinyl packaging is to place the exposed film, still in the protective plastic envelope, in an approved disinfecting solution when it is removed from the mouth and after wiping it with a paper towel. It should remain in the disinfectant after the exposure of the last film for the recommended time. Immersion for 30 seconds in a 5.25% solution of sodium hypochlorite is effective. 9|Page Automatic film processors with daylight loaders present a special problem because of the risk for contaminating the sleeves with contaminated gloves or film packets. One approach is to clean the films by immersion in a disinfectant, with or without a plastic envelope, as previously described. With this method, the operator cleans the films, puts on clean gloves, and takes only cleaned film packets into the daylight loader. An alternative approach is to open the top of the loader, place a clean barrier on the bottom, and insert the cup of exposed film packets into a clean cup. The operator closes the top, puts on clean gloves, pushes his or her hands through the sleeve, and opens the film packets, allowing the film to drop into the clean cup. After all film packets have been opened, the contaminated gloves are removed, the films are loaded into the developer, and hands are removed. The top of the loader may be removed, and the contaminated materials are then removed. 10 | P a g e