• Exposure limit of 2 ppm of halogenated anesthetic used alone or 0.5 ppm of halogenated anesthetic combined with 25 ppm of nitrous oxide
• Proper functioning scavenging system
• Low pressure leaks of <100 ml/min at 30 cm water pressure
• High pressure leaks from gas cylinder or pipeline of <10 ml/min
• Anesthetic gas flows turned off when not in use
• Employee training on handling of hazardous chemicals
• Air sampling performed in all locations of possible exposure to chemicals
• Documentation of abnormal outcome of pregnancies of employees or spouses of employees
Radiation Safety
The widespread use of fluoroscopic guidance techniques in modern surgical procedures has dramatically increased the level of radiation to which the OR personnel are exposed. Decreasing time of exposure, proper shielding, and increasing distance from the radiation source are three factors which help to limit the degree of exposure. Body shielding by wearing lead aprons, though effective in blocking radiation, does not protect all areas of the body. Therefore, a thyroid shield and eye protection should also be worn. As radiation intensity decreases proportionally with the inverse square of the distance from the source, maintaining a distance of at least 36 inches (3 feet) from the radiation source is one of the most effective methods of decreasing radiation exposure.
Radiation is carcinogenic at high levels. The US Nuclear Regulatory Commission (US-NRC) has set an annual radiation exposure limit of 5 rem/year (Table 55.2). As developing fetuses are particularly vulnerable to the adverse effects of radiation, the maximal dose should be <0.5 rem during the gestational period. Healthcare workers exposed to constant radiation should wear radiation monitoring badges, so that they are not exposed to excessive radiation above the annual radiation exposure limit.
Table 55.2
NRC occupational radiation dose limits
Site | Limits (Rem/year) |
---|---|
Whole body | 5 |
Any organ | 50 |
Skin | 50 |
Extremity | 50 |
Lens of eye | 15 |
Embryo/fetus | 0.5 |
Member of public | 0.1 |
Latex Sensitivity
Healthcare workers have an increased risk of allergic reactions to latex. The prevalence of sensitivity in anesthesiologists is reported to be about 15 % and in other healthcare workers to be about 8–12 %. These reactions generally manifest as irritant contact dermatitis, but anaphylaxis is also possible. People with spina bifida have increased risk of latex allergy, as well as people with allergies to certain foods, such as banana, tomato, potato, and kiwi fruit.
Infectious Diseases
Healthcare workers are routinely exposed to a variety of infectious agents including respiratory viruses (influenza and respiratory syncytial virus), measles, rubella, and, perhaps most concerning, hepatitis B and C and the human immunodeficiency viruses (HIV). The risk of contracting an infectious disease can be attenuated by rigorous adherence to universal and contact precautions. Serologic studies in the 1970s, prior to routine vaccination and postexposure prophylaxis, showed that healthcare workers had 10 times the prevalence of hepatitis B virus (HBV) infection compared to the general population. Routine HepB vaccination with verification of immunity by antibody titers is recommended for all healthcare providers who have direct contact with patients.
Acute HBV infection may be asymptomatic or may cause chronic hepatitis and rarely fulminant hepatitis. The degree of infectiousness of a patient is related to the presence of HBeAg (antigen) which is an indicator of active viral replication. The risk of transmission of hepatitis B after needlestick injury from a needle contaminated with blood from an HBV-positive patient is 1–6 % if the patient is HBeAg negative and 1–30 % if the patient is HBeAg positive. Acquisition of HBV by healthcare workers may be prevented by prophylactic vaccination or postexposure prophylaxis with HepB immune globulin. However, many healthcare workers with acquired HBV do not recall a percutaneous injury. HBV can survive in dried blood on environmental surfaces for up to 1 week, so it is possible that some healthcare workers may be infected by inoculation of the virus into cutaneous lesions or mucosal surfaces.
Hepatitis C virus (HCV) is much more likely than HBV to cause chronic infection and cirrhosis of liver. However, it is much less easily transmissible than HBV. The risk of transmission after percutaneous exposure to infected blood is ~1.8 %, with transmission from mucous membrane exposure being rare. Transmission through skin exposure has not been documented, and unlike HBV, HCV is thought to have a limited ability to survive in dried blood on environmental surfaces. In 1994 the Advisory Committee on Immunization Practices found that routine postexposure immunoglobulin administration for HCV was not supported by existing evidence. The use of postexposure antiviral agents is not currently recommended; however, there is some evidence that a short course of interferon early in the course of documented acute HCV infection may increase the rate of resolution of the infection.
Acquisition of HIV is perhaps one of the most feared complications of exposure to infected body fluids. The risk of transmission of HIV is 0.3 % after percutaneous exposure to blood and 0.09 % after mucous membrane exposure. Animal and human studies suggest that postexposure prophylaxis with antiretroviral agents is effective in decreasing the seroconversion rate after exposure to HIV. A two- or a three-drug regimen is recommended for postexposure prophylaxis depending on the level of risk from the particular exposure.