Because of the need for frequent invasive procedures, the often-urgent nature of these procedures, and the patient population that is served, critical care personnel are at risk of exposure and infection with blood-borne pathogens. The most common mechanism by which ICU personnel are exposed is by a percutaneous injury, usually an inadvertent needle stick. The risk of infection after a percutaneous exposure varies significantly depending on the virus. The risk of infection with HIV after a percutaneous exposure to infected blood or bloody fluids has been estimated to be 0.3%. The risks associated with occupational mucous membrane and cutaneous exposures to HIV-infected blood appear to be substantially smaller. For hepatitis C virus, the risk of infection after percutaneous exposure is between 0% and 7%, and for hepatitis B virus, the risk of developing serologic evidence of infection in a nonimmune person is 23% to 62%, depending on whether the source patient is positive for the hepatitis B e antigen.54
Infection control efforts against these viruses focus primarily on preventing exposure to blood and, in the case of hepatitis B virus, offering vaccination on employment. Practices that minimize the risk of percutaneous injury (e.g., discarding disposable sharp devices in puncture-resistant containers immediately after use) are key aspects of prevention. Precautions also should be applied to other body fluids containing visible blood and to cerebrospinal, synovial, pleural, peritoneal, pericardial, and amniotic fluids and vaginal secretions and semen.55 Protective equipment (i.e., gloves, gowns, masks, and eyewear) should be used when there is a potential for exposure to these fluids. Following an exposure, the affected skin should be cleaned immediately with soap and water, and mucous membranes should be rinsed with copious amounts of water. Zidovudine chemoprophylaxis following needle-stick exposure to HIV-1 decreases transmission risk by 80%.56 Current guidelines recommend 4 weeks of combination antiretroviral therapy with either a two- or three-drug regimen for postexposure prophylaxis, taking into consideration degree of exposure, level of viremia in the source patient, and the potential for resistant virus. For hepatitis C virus, no prophylaxis is currently available; exposed workers generally are monitored for 6 months for evidence of infection. For hepatitis B virus exposure, the immune status of the employee should be determined, and hepatitis B immunoglobulin and vaccination should be offered to nonimmune employees.