by Alan Tait, M.D.
As of March 1993, 284,840 cases of acquired immunodeficiency syndrome (AIDS) had been reported to the Centers for Disease Control (CDC) and it is estimated that approximately 1.5 million individuals in the United States and 13 million worldwide are infected with the human immunodeficiency virus (HIV). By September 1992, the CDC had received reports of 32 health care workers in the United States with documented seroconversion after occupational exposure to HIV and an additional 69 individuals with suspected occupational acquisition. Of those with documented occupational transmission of HIV, 84% had received a percutaneous exposure, 13% a mucocutaneous exposure, and 3% both.
Although the population at greatest risk appears to be clinical laboratory technologists and nurses, anesthesiologists by virtue of their exposure to needles and patients' blood are at risk. But to what degree? Despite the focus on HIV exposure, the overall risk of occupational transmission is considered low (0.1% overall and 0.35%- 0.5% following a needle-stick injury). Compare this with the risk of hepatitis B virus after needle-stick exposure which is thought to be in the neighborhood of 10%-35%. Fortunately, the availability and acceptance of the hepatitis B vaccine has made this risk much less of an issue for anesthesiologists.
Of particular concern now, however, is the appearance of hepatitis C virus (HCV) as a source of occupational transmission. Transmission of HCV has been documented among health care workers following needle-stick injuries and a recent report from Australia has implicated patient-to-patient transmission via a contaminated breathing circuit. The risk of transmission of this virus via a contaminated needle-stick injury has been estimated to be approximately 4% which in the absence of a vaccine should be a growing cause for concern.
With this information in mind, to what extent need anesthesiologists comply with universal barrier precautions in their practice? In a recent national survey conducted by our department it was apparent that universal precautions are not universally practiced by anesthesiologists (Anes Analg 1994; 79:623-8). Information obtained from the 493 responding anesthesiologists indicated that although 85.2% were aware of the CDC guidelines on universal precautions only 59% had actually read them. Additionally, although 88% reported that they always complied with the guidelines when presented with an HIV-infected patient, only 24.7% adhered to them when the patient was considered low risk. Needle-stick injuries are perhaps the greatest occupational infection hazard for the anesthesiologist.
In our study, 31.8% and 71.9% of respondents, respectively reported at least one contaminated or clean needle-stick injury within the preceding 12 months and 69.8% stated that they recapped needles on a frequent basis. Interestingly, despite the CDC's recommendations not to recap needles, there was no correlation in our study between recapping and needle-stick injuries, however, those that recapped using the one-handed method were less likely to sustain a needle-stick.
In July, 1992 the Occupational Safety and Health Administration (OSHA) mandated that all employers subject to OSHA regulations implement an exposure control plan requiring use of gloves and other universal precautions when performing tasks that may result in exposure to blood or body fluids. It is hoped that implementation of such a plan can reduce the risk of occupational transmission. However, Dr John Tinker in an editorial related to our article suggests that the reasons for anesthesiologists' poor compliance with universal precautions may not be simply a function of low perception of risk or inertia but "because our tools aren't adequate".
Although the use of gloves and eyewear can prevent incidental exposure to blood and bodily fluids they are ineffective barriers to a hypodermic needle. Perhaps, therefore, there needs to be a greater emphasis on the development of engineering controls such as needleless systems to further ensure the safety of the anesthesiologist. Barring the immediate development of an HIV or HCV vaccine, the anesthesiologist can be expected to be presented with an increasing number of patients who are infected or who are at risk for these infections. Can we afford to be complacent?