Page 272 - AIDSBK23C

Page 272

THE SURGICAL PATHOLOGY LABORATORY

Pathologists receive the greatest potential exposure to infectious agents in surgical
pathology activities. Many specimens are received fresh from surgery without fixation. Surgical
pathology activities should take place in a separate, well-lighted and ventilated room out of the
main flow of traffic. The cutting bench and adjacent sink should be large enough for adequate
manipulation of all submitted fresh or fixed tissues, including amputation and exenteration
specimens. Provide a puncture-proof container for disposal of sharps--blades and needles. Work
surfaces should be designed for easy cleanup and to withstand 0.5% sodium hypochlorite
(bleach) disinfection.[1091]
Specimens sent to the laboratory for routine tissue processing should be in sealed, leak
proof containers with fixative and within a second sealed, leak proof container. Requisition
forms that accompany specimens should be handled in a manner that avoids contamination. If
contaminated, copy the information on to a clean form. Avoid contamination of materials or
equipment--reports, tapes, floppy disks, keyboards, telephones, etc.--that are used by others or
are carried to non-contaminated clerical areas. Use dictation equipment that allows "hands-off"
operation or that can be disinfected.
Personnel handling the surgical specimens should wear a gown, protective mask and
eyewear (or face shield), and disposable gloves. Practice careful dissection technique with good
equipment and do not be hurried or distracted. Clean up and decontamination can be
accomplished with detergents, followed by disinfection with bleach. Determine procedures and
equipment for use when accidental spills or splashes occur. The barrier provided by latex gloves
is compromised by disinfectants and fixatives, so that heavy duty or utility gloves may be needed
for jobs with exposure to these chemicals.
Consider the cryostat a contaminated area. Wear the same protective gear as when
dissecting a fresh specimen. Remember that freezing propellants can potentially spread
infectious agents outside of the cryostat. Decontaminate the cryostat at regular intervals, using
recommended disinfectants that will not harm sensitive surfaces or seals.
Specimens for histopathologic examination can be routinely fixed in 10% (v/v) neutral
buffered formalin, or alternatively in mercurial fixatives (such as B5 or Zenker's) or Bouin's
fixative. Cytologic smears can be fixed with 95% ethanol. HIV will be rendered inactive in
tissues or smears by proper fixation. Fixatives may not thoroughly penetrate large tissue
specimens. If specimens arrive in the histology laboratory in containers whose outer surfaces are
contaminated with blood or body fluids, the surfaces can be disinfected by application of 0.5%
sodium hypochlorite.
Saved tissues not blocked and embedded can be stored in fixative before discarding either
via a tissue grinder attached to a sink or via incineration. Large specimens not suitable for
fixation or tissues saved fresh must be placed in containers or bags marked as hazardous
infectious waste before disposal in accordance with local statutes.