Biomedical Engineering Reference
In-Depth Information
Figure 7.9
Patient identification. (Photo courtesy of Cynthia Shields, MD.)
the contaminant is known, is the introduction of
a surrogate marker onto casualties as they enter
the system. The simulant should be either visible
to the unaided eye, such as food coloring, or
detectable with routinely available means, such
as with a Wood's ultraviolet lamp (fluorescein
injectable USP, or fluorescein, alcohol soluble,
USP). The marker can be diluted and mixed with
a suitable carrier (mineral oil, vegetable oil, and
vegetable fat) to simulate the consistency of a
persistent chemical agent. The marker should be
non-toxic, hypoallergenic, and not permanently
stain the skin. Neither should it be removable by
a cursory rinsing of the skin. Total removal of a
moderately adherent, poorly soluble simulant is a
reliable way to assure adequate decontamination
of virtually any foreign substance. This technique,
not only allows a continuous quality indicator
at the decontamination site, it provides assurance
to those further down stream in the chain of
casualty care.
An evaluation in Sweden [10] of a three chamber
decontamination system using ethyl lactate, a
water-soluble simulant for sarin, and methyl sali-
cylate, a poorly soluble simulant of sulfur mustard,
was performed on volunteers. Volunteers were
showered for 3 minutes with 30
C water then
thoroughly washed twice with soap and water
in a second chamber. Vapor measurements were
reduced by as much as 10
4
fold by the third
chamber. The levels abruptly increased when staff
members, who had self-decontaminated, entered
the room. This emphasizes the need to assess the
thoroughness of staff decon in a similar manner to
patients. All staff should always be assisted when
removing PPE and undergoing decontamination by
a trained individual (also wearing PPE) who can
prevent recontamination. Special attention should
be paid to footwear.
Along with a physical method of measurement,
there should be a written record of decon certifi-
cation to accompany each patient. This can consist
of bracelets, tags, or be as simple as indelible ink
marking on the forearm, forehead, or chest. Critical
to the success of this technique is the acceptance
of the method used throughout the affected region
and across all appropriate jurisdictions (fire, EMS,
hospitals). Potentially infectious patients should
be labeled as such and segregated to isolation
units. If proper procedure is followed, the risk of
contaminating a medical treatment facility is then
extremely low [10].
7.9 Personal Protection Equipment
Chemical and biological threats can be vapor,
liquid, or aerosol. Radiological contamination
is most commonly solid or particulate. These
