[Federal Register Volume 61, Number 233 (Tuesday, December 3, 1996)]
[Notices]
[Pages 64189-64191]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-30759]
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DEPARTMENT OF TRANSPORTATION
Federal Railroad Administration
[FRA Docket No. RSOR-6, Notice No. 43]
RIN 2130-AA81
Alcohol/Drug Regulations: Temporary Post-Accident Blood Testing
Procedures
AGENCY: Federal Railroad Administration (FRA).
ACTION: Notice.
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SUMMARY: Some of the currently distributed FRA post-accident toxicology
testing (PATT) kits contain blood tubes with expiration dates ranging
from October 1996 to January 1997. Since the blood tube lots that are
currently available will expire in a few months, FRA decided to delay
replacing the expiring tubes until new lots of 18-24 month blood tubes
become available in early 1997. This notice explains the procedures to
be followed until FRA distributes replacement blood tubes.
FOR FURTHER INFORMATION CONTACT: Lamar Allen, Alcohol and Drug Program
Manager (RRS-11), Office of Safety, FRA, 400 7th Street, S.W.,
Washington, D.C. 20590 (Telephone: (202) 632-3378) or Patricia V. Sun,
Trial Attorney (RCC-11), Office of Chief Counsel, FRA, 400 7th Street,
S.W., Washington, D.C. 20590 (Telephone: (202) 632-3183).
Background
Since 1986, FRA has included Vacutainer brand 10 milliliter (mL)
evacuated blood collection tubes, manufactured by Becton Dickinson
(Becton), in its post-accident toxicology testing (post-accident) kits.
Each individual post-accident kit (there are three kits in each post-
accident toxicology testing box) contains two Vacutainer brand grey-top
glass tubes. These tubes, which have no interior coating, contain
silicone, a rubber stopper lubricant, sodium fluoride, an antibacterial
agent and mild anticoagulant, and potassium oxalate, an anticoagulant.
On each tube, Becton has printed an expiration date, the date
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until which it warrants that the tube has sufficient vacuum to draw
blood and chemical additives that remain potent. Becton normally
releases its blood tubes in lots which expire within 18-24 months of
manufacture.
Many of FRA's post-accident kits that have been distributed to
railroads contain blood tubes that will expire beginning this fall
(from October 1996 to January 1997). The replacement blood tube lots
that are now available have only a few months remaining before they
expire. FRA has decided to delay tube replacement until newly prepared
18-24 month lots become available in early 1997.
Interim Procedures
Until the current inventory of blood tubes in the field is replaced
in early 1997, FRA authorizes railroads to instruct local medical
personnel to replace the expired tubes with their own stock of
unexpired 10 mL grey-top tubes. (Substituted tubes must be 10 mL, not
the 5 mL type, to ensure sufficient blood for analysis.) This action is
requested, but not required, and need only be considered when expired
tubes are discovered during an actual post-accident collection.
Tube replacement is always preferred to using expired tubes, but,
if no opportunity for replacement arises, railroads are authorized to
complete the post-accident collection using the expired blood tubes.
FRA's post-accident testing program incorporates testing and analysis
protocols designed to protect employees from unwarranted accusations of
alcohol or drug use.
As explained below, grey-top tubes are the only commercial blood
collection tubes generally available that contain sodium fluoride. They
are FRA's tubes of choice for FRA's post-accident testing.
Scientific/Technical Issues
Although FRA's interim procedures require railroads to replace
expired blood tubes with unexpired tubes if possible, FRA believes that
use of an expired blood tube, if necessary, will not have a significant
impact on the validity of post-accident test results. Discussed below
are the two primary scientific/technical issues concerning the use of
expired tubes: (1) the integrity of the vacuum present in the tube (to
draw blood properly), and (2) the potency of the chemical additives.
Evacuated blood tubes that have recently expired (i.e., within the
past several months) are not expected to show a dramatic decrease in
tube vacuum. Moreover, a loss of vacuum only affects the efficiency of
the medical professional's ability to draw a blood specimen from the
donor. As pressure from the body's circulatory system forces blood into
the evacuated tube, less vacuum will cause the blood to draw slower or
not at all.
Until its expiration date, each grey-top blood tube is warranted by
Becton to have 90% or more of its vacuum left (at an estimated
deterioration rate of no greater than 5% per year). If a particular
tube draws inefficiently due to lack of vacuum, a medical professional
would ordinarily discard it and simply use another grey-top tube.
The presence or absence of the chemical additives contained in
grey-top tubes does not affect the detection of any of the drugs tested
for in FRA's post-accident testing panel, with the exception of parent
cocaine. In fact, each grey-top blood tube contains sodium fluoride, an
inorganic substance that contributes to the detectability of parent
cocaine in blood, by helping to stabilize the spontaneous conversion of
cocaine in vitro to cocaine metabolites (specifically to ecgonine
methyl ester, or EME). However, sodium fluoride does not impact either
the stability or the ability to detect the principal cocaine metabolite
of interest, benzoylecgonine (BE). Whether the amount of sodium
fluoride present in grey-top blood tubes is sufficient to retard
conversion of parent cocaine continues to be a matter of scientific
interest [see Iscenschmid et al, 1989; Brogan et al, 1992; Baselt et
al, 1993; others]. Moreover, other factors, including the pH of the
sample and the temperature of storage, can also affect the stability of
parent cocaine in blood.
Since it is an inorganic compound, sodium fluoride oxidizes very
slowly and in a vacuum environment is unlikely to deteriorate
dramatically in the first few months after tube expiration. In the
period between expiration of the older grey-top tubes and replacement
with new ones, anticipated to be 90 days or less, there will be little,
if any, significant difference in FRA's ability to detect parent
cocaine. More importantly, there is no possibility that a ``false
positive'' for cocaine or any of its metabolites would occur because of
an expired blood tube.
Sodium fluoride is also widely established as an effective
antimicrobial agent in retarding endogenous alcohol production [see
Harper and Correy, 1988; Anderson and Prouty, 1995; Sulkowski et al,
1995; and others]. The production of ethyl alcohol in the body is a
well known phenomenon, especially in post-mortem samples. In the
presence of certain contaminating microorganisms, alcohol identical to
that found in alcoholic beverages may be created. That is, under
certain extreme conditions, alcohol can appear in an individual's
urine, blood, or tissues without having been ingested. For alcohol to
be produced under these circumstances, both glucose and certain
bacteria or yeast must be present. Other factors, such as the storage
temperature of the specimen or the condition of the body (if the donor
is deceased), can also be significant. Obviously, endogenous production
of alcohol is of concern in the post-accident alcohol testing of both
surviving and deceased crew members.
The presence of alcohol-producing bacteria or yeast and glucose in
a blood sample of a surviving crew member can occur only through a
combination of disease processes and is extremely rare. Direct
contamination of a specimen is also extremely unlikely given the
collection and laboratory protocols of FRA's post-accident testing
program, and the presence of sodium fluoride in sufficient amounts,
such as the amounts contained in Vacutainer grey-top collection tubes.
For surviving crew members, even if the sodium fluoride in the tube
were rendered totally inert by age, its absence would not be a problem
unless contaminating bacteria or yeast were present. The blood tube
itself, with its remaining vacuum, also serves to physically protect
against that eventuality. In addition, FRA has in the past tested
specifically for contaminating bacteria or yeast in both the urine and
the blood, if their presence is suspected.
For deceased crew members, postmortem alcohol generation is always
a potential issue when interpreting a positive alcohol result. In FRA's
post-accident testing, there have been several cases where, given
severe trauma and the correct environmental factors, alcohol was
produced post-mortem in detectable amounts, even in the presence of
fully potent sodium fluoride.
To account for this possibility, FRA has taken and will continue to
take whatever scientific and technical steps are necessary to protect
post-accident specimen donors from an incorrect interpretation of a
positive test result. Among the procedures used by FRA to rule out an
alcohol positive as coming from endogenous production are: examining
other tissues or fluids (i.e., urine, brain, vitreous) which may have
been protected from trauma or decomposition; determining that the
distribution of alcohol in the various body fluids and tissues is
inconsistent with that expected in a living person; detecting the
presence of other volatiles
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or physiological byproducts which can sometimes be present during post-
mortem decomposition; repetitive analyses of a specimen to determine if
the alcohol concentration is increasing; and determining the identity
of any microorganisms present to assess whether they have alcohol-
producing capability.
Authority: 49 U.S.C. 20103, 20107, 20111, 20112, 20113, 20140,
21301, 21304, and 49 CFR 1.49(m).
Issued in Washington, D.C. on November 27, 1996.
Grady C. Cothen,
Deputy Associate Administrator for Safety.
[FR Doc. 96-30759 Filed 12-2-96; 8:45 am]
BILLING CODE 4910-06-P