
Needlesticks: Are “Safety” Syringes Really Safe?
By William A. Hyman
The Occupational Safety and Health
Administration (OSHA) requirement for “safety-engineered” sharps protection
has resulted in a wide range of syringe products that are explicitly or
implicitly said to provide a reduced incidence of user needlesticks, and
therefore an improvement in biohazard safety. Note that clean needlesticks are
certainly unpleasant and undesirable, but do not offer a direct infection risk.
Given the diversity of available needle-cover designs, it is
unlikely that they offer an equal degree of risk reduction. While there have
been a few bench evaluations published, it is striking that given the large
number of reported sticks, the associated risk to health, and the number of
general publications on needlestick prevention, that there has not been
published work on how effective the various devices really are in the clinic.
Worse, the publications that do exist, and the reported federal data, do not
identify exactly what products were involved, even though such data is mandated
by OSHA for collection by hospitals, and also collected by the Centers for
Disease Control and Prevention (CDC) and in various private studies. Similarly,
the number of Food and Drug Administration (FDA) MDR reports on needlesticks is
extremely small compared to the generally accepted total number of needlesticks.
This remains true despite the 2002 revision in the FDA guidance on reporting
needlesticks that changed from no reporting of “user error” needlesticks to
partial reporting if medical intervention was required. If hospitals are
collecting needlestick data as required by OSHA, is OSHA looking at it? And if
OSHA is looking at it, is there any communication with the FDA on why the number
of MDRs is so low?
There is also an OSHA requirement that there be a formal and
periodic product evaluation process of needlestick protective devices involving
front-line workers. However, these workers cannot perform an effective
evaluation, even if they are given the opportunity, unless they have adequate
information on what features to look for and how to evaluate them. The simple
observation that a product appears to offer the capacity to cover the used
needle is not an adequate evaluation, since the important issue is not whether
the device can work, but whether it will actually work. In this regard, nurses
and other clinical personnel have often been too willing to blame themselves for
errors in device use rather than to appreciate the role of design in preventing
or reducing error.
There are three basic designs for such syringe products, all
requiring direct action by the user. One is the sliding shield that is moved
forward on the syringe barrel to cover the used needle. The second is the hinged
cover that is activated at or near the needle end of the syringe to advance a
cover over the needle. In most cases, both the sliding cover and the hinged
cover offer a cover locking mechanism, although from a tampering perspective,
these mechanisms can be easily defeated. The third design is the retractable
needle in which a mechanism is provided to withdraw the needle into the syringe
barrel after the needle is no longer needed (e.g., post-injection). The various
retractable designs have different means of activation (e.g., push button, or
final increased pressure on the syringe plunger).
All of these designs can, in principle, cover the used needle
and therefore protect personnel from subsequent needlesticks. Given this fact,
it is apparent that needlesticks that do occur are a result of usage error. (“Usage,”
rather than “user error,” is used here to emphasize the immediate cause
without affixing blame.) Is the answer then more in-service training and telling
the surviving users to be more careful? Or do the designs need to be more
carefully evaluated to determine their means of use and their propensity for
error? Critical issues here are how the user activates the cover or retraction
mechanism, and whether the task can be and will be consistently accomplished
without needlestick injury. In this regard, one-handed devices are preferred
over those that require two hands to operate. The reason for this is two-fold.
First, the other hand may be directly engaged in ongoing patient care. This
reality of clinical syringe use is often overlooked, as if the post-use period
was free of any ongoing clinical tasks, allowing the user to devote all of
his/her attention to safe disposal. When the other hand is busy, in fact, when
the user is busy, there will be a delay in the operation of a two-hand covering
mechanism, with the used syringe perhaps even being put down to be dealt with
later. Any increase in the duration over which the used needle is exposed
provides increased opportunity for a stick to occur, and furthermore provides
the opportunity to forget to retrieve the syringe and activate the mechanism at
all. Even the act of picking up the syringe again presents a needlestick risk.
The second concern in two-handed use is that bringing the other hand into play
creates the opportunity to stick the other hand, especially if the other hand
needs to be engaged toward the needle end of the device. This observation is the
origin of the no-recapping rule because users were sticking the hand holding the
cap during this process.
While user inadvertence is generally the focus of human-factor
considerations, here, self-perception of the risk of using the other hand can
lead to intentional non-use of the covering mechanism in order to avoid this
risk. Hospital-based studies have demonstrated substantial numbers of used
protective-cover needles in disposal boxes in which the protective device was
not activated. Protective systems that are not used offer no risk reduction, and
can even increase risk through the false expectation of increased safety arising
from the provision of “safe” devices.
While some covering mechanisms require the use of two hands,
others may claim to be one-handed but in reality the users will innovate a
two-handed approach, since the one-handed process is unrealistically difficult,
requiring a degree of one-handed dexterity worthy of a baton twirler or a
magician. This is particularly true when the using hand must be moved from the
syringe-operating grip to a position up on the barrel in order to reach the
covering mechanism.
Devices that are truly one-handed must still be distinguished
with respect to the obviousness and ease of operation, and the degree of
training and supervision required to achieve consistent staff compliance. Correct use is enhanced by intuitively obvious
operation that can be easily achieved under real use conditions (i.e., without
complex, challenging and time-consuming manipulations). This is the essence of
effective user-friendly design. It is noteworthy here that the simple disposal
box also offers theoretical protection from inadvertent needlesticks in that all
the user needs to do is carefully and immediately transport the used needle to
the disposal box, while using the box correctly, and assuring that it is not
over-full. If this were being consistently done there would not have been
a needlestick crisis and call for “safer” needle sharps in the first place.
An interesting issue here is that while device-specific
needlestick injury data collection is required by OSHA, and also obtained by the
CDC and various private studies, this data has not been published in agency
reports or journals. But it is this data that is needed to sort out the good
products from those that are not actually effective.
Without public disclosure of device-specific injury rates, it
remains the province of the local institution to select products, assuming that
this option has not been already precluded by group purchasing contracts. When
this assessment is made, the key questions are (1) how is the covering mechanism
operated, (2) is it truly one-handed, (3) is it simple and obvious while
requiring minimal manipulation, and (4) will the users understand how to do it
with minimal training? Effectively answering these questions can distinguish between
devices that will actually reduce risk in the clinical setting, as opposed to
those devices that offer only theoretical risk reduction. ICT
William A. Hyman is professor and interim head of the
Department of Biomedical Engineering at Texas A&M University.
Call for Nominations for 2005 Primary Prevention Sharps Safety
Award
Infection Control Today and the
National Alliance for the Primary Prevention of Sharps Injuries (NAPPSI) are now
accepting nomination forms for the 2005 Primary Prevention Sharps Safety Award.
This award will be presented this June to the healthcare facility/network that
has developed and implemented an outstanding primary-prevention sharps safety
campaign. Criteria and nomination forms (in PDF format) are available on
www.infectioncontroltoday.com and
www.nappsi.org. The deadline for nomination
submissions is Friday, April 29, 2005. For more information on this award,
please contact Bill Eikost, Publisher at (480) 990-1101 x1191 (email:
weikost@vpico.com).
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