Needlesticks: Are Safety Syringes Really Safe?

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 and 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:

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