By William A. Hyman
The Occupational Safety and HealthAdministration (OSHA) requirement for safety-engineered sharps protectionhas resulted in a wide range of syringe products that are explicitly orimplicitly said to provide a reduced incidence of user needlesticks, andtherefore an improvement in biohazard safety. Note that clean needlesticks arecertainly unpleasant and undesirable, but do not offer a direct infection risk.
Given the diversity of available needle-cover designs, it isunlikely that they offer an equal degree of risk reduction. While there havebeen a few bench evaluations published, it is striking that given the largenumber of reported sticks, the associated risk to health, and the number ofgeneral publications on needlestick prevention, that there has not beenpublished work on how effective the various devices really are in the clinic.Worse, the publications that do exist, and the reported federal data, do notidentify exactly what products were involved, even though such data is mandatedby OSHA for collection by hospitals, and also collected by the Centers forDisease Control and Prevention (CDC) and in various private studies. Similarly,the number of Food and Drug Administration (FDA) MDR reports on needlesticks isextremely small compared to the generally accepted total number of needlesticks.This remains true despite the 2002 revision in the FDA guidance on reportingneedlesticks that changed from no reporting of user error needlesticks topartial reporting if medical intervention was required. If hospitals arecollecting needlestick data as required by OSHA, is OSHA looking at it? And ifOSHA is looking at it, is there any communication with the FDA on why the numberof MDRs is so low?
There is also an OSHA requirement that there be a formal andperiodic product evaluation process of needlestick protective devices involvingfront-line workers. However, these workers cannot perform an effectiveevaluation, even if they are given the opportunity, unless they have adequateinformation on what features to look for and how to evaluate them. The simpleobservation that a product appears to offer the capacity to cover the usedneedle is not an adequate evaluation, since the important issue is not whetherthe device can work, but whether it will actually work. In this regard, nursesand other clinical personnel have often been too willing to blame themselves forerrors in device use rather than to appreciate the role of design in preventingor reducing error.
There are three basic designs for such syringe products, allrequiring direct action by the user. One is the sliding shield that is movedforward on the syringe barrel to cover the used needle. The second is the hingedcover that is activated at or near the needle end of the syringe to advance acover over the needle. In most cases, both the sliding cover and the hingedcover offer a cover locking mechanism, although from a tampering perspective,these mechanisms can be easily defeated. The third design is the retractableneedle in which a mechanism is provided to withdraw the needle into the syringebarrel after the needle is no longer needed (e.g., post-injection). The variousretractable designs have different means of activation (e.g., push button, orfinal increased pressure on the syringe plunger).
All of these designs can, in principle, cover the used needleand 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 causewithout affixing blame.) Is the answer then more in-service training and tellingthe surviving users to be more careful? Or do the designs need to be morecarefully evaluated to determine their means of use and their propensity forerror? Critical issues here are how the user activates the cover or retractionmechanism, and whether the task can be and will be consistently accomplishedwithout needlestick injury. In this regard, one-handed devices are preferredover 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. Thisreality of clinical syringe use is often overlooked, as if the post-use periodwas free of any ongoing clinical tasks, allowing the user to devote all ofhis/her attention to safe disposal. When the other hand is busy, in fact, whenthe user is busy, there will be a delay in the operation of a two-hand coveringmechanism, with the used syringe perhaps even being put down to be dealt withlater. Any increase in the duration over which the used needle is exposedprovides increased opportunity for a stick to occur, and furthermore providesthe opportunity to forget to retrieve the syringe and activate the mechanism atall. 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 playcreates the opportunity to stick the other hand, especially if the other handneeds to be engaged toward the needle end of the device. This observation is theorigin of the no-recapping rule because users were sticking the hand holding thecap during this process.
While user inadvertence is generally the focus of human-factorconsiderations, here, self-perception of the risk of using the other hand canlead to intentional non-use of the covering mechanism in order to avoid thisrisk. Hospital-based studies have demonstrated substantial numbers of usedprotective-cover needles in disposal boxes in which the protective device wasnot activated. Protective systems that are not used offer no risk reduction, andcan even increase risk through the false expectation of increased safety arisingfrom 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 atwo-handed approach, since the one-handed process is unrealistically difficult,requiring a degree of one-handed dexterity worthy of a baton twirler or amagician. This is particularly true when the using hand must be moved from thesyringe-operating grip to a position up on the barrel in order to reach thecovering mechanism.
Devices that are truly one-handed must still be distinguishedwith respect to the obviousness and ease of operation, and the degree oftraining and supervision required to achieve consistent staff compliance. Correct use is enhanced by intuitively obviousoperation that can be easily achieved under real use conditions (i.e., withoutcomplex, challenging and time-consuming manipulations). This is the essence ofeffective user-friendly design. It is noteworthy here that the simple disposalbox also offers theoretical protection from inadvertent needlesticks in that allthe user needs to do is carefully and immediately transport the used needle tothe disposal box, while using the box correctly, and assuring that it is notover-full. If this were being consistently done there would not have beena needlestick crisis and call for safer needle sharps in the first place.
An interesting issue here is that while device-specificneedlestick injury data collection is required by OSHA, and also obtained by theCDC and various private studies, this data has not been published in agencyreports or journals. But it is this data that is needed to sort out the goodproducts from those that are not actually effective.
Without public disclosure of device-specific injury rates, itremains the province of the local institution to select products, assuming thatthis option has not been already precluded by group purchasing contracts. Whenthis assessment is made, the key questions are (1) how is the covering mechanismoperated, (2) is it truly one-handed, (3) is it simple and obvious whilerequiring minimal manipulation, and (4) will the users understand how to do itwith minimal training? Effectively answering these questions can distinguish betweendevices that will actually reduce risk in the clinical setting, as opposed tothose devices that offer only theoretical risk reduction. ICT
William A. Hyman is professor and interim head of theDepartment of Biomedical Engineering at Texas A&M University.
Infection Control Today and theNational Alliance for the Primary Prevention of Sharps Injuries (NAPPSI) are nowaccepting nomination forms for the 2005 Primary Prevention Sharps Safety Award.This award will be presented this June to the healthcare facility/network thathas developed and implemented an outstanding primary-prevention sharps safetycampaign. Criteria and nomination forms (in PDF format) are available onwww.infectioncontroltoday.com and www.nappsi.org. The deadline for nominationsubmissions is Friday, April 29, 2005. For more information on this award,please contact Bill Eikost, Publisher at (480) 990-1101 x1191 (email:email@example.com).