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Preventing Needle-stick Injuries and the Use of Dental Safety Syringes
RS2009-IG03
Final Report Date: October 2010
| Principal Applicant: | Mel Sawyer (UBC) |
| Co-applicants: | Edward Putnins, J. Douglas Waterfield, N. Dorin Ruse |
For more information about this project, please contact Mel Sawyer.
Issue
Documented evidence shows that accidental needle sticks create a risk of transmission of infectious agents (blood borne pathogens) to healthcare providers. In light of the potential for these kinds of accidental exposures, regulators across North America have established guidelines and standards aimed at reducing the risk of such injuries. While the regulations are broad enough to include all healthcare workers, there are unique considerations that should be taken into account with regard to the use of needles in dentists’ offices.
In dental care settings, local anaesthetic is administered using aspirating syringes that can be sterilized, loaded with disposable pre-measured anaesthetic cartridges and single-use sterile narrow-bore needles. It is fairly unique (and common) to dentistry that a single needle be used multiple times during the course of administering anaesthetic.
Dentists have indicated that currently available safety-engineered syringes are not clinically appropriate for use in patients’ mouths. The objective of this project was to use an established set of criteria to determine whether safety-engineered syringes are perceived to contribute to practitioner and patient safety and decrease the risk of accidental needle sticks and disease transmission.
Key findings
Study participants (novice and experienced dental practitioners) noted:
- instability of the needle apparatus and its’ ease of separation from the syringe handle while engaging the safety feature – patient and operator safety concern
- potential of deflection of the needle upon and during injection – patient safety concern
- visualization challenges during aspiration – patient safety concern
- failure to clearly tell if the safety feature is fully engaged, increasing chance of injury – operator safety concern
In addition, participants described technical problems associated with the use of the test syringe:
- more physical manipulation required to load and retrieve the cartridge than with a conventional syringe
- more difficult to learn how to use than a conventional syringe
- the safety device requires more physical manipulation, as the device has no automatic re-sheathing capability
Objectives
The main objectives of the study were:
- to complete a literature-based review of the risks of disease transmission as a result of a needle stick injury to healthcare workers (HCWs), particularly for dental healthcare providers (DHCPs)
- to review current regulations in Canada and the United States designed to help protect and reduce the risk of percutaneous injuries and needle stick injuries to DHCPs
- to propose methods to reduce needle stick injury risk through education and implementation of administrative, workplace and engineering controls
- to examine and evaluate the use of a recently developed safety-engineered syringe
- to propose an injury reporting template that documents percutaneous injuries (including needle stick injuries) for implementation in dentistry
Method
The first stage of the project included an extensive review of the literature. In the second stage, a dental safety syringe recently made available in Canada was tested at the University of British Columbia’s Faculty of Dentistry. Pre-clinical assessments were made by a variety of novice and experienced practitioners who typically use conventional dental anesthetic syringes. The participant groups (including ten junior dental students, ten senior dental students, and ten experienced dentists/faculty members) carried out these assessments by injecting a ripe avocado with local anaesthetic, using both a conventional syringe and a safety syringe in a prescribed manner. Following the testing, participants completed questionnaires regarding the test device. Additionally, the physical properties of the needle and syringe were tested under a variety of loading conditions. The results were analyzed, and the investigators were unconvinced that the study should move forward in a clinical trial, as it was felt that the design of the safety syringe posed a possible risk for patients and practitioners. These risks were the same noted in the literature review, including the instability of the needle apparatus and difficulty for an operator to determine whether the safety feature was engaged.
Results
Although the risk of a dental healthcare provider contracting a blood borne disease through needle stick injury is significantly less than with other healthcare providers, this study determined that a better surveillance system for tracking and documenting needle stick injuries to dental healthcare providers should be implemented to gather further information as to the incidence and the nature of dental needle stick injuries.
The introduction and use of safety-engineered syringes in the healthcare model setting has the potential to reduce the transmission of blood borne disease to health care workers. The practice of needle capping and recapping during local anaesthetic delivery in dentistry can potentially increase the risk of an inadvertent needle stick injury, but requirements for a specifically engineered syringe and needle apparatus have presented challenges in the design and therefore implementation of safety engineered syringes in dentistry.
In light of the concerns expressed by participants during pre-clinical testing, the researchers determined that while the safety-engineered syringe can be considered as an option for use, additional design modifications are required prior to recommending universal use of the apparatus. The researcher suggests that strict adherence to existing engineering and workplace controls designed to minimize risk of needle stick injuries would help minimize the risk of such injuries in the interim, including placing used disposable syringes and needles, scalpel blades and other sharp items in appropriate puncture-resistant containers located as close as feasible to the area in which the items are used, not recapping used needles by using both hands or any other technique that involves directing the point of a needle toward any part of the body, and not bending, breaking or removing needles before disposal.
The final report includes suggestions for reducing the risk of needle stick injuries in dentistry, including immunization, implementation of strategies to minimize needle stick injuries in the dental workplace, improvement in reporting of needle stick injuries in dentistry, and providing constructive feedback to manufacturers so they can design a more compatible safety-engineered device for the delivery of local anesthetic in the dental setting.
Future directions
Percutaneous injuries, and specifically needle stick injuries do occur in dentistry, Safety-engineered needles are typically used in healthcare settings to help prevent such injuries. Needs and approaches in dentistry pose some challenges for the design of safety-engineered devices for use in that setting. The report presents suggestions for reducing the risk of needle stick injuries in dentistry, including immunization, implementation of strategies to minimize needle stick injuries in the dental workplace, improvement in reporting of needle stick injuries in dentistry, and providing constructive feedback to manufacturers so they can design a more compatible safety-engineered device for the delivery of local anesthetic in the dental setting.