A closed system drug transfer device or "CSTD" is a drug transfer device that mechanically prohibits the transfer of environmental contaminants into a system and the escape of hazardous drug or vapor concentrations outside the system. Open versus closed systems are commonly applied in medical devices to maintain the sterility of a fluid pathway. CSTDs work by preventing the uncontrolled inflow and outflow of contaminants and drugs, preserving the quality of solution to be infused into a patient. Theoretically, CSTDs should enable complete protection to healthcare workers in managing hazardous drugs, but possibly due to improper handling or incomplete product design, contaminants can still be detected despite use of CSTDs.
Medical use
Hazardous drugs are often used for patients suffering from cancer. For example, chemotherapy agents are routinely used in the treatment of cancer. However, chemotherapy can be dangerous to a person even if they don't have cancer, as chemotherapy often indiscriminately affects both healthy and cancerous cells. For the healthcare worker tasked with preparing hazardous medications like chemotherapy, manipulation of these agents presents a substantial risk; for example, it may negatively affect their fertility, increase their risk of developing certain cancers themselves, or have unwelcome effects on fetuses. As an addition to standard safe handling practices, CSTDs are devices that are designed to additionally limit exposure of hazardous drugs to the personnel that manipulate them.
Efficacy
Investment and interests in CSTDs continue to grow over the past decade as concerns of Occupational Safety and Health, together with increased awareness of drug risks have pushed the market to explore better options for handling hazardous materials. A Cochrane review found "no evidence for or against adding CSTD to safe handling of hazardous medicines" based on a review of 23 studies, but acknowledged that the studies did not use randomised controlled trials nor evaluate the value of treatment. CSTDs used in this study include PhaSeal, Tevadaptor and SpikeSwan. It remains that new solutions to increasing safety of handling hazardous drugs have to be developed. Conceptually, through operating in a closed system, CSTDs should significantly reduce risks to nurses. However, the robustness of product design and extent of proper usage by nurses affects the efficacy of the CSTD in achieving OSH.
History
The first FDA-approved CSTD was in 1998, called PhaSeal. Since that time, many other CSTD products have been developed in the United States. MD Anderson hospital was the first hospital in the United States to widely implement CSTD technology.
Definition
The definition of a closed system drug transfer device was first published in an alert warning released by the AmericanNational Institute for Occupational Safety and Health. This warning was issued in relation to studies that showed a correlation between working with or near hazardous drugs in a health care environment and the increased risk of developing skin rashes, infertility, miscarriage and infant birth defects, as well as the possibility of developing leukemia and other forms of cancer. This NIOSH alert recommended that a closed system drug transfer device be used whenever hazardous drugs were to be handled.
NIOSH
NIOSH, in response to the need for a working model as to what a "closed system" and what a "closed system drug transfer device" was, provided the following definition:
A closed system is a device that does not exchange unfiltered air or contaminants with the adjacent environment. This closed system definition originally referred to a biological safety cabinet and not to the drug containment devices. A drug containment device is one that is both airtight and leakproof.
A closed system drug transfer device is a drug transfer device that mechanically prohibits the transfer of environmental contaminants into the system and the escape of hazardous drug or vapor concentrations outside the system.
The NIOSH definition is the only definition that includes drug vapors. NIOSH considers the containment of vapor extremely important, such that in September 2015, NIOSH issued a Testing Protocol to assess the effectiveness of closed systems. NIOSH developed and tested 5 CSTDs to assess its "closeness." 2 of the 5 CSTDs tested passed. This protocol is aimed as being a test standard for CSTDs to assess the "closeness" of each system.
ISOPP
ISOPP, the International Society of Oncology Pharmacy Practitioners, splits the definition of a closed system into two different categories:
The first defines "closed" in terms of microbiological contamination. This definition deals purely with introducing micro-organisms into a sterile product, and there is no consideration of the sterile product coming out of the vial contaminating the environment.
The second category defines "closed" in relation to chemical contamination and refers to drug transfer devices that mechanically prohibit the transfer of environment contaminants into the system and the escape of hazardous drug or vapour concentrations outside the system. ISOPP, however, agree that the NIOSH definition is the most comprehensive and complete.
NIOSH Vapor Containment Protocol Proposal Comment Period Developments
In September 2015, the CDC issued a proposal for a testing protocol designed to test various CSTDs on the market today to help healthcare decision makers decipher between various systems available on the market today. This protocol had an initial close date of November 2015 but was extended until March 2016. Findings from "Fred Massoomi's Response to Docket No. CDC-2015-0075, NIOSH-288" include:
Testing performed under "Report on NIOSH's Vapor Containment Performance Protocol for CSTDs" showed that Equashield and PhaSeal systems had contamination below the 1ppm recommendation.
Testing performed under "5-FU leakage study" showed that Equashield CSTD passed the leakage testing.
Testing performed under "Testing of Tevadaptor Efficiency in Preventing Cyclophosphamide" showed that the Tevadaptor system FAILED the contain drug vapor within the system.
Solutions
Commercially available CSTD products include the following:
