Closed-System Transfer Devices: What Do They Offer?
Michael R. Page, PharmD, RPh | December 08, 2016
According to a document published by NIOSH in 2004, closed-system transfer devices (CSTDs) are drug transfer devices “that mechanically prohibit the transfer of environmental contaminants into the system and the escape of hazardous drug or vapor concentrations outside the system.”
In other words, these both prevent medication from escaping during transfer of medication and prevent outside contaminants from reaching the interior of medication vials.1 Under USP standards, CSTDs are classified as supplementary engineering controls to protect health care workers from hazardous drugs (HDs). In the pharmacy setting, CSTDs complement the protective effect of primary engineering controls (eg, biological safety cabinets), offering additional protection from HD exposure.2,3
For nurses, under the provisions of USP <800>—a legally binding regulation—all nurses administering medication to patients at the bedside must use CSTDs when administering cytotoxic medications to a patient, provided the dosage form is compatible with use of a CSTD.2,3
Given that all nurses who administer HDs to patients will eventually have access to CSTDs, pharmacists are likely to gain access to these devices, as well. Although some pharmacists may view these devices as a barrier to efficient preparation of chemotherapeutic medications, or may be resistant to change, the use of supplementary engineering controls is an important step forward in the protection of health care workers from occupational hazards.2-4
CSTDs offer several benefits for pharmacists. These devices provide an additional layer of protection from the potential hazards of chronic low-level exposure to HDs, reduce contamination of work areas, and reduce staff exposure to cytotoxic medications. These devices have also been shown to prevent microbial ingress into preservative-free vials, offering greater assurance of product integrity. In addition to these benefits, some CSTDs have been show to enable more rapid and efficient product preparation.2-5
Although many reasons to use CSTDs relate to the safe and efficient preparation of pharmaceutical products, other compelling reasons relate to staff safety and institutional liability. Compounding pharmacies, hospitals, and health care systems that ignore changing standards and regulations may be liable for damages related to the downstream effects of HD exposure.6
The most recent update of the Occupational Safety and Health Administration (OSHA) guidelines for handling of HDs addresses the use of CSTDs and emphasizes their value as a risk-reduction tool. With abundant evidence of serious risks associated with chronic low-level exposure to HDs, pharmacists and other health care workers are increasingly concerned with the potential occupational risks of handling and administering these medications. In fact, in some cases, the occupational risks associated with handling of HDs have led to litigation.1-6
An Additional Layer of Protection
Frequent handling of HDs—even with appropriate procedures in place—is not a risk-free occupational activity. McDairmid et al identified higher rates of damage to chromosomal targets associated with acute myeloid leukemia among 109 individuals: 63 oncology nurses and pharmacists and 46 hospital employees who did not handle HDs. Researchers identified chromosomal abnormalities on 2 of 3 chromosomes associated with acute myeloid leukemia (ie, chromosomes 5, 7, and 11) at a significantly higher rate than in the control group (P = .01). These abnormalities were especially associated with increased handling of alkylating agents, including cyclophosphamide.5,7
Additionally, frequent handling of HDs may increase reproductive risk. Valanis and colleagues compared pregnancy outcomes in 2976 nurses, pharmacists, and pharmacy technicians who handled HDs with pregnancy outcomes in 4118 women who were not health care workers. Researchers identified a statistically significant 40% greater risk of stillbirth and spontaneous abortion in women handling HDs during pregnancy (odds ratio: 1.4; 95% CI, 1.2-1.7).8 These are not the only studies linking HD handling with genotoxicity and reproductive risk.
Thomas H. Connor, PhD, research biologist in the NIOSH Division of Applied Research and Technology, in collaboration with other experts at the CDC, compiled a 64-page report summarizing the available evidence related to reproductive risks. NIOSH also catalogs recent publications, including guidelines, review articles, and surveys, related to the risks associated with HD exposure.
In addition, NIOSH develops a comprehensive list of HDs for identification of products that may require special handling, as part of USP <800> implementation. The list, which was updated in September 2016, includes more than 150 pharmaceutical products.3,9-11
As part of a comprehensive risk-reduction strategy, supplemental controls—including CSTDs—help protect health care workers from the potential harms of chronic low-level exposure to HDs. USP <800> mandates use of CSTDs when health care workers administer HDs to patients, provided the HD being administered is compatible with the CSTD used.2,3