Walton Submits DCI Proposal

Kudos to AnnMarie Walton, assistant professor, and her entire team for the submission of her Duke Cancer Institute (DCI) proposal entitled "Examining the efficacy of toilet seat covers and routine discharge cleaning in minimizing antineoplastic drug contamination on an inpatient bone marrow transplant unit."

Antineoplastic drug (AD) exposure remains a significant concern for healthcare workers. Even at low levels, exposure to ADs can cause acute toxicities, reproductive problems, and an increased risk for cancer including abnormalities in chromosomes 5 & 7 which mirror therapy-related myelodysplastic syndrome (t-MDS) and therapy-related acute myeloid leukemia (t-AML). Our own recent work on the inpatient bone marrow transplant unit at Duke University Medical Center (DUMC) showed the highest levels of AD contamination in patient rooms were on toilet seats, which supports concern about AD contaminated excreta as a source of exposure for healthcare workers. Surprisingly, it also showed the presence of drugs not given to the patient occupying the room in 26% of the samples from patient rooms (n=9/34), suggesting the presence of residues leftover from a prior patient. Taken together, we hypothesize that current handling and discharge cleaning practices may not be sufficient. However, we did not examine what the current cleaning methods entail and believe this is worth exploring. Recommendations exist to minimize exposure for healthcare workers handling AD contaminated excreta but are inconsistently followed. The Oncology Nursing Society (ONS) recommends use of plastic backed pads to minimize exposure to AD contaminated excreta when flushing but there are no data to support this recommendation, and we found they were used only 25% of the time in the prior study on this unit.  Since we learned that toilets were the most contaminated surfaces within the patient’s room, we are concerned about aerosolization from flushing that could contaminate toilet seats and surrounding surfaces which healthcare workers may contact unknowingly. In this proposed study we aim to: 1. Test whether plastic backed pads over the toilet while flushing (experimental condition) are more efficacious than regular flushing (control condition) in minimizing AD contamination on toilet seats and on other bathroom surfaces, 2. Explore and test the efficacy of the current discharge cleaning method to remove AD contamination from toilet seats and other bathroom surfaces. We will conduct this study on DUMC’s inpatient bone marrow transplant unit where staff have extensive contact with the AD contaminated excreta of patients as they measure output on all patients as standard care. We will utilize a paired two-sample design with the entire unit assigned to either the control or experimental condition for a period of time, followed by a brief washout and assignment to the opposite condition. Rooms of patients who will receive cyclophosphamide or etoposide in the next 48 hours will be eligible for recruitment into this study. Three surfaces (toilet seat, wall beside toilet, and floor in front of toilet) in the patient bathroom will be swabbed at three time points; prior to chemotherapy administration, between 24-72 hours after administration, and after discharge cleaning. The swabbing solvent will be a combination of acetonitrile, methanol, and water and the swabbing will follow a standardized procedure for surfaces that approximate 200 cm². All swabs will be stored in the Pharmacokinetics/Pharmacodynamics core lab until analysis and then analyzed using liquid chromatography/mass-spectrometry with highly sensitive assays. Paired t-tests will be used to compare results across groups as well as before and after discharge cleaning. Quantifiable detection of AD exposure and the development of means to reduce exposure to ADs is an important cancer control strategy for healthcare workers as well as for the families of patients receiving these drugs, who may experience exposure by the same mechanism. The results of this study will provide preliminary data for a more highly powered study to examine the efficacy of current recommendations in handling and cleaning after AD contaminated excreta in reducing AD exposure. This study is exceptionally timely and provides strategies for containment of hazardous drugs; DUMC is moving into compliance with a national pharmacopoeial standard called USP <800> designed to minimize exposure to hazardous drugs in the workplace and DUMC must comply by December 1, 2019. This study will also inform safe-handling and cleaning practices and the design of medical devices which can minimize exposure.