The Splashblocker was found to be an effective way to reduce contaminated particles. Plastic backed pads had mixed reviews.
The Splashblocker device was an effective, and environmentally friendly way to decrease the risk of drug contaminated aerosols emitted with toilet flushing, according to a presentation at the 48th Annual Oncology Nursing Society (ONS) Annual Congress.1 However, experiences with plastic backed pads (PBPs) were mixed.1,2
“As a reusable barrier control, the Splashblocker is an environmentally friendly option with the benefit of potential long-term cost savings for health care organizations,” Seth Eisenberg, ASN, RN, OCN, BMTCN, said in a poster presentation. “Both interventions significantly reduced the number of particles, which can provide measurable safety benefits for health care workers. However, the PBP was sucked into the toilet bowl as a result of negative pressure generated by the siphonic action of the toilet.”
Because hospital toilets have a high-pressure flushing capacity, and do not have a lid, they produce aerosols which carry bacteria and viruses—and droplet nuclei containing remnants of hazardous drugs. Reducing toilet-seat related contaminants is a safety goal of oncology care, as workers are at risk of antineoplastic drug (AD) exposure. When health care workers are exposed to ADs, even at low levels, they are at risk of acute toxicities, reproductive problems, and developing cancerous malignancies.
ONS guidelines recommend that the toilet be covered with a PBP when flushing, but no studies have been published on its efficacy.
Eisenberg, who is an oncology nurse consultant, and his coinvestigator, Changjie Cai, PhD, who is an assistant professor in occupational & environmental health at the University of Oklahoma Health Sciences Center, sought to evaluate the efficacy of these 2 methods. Their study was conducted in a university laboratory specifically designed for aerosol research. This was a controlled-environment bathroom chamber using a zurb-z5665 hospital-grade toilet, which was connected to a commercial American Standard Flushometer valve. The test chamber was sealed, and the air was HEPA filtered, to minimize ambient particles. A TSI 9306 Optical Particle Counter (OPC), which records particles form 0.3 um to 20.0 um every 2 seconds for a total of 5 minutes, was used to measure the particle size distributions.1
Prior to each test, initial readings were conducted for 2 minutes. For both the Splashblocker and the PBP, 3 tests were performed: one test in which the OPC was at 16 inches off the floor (H1), one in which the PC was 40 inches off the floor (H2), and one test where the toilet was uncovered. Each PBP was only used once.
Both the PBP and the Splashblocker reduced the total number of particles, at both tested heights (H1 + H2) compared with the uncovered toilets. At H1, the PBP and the Splaschblocker, respectively, reduced the number of particles from 61,344 to –60/L and 121/L; a decrease of over 99% (P = .034). At H2, the reductions were also greater than 99% (P = .033 and P = .008, respectively).
However, each time the PBP was used it was sucked into the toilet bowl, which counteracted the safety benefit. In comparison, the SplashBlocker, which is reusable, and is easy to clean, did not present this issue.
PBP Delivers Mixed Results
AnnMarie Walton, PhD, MPH, RN, OCN, CHES, FAAN, who is an associate professor at the Duke University School of Nursing, also experienced mixed results with the PBP. Of note, her study did not evaluate the Splashblocker’s efficacy.
“We expected consistently lower levels of contamination in the experimental condition, which would support the efficacy of PBPs that has been described in another recent study,”2,3 she wrote in a poster presentation of her research, which was also presented at the Congress. “This was not consistent with our results.”2
Prior research conducted in the inpatient bone marrow transplant unit at Duke University Hospitals (DUH) demonstrated that toilet seats were the greatest source of AD contamination in patient rooms. This finding exacerbated concerns about AD contaminated excreta representing a possible source of AD exposure. This data also demonstrated that in 33.35% of collected samples from the toilets, there was residue of drugs that the patient had not been prescribed. This finding suggests that remnants from agents from the prior patient were still present.
Therefore, Duke investigators sought to evaluate the practice of placing PBPs over the toilet during flushing and determine if this method was more capable of reducing AD contamination than regular flushing. In addition, they sought to explore the discharge cleaning method and evaluate its efficacy.
The study was conducted in the inpatient bone marrow transplant unit at Duke. A cross-over design was implemented, meaning that the entire unit was assigned to either the experimental or control tactic for 2 months, followed by a washout period, and then assignment to the opposite condition. To maximize the results, this cross-over approach was repeated once more following the 1-month washout period.
Only rooms where patients where receiving cyclophosphamide (CP) or etoposide (ETP) were chosen for this study. Investigators swabbed 3 surfaces in this rooms for collection: the toilet seat, the wall beside the toilet, and the floor in front of the toilet. These samples were collected at the following 3 times points: prior to chemotherapy administration, between 24 to 72 hours after administration, and after discharge cleaning.
All the samples were stored at Duke. The samples were analyzed via liquid chromatography/mass-spectrometry. Contamination was defined as greater than 0.05 ng/cm2 detectable traces in the sample.
Results showed that in the control group (n = 144), ETP was detected in 10.4% (n = 15) of samples and CP was detected in 41.0% (n = 59) of samples. Comparatively, in the experimental group (n = 144), ETP was detected in 10.4% of samples (n = 15) and CP was detected in 51.4% (n = 74).
There were no significant differences in mean contamination levels of ETP (P = .565) or CP (P = .227) between the control and experimental groups, respectively. The mean contamination levels by control and experimental condition were 0.36 ng/cm2 and 2.36 ng/cm2 for ETP and CP in the control arm, respectively. In the experimental arm, these mean levels were 0.7 ng/cm2 and 1.0 ng/cm2, respectively.
Moreover, in the prechemotherapy samples, contamination by ETP and CP in the control arm was 0% vs 29.2%, respectively. In the experimental arm, these rates were 0% and 31.3%. In the postchemotherapy setting, the contamination rates in the control arm were 25% vs 54.2%; in the experimental arms these rates were 20.8% vs 72.9%, respectively. Lastly, postdischarge, the ETP rates and CP rates in the control arm were 6.3% vs 39.6%, respectively. In the experimental arms, these were 10.4% vs 50.05%.
Overall, the mean ETP contamination levels in the prechemotherapy, postchemotherapy, and postdischarge settings were less than 0.01 ng/cm2, 1.54 ng/cm2, and 0.06 ng/cm2, respectively. Regrading CP, these rates were 0.08 ng/cm2, 4.42 ng/cm2, and 0.56 ng/cm2.
“Our results suggest that daily PBPs did not significantly reduce surface contamination with ADs,” Walton concluded. “A more efficacious routine and discharge cleaning process is needed to remove surface contamination with ADs.”
Updated May 4, 2023