Wipe Testing
A January 2018 article published by Chauchat et al presented the results of HD surface contamination in 83 Canadian hospitals (n=953 samples). This is the largest wipe test study published to date, eclipsing the 2015 study of 51 Canadian centers by Janes and colleagues (n=584 samples).
Of the 953 samples, 495 were collected from inside the pharmacy and 458 were from patient care areas. The test looked at 10 different HDs including cyclophosphamide (CY). Although slightly lower than prior studies, 36% of the samples were positive for CY, with contamination found in both pharmacy and administration areas. A startling 75% of the armrests in patient care areas were positive for CY—a huge concern for nurses and other ancillary patient care staff.
Lest we believe this is just a Canadian problem, surface contamination has been identified in 12 other studies from various countries in the past 5 years. Positive samples have ranged from 3% to an alarming 95%.
Would any of these hospitals have known about the contamination had wipe testing not been conducted? No, which is the value of conducting wipe sampling.
Surface wipe testing is not required by USP <800> but is highly recommended. Wipe testing is extensively discussed and recommended in the latest ASHP HD guidelines (Power & Coyne, 2018), as well as by CriticalPoint, a leader in compounding safety. Wipe testing provides insight into whether policies, procedures and products are preventing exposure, and allow an organization to make changes and subsequently reevaluate those changes as continuing process improvement.
CricicalPoint’s latest USP <800> survey shows that only 12% of 444 hospitals performed wipe testing within the past year (https://www.criticalpoint.info/tools-resources/gap-analysis/).
So why aren’t we doing more testing?
For years, the argument was that samples needed to be collected by trained industrial hygienists, with samples packed in dry ice and shipped to the Netherlands. Results would come many weeks later.
But there are now several laboratories in the US that perform wipe testing and most have do-it-yourself kits with easy-to-follow instructions. Results are obtained in 2-3 weeks.
Technology is making wipe testing even easier, with the availability of BD’s HD Check system. While currently tests only are available for doxorubicin and methotrexate, cyclophosphamide and 5FU should be available Q1 of 2020.
Again, so why aren’t we doing more testing?
Aside from the cost argument, it is also likely that many organizations do not want to look because they will probably find problems—and then have to fix them. This is essentially the ostrich version of HD safety.
According to the CDC, more than 20,000 people are poisoned by carbon monoxide (CO) each year, killing more than 400.
Most states now require CO detectors in because they protect us from what we cannot see, smell, taste or hear. Until such time as we have detectors for hazardous drugs, we need to rely upon wipe testing to provide useful information about problems with practice, policies and equipment, and make the necessary changes. We should be encouraging our hospital administrators, pharmacy and nursing managers to implement a wipe testing program. Until then, we are all at risk.