A Cost and Waste-Savings Comparison Between Single-Use and Reusable Pulse Oximetry Sensors
Myron Yaster MD, Lynn D. Martin MD MBA, and Elizabeth E. Hansen MD PhD
“I can’t prove it, but I just it know it’s true.”
There was a time when many of my closest friends and colleagues punched their leadership tickets with executive MBA degrees. Some used their newly gained knowledge and degrees with spectacular results and others not so much. To be honest, I was never interested in getting an MBA. The very thought made me gag and brought back nightmares of how much I hated my basic economics and accounting courses in college. Indeed, I remember telling my wife, that if I signed up for an executive MBA course, she had my permission to get me immediately admitted for a full neuro, brain tumor workup.
Today’s PAAD by Stockert et al.1 is unusual for the PAAD. It doesn’t have real patient or outcome data, rather, it’s really a very formal theoretical mind experiment asking the question: “Can switching to reusable pulse oximeters save money and the environment?” I’ve asked members of our executive council with expertise in these issues, Drs. Lynn Martin and Liz Hansen to help. Myron Yaster MD
Original articles
Stockert EW, Carvalho B, Sun EC. A Cost and Waste-Savings Comparison Between Single-Use and Reusable Pulse Oximetry Sensors Across US Operating Rooms. Anesth Analg. 2024 Jul 1;139(1):220-225. doi: 10.1213/ANE.0000000000006778. Epub 2024 Jan 9. PMID: 38195082; PMCID: PMC11182726.
Health care costs continue to go up and up and amazingly now make up almost 20% of the U.S. gross national product. “Surgical costs (including the operating room) account for nearly one-third of total health care spending.2 Concomitantly, there is growing concern for climate change and global warming. American hospitals generate roughly 5.9 million tons of waste annually,3 with 20% to 33% (1.2–1.9 million tons) of this waste being generated in the OR.”1 A really simple way to reduce costs and waste is, as we’ve discussed in many previous PAADs, to simply to substitute single-use equipment with reusable equipment.
In thinking about this type of change, Stockert et al. laid out the following ground rules: “(1) patient safety and clinical equivalence, (2) added cleaning expense, (3) potential changes in workflow and supply chain management, and (4) differences in economic cost of capital.” The authors “identified the use of pulse oximetry sensors as an appropriate area for analysis because single-use pulse oximetry sensor stickers (“single-use stickers”) and reusable pulse oximetry sensor clips (“reusable clips”) are largely equivalent with respect to the first 3 items. For example, it is widely accepted that single-use stickers and reusable clips from the same vendor can be interchangeably applied to the same pulse oximetry sensor cable (“sensor cable”), and have equivalent saturation and pulse rate accuracy; including during low perfusion events and with motion.4 In addition, cleaning reusable clips creates minimal added workload. Reusable clips are simply wiped entirely with a 70% isopropyl alcohol pad and allowed to air dry—the same process utilized for cleaning the sensor cable between uses—thereby eliminating the need for additional cleaning supplies by utilizing the same wipe. Contrast this with the time to retrieve, open the packaging, and attach a single-use sticker to the same sensor cable. Furthermore, understanding the benefits of a national transition to reusable clips is important because it is feasible to accomplish.”1
Based on the economical modelling applied by Stockert et al1, if everyone in the U.S. made the transition to reusable clips, net annual savings would range between $510-519 million dollars and includes the costs of cleaning, replacing reusable pulse oximetry clips, and the cost of capital. The annual waste that could be diverted from landfill by transitioning to reusable clips was found to be between 587 tons (conservative state) up to 589 tons (favorable state), which is roughly the equivalent to 57 million half-liter plastic bottles. The authors conclude: “Using reusable clips versus single-use stickers across all ORs nationally would result in appreciable annual cost savings and waste generation reduction impact. As both single-use stickers and reusable clips are equally accurate and reliable, this cost and waste savings could be instituted without a compromise in clinical care.”1
The economic model used by Stockert et al1 is simple, elegant, and contained reasonable and explicitly defined assumptions or estimates. The unit pricing data is not institutionally specific, but rather based on open market sources from January 2021. Time costs for cleaning or replacing oximeter were established by independent observations and set for 2019 AHA anesthesia tech salary + fringe benefits ($37.52 per hour). Investment losses associated with capital expenditures were established from 2 benchmarks: low return (US 1-year treasury rate for 2022-2.85%) and high return (S&P 500 1-year return for 2022-7.08%). Their modeling compared reusable to disposable oximeters under a favorable state (high interest rate-7%, low replacement rate-6 months, short cleaning time: -1 second) and conservative state (low interest rate-2%, high replacement rate-4 months, long clean time: +2 seconds). The authors call out their model limitations (no formal life-cycle analysis and no estimates for carbon emissions or disposal costs). The two most important limitations were a failure to assess costs or savings in inventory management (likely favorable for reusable oximeters) and potential reprocessing of the disposable single use oximeters (a relatively common practice in many hospitals).
Reprocessing of single use pulse oximetry cables has already been evaluated using life cycle assessment and life cycle cost assessment. This paper demonstrated decreased costs and environmental impact, especially if the item was reprocessed multiple times.4 A more recent life cycle assessment was performed, and found that “reusable oximeters only need to be used 2.3 times before they match the emissions created by a single disposable oximeter.”5
Like us, we don’t think anyone of you will find these results surprising. This paper is really a call to action. Nevertheless, there are certain problems with this mind experiment. The basic assumption is that the reusable clips will need to be replaced every 4-6 months. But what if they are “lost” more frequently? Like during transitions from the OR to the PACU or to the floor or during simple cleaning and OR room turnover? And what about institutions that are already reprocessing used disposable sensors?
Further, in pediatrics, one size does not fit all and multiple types of reusable clips will be necessary. Finally, using disposable sensors may be important for patients who are admitted to the hospital after surgery or in whom infection control requires it.
We think switching to reusable sensors or using reprocessed products is low lying fruit and an easy target for all of us to save money and the environment. What do you think? What are you doing in your practices? Send your thoughts and comments to Myron who will post in a Friday reader response.
References
1. Stockert EW, Carvalho B, Sun EC. A Cost and Waste-Savings Comparison Between Single-Use and Reusable Pulse Oximetry Sensors Across US Operating Rooms. Anesthesia and analgesia 2024;139(1):220-225. (In eng). DOI: 10.1213/ane.0000000000006778.
2. Muñoz E, Muñoz W, 3rd, Wise L. National and surgical health care expenditures, 2005-2025. Annals of surgery 2010;251(2):195-200. (In eng). DOI: 10.1097/SLA.0b013e3181cbcc9a.
3. Chung JW, Meltzer DO. Estimate of the carbon footprint of the US health care sector. Jama 2009;302(18):1970-2. (In eng). DOI: 10.1001/jama.2009.1610.
4. Unger S, Landis A. Assessing the environmental, human health, and economic impacts of reprocessed medical devices in a Phoenix hospital's supply chain. Journal of Cleaner Production 2016;112:1995-2003.
5. Duffy J, Slutzman JE, Thiel CL, Landes M. Sustainable Purchasing Practices: A Comparison of Single-use and Reusable Pulse Oximeters in the Emergency Department. West J Emerg Med 2023;24(6):1034-1042. (In eng). DOI: 10.5811/westjem.58258.