To understand reusable and disposable laryngoscope safety, it is helpful to review both Center for Disease Control and Prevention (CDC) infection risk classification¹ as well as device procurement criteria: safety, efficacy, ease of use, cost, and regulatory compliance.²

Tongue blades come in contact with mucous membranes and are considered intermediate risk or semi-critical. They therefore require a minimum of high-level disinfection, typically performed in the Central Sterilization and Supply Department (CSSD).¹ Handles come in contact with skin, and historically have been considered low risk or noncritical. They therefore require a minimum of low-level disinfection, typically performed using a chemical cloth wipe in the operating room.²

The CDC language on laryngoscope handle classification is vague, and thus the CDC defers to device manufacturer “Instructions for Use” (IFU) to determine risk level.¹ IFUs are intended to describe manufacturer-approved alternative methods for cleaning equipment that meet CDC compliance, and it is up to the institution to choose which method to use.³ Oversight bodies, such as The Joint Commission, are tasked with enforcing CDC regulations and recently started holding facilities accountable for laryngoscope IFUs. CDC deference to industry for risk determination has invited potential “up-classification” of device risk and therefore disinfection requirements. Thus, while manufacturers are not infection experts, many are now starting to include intermediate risk designations on laryngoscope IFUs, even though historically handles have been safely treated as low risk. This means that facilities now have two choices to remain in regulatory compliance: send the handles to CSSD for a minimum of high-level disinfection, or switch to single-use disposables (SUDs). Many facilities may be electing to do the latter, owing mostly to convenience.² The letter on page 90 of this issue of the APSF Newsletter raises many typical concerns regarding taking the expedient route.

There are multiple small studies demonstrating inferior SUD blade performance in the peer-reviewed literature owing to the higher deformability of the blade/joint, especially those comprised of plastic materials. Increased deformability makes vocal cord visualization more difficult.⁴ Institutions electing to use SUDs may for this reason opt for “disposable” steel; however, this is an even more concerning material from an environmental perspective.⁴ The International Standards Organization (ISO) determines performance criteria necessary to achieve FDA approval of equipment. Of note, the ISO 7376 standards permit tongue blade tip excursion of up to 1 cm. While traditional reusable steel devices have much less tip excursion, SUDs can take advantage of the permissible “wiggle room” to save on materials. SUDs can be made to approximate reusable laryngoscopes, but it requires higher quality materials and cost increases.

Disposable laryngoscopes are often perceived to be cheaper than reusable alternatives, due to CSSD reprocessing labor and material costs. However, when considered across an entire institution, the cost of SUDs can exceed the lifecycle costs of an equivalent number of reusable laryngoscopes. Assuming average CSSD laborer salary of $50,000 per annum, standard cleaning times, and including periodic refurbishment, Sherman and colleagues estimated that reusable handles would be more economical than SUDs if they last through at least 4–5 uses, and reusable blades, 5–7 uses. Typical steel reusable devices are rated for thousands of uses, and thus the advantage over disposables can be considerable. In terms of infrastructure complexity, treating reusable laryngoscope handles and blades is likely a very small fraction (e.g., 2%) of CSSD facility duties.⁴

Environmental health is a new safety consideration. It’s not just about what goes to the landfill, but also natural resource extraction, manufacturing, packaging, transportation, use/reuse, and eventual waste management—the entire life cycle. Sherman and colleagues performed a life cycle assessment and found that SUD rigid laryngoscope handles and blades result in 16–25 and 6–8 times more greenhouse gas (GHG) emissions using standard U.S. energy mix, respectively, when compared to alternative reusable cleaning scenarios. Of the reusable reprocessing options, surprisingly, low-level disinfection of the handle resulted in slightly higher GHG emissions than high-level disinfection, despite lower cost.⁴

There is a disturbing trend towards single-use disposable materials throughout the world. Pollution is a leading cause of non-communicable disease, responsible for an annual 9 million deaths, or 16% of annual deaths globally.⁵ Climate change has been called the number one public health issue of the 21st century.⁶ Plastics are so pervasive in our environment that they are now prevalent in our tap water, table salt,⁷ and stools.⁸ Patient safety considered in its broadest context includes public health. You are correct to question the safety of disposable laryngoscopes. Not only do SUDs have a significantly negative environmental impact compared with reusable laryngoscopes, analysis of the entire life cycle indicates that SUDs do not achieve the intended impact of reducing cost.

 

Dr. Sherman is presently associate professor of anesthesiology, Yale School of Medicine and associate professor of epidemiology in environmental health sciences, Yale School of Public Health. She is also co-chair of the ASA Subcommittee on Environmental Health.

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Dr. Sherman has no conflicts of interest.

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References

1. Rutala WA, Weber D. The Healthcare Infection Control Practices Advisory Committee (HIPAC): Guideline for disinfection and sterilization in healthcare facilities. Centers for Disease Control, 2008.
2. Sherman JD, Hopf HW. Balancing infection control and environmental protection as a matter of patient safety: the case of laryngoscope handles. Anesth Analg. 2018;127: 576–579.
3. Global Harmonization Task Force. Label and instructions for use for medical devices, 2011.
4. Sherman JD, Raibley LA IV, Eckelman MJ. Life cycle assessment and costing methods for device procurement: comparing reusable and single-use disposable laryngoscopes. Anesth Analg. 2018;127:434–443.
5. Landrigan PJ, Fuller R, Acosta NJR, et al. The Lancet Commission on pollution and health. Lancet. 2018;391:462–512.
6. Costello A, Abbas M, Allen A, et al. Managing the health effects of climate change. Lancet. 2009;373:40.
7. Kim JS, Lee HJ, Kim SK, et al. Global pattern of microplastics (mps) in commercial food-grade salts: sea salt as an indicator of seawater MP pollution. Environ Sci Technol. 2018;Oct 16. doi: 10.1021/acs.est.8b04180. [Epub ahead of print].
8. Schwabi PL, Koppel S, Konigshofer TP, et al. Assessment of microplastics concentrations in human stool—preliminary results of a prospective study. United European Gastroenterol J. 2018;6:A127.