Providing Cleaning Recommendations for Positive Airway Pressure Devices

Positive airway pressure (PAP) remains the first-line therapy for obstructive sleep apnea (OSA). Although PAP improves patient-centered outcomes (1), there are burdens of regular PAP use such that long-term adherence is only about 50% (2). To address this problem, substantial attention has been paid to addressing side effects of applying PAP. However, the burden of maintenance and cleaning of PAP equipment has been ignored. Instructions for the care of PAP equipment are complex and can overwhelm patients and their families, potentially limiting PAP uptake.

Aggressive Cleaning Does Not Reduce Infection Risk

The primary rationale for aggressive cleaning is that PAP use without regular cleaning will lead to an increased risk of respiratory infections (3). The evidence to support this contention, however, is weak. Mask colonization has been used frequently as a surrogate marker for infection risk. A 2009 abstract swabbed masks from 24 PAP users and found cultures grew bacterial and yeast colonies (4). Cleaning the mask just before swabbing reduced colony counts; however, the frequency of cleaning by patients at home did not predict microbial burden. Furthermore, the organisms isolated from the cultures were normal skin flora, and no patient reported respiratory infections despite PAP colonization. A subsequent study found no difference in nasal swab results between patients using versus not using PAP (5). Multiple studies have found swabs taken from the mask and hose grow typical skin flora, most commonly coagulase-negative Staphylococcus (5, 6). Similarly, the microbes identified from the air blowing out of used PAP devices are nonpathogenic and not substantially different from a brand new device (7).

The humidifier chamber of PAP machines has also been proposed to be a source of nosocomial infections. Swabs of humidifier chambers are more likely to grow gram-negative bacteria than other parts of the PAP device. However, it is unclear that humidifier colonization increases the risk of infection. There is no difference in sinusitis symptoms between PAP users with and without humidifier colonization (6). Similarly, studies have not found an increased risk of respiratory infections in PAP use with a humidifier versus without one (5, 8). There have been two case reports of Legionella colonization of a humidifier chamber leading to pneumonia (9, 10). However, Legionella colonization is rare because no study that prospectively swabbed humidifier chambers has grown this organism (5, 6). Beyond the two cases of Legionella, only two additional case reports of infection tied to PAP equipment have been published: one caused by Pneumocystis jiroveci in a normal host and one because of Mycobacterium gordonae in an immunosuppressed patient (11, 12). Given the millions of PAP devices sold worldwide each year, the overall risk of serious infections related to PAP equipment appears low.

Studies evaluating the frequency of respiratory tract infections have found no increased risk of sinusitis, bronchitis, or pneumonia among patients with OSA initiating PAP therapy versus those not treated with PAP (5, 13). Similarly, a study of 482 newly diagnosed patients with OSA found no difference in respiratory infection rates among those accepting versus declining PAP or in those adherent versus nonadherent with PAP (14). Furthermore, no change in the rate of infections was found in the 2 years after initiating PAP compared with the 2 years before. One study did identify a greater rate of rhinitis symptoms in PAP users compared with nonusers, but this was based on self-report, and no attempt to differentiate infectious from noninfectious causes was made (13). In contrast, multiple studies have suggested that increased PAP use is associated with decreased risk of viral respiratory infections (15–17).

Current Recommendations about Cleaning Do Not Match the Evidence Base

Thus, there is little scientific evidence to support the hypothesis that infections will occur if frequent cleaning of PAP equipment is not performed. Nevertheless, this assertion has been widely disseminated by durable medical equipment (DME) providers and physician practices. Widely trusted sources such as Harvard, Cornell, and the Mayo Clinic have highlighted serious risks of not cleaning and therefore recommend unrealistic cleaning regimens (3, 18, 19). The American Thoracic Society has published a patient education sheet promoting manufacturer-recommended cleaning instructions (20). Even the U.S. Food and Drug Administration (FDA) states on a patient-facing website that “[a]ll types of CPAP machines need to be cleaned regularly so that these germs and contaminants do not grow inside your equipment and make you sick” (21).

Aggressive Cleaning Is Burdensome to Patients and Can Reduce Adherence

At the same time that the risks of not cleaning PAP devices have been overestimated, many clinicians underestimate the harms of recommending frequent cleaning. The recommendations promulgated by PAP manufacturers call for disassembling the mask to clean the cushions and emptying the humidifier chamber of excess water and drying completely every day, as well as cleaning the headgear, frame, humidifier chamber, and hose on a weekly basis (22, 23). The burden of following these recommendations is substantial in terms of the time necessary to take apart one’s equipment and preparing a basin to wash the equipment. The requirement to allow equipment to dry before next use requires patients to clean in the morning, a typically rushed time. One study found that 33% of PAP users reported difficulty with cleaning their equipment (24). It is no surprise that adherence to recommendations is poor. In one survey, only 62% of patients reported cleaning their mask even once, 52% the humidifier chamber, and only 17% had ever cleaned the hose (5).

Although clinicians may believe that setting a high standard for cleaning has little downside, focus groups of patients with OSA have identified the risk of infection and burdensome cleaning as an important barrier to PAP adherence (25). Patients knowing they will not follow the cleaning regimen decide to forego PAP use rather than put themselves at perceived risk of infection by wearing a “dirty” mask. Further evidence of the burden placed on patients is apparent from the profitability of third-party PAP cleaning systems. Numerous PAP cleaners using ozone gas or ultraviolet light to kill germs on the PAP device are marketed to patients with OSA. The manufacturers of these products feed off the fear of germs on PAP machines and the convenience of cleaning with these devices despite a lack of evidence that they reduce infections or are even safe (26). In fact, there is increasing evidence of harm from these devices. Ozone gas is a known lung irritant, and the FDA received 11 reports of adverse effects from ozone cleaners ranging from headache and nasal irritation to cough, breathing difficulties, and asthma exacerbations between 2017 and 2019 (26). The reports of adverse events from ozone PAP cleaners have skyrocketed since a safety warning was issued by the FDA in 2020 (27). These currently unregulated PAP cleaning devices cause financial harm as patients feel pressured to purchase these devices out of pocket as well as medical harm from both direct toxic effects of the cleaning agents and indirect effects because the cleaning agents have been implicated in foam degradation and toxin release from PAP devices (28).

Another concern is that barriers caused by cleaning may exacerbate disparities in OSA care. African Americans with OSA have lower PAP adherence, and the burdens of cleaning may contribute to this disparity. There is some evidence that African Americans have greater concerns about cleanliness (29). Certainly, greater mistrust of the healthcare system because of prior abuses can lead to greater concerns about side effects such as nosocomial infections. Furthermore, individuals of lower socioeconomic status have reduced ability to devote the time and resources necessary to follow aggressive cleaning regimens.

Key Stakeholders Have Secondary Motivations to Exaggerate Infection Risks

There are a number of reasons why aggressive cleaning recommendations may be emphasized by PAP manufacturers and DME providers. The most important rationale for manufacturers is to minimize legal liability for any adverse events. In addition, highlighting the risk of infection justifies frequent replacement of PAP disposables, thereby increasing sales for both manufacturers and DME providers. Given that virtually no patient can faithfully follow the frequency of cleaning recommended by manufacturers, patients can more easily be convinced to replace PAP equipment to prevent themselves from becoming sick.

Physicians Need to Ensure Accurate Patient Education about Cleaning

Given the conflicts of interest of other stakeholders, it is imperative that physicians and their professional organizations take the lead in defining best cleaning practices. Physicians can directly address cleaning with their patients. Professional organizations such as the American Thoracic Society should revise educational material based on careful evidence-based review and actively disseminate this information. This includes updating websites with accurate information and ensuring active education of trainees, including those in ancillary fields such as respiratory therapists and sleep technicians. Partnering with patient organizations would help ensure that information is designed to meet patient needs and is available in places patients go to obtain information. It is also important for professional organizations to engage PAP manufacturers and DME providers to make clear expectations regarding best practices. For example, DME providers that continue to market and sell ozone cleaners to patients should be boycotted. Finally, stakeholders need to engage in legislative advocacy to provide the FDA with statutory authority to regulate the sale of PAP accessories such as ozone cleaners. Altering the belief structure around PAP cleaning and safety will require sustained efforts, so it will be vital to remain focused to effect meaningful change that benefits our patients.