INTRODUCTION
People with total laryngectomy (PTL) have a permanent separation of the trachea and oesophagus and rely on a surgically created neck tracheostoma to breathe. This altered anatomy results in a loss of filtering and humidification capacity of the upper airways and consequent reduced respiratory resistance. The detrimental impact of this on pulmonary health is well-established, with increased bronchial secretions and reduced mucociliary clearance resulting in increased risk of chest infections, reduced respiratory capacity and negative effects on quality of life1,2. Additionally, the permanent tracheostoma leaves PTL at risk of airway invasion by airborne particles or foreign bodies. PTL are advised to use a tracheostoma cover to protect the airway and to optimise pulmonary health.
A number of different tracheostoma covers are available: simple covers with no humidification properties (e.g. scarves); foam-based covers or bibs that offer some humidification3; closed-system heat moisture exchange (HME) devices comprising a filter cassette secured with an adhesive baseplate or laryngectomy tube (Figure 1). Closed-system HMEs have been available on prescription in the UK since the mid-1990s and are now considered the gold standard for humidification for PTL. UK guidelines recommend the use of HME as soon as possible post-surgery4 and initiation of HME use at day one post-surgery has been reported5.
While closed system HMEs are more expensive than alternative stoma covers3, the benefits are well recognised including reduced coughing, shortness of breath, mucous production, plug formation and chest infections5,6,7. There is a correlation between duration of HME use and pulmonary benefit8.  HME use has been found to significantly enhance quality of life for PTL9, and can offer PTL with surgical voice restoration (SVR) improved digital occlusion for voicing and better speech intelligibility8,9.
Despite evidence of efficacy, variable compliance rates with HME use have been reported, from 35% to 83%10,5. Reported reasons for resistance to HME use include excessive mucus production, blockage of the filter and poor baseplate seal6.  In some healthcare systems the financial burden of HME use may be a barrier3. Additional factors that could influence use of HME include patient age, time elapsed since surgery, neck contour, and the recommendations from different health services, clinicians and patient communities.
With the onset of the Covid-19 pandemic in March 2020, PTL were thought to be a high-risk group for contracting and transmitting Covid-19 infection through respiratory droplet formation and aerosolisation due to their altered airways11,13.  This paper reports on the use of tracheostoma  covers as reported by patients and/or their clinicians during a UK-wide audit of PTL during the first UK national lockdown period. The audit was initiated in response to queries regarding the specific risks associated with Covid-19 for PTL. Data on shielding, hospital admission and mortality have been reported previously13. The objectives of the current paper are to report on the following:
The usage of tracheostoma covers by PTL in the UK, specifically use of a commercially available closed-system HME (termed “HME” for this analysis) versus all alternatives (termed “non-HME” for this analysis).
The factors that may influence HME use by PTL in the UK.
Based on literature and clinical experience, we postulate the following factors may influence HME use in the UK: age, gender, time elapsed since surgery, distance from the treating centre, employment status, living circumstances and primary communication method.