A mixed methods study on the expected effectiveness of new heat and moisture exchangers for laryngectomized patients in Germany (Preprint)

BACKGROUND Notwithstanding the benefits of Heat and Moisture Exchangers (HMEs) in both clinical research and practice, a gap exists between the optimal physiological humidification levels by the nasal function and the humidification capacity by HMEs for patients after total laryngectomy. In this study, five new HMEs (Provox® Life™) specialized for situational use with improved humidification capacities were evaluated. OBJECTIVE 1. To evaluate the effectiveness of existing HMEs; 2. to assess the potential effectiveness of the new HMEs; 3. to elicit expert judgments on the expected effectiveness and impact on healthcare use of the new HMEs. METHODS First, a rapid literature review (RLR) was performed identifying evidence on the clinical outcomes, health outcomes, and complications of HMEs in laryngectomised patients. Second, semi-structured interviews with German experts (n=4) were conducted to validate the findings of the RLR and to identify reasonable expectations regarding the potential of the new HMEs. Third, structured expert elicitation (SEE) among German experts (n=19) was used to generate quantitative evidence on the expected effectiveness of the new HMEs on clinical and health outcomes. RESULTS The RLR included ten studies and demonstrated that HME use by patients has advantages compared to no HME use concerning breathing resistance, tracheal dryness and irritation, mucus production and plugging, frequency of cough and forced expectorations, sleep quality, voice quality, use of physiotherapy, tracheobronchitis and/or pneumonia episodes, and ultimately quality of life and patient satisfaction. From the expert interviews and the SEE, it was found that on average, experts expect that the new HMEs compared to second generation HMEs will lead to a decrease in tracheal dryness/irritation (51%±24% of patients), mucus plug events (33%±32% of patients), mucus production (53%±22% of patients), physiotherapy (0.74±0.70 days), pulmonary infections (34%±32%), and an increase or improvement in speech quality (25%±23% of patients), social contacts (13%±18%), QoL (33%±30%) and patient satisfaction (44%±30%). An improvement in breathing (53%±28% of patients) and shortness of breath (48%±25% of patients) is expected. The average number of daily cough periods is expected to be 2.95 (±1.61) and the number of forced expectorations 2.46 (±1.42). Experts expect that on average less than half of patients will experience sleeping problems (48%±22%), and psychosocial problems (24%±20%). CONCLUSIONS According to German experts, it is expected that the new HMEs with improved humidification levels, will lead to additional (clinical) effectiveness on pulmonary health, and an improved overall QoL of patients compared to HMEs currently available.