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Background: To improve the understanding of the thermodynamics and performance of small passive hygroscopic Heat and Moisture Exchangers (HMEs), a computer model simulating HME function is required. Methods: We developed a numerical HME model to calculate the HME's water and heat exchange. The model was tuned and verified with experimental data and validated by applying it to HME design variations. Results: Verification of the model's results to the experimental data shows that the tuned model yields reliable results. The mass of the core, which determines the HME's total heat capacity, is the most important parameter influencing the performance of passive HMEs. Conclusions: Increasing the HME's diameter is an effective way to improve an HME, as it yields higher performance and lowers breathing resistance. HMEs intended for use in warm or dry climates should contain more and those for use in cold humid climates should contain less hygroscopic salt.

Objective Voice prosthesis leakage significantly affects the quality of life of patients undergoing laryngectomy, causing insecurity and frequent unplanned hospital visits and costs. In this study, the concept of prophylactic voice prosthesis replacement was explored to prevent leakages. Study Design Retrospective cohort study. Setting Tertiary hospital. Methods This study included all patients who underwent laryngectomy between 2000 and 2012 in the Netherlands Cancer Institute. Device lifetimes and voice prosthesis replacements of a retrospective cohort were used to calculate the number of needed voice prostheses per patient per year to prevent 70% of the leakages by prophylactic replacement. Various strategies for the timing of prophylactic replacement were considered: adaptive strategies based on the individual patient's history of replacement and fixed strategies based on the results of patients with similar voice prosthesis or treatment characteristics. Results Patients used a median 3.4 voice prostheses per year (range, 0.1-48.1). We found high inter- and intrapatient variability in device lifetime. When prophylactic replacement is applied, this would become a median 9.4 voice prostheses per year, which means replacement every 38 days, implying >6 additional voice prostheses per patient per year. The individual adaptive model showed that preventing 70% of the leakages was impossible for most patients and only a median 25% can be prevented. Monte-Carlo simulations showed that prophylactic replacement is not feasible due to the high coefficient of variation (SD/mean) in device lifetime. Conclusion Based on our simulations, prophylactic replacement of voice prostheses is not feasible due to high inter- and intrapatient variation in device lifetime.

Wound healing is a complex biological process subject to complications that might jeopardize the patient's postoperative care. Appropriately approaching surgical wounds after head and neck surgery positively influences the quality and speed of wound healing and increases patient comfort. A large variety of dressing materials currently exist that allow the care of different types of wounds. Nevertheless, there is limited literature on the most suitable types of dressings after head and neck surgery. The objective of the present article is to review the most commonly used wound dressings, their benefits, indications, and disadvantages, and to provide a systematic approach for wound care within the head and neck. The Woundcare Consultant Society distinguishes wounds into three groups: black, yellow, and red. Each type of wound represents distinctive underlying pathophysiological processes with unique needs. Utilizing this classification along with the TIME model allows a proper characterization of wounds and the identification of potential healing barriers. This evidence-based and systematic approach can facilitate and guide the head and neck surgeon in selecting a wound dressing upon acknowledging their properties, which are herein reviewed and exemplified with representative cases.

Objective: This study aims to assess the product performance of a new moldable peristomal adhesive with corresponding heating pad designed to facilitate and improve automatic speaking valve (ASV) fixation for hands-free speech in laryngectomized patients. Methods: Twenty laryngectomized patients, all regular adhesive users with prior ASV experience, were included. Study-specific questionnaires were used for data collection at baseline and after two weeks of moldable adhesive use. The primary outcome parameters were adhesive lifetime during hands-free speech, use and duration of hands-free speech, and patient preference. Additional outcome parameters were satisfaction, comfort, fit, and usability. Results: The moldable adhesive enabled ASV fixation adequate for hands-free speech in the majority of participants. Overall, the moldable adhesive significantly increased adhesive lifetime and duration of hands-free speech compared to participants' baseline adhesives (p < 0.05), regardless of stoma depth, skin irritation, or regular use of hands-free speech at baseline. The participants who preferred the moldable adhesive (55% of participants) experienced a significant increase in the adhesive lifetime (median of 24 h, range 8–144 h) and improved comfort, fit, and ease of speech. Conclusion: The moldable adhesive's lifetime and functional aspects, including the ease of use and custom fit, are encouraging outcomes and enable more laryngectomized patients to use hands-free speech more regularly. Level of Evidence: 4 Laryngoscope, 2023.