Introduction
Coronavirus disease 2019 (Covid-19) is an acute respiratory syndrome caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), which emerged in Wuhan, China in 2019, and was declared a pandemic in March 2020.Reference Kunstler, Newton, Hill, Ferguson, Hore and Mitchell1,Reference Tabatabaeizadeh2 The main modes of transmission of the virus are droplet, contact, and airborne transmission during aerosol-generating procedures.Reference Tabatabaeizadeh2,3 Droplet transmission occurs due to contact with symptomatic individuals at close distances (less than 1 m).3,Reference Wang, Pan, Tang, Ji and Shi4 Airborne transmission occurs by respiratory droplets smaller than 5 μm and can remain in the air for a long time.Reference Tabatabaeizadeh2,3 Aerosol contamination may occur in procedures such as intubation, tracheostomy opening, cardiac resuscitation and bronchoscopy.Reference Bartoszko, Farooqi, Alhazzani and Loeb5
As a consequence of the Covid-19 pandemic, the wearing of masks is now crucial and is accepted by the majority of the population as a reasonable measure for preventing infection. Masks are used as a method of protection because transmission can occur from asymptomatic and mildly symptomatic individuals.Reference Wang, Pan, Tang, Ji and Shi4 The use of masks varies according to the environment and the policies of individual countries.Reference Azap and Erdinç6 Data regarding the symptoms that appear after using masks are lacking.
Mask use may influence Eustachian tube functions as a result of changes in upper respiratory tract pressures during mask use. In terms of classic aetiology, Eustachian tube dysfunction may develop in cases of obstruction, dilatation, barotrauma and patulous Eustachian tube conditions.Reference Tysome and Sudhoff7–Reference Maddineni and Ahmad9 Symptoms such as auditory fullness, pain, bursting symptoms, pressure in the ear, a crackling-rustling sound, autophony, a muffled sound, and feeling under water can be observed.Reference Tysome and Sudhoff7–Reference Lim, Seet, Lee, Wilder-Smith, Chuah and Ong10
Eustachian tube dysfunction may develop after mask use because of changes in carbon dioxide (CO2) pressure, an increase in respiratory resistance and changes in mucociliary function. In the literature, complaints such as headache, respiratory distress, drowsiness, dizziness and pressure sores on the face have been reported in healthcare workers using N95/filtering facepiece type 2 (FFP2) masks.Reference Kunstler, Newton, Hill, Ferguson, Hore and Mitchell1,Reference Lim, Seet, Lee, Wilder-Smith, Chuah and Ong10
This study aimed to investigate the effects of using different mask types on Eustachian tube dysfunction related symptoms and quality of life.
Materials and methods
The present study was carried out in the otorhinolaryngology clinic of a training and research hospital after it was approved by the ethics committee of the local council (approval number: 2011-KAEK-25 2021/12-15). The study was conducted in accordance with the requirements of the Declaration of Helsinki principles. The procedure was explained to participants and their written informed consent was obtained before the study was initiated.
Study design and participant selection
This prospective clinical study enrolled 133 participants referred to our out-patient clinics because of any otolaryngological symptoms after mask use between January 2022 and January 2023.
Among the 133 participants, after the application of the below inclusion and exclusion criteria, 5 participants with occupational risk factors for Eustachian tube dysfunction, 2 participants with allergic rhinoconjunctivitis, 4 participants with gastroesophageal reflux disease, 2 participants with laryngopharyngeal reflux disease and 6 participants with co-morbidities were excluded from the study. Finally, a total of 114 participants were included in the study.
Healthcare workers used masks for 3 hours in the morning (09.00–12.00) and 3 hours in the afternoon (13.00–16.00) during their shifts for at least one year. The tests were performed on the subjects in the resting, effortless, sitting position.
Inclusion criteria
These included: (1) healthcare workers aged 18–50 years who use surgical masks for at least 6 hours per day; (2) healthcare workers aged 18–50 years who use N95/FFP2 masks for at least 6 hours per day; (3) individuals aged 18–50 years who use surgical masks less than 6 hours per day and are not healthcare workers; and (4) no additional condition or disease that may cause Eustachian tube dysfunction (e.g. continuous positive airway pressure use due to obstructive sleep apnoea, cleft palate, maxillofacial dysmorphic or syndromic findings, nasal pathology, and allergy).
Exclusion criteria
These included: (1) individuals aged under 18 years or over 50 years; (2) individuals with acute or active upper respiratory tract infection; (3) individuals who received treatment for otitis media in the previous month; (4) individuals with a pathological finding other than Eustachian dysfunction in their otological examination; (5) individuals with external auditory canal anomalies who were not suitable for tympanometry in the ear canal; and (6) individuals with a history of medical or surgical treatment for Eustachian tube dysfunction.
Physical examination
All participants underwent a full ENT examination. The presence or absence of symptoms of autophony, aural fullness, and hearing one's own breath in the ear were noted before and after the use of the mask.
Tympanometry
The tympanometer used was a Maico MI34 device (Maico Diagnostics, Eden Prairie, Minnesota, USA). Tympanometry was performed at 226 Hz in the pressure range of +200 to −400 daPa using probe tone stimulators. Modified Jerger tympanogram classification was used (types A, B, C1 and C2). Basal mean peak pressure values and pressures after a Valsalva manoeuvre were recorded.
Eustachian Tube Dysfunction Questionnaire-7
The Eustachian Tube Dysfunction Questionnaire, consisting of seven questions, was completed before and after mask use. Scores range from 7 to 49 points.Reference Teixeira, Swarts and Alper11 In order to prevent recall bias, symptoms present in the last one month were questioned at both assessment timepoints.
Statistical analysis
Statistical analyses were performed using SPSS Statistics for Windows, version 22.0 (IBM, Armonk, New York, USA). The normality of distributions of the variables was examined by the Shapiro–Wilk test. As the variables were not distributed normally, continuous variables were expressed as median (range) values. Categorical variables were expressed in numbers and related percentages. In the comparison of continuous variables between study groups, the Kruskal–Wallis test was used, and post-hoc subgroup analysis was performed using the Dunn–Bonferroni test. Comparisons of categorical variables between groups were performed using the chi-square and Fisher–Freeman–Halton tests. The presence of categorical variables before and after mask use was analysed using the McNemar test. Spearman's correlation analysis was used to examine whether tympanometric peak pressure values and questionnaire scores were in agreement. The level of p < 0.05 was taken as the limit of significance in analytical relationships.
Results
In this study, 44 men (38.6 per cent) and 70 women (61.4 per cent) with a mean age of 32 years (range, 21–50 years) were enrolled. The median Eustachian Tube Dysfunction Questionnaire score was 10 (range, 7–30).
Regarding the tympanogram type of the 114 participants, 97 (85.1 per cent) were type A and 17 (14.9 per cent) were type C1 for the right ear, and 99 (86.8 per cent) were type A and 15 (13.2 per cent) were type C1 for the left ear. In healthcare workers who used N95/FFP2 masks for at least 6 hours, 22 (59.5 per cent) tympanograms were type A and 15 (40.5 per cent) were type C1 for the right ear, and 24 (64.9 per cent) were type A and 13 (35.1 per cent) were type C1 for the left ear. In healthcare workers who used surgical masks for at least 6 hours, 33 tympanograms (94.3 per cent) were type A and 2 (5.7 per cent) were type C1 for both ears. For those who used surgical masks for less than 6 hours, 42 tympanograms (100 per cent) were type A for the right and left ears. There were significant changes with respect to tympanogram type in those who used N95/FFP2 masks for at least 6 hours (Table 1).
Table 1. Descriptive and analytic data with comparisons between different mask groups
* Kruskal–Wallis; †chi-square test; ‡Fisher–Freeman–Halton test. FFP = filtering facepiece; ETDQ-7 = Eustachian Tube Dysfunction Questionnaire-7
Pre-mask autophony was present in one (0.9 per cent) of the participants. This participant did not report any other Eustachian tube dysfunction related symptoms; they had no aural fullness in the pre-mask period and no symptoms of hearing their own breathing in the ear in the pre-mask period. Post-mask autophony was present in 10 participants (8.8 per cent), post-mask aural fullness was present in 23 (20.2 per cent) and post-mask self-breathing symptoms were present in 5 individuals (4.4 per cent) (Table 1). There was no difference between the groups in terms of symptoms in the pre-mask period.
In all participants, autophony and aural fullness complaints were higher in the post-mask period than before mask use (p = 0.012 and p < 0.001, respectively, Mc Nemar test). Complaints of hearing their own breath in the ear did not significantly differ (p = 0.063). In the use of surgical mask <6 hours group, no complaint was present in pre-mask period. The complaint of aural fullness was the only symptom significantly observed in the post-mask period (p = 0.031 in surgical mask >6 hours group, p < 0.001 the use of N95/FFP2 mask >6 hours group).
Table 1 shows the analysis done between the groups. The healthcare workers who used N95/FFP2 masks for at least 6 hours per day showed higher incidences of autophony and aural fullness (p = 0.014 and p < 0.001, respectively), while no difference was detected in the symptom of hearing one's own breath in the ear (p = 0.055). Aural fullness was found to be higher in healthcare professionals using N95/FFP2 masks for more than 6 hours per day (p < 0.001) and healthcare workers using surgical masks for more than 6 hours per day (p = 0.031).
Middle-ear peak pressures, for the right and left ears, were higher in healthcare workers who used N95/FFP2 masks for at least 6 hours per day (p < 0.001 and p = 0.003, respectively), compared to healthcare workers who used surgical masks for at least 6 hours per day (p < 0.001 and p = 0.008, respectively) and non-healthcare volunteers who used surgical masks for less than 6 hours per day (p = 0.014 and p = 0.007, respectively).
The Eustachian Tube Dysfunction Questionnaire scores were higher (p < 0.001) in healthcare workers who used N95/FFP2 masks for at least 6 hours per day, compared to healthcare workers who used surgical masks for at least 6 hours per day (p = 0.007) and non-healthcare volunteers who used surgical masks for less than 6 hours per day (p < 0.001). Healthcare workers who used surgical masks for at least 6 hours also had higher Eustachian Tube Dysfunction Questionnaire scores than non-healthcare volunteers who wore surgical masks for less than 6 hours per day (p < 0.001).
There was a weak negative relationship between middle-ear peak pressures and Eustachian Tube Dysfunction Questionnaire scores (rho = −0.369, p < 0.001 for the right ear; rho = −0.376, p < 0.001 for the left ear).
Discussion
In this study, the effects on Eustachian tube dysfunction of using different types of masks (N95/FFP2 and surgical masks) with different durations of surgical mask use were investigated. The main findings of the study were that the healthcare workers using N95/FFP2 masks showed significantly higher rates of autophony and aural fullness complaints, lower middle-ear peak pressure values, and worse Eustachian Tube Dysfunction Questionnaire-7 scores compared to other participants. The Eustachian Tube Dysfunction Questionnaire scores were worse in all healthcare workers using N95/FFP2 or surgical masks compared to other participants.
The most bothersome symptoms reported in the literature are nasal congestion, nose itching, ear pain, ear itching, and difficulty in breathing, talking and understanding speech. Individuals seek healthcare because of mask-related symptoms, although they take precautions; they prefer intermittent mask use and may even stop using masks.Reference Vakharia, Jani, Yadav and Kurian12–Reference Kisielinski, Giboni, Prescher, Klosterhalfen, Graessel and Funken17 A statistically significant increase in speech reception threshold and a decrease in speech discrimination score have been reported while using N95 respirators.Reference Bandaru, Augustine, Lepcha, Sebastian, Gowri and Philip18
The type of mask used by healthcare workers during the Covid-19 pandemic period varies according to the departments they work in and the procedures they perform. The surgical mask protects the individual from contamination where there is no direct contact and there is safe distance to the source. However, it does not protect from infectious aerosols, as it porous and permeable to secretions. Thus, it is recommended that N95/FFP2 masks are used for aerosol-generating procedures, with surgical masks being used by those who have adequate distance to the infectious index, or who have their own respiratory problems and who are sick at home or in hospital.Reference Bartoszko, Farooqi, Alhazzani and Loeb5,Reference Azap and Erdinç6 A surgical mask can also be worn over N95/FFP2 masks, to prevent surface contamination and waste of an N95/FFP2 mask.19,Reference Huang and Huang20
It has been reported that mask use causes physiological, psychological, somatic and pathological changes. Some of the changes reported include increases in respiratory rate, heart rate, dead space volume, respiratory resistance and the amount of CO2 in the blood.Reference Bandaru, Augustine, Lepcha, Sebastian, Gowri and Philip18 Few previous studies have investigated the associations between mask use and upper respiratory tract physiology and symptoms.
Lim et al. reported that long-term (more than 4 hours) N95/FFP2 mask use causes hypercapnia and hypoxia, risk factors for the development of headache.Reference Lim, Seet, Lee, Wilder-Smith, Chuah and Ong10 Huang and Huang reported that the use of N95/FFP2 masks increased respiratory resistance and decreased the oxygen value in inhaled air.Reference Huang and Huang20 Respiratory pressure increases with greater oxygen consumption associated with mask use.Reference Kisielinski, Giboni, Prescher, Klosterhalfen, Graessel and Funken17,Reference Sinkule, Powell and Goss21 Lee and Wang reported an average increase of 126 per cent and 122 per cent in inspiratory and expiratory flow resistances, respectively, with the use of N95/FFP2 masks, and increased respiratory resistance has been suggested to affect nasal airflow.Reference Lee and Wang22
Kunstler et al. reported that complaints such as headache, respiratory distress, drowsiness, dizziness and facial pressure sores developed more frequently in healthcare workers wearing N95/FFP2 masks compared to surgical masks.Reference Kunstler, Newton, Hill, Ferguson, Hore and Mitchell1 Koseoglu et al. investigated otolaryngological symptoms of mask-wearing in the Covid-19 era, but they did not mention Eustachian tube dysfunction symptoms.Reference Koseoglu, Cakıcı, Demirtaş, Gokdogan and Ucuncu16 In this study, healthcare workers using N95/FFP2 masks more frequently had complaints of autophony and aural fullness; aural fullness is suggested to be a cardinal symptom for Eustachian tube dysfunction.
There are different types of Eustachian tube dysfunction, defined as obstructive, dilatatory, patulous and barotrauma-related.Reference Tysome and Sudhoff7–Reference Maddineni and Ahmad9 Eustachian tube dysfunction may develop due to pressure changes and respiratory resistance associated with mask use.Reference Sinkule, Powell and Goss21 In this study, increases in Eustachian tube dysfunction symptoms and Eustachian Tube Dysfunction Questionnaire-7 scores were observed in healthcare workers using masks compared to the non-healthcare volunteer group. This can be explained by the increased respiratory pressure and increased respiratory resistance resulting from the use of masks.
Another mechanism that may affect Eustachian tube function is impaired mucociliary clearance. Mucociliary clearance is a defence mechanism of the upper respiratory tract. Yildiz et al. reported an increase in nasal mucociliary clearance time and sinonasal obstruction symptoms associated with the use of filtering facepiece type 3 (FFP3) masks.Reference Yildiz, Yankuncu, Toros and Karaca15 Cengiz and Can reported that the use of N95/FFP2 masks leads to deterioration in mucociliary clearance function, while the use of surgical masks does not affect mucociliary clearance function.Reference Cengiz and Can14 In this study, tests for mucociliary clearance were not conducted, as we excluded patients with otitis media with effusion in order to eradicate confounding factors for the development of Eustachian tube dysfunction.
In this study, greater increases in aural fullness, autophony and Eustachian Tube Dysfunction Questionnaire-7 scores were observed, especially in those using N95/FFP2 masks, compared to the group using surgical masks. We think that these increases observed in N95/FFP2 mask users are because of the long duration of mask use and the type of mask used.
In this study, healthcare workers worked actively for at least 6 hours during working hours. Nanda et al. reported that there were no significant changes in vital signs and inhaled CO2 or oxygen pressure when using a N95/FFP2 mask for 45 minutes followed by a 15-minute break.Reference Nanda, Sangineni, Pakhare, Ramachandran and Chellaboyina23 In a study by Singh et al., more than half of healthcare workers (86.9 per cent) used a mask for at least 4 hours.Reference Singh, Nandini, Phulsunga, Gupta, Naik and Goel24 All participants were wearing N95 masks; there was no control group and no surgical mask group.
• Autophony was greater in healthcare workers using N95/filtering facepiece type 2 (FFP2) masks for at least 6 hours per day than in the non-healthcare group
• Aural fullness was greater in healthcare workers who used N95/FFP2 masks or surgical masks for at least 6 hours per day
• Autophony and aural fullness complaints were significantly greater post-mask use rather than pre-mask use
• Middle-ear peak pressures were higher in healthcare workers who used N95/FFP2 masks for at least 6 hours per day, compared to all surgical mask users
• Eustachian Tube Dysfunction Questionnaire scores were higher in healthcare workers who used N95/FFP2 masks for at least 6 hours per day, compared to all surgical mask users
There have been some previous studies on the short-term use of masks. The strength of this study was that healthcare workers were included in the study after the long-term use of masks. The limitation of this study is that mucociliary function was not examined, as patients with otitis media with effusion were excluded. Another limitation was that tympanometry was not performed under the Valsalva manoeuvre. We might assume that 85.1 per cent of the right ears and 86.8 per cent of the left ears had a type A tympanogram, because conventional tympanometry was performed without Eustachian tube manoeuvres. We suggest that further studies with larger sample sizes are conducted to investigate the effects of mask use on upper respiratory tract physiology.
Conclusion
The use of either N95/FFP2 or surgical masks leads to Eustachian tube dysfunction related symptoms and deterioration in quality of life. The use of N95/FFP2 masks causes higher rates of autophony and aural fullness complaints and worse Eustachian tube dysfunction scores compared to the use of surgical masks.
Competing interest
None declared
