key: cord-0875023-92jejfv7
authors: Cengiz, Ceyhun; Can, İlknur Haberal
title: The effect of N95 and surgical masks on mucociliary clearance function and sinonasal complaints
date: 2021-04-28
journal: Eur Arch Otorhinolaryngol
DOI: 10.1007/s00405-021-06838-x
sha: 729ddfecf01cd2d4d4df0b58ebe86d8fb27d4fe6
doc_id: 875023
cord_uid: 92jejfv7

PURPOSE: The aim of this study was to reveal the effect of N95 and surgical masks on mucociliary clearance function and sinonasal complaints. METHODS: Sixty participants were enrolled in this study, including 30 people in N95 mask group and 30 people in surgical mask group. Two interviews, three days apart, were performed with all participants. The participants were asked not to use any mask before the first interview while they were asked to use the determined mask just before the second interview for 8 h. In both interviews, the mucociliary clearance times (MCTs) were measured and participants were asked to score ten distinct sinonasal complaints using visual analog scale (VAS). Data obtained from first interview were named pre-mask data, data obtained from second interview were called after-mask data. In both groups, pre-mask MCTs and VAS scores were compared with after-mask MCTs and VAS scores. RESULTS: After-mask MCTs (mean = 13.03 ± 6.05 min) were significantly longer than pre-mask MCTs (mean = 10.19 ± 4.21 min) in N95 mask group (p = 0.002). No significant difference was found between after-mask and pre-mask MCTs (mean = 12.05 ± 5.21 min, mean = 11.00 ± 5.44 min, respectively) in surgical mask group (p = 0.234). When after-mask VAS scores were compared with pre-mask VAS scores, it was found that N95 mask use increased nasal blockage and postnasal discharge, surgical mask usage increased nasal blockage. CONCLUSION: While the use of N95 mask leads to nasal blockage and postnasal discharge, surgical mask use results in nasal blockage. N95 masks cause impairment in mucociliary clearance function. But all these effects are mild. Surgical masks have not been found to have any effect on mucociliary clearance function.

N95 and surgical masks are among the personal protective equipment that are commonly used. The importance of these equipment is better appreciated in the COVID-19 pandemic. During this pandemic, healthcare professionals had to wear the N95 and surgical mask for long hours. It is also recommended that the masks be used by the people in public areas due to the pandemic. During the use of these masks, the breathing takes place through the pores on the masks. Since respiration made in this way is not a physiological respiration, some effects in the body are inevitable. The literature review revealed that there are many studies on how masks affect the systems in the body [1, 2] . On the other hand, there are small number studies on how the various types of masks affect the upper respiratory tract physiology and complaints related to the upper respiratory tract.

Mucociliary clearance function is a crucial defense mechanism of the nose and paranasal sinuses. Disruption of this function causes accumulation of secretions and secondary infections [3] . Temperature, humidity, pH and partial oxygen pressure are factors that affect this function [4] . Furthermore, it has been found that this function is impaired in many pathologies that affect the upper respiratory tract directly or indirectly [5, 6] . During breathing through masks, the humidity, temperature, and resistance of inhaled air are altered [7] . Changes in all these parameters may affect mucociliary clearance function. In addition, breathing through these masks for a long time may cause an increase in complaints related to the upper respiratory tract.

In this study, the effect of N95 and surgical masks on mucociliary clearance function and sinonasalcomplaints was investigated.

This study was conducted in the Department of Otorhinolaryngology of XXXXXXX Yozgat Bozok University after the approval of the local ethics committee. Sixty participants were enrolled in the study, including 30 individuals in N95 mask group and 30 individuals in surgical mask group. Written informed consent was obtained from all participants before enrollment in the study. Those with a diagnosis of nasal polyposis, sinusitis, allergic rhinitis, vasomotor rhinitis, diabetes, kidney failure, smokers, a history of nasal surgery and those younger than 18 and older than 65 years were excluded from the study. Participants were randomly allocated to the groups. Fifteen of the N95 mask group were women and 15 were men. Of the surgical mask group, 16 were women and 14 were men. The mean age of the N95 mask group was 29.17 ± 3.98, while the average age of the surgical mask group was 28.03 ± 4.30. There was no difference between the two groups in terms of age and gender (For gender p = 0.796, for age p = 0.294). Two interviews were performed with all participants, three days apart. Before the first interview, the participants were asked not to use any type of mask. Just before the second interview, they were asked to wear the specified mask type (N95 or surgical mask) for 8 h. In both interviews, the mucociliary clearance function of the participants was evaluated and they were asked to score determined sinonasal complaints according to their feelings during the interview using VAS (0 = No complaints, 10 = the worst possible level). The data obtained from the first interview were named pre-mask data, and the data obtained from the second interview were called aftermask data. Mucociliary clearance function was evaluated using the saccharin test. This test was carried out by the same otorhinolaryngologist. The saccharin test was applied from the same nasal passage in both interviews. Participants were asked not to eat or drink within one hour before the test. During the test, the participants were told to stay in an upright position, not to blow their nose or sniff. A 1-mmwide piece of sodium saccharin was placed on the anteromedial surface of the inferior concha. MCT was accepted as the time from tablet insertion until the sugar was tasted. In addition, the participants were asked to rate their complaints of need to blow nose, nasal blockage, sneezing, runny nose, cough, postnasal discharge, thick nasal discharge, ear fullness, ear pain, facial pain/pressure using VAS, according to what they felt during the first and second interviews. The mean MCT and the mean VAS score for each complaint in the N95 and surgical mask group at the second interview (after-mask) were compared with those obtained in the first interview (pre-mask). The aim of the study was to reveal the effect of N95 and surgical mask on mucociliary clearance function and sinonasal complaints.

Statistical analyses were performed using the Statistical Package for Social Sciences (SPSS) version 15. The variables were investigated using visual (histograms, probability plots) and analytical methods (Kolmogorov-Smirnov test) to determine whether or not they are normally distributed. Paired samples t test/Wilcoxon signed-rank test was run to compare the data at two time points (pre-mask and aftermask) for MCT and VAS scores of sinonasal complaints in N95 mask group and surgical mask group. A p value of less than 0.05 was considered to show a statistically significant result.

In the N95 mask group, pre-mask mean MCT was 10.19 ± 4.21 min. and aftermask mean MCT was 13.03 ± 6.05 min. This difference was statistically significant (p = 0.002, Table 1 ). There was no statistically significant difference between the pre-mask mean MCT (11.00 ± 5.44 min.) and after-mask mean MCT (12.05 ± 5.21 min.) in the surgical mask group (p = 0.234, Table 1 ).

After-mask mean VAS scores of nasal blockage and postnasal discharge complaints (3.27 ± 2.97, 2.90 ± 2.88, respectively) were higher than pre-mask mean VAS scores (1.97 ± 2.18, 2.13 ± 2.44, respectively) in the N95 mask group. These differences were also statistically significant (p = 0.010, p = 0.015, respectively, Table 2 ). Similarly, in the surgical mask group, after-mask mean VAS score of the nasal blockage complaint (3.97 ± 2.48) was statistically significantly higher than pre-mask mean VAS score of this complaint (3.67 ± 2.38, p = 0.037, Table 2 ). In the N95 mask group, there was no statistically significant difference between pre-mask mean VAS scores of need to blow nose, sneezing, runny nose, cough, thick nasal discharge, ear fullness, ear pain, facial pain/pressure and after-mask mean VAS scores of these complaints (Table 2) .

There was no statistically significant difference between pre-mask mean VAS scores of need to blow nose, sneezing, runny nose, cough, postnasal discharge, thick nasal discharge, ear fullness, ear pain, facial pain/pressure complaints and after-mask mean VAS scores of these complaints in the surgical mask group (Table 2 ).

N95 and surgical mask types have multiple overlapping layers of polypropylene [8, 9] . These fiber structures not only provide mechanical filtration, but also contribute to filtration by creating an electrostatic charge [10, 11] . N95 and surgical masks can be used separately or by wearing a surgical mask on the N95 mask to prevent surface contamination [12] . A surgical mask protects the patient and the surgical area from contamination, however, it does not protect the person from infectious aerosols. The N95 mask is designed to protect the person from infectious agents [13] . During the use of masks, air passes through a narrow passage and breathing pressure, breathing resistance and breathing quality are affected [14] . Therefore, besides the filtration capacity, the breathability of the masks is also crucial [15] . It has been suggested that breathability will not be altered if the flow rate of the air passing through the mask is above 85 L/ min [16] . Lee et al. performed rhinomanometry and nasal spirometry on 14 participants using N 95 masks in their study and found 126% increase in inspiratory flow resistance and 122% increase expiratory flow resistance [17] . In the same study, it is also emphasized that there is an average decrease of 37% in air exchange volume due to the use of N95 masks. In their study, Yang et al. used surface EMG signals and respiratory signals to reveal the breathing resistance that occurs due to the N95 mask [18] . All these studies prove that breathing performed through masks differs from physiological respiration.

There are various studies investigating the effect of this non-physiological breathing pattern through masks on the body systems. In a study investigating the effects of masks, an increase in perceived exertion, perceived shortness of air, complaints of headache, lightheadedness, difficulty in communicating due to prolonged use of mask was found [19] . It has been shown that the use of N95 mask in patients with chronic obstructive pulmonary disease affects breathing frequency, blood oxygen saturation, and carbon dioxide level in exhaled air [20] . Bharatendu et al. suggested that the use of N95 mask may alter cerebral hemodynamics [21] . It was stated in the literature that using personal protective equipment, including the N95 mask, may cause headache [22] . Headache following the use of N95 mask may be due to changes in cerebral hemodynamics. Lässing et al. evaluated the cardiopulmonary and metabolic responses due to the use of surgical masks with impedance cardiography and ergo-spirometry and found that the use of surgical masks increased airway resistance and heart rate [23] . In another study conducted on healthcare professionals working in intensive care, it was shown that the use of personel protective equipment along with a mask caused changes in heart rate, oxygen saturation and perfusion index [24] . Breathing through masks is not a physiological respiration and this type of respiration affects several systems in the body. It is inevitable that the masks will affect the physiology of the upper respiratory tract since the masks completely cover the mouth and nose, which constittue the opening to the upper respiratory tract, and the air inhaled through the masks comes into direct contact with the upper respiratory tract. However, there are small numbers of studies in the literature on how mask types affect sinonasal physiology. There are changes in the temperature and humidity of the inhaled air due to the use of face mask [25] . Furthermore, changes in the temperature, humidity, and pH of the inhaled air affect the cilia functions in the upper respiratory tract. Klimek et al. described a new form of irritant rhinitis due to the use of N95 mask [26] . It is suggested that the irritation here may be due to polypropylene fibers seen in the nasal passage due to the use of N95 mask. In addition, in this study, an increase in complaints of sneezing, itching, nasal blockage and rhinorrhea was observed due to the use of the N95 mask. In a study conducted with 87 participants, who used a N95 mask in the first session and a surgical mask in the second session, received acoustic rhinometry and rhinomanometry tests before and after the mask. No difference was found in terms of mean minimum cross-sectional area values obtained before and after the mask in both sessions [27] . However, in this study, the duration of use of masks was three hours. In another study conducted with 250 participants, the effects of the masks were investigated. Excessive sweating around the mouth was found in 67.6% of the participants, difficulty in breathing on exertion at 58.2%, acne in 56.0%, and itchy nose in 52.0% [28] . In our study, a statistically significant prolongation was noted in MCT in the N95 mask group, whereas no statistically significant prolongation was observed in MCT in the surgical mask group (Table 1 , Fig. 1 ). This elongation detected in the N95 mask group may be due to changes in the temperature, humidity, pH of the breathing air or irritant rhinitis. In addition, this type of mask creates higher resistance to inhaled air, which results in negative pressure on the nasal mucosa. This negative pressure may lead to edema of the nasal mucosa, impaired mucociliary clearance function and increased complaints of nasal blockage. Increasing the temperature of the inhaled air may be associated with the thickening of the postnasal discharge and the increased complaints of postnasal discharge. There was no increase in sinonasal complaints other than nasal blockage in the surgical mask group and mucociliary clearance function was not affected (Tables 1, 2 ). This can be attributed to a more physiological respiration, due to the open edges of the surgical mask.

In the literature, similar to our study, mucociliary clearance function and sinonasal complaints were evaluated in pathologies that directly affect the nasal mucosa, such as acute rhinitis and chronic rhinosinusitis. More significant changes were found in these studies compared to those obtained in our study [29, 30] . This suggests that increases in MCT, nasal blockage and postnasal discharge complaints detected in the N95 mask group and the increase in nasal blockage complaint seen in the surgical mask group were mild. Furthermore, N95 and surgical masks have been frequently used during the COVID-19 pandemic. However, no increase in number of patients with acute rhinosinusitis was noted both in our practice and in the literature review, and these masks are well tolerated by users. Although the increases in the MCT, nasal blockage and postnasal discharge were statistically significant in our study, these differences did not reach clinically significant level. In the N95 mask group, a slight increase in MCT due to the use of the mask was observed in most of the participants (Fig. 2) . On the other hand, it was determined that the increase in nasal blockage complaint in the surgical mask group and the increase in nasal blockage and postnasal discharge complaints in the N95 mask group were more common in some participants (Fig. 2) . This may be associated with the VAS being more subjective than the saccharine test, or more frequent occurrence of nasal blockage and postnasal discharge complaints due to irritant rhinitis in some participants.

In this study, there was a short period of 3 days between the first and the second interview to prevent the intervention of other factors that may affect mucociliary clearance. Furthermore, pre-mask and after-mask mucociliary clearence measurements were not performed on the same day, as this may affect the results. These are the strengths of this study. On the other hand, in this study, the effects of using the masks for eight hours were investigated. Especially healthcare professionals have to use these masks for much longer hours and months. Therefore, further studies are needed to investigate the effects of prolonged mask use. 

The use of N95 mask causes complaints of nasal blockage and postnasal discharge, while the use of surgical mask causes nasal blockage. N95 masks lead to impairment in mucociliary clearance function. But all these effects are mild and these masks are well tolerated by users. Surgical masks have not been found to have any effect on mucociliary clearance function.

The authors declare that they have no conflict of interest. 

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