Pathophysiological relationship between COVID-19 and olfactory dysfunction: A systematic review

IntroductionSARS-CoV-2 is the pathogen of COVID-19. The virus is composed of the spike, membrane and envelope. On physiological smell, odoriferous substances bind to proteins secreted by sustentacular cells in order to be processed by olfactory receptor neurons. Olfactory disorder is one of the main manifestations of COVID-19, however, research is still required to clarify the mechanism involved in SARS-CoV-2 induced anosmia.ObjectiveThis article aims to analyze current scientific evidence intended to elucidate the pathophysiological relationship between COVID-19 and the cause of olfactory disorders.MethodsPubmed, Embase, Scopus and ScienceDirect were used to compose this article. The research was conducted on November 24th, 2020. Original articles with experimental studies in human, animal and in vitro, short communications, viewpoint, published in the English language and between 2019 and 2020 were included, all related to the pathophysiological relationship between olfactory disorders and COVID-19 infection.ResultsBoth human cell receptors ACE2 and TMPRSS2 are essential for the SARS-CoV-2 entrance. These receptors are mostly present in the olfactory epithelium cells, therefore, the main hypothesis is that anosmia is caused due to damage to non-neuronal cells which, thereafter, affects the normal olfactory metabolism. Furthermore, magnetic resonance imaging studies exhibit a relationship between a reduction on the neuronal epithelium and the olfactory bulb atrophy. Damage to non-neuronal cells explains the average recovery lasting a few weeks. This injury can be exacerbated by an aggressive immune response, which leads to damage to neuronal cells and stem cells inducing a persistent anosmia. Conductive anosmia is not sufficient to explain most cases of COVID-19 induced anosmia.ConclusionOlfactory disorders such as anosmia and hyposmia can be caused by COVID-19, the main mechanism is associated with olfactory epithelium damage, targeting predominantly non-neuronal cells. However, neuronal cells can also be affected, worsening the condition of olfactory loss.     

Incomplete and late recovery of sudden olfactory dysfunction in COVID-19

IntroductionSudden olfactory dysfunction is a new symptom related to COVID-19, with little data on its duration or recovery rate.ObjectiveTo characterize patients with sudden olfactory dysfunction during the COVID-19 pandemic, especially their recovery data.MethodsAn online survey was conducted by the Brazilian Society of Otorhinolaryngology and Cervico-Facial Surgery, and Brazilian Academy of Rhinology, including doctors who assessed sudden olfactory dysfunction patients starting after February 1st, 2020. Participants were posteriorly asked by e-mail to verify data on the recovery of sudden olfactory loss and test for COVID-19 at the end of the data collection period.Results253 sudden olfactory dysfunction patients were included, of which 59.1% were females with median age of 36 years, with a median follow-up period of 31 days. 183 patients (72.3%) had been tested for COVID-19, and of those 145 (79.2%) tested positive. Patients that tested positive for COVID-19 more frequently showed non-specific inflammatory symptoms (89.7% vs. 73.7%; p = 0.02), a lower rate of total recovery of sudden olfactory dysfunction (52.6% vs. 70.3%; p = 0.05) and a longer duration to achieve total recovery (15 days vs. 10 days; p = 0.0006) than the ones who tested negative for COVID-19. Considering only positive-COVID-19 patients, individuals with sudden hyposmia completely recovered more often than the ones with sudden anosmia (68.4% vs. 50.0%; p = 0.04).ConclusionPositive-COVID-19 patients with sudden olfactory dysfunction showed lower total recovery rate and longer duration than negative-COVID-19 patients. Additionally, total recovery was seen more frequently in positive-COVID-19 patients with sudden hyposmia than the ones with sudden anosmia.     

Factors associated with voice disorders among the elderly: a systematic review

Introduction

During the aging process, natural modifications occur in the larynx and the structures involved in phonation which explain the specific characteristics found in the voices of elderly persons. When, at any moment, a voice fails and there is interference with communication, a voice disorder has occurred. This can generate disadvantages in communicative efficiency and have a negative impact on quality of life, compromising mechanisms of socialization, the maintenance of autonomy, and the sense of well-being. Nevertheless, there appears to be little clarity about which factors are associated with voice disorders in this population, especially from an epidemiological perspective.

Impact of COVID-19 on maxillofacial surgery practice: a systematic review

ObjectivesThe aim of this systematic review was to evaluate the possible impacts of COVID-19 on oral and maxillofacial surgery practice, as well as the protocols employed by oral and maxillofacial surgeons to minimize the risks of contamination.MethodsSearches were performed in different databases up to 15 March 2021. Articles related to oral surgery dynamics within the context of the COVID-19 pandemic were included. The articles were considered eligible if they met the following inclusion criteria: observational studies that provided recommendations regarding maxillofacial surgery measures during the COVID-19 pandemic and that analyzed the risk of contamination of patients/professionals with SARS-CoV-2.ResultsSeven studies met the inclusion criteria and were selected for the present systematic review. Demands for personal protective equipment increased significantly, with studies reporting the scarcity of fundamental equipment such as FFP2/N95 masks. Significant changes in the infrastructure of outpatient, surgical and inpatient units and in the care protocols themselves were observed.ConclusionThe COVID-19 pandemic particularly affected the routine of oral and maxillofacial surgery residents. Several additional recommendations for surgical practice or for the surgical team were evaluated and discussed, such as performing primarily urgent and emergency surgeries, remote patient care and screening, postponing elective surgeries, and new teaching methods in oral and maxillofacial surgery residency programs. In addition, screening of patients and of the surgery team for COVID-19 is strongly recommended.     

The close relationship between sudden loss of smell and COVID-19

IntroductionThe real number of COVID-19 cases may be underestimated since several countries have difficulty offering laboratory tests for all the population. Therefore, finding a symptom with a high predictive value would help in diagnostic and isolation strategies.ObjectiveTo correlate the sudden loss of the sense of smell in the context of the COVID-19 pandemic with results of diagnostic tests for COVID-19.MethodsThis is a cross-sectional observational study. An online questionnaire was digitally addressed to 725 outpatients in Brazil who reported partial or total sudden loss of the sense of smell from March to April 2020.ResultsTotal or partial sudden loss of the sense of smell showed high positive predictive value for COVID-19 diagnosis, during the COVID-19 pandemic in Brazil (88.8%). There were no differences between groups tested positive and negative in regard to demographic and clinical characteristics such as presence of allergy, rhinitis, neither to olfactory recovery time.ConclusionThe identification of sudden loss of the sense of smell during COVID-19 pandemic may serve as a sentinel symptom and may be a warning to establish measures to prevent the transmission of the disease.     

治疗阻塞性睡眠呼吸暂停低通气综合征的咽成形术对嗅觉和味觉的影响

目的:观察治疗阻塞性睡眠呼吸暂停低通气综合征(OSAHS)的咽成形术对嗅、味觉的影响。方法:总结2005年4月~12月行咽成形术的39例患者中有嗅、味觉改变的主诉情况。结果:4例诉术后味觉改变,其中1例诉同时有嗅觉改变。例1嗅觉减退,酸和咸感觉丧失,2个月后部分恢复,对甜感觉过敏;例24种味觉均减退;例3对酸的感觉过度敏感;例4感痰中有酸和苦的感觉,属味幻觉。味觉改变的发生率达10%。结论:嗅觉和味觉的改变可能是咽成形术的并发症,影响患者的生活质量,必须给予重视,术前应向患者交代清楚,以免引起不必要的医疗纠纷。术中尽可能避免损伤味觉功能,如果发生嗅、味觉损伤,术后需给予处理。     

SARS-CoV-2 and hearing: An audiometric analysis of COVID-19 hospitalized patients

PurposeCOVID-19 associated hearing loss is still an ongoing matter of debate. No original studies exist on audiological effects of SARS-CoV-2 infection in hospitalized patients. The main objective was to determine whether SARS-CoV-2 may affect auditory function in clinically ill COVID-19 patients.Materials and methodsCOVID-19 patients with moderate-severe disease and without prior history of hearing abnormalities were enrolled from a tertiary referral center, and matched with controls. Participants performed an audiometric evaluation, and thresholds were compared.Results120 ears from 60 patients were enrolled. Patients with COVID-19 showed worse mean auditory thresholds starting from 1000 Hz through higher frequencies, when compared to controls (1000 Hz: 18.52 ± 5.49 dB HL in controls vs 25.36 ± 6.79 dB HL in COVID-19, p < 0.001; 2000Hz: 17.50 ± 5.57 dB HL in controls vs 21.96 ± 7.05 dB HL in COVID-19, p = 0.010; 3000Hz: 17.97 ± 8.07 dB HL in controls vs 25 ± 9.38 dB HL in COVID-19, p = 0.003; 4000 Hz: 20.16 ± 10.12 dB HL in controls vs 29.55 ± 11.26 dB HL in COVID-19, p = 0.001; 8000 Hz: 31.09 ± 12.75 dB HL in controls vs 40.71 ± 19.40 dB HL in COVID-19, p = 0.030; Pure Tone Average: 20.42 ± 4.29 dB HL in controls vs 24.85 ± 5.62 dB HL in COVID-19, p = 0.001). Statistical significance persisted after adjusting for confounders such as age, gender and various comorbidities (p < 0.05).ConclusionsSARS-CoV-2 may affect hearing in COVID-19 patients with moderate-severe disease. Results are in line with the previous suggested effects of COVID-19 on auditory system. This study is expected to encourage further research on this topic.     

COVID-19 and the Otolaryngologist: Preliminary Evidence-Based Review

The SARS-CoV-2 virus, which causes coronavirus disease 2019 (COVID-19), has rapidly swept across the world since its identification in December 2019. Otolaryngologists are at unique risk due to the close contact with mucus membranes of the upper respiratory tract and have been among the most affected healthcare workers in Wuhan, China. We present information on COVID-19 management relevant to otolaryngologists on the frontlines of this pandemic and provide preliminary guidance based on practices implemented in China and other countries and practical strategies deployed at Stanford University. Laryngoscope, 130:2537–2543, 2020     

COVID-19 and ENT Surgery

In Otorhinolaryngology – Head and Neck Surgery, clinical examination and invasive procedures on the respiratory tract and on airway-connected cavities, such as paranasal sinuses and the middle ear, expose people to direct transmission of SARS-CoV-2 by inhalation or ocular projection of contaminated droplets, and to indirect transmission by contact with contaminated hands, objects or surfaces. Estimating an R₀ of COVID-19 at around 3 justified postponing non-urgent face-to-face consultations and expanding the use of teleconsultation in order to limit the risks of SARS-CoV-2 infection of patients or health workers and comply with the lockdown. The health authority recommends cancellation of all medical or surgical activities, which are not urgent as long as this does not involve a loss of chance for the patient. The purpose of this cancellation is to significantly increase critical care capacity, prioritise the reception of patients with COVID-19, prioritise the allocation of staff and provision of the equipment necessary for their medical or surgical management, and contribute to the smooth running of downstream critical care within their establishment. Another goal is to reduce the risks of patient contamination within healthcare facilities. This document provides guidance on how to proceed with and adapt ENT surgery in the current pandemic context, as well as on the management of postponed operations. This best practice advice must of course be adapted in each region according to the development of the epidemic and pre-existing arrangements. Their local application can only be decided within the framework of collaboration between the ENT teams, the operational hygiene units and all the other specialties concerned.     

Diagnostic validity of methods for assessment of swallowing sounds: a systematic review

Introduction

Oropharyngeal dysphagia is a highly prevalent comorbidity in neurological patients and presents a serious health threat, which may lead to outcomes of aspiration pneumonia, ranging from hospitalization to death. This assessment proposes a non-invasive, acoustic-based method to differentiate between individuals with and without signals of penetration and aspiration.

Guidelines of clinical practice for the management of swallowing disorders and recent dysphonia in the context of the COVID-19 pandemic

Procedures putting healthcare workers in close contact with the airway are particularly at risk of contamination by the SARS-Cov-2 virus, especially when exposed to sputum, coughing, or a tracheostomy. In the current pandemic phase, all patients should be considered as potentially infected. Thus, the level of precaution recommended for the caregivers depends more on the type of procedure than on the patient's proved or suspected COVID-19 status. Procedures that are particularly at high risk of contamination are clinical and flexible endoscopic pharyngo-laryngological evaluation, and probably also video fluoroscopic swallowing exams. Voice rehabilitation should not be considered urgent at this time. Therefore, recommendations presented here mainly concern the management of swallowing disorders, which can sometimes be dangerous for the patient, and recent dysphonia. In cases where they are considered possible and useful, teleconsultations should be preferred to face-to-face assessments or rehabilitation sessions. The latter must be maintained only in few selected situations, after team discussions or in accordance with the guidelines provided by health authorities.     

2019冠状病毒疾病相关嗅觉障碍

2019冠状病毒疾病(COVID-19)的致病病毒为新型冠状病毒SARS-CoV-2,其主要临床表现为发热、干咳、乏力等上呼吸道感染症状,严重者可快速进展为急性呼吸窘迫综合征、脓毒症休克、难以纠正代谢性酸中毒和出凝血功能障碍及多器官功能衰竭等.多国流行病学研究调查表明嗅觉障碍是COVID-19的临床症状之一,甚至是部分...     

Percutaneous dilatational tracheostomy for saturating influx of COVID-19 patients: Experience of military ENT physicians deployed in Mulhouse,France

ObjectivesThe main objective was to demonstrate the feasibility of percutaneous tracheostomy performed under difficult conditions by military ENT physicians during their deployment in the military intensive care field hospital of the French Military Medical Service in Mulhouse to confront the exceptional COVID-19 pandemic. The secondary objective was to assess reliability and safety for patient and caregivers, with a risk of iatrogenic viral contamination.Material and methodsA single-center retrospective study was conducted between March 25 and April 25, 2020, in 47 COVID-19 patients requiring prolonged mechanical ventilation. The inclusion criterion was having undergone percutaneous tracheostomy.ResultsEighteen consecutively included patients had successfully undergone percutaneous tracheostomy despite unfavorable anatomical conditions (short neck: 83.3%, overweight or obese: 88.9%). Median time to completion was 11 days after intubation, with an average duration of 7 minutes. The procedure was technically compliant in 83.3% of cases, and considered easy (on self-assessment) in 72.2%, with 2 minor per-procedural complications. No crossover to surgery was required. There was only 1 major post-procedural complication (late hemorrhage).ConclusionThis study showed the feasibility of percutaneous tracheostomy by an ENT physician under COVID-19 biohazard conditions. The technique was fast, easy and safe and met safety requirements for patient and staff.