Powered air-purifying respirators used during the SARS-CoV-2 pandemic significantly reduce speech perception.

BACKGROUND: Due to the coronavirus disease 2019 (COVID-19) pandemic, interventions in the upper airways are considered high-risk procedures for otolaryngologists and their colleagues. The purpose of this study was to evaluate limitations in hearing and communication when using a powered air-purifying respirator (PAPR) system to protect against severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) transmission and to assess the benefit of a headset. METHODS: Acoustic properties of the PAPR system were measured using a head and torso simulator. Audiological tests (tone audiometry, Freiburg speech test, Oldenburg sentence test (OLSA)) were performed in normal-hearing subjects (n = 10) to assess hearing with PAPR. The audiological test setup also included simulation of conditions in which the target speaker used either a PAPR, a filtering face piece (FFP) 3 respirator, or a surgical face mask. RESULTS: Audiological measurements revealed that sound insulation by the PAPR headtop and noise, generated by the blower-assisted respiratory protection system, resulted in significantly deteriorated hearing thresholds (4.0 ± 7.2 dB hearing level (HL) vs. 49.2 ± 11.0 dB HL, p < 0.001) and speech recognition scores in quiet (100.0 ± 0.0% vs. 2.5 ± 4.2%, p < 0.001; OLSA: 20.8 ± 1.8 dB vs. 61.0 ± 3.3 dB SPL, p < 0.001) when compared to hearing without PAPR. Hearing with PAPR was significantly improved when the subjects were equipped with an in-ear headset (p < 0.001). Sound attenuation by FFP3 respirators and surgical face masks had no clinically relevant impact on speech perception. CONCLUSIONS: The PAPR system evaluated here can be considered for high-risk procedures in SARS-CoV-2-positive patients, provided that hearing and communication of the surgical team are optimized by the additional use of a headset.

Aerosol Exposure During Surgical Tracheotomy in SARS-CoV-2 Positive Patients.

INTRODUCTION: Since December 2019, the novel coronavirus SARS-CoV-2 has been spreading worldwide. Since the main route of infection with SARS-CoV-2 is probably via contact with virus-containing droplets of the exhaled air, any method of securing the airway is of extremely high risk for the health care professionals involved. We evaluated the aerosol exposure to the interventional team during a tracheotomy in a semiquantitative fashion. In addition, we present novel protective measures. PATIENTS AND METHODS: To visualize the air movements occurring during a tracheotomy, we used a breathing simulator filled with artificial fog. Normal breathing and coughing were simulated under surgery. The speed of aerosol propagation and particle density in the direct visual field of the surgeon were evaluated. RESULTS: Laminar air flow (LAF) in the OR reduced significantly the aerosol exposure during tracheostomy. Only 4.8 ±â€Š3.4% of the aerosol was in contact with the surgeon. Without LAF, however, the aerosol density in the inspiratory area of the surgeon is 10 times higher (47.9 ±â€Š10.8%, P < 0.01). Coughing through the opened trachea exposed the surgeon within 400 ms with 76.0 ±â€Š8.0% of the aerosol-independent of the function of the LAF. Only when a blocked tube was inserted into the airway, no aerosol leakage could be detected. DISCUSSION: Coughing and expiration during a surgical tracheotomy expose the surgical team considerably to airway aerosols. This is potentially associated with an increased risk for employees being infected by airborne-transmitted pathogens. Laminar airflow in an operating room leads to a significant reduction in the aerosol exposure of the surgeon and is therefore preferable to a bedside tracheotomy in terms of infection prevention. Ideal protection of medical staff is achieved when the procedure is performed under endotracheal intubation and muscle relaxation.

Typical symptoms of common otorhinolaryngological diseases may mask a SARS-CoV-2 infection.

PURPOSE: Severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) replicates predominantly in the upper respiratory tract and is primarily transmitted by droplets and aerosols. Taking the medical history for typical COVID-19 symptoms and PCR-based SARS-CoV-2 testing have become established as screening procedures. The aim of this work was to describe the clinical appearance of SARS-CoV-2-PCR positive patients and to determine the SARS-CoV-2 contact risk for health care workers (HCW). METHODS: The retrospective study included n = 2283 SARS-CoV-2 PCR tests from n = 1725 patients with otorhinolaryngological (ORL) diseases performed from March to November 2020 prior to inpatient treatment. In addition, demographic data and medical history were assessed. RESULTS: n = 13 PCR tests (0.6%) were positive for SARS-CoV-2 RNA. The positive rate showed a significant increase during the observation period (p < 0.01). None of the patients had clinical symptoms that led to a suspected diagnosis of COVID-19 before PCR testing. The patients were either asymptomatic (n = 4) or had symptoms that were interpreted as symptoms typical of the ORL disease or secondary diagnoses (n = 9). CONCLUSION: The identification of SARS-CoV-2-positive patients is a considerable challenge in clinical practice. Our findings illustrate that taking a medical history alone is of limited value and cannot replace molecular SARS-CoV-2 testing, especially for patients with ORL diseases. Our data also demonstrate that there is a high probability of contact with SARS-CoV-2-positive patients in everyday clinical practice, so that the use of personal protective equipment, even in apparently "routine cases", is highly recommended.

In vitro comparison of surgical techniques in times of the SARS-CoV-2 pandemic: electrocautery generates more droplets and aerosol than laser surgery or drilling.

INTRODUCTION: Based on current knowledge, the SARS-CoV-2 is transmitted via droplet, aerosols and smear infection. Due to a confirmed high virus load in the upper respiratory tract of COVID-19 patients, there is a potential risk of infection for health care professionals when performing surgical procedures in this area. The aim of this study was the semi-quantitative comparison of ENT-typical interventions in the head and neck area with regard to particle and aerosol generation. These data can potentially contribute to a better risk assessment of aerogenic SARS-CoV-2-transmission caused by medical procedures. MATERIALS AND METHODS: As a model, a test chamber was created to examine various typical surgical interventions on porcine soft and hard tissues. Simultaneously, particle and aerosol release were recorded and semi-quantitatively evaluated time-dependently. Five typical surgical intervention techniques (mechanical stress with a passive instrument with and without suction, CO2 laser treatment, drilling and bipolar electrocoagulation) were examined and compared regarding resulting particle release. RESULTS: Neither aerosols nor particles could be detected during mechanical manipulation with and without suction. The use of laser technique showed considerable formation of aerosol. During drilling, mainly solid tissue particles were scattered into the environment (18.2 ± 15.7 particles/cm2/min). The strongest particle release was determined during electrocoagulation (77.2 ± 30.4 particles/cm2/min). The difference in particle release between electrocoagulation and drilling was significant (p < 0.05), while particle diameter was comparable. In addition, relevant amounts of aerosol were released during electrocoagulation (79.6% of the maximum flue gas emission during laser treatment). DISCUSSION: Our results demonstrated clear differences comparing surgical model interventions. In contrast to sole mechanical stress with passive instruments, all active instruments (laser, drilling and electrocoagulation) released particles and aerosols. Assuming that particle and aerosol exposure is clinically correlated to the risk of SARS-CoV-2-transmission from the patient to the physician, a potential risk for health care professionals for infection cannot be excluded. Especially electrocautery is frequently used for emergency treatment, e.g., nose bleeding. The use of this technique may, therefore, be considered particularly critical in potentially infectious patients. Alternative methods may be given preference and personal protective equipment should be used consequently.

[Implementation of an operational concept in an ENT clinic in the context of the SARS-CoV-2 pandemic]. / Implementierung eines Betriebskonzeptes in einer HNO-Klinik im Rahmen der SARS-CoV-2-Pandemie.

The SARS-CoV-2 pandemic poses major challenges for the entire medical care system. Especially in university institutions as maximum care providers, a higher exposure to potentially infectious patients or actual COVID-19 patients is to be expected. In a short period of time, an operational concept had to be developed regarding the current hygiene recommendations of the Robert Koch Institute (RKI), the leading medical societies and the internal hospital hygiene plan. Here, patient safety and employee protection are equally important.In cooperation with the Institute for Medical Microbiology and Hospital Hygiene and the occupational medical service, interventions were defined to develop solutions to minimize the COVID-19 transmission risk for examiners and patients despite limited diagnostic and equipment resources. For this purpose, an operational concept was developed, consisting of various individual actions, e. g. the reduction of outpatient treatment to emergencies, life-threatening diseases and urgent aftercare, a double triage of patients and the introduction of treatment teams.The newly developed operational concept was successfully implemented within a few days. After the initial rollout and several "hygiene inspections" only minor improvements to the concept were necessary. All measures were documented in the internal quality handbook and are accessible to all employees. Since the SARS-CoV-2 pandemic is a dynamic process with regular changes in the development and information status, the operational concept is regularly reviewed for validity and adjusted as necessary.