Comparison of aerosol generation between electrocautery and cold dissection tonsillectomy.

OBJECTIVE: Coronavirus disease 2019 can spread through aerosols produced by surgical procedures, but knowledge of the extent of aerosol production and the risk posed by many common procedures does not exist. This study analysed aerosol generation during tonsillectomy and how it differs between distinct surgical techniques and instruments. The results can be used in risk assessment during current and future pandemics and epidemics. METHOD: An optical particle sizer was used to measure particle concentrations generated during tonsillectomy from the perspectives of the surgeon and other staff. Coughing is commonly used as a reference for high-risk aerosol generation; therefore, coughing and the operating theatre's background concentration were chosen as reference values. Different instruments were also compared to find the safest way to perform the tonsillectomy from the perspective of airborne transmission. RESULTS: Eighteen tonsillectomies were evaluated; all techniques mostly generated less than 1 µm particles. For the surgeon, bipolar electrocautery significantly exceeded the particle generation of coughing in both total and less than 1 µm particles and was found to produce significantly higher total and less than 1 µm aerosol concentrations than cold dissection and BiZact. No technique exposed other staff to a greater aerosol concentration than is generated by a cough. CONCLUSION: Bipolar electrocautery generated high aerosol concentrations during tonsillectomy; cold dissection generated significantly less. The results support cold dissection as the primary tonsillectomy technique, particularly during the epidemics of airborne diseases.

Rhinological procedures result in minimal generation of aerosols.

BACKGROUND: COVID-19 and other respiratory infections spread through aerosols produced in respiratory activities and in certain surgical procedures considered as aerosol-generating procedures (AGP). Due to manipulation of the upper airway mucosa, rhinosurgery has been considered a particular risk for spread of respiratory infections. Our aim was to assess staff exposure to aerosols during common rhinosurgical procedures METHODS: Staff exposure to generated particle concentrations and size distributions between 0.3 λm and 10 λm were measured during rhinosurgery using an optical particle sizer without any additional collection methods. Similarly measured aerosol exposure during coughing (a commonly used risk reference for aerosol generation) and the operating room’s background concentration were chosen as reference values. RESULTS: Altogether 16 common rhinological surgeries (septoplasties and endoscopic sinus surgery) were measured. The use of suction produced significantly lower aerosol concentration compared to coughing. Low aerosol generation was observed during injection anaesthesia of the nasal mucosa. Instrument comparison revealed that the microdebrider produced fewer aerosols than cold dissection in particles of 1-5 λm and >5 λm. CONCLUSIONS: Common rhinosurgeries do not seem to generate as high aerosol concentration exposures as previously believed. Rather, the observed aerosol exposure is lower or similar to exposures during coughing. Therefore, the classification of common rhinosurgeries as AGPs should be re-assessed or possibly discarded.

Aerosol generation during coughing: an observational study.

OBJECTIVE: Coronavirus disease 2019 has highlighted the lack of knowledge on aerosol exposure during respiratory activity and aerosol-generating procedures. This study sought to determine the aerosol concentrations generated by coughing to better understand, and to set a standard for studying, aerosols generated in medical procedures. METHODS: Aerosol exposure during coughing was measured in 37 healthy volunteers in the operating theatre with an optical particle sizer, from 40 cm, 70 cm and 100 cm distances. RESULTS: Altogether, 306 volitional and 15 involuntary coughs were measured. No differences between groups were observed. CONCLUSION: Many medical procedures are expected to generate aerosols; it is unclear whether they are higher risk than normal respiratory activity. The measured aerosol exposure can be used to determine the risk for significant aerosol generation during medical procedures. Considerable variation of aerosol generation during cough was observed between individuals, but whether cough was volitional or involuntary made no difference to aerosol production.