Nasolaryngoscopy hood effectively reduces patient aerosol exposures

The COVID-19 pandemic has continued to bring about dramatic changes in the practice of otolaryngology. Even with standard precautions such as physical distancing and wearing of personal protective equipment, aerosol-generating procedures such as nasolaryngoscopy (a procedure commonly performed in the office in which a soft, flexible fiber is passed through the nose and in the throat) and intranasal it has been determined that the instrumentation poses a risk of potential transmission if not properly protected.

In an effort to mitigate exposure to these airborne particles, researchers at Boston University School of Medicine (BUSM) designed and tested a prototype nasolaryngoscopy hood, worn by the patient, that provides protection safe and effective in reducing aerosol exposure.

In order to test the effectiveness of the hood, a particle counter was used to calculate the average number of 0.3 mm / L particles detected during various clinical scenarios including sneezing, nasolaryngoscopy, sneezing during nasolaryngoscopy and topical administration of lidocaine by spray. Experiments were repeated to compare the effectiveness of the hood with the lack of protection.

When no patient barrier (hood or mask) was used, a significant increase in aerosols was detected during sneezing, sneezing during nasolaryngoscopy and administration of topical spray. Once the hood was in place, the aerosol level returned to reference levels in each scenario.

This simple procedure allows patients to undergo routine flexible nasal laryngoscopy, even with topical administration of lidocaine as a spray, with less risk to the provider. If a patient begins to sneeze during the exam, our data suggests that providers will remain protected through the use of the hood. “

Christopher Brook, MD, Corresponding Author, Assistant Professor of Otolaryngology – Head and Neck Surgery, BUSM

While this study evaluated the effectiveness of the hood as part of routine nasolaryngoscopy in reducing the spread of aerosols, there are other possible applications, but also a major hurdle to overcome. “For clinical use, either the hood should be mass produced to allow for one-time use or a safe and efficient protocol for cleaning and reuse of each hood should be established,” said Brook, who is also an ENT. laryngologist at Boston Medical Center.

These results appear online in the journal Ear, nose and throat surgery of the head and neck.