Fluorescein Markers for Droplet Spread
We used fluorescein dye and ultraviolet (UV) light to assess the
efficacy of the negative pressure housing system in minimizing aerosol
dispersion. Droplet formation and patient secretion spread was evaluated
with the application of fluorescein into the nasal cavity. We diluted
fluorescein (Fluorescite, fluorescein injection USP, 10% at 100mg/ml;
Alcon Laboratories; Fort Worth, TX) to a concentration of 1%
fluorescein in 10ml of normal saline solution and topically applied
dropwise to the nasal cavity and nasopharynx at the beginning of the
case. This was further diluted with saline during the case. The
fluorescein solution washes away easily with saline irrigation, so
regular reapplication of fluorescein dye was performed the nasal cavity
prior to use of instruments like the microdebrider, bipolar and
monopolar cautery and high-speed drilling. At the conclusion of the
surgery, an evaluation of the surgical drapes and gowns was performed
using an ultraviolet Wood’s lamp.
We did not have a control group because routine preoperative SARS-CoV-2
testing is not being performed at our institution at this time. As such,
a universal personal protective equipment (PPE) policy was applied for
all aerosol generating surgeries, including endoscopic endonasal and
endo-oral surgery, consisting of an N95 mask or powered air-purifying
respirator (PAPR), eye protection, and fluid resistant gown.