Drill splatter in orthopaedic procedures and its importance during the COVID-19 pandemic

Aims During the COVID-19 pandemic, drilling has been classified as an aerosol-generating procedure. However, there is limited evidence on the effects of bone drilling on splatter generation. Our aim was to quantify the effect of drilling on splatter generation within the orthopaedic operative setting. Methods This study was performed using a Stryker System 7 dual rotating drill at full speed. Two fluid mediums (Videne (Solution 1) and Fluorescein (Solution 2)) were used to simulate drill splatter conditions. Drilling occurred at saw bone level (0 cm) and at different heights (20 cm, 50 cm, and 100 cm) above the target to simulate the surgeon ‘working arm length’, with and without using a drill guide. The furthest droplets were marked and the droplet displacement was measured in cm. A surgical microscope was used to detect microscopic droplets. Results Bone drilling produced 5 cm and 7 cm droplet displacement using Solutions 1 and 2, respectively. Drilling at 100 cm above the target produced the greatest splatter generation with a 95 cm macroscopic droplet displacement using Solution 2. Microscopic droplet generation was noticed at further distances than what can be macroscopically seen using Solution 1 (98 cm). Using the drill guide, there was negligible drill splatter generation. Conclusion Our study has shown lower than anticipated drill splatter generation. The use of a drill guide acted as a protective measure and significantly reduced drill splatter. We therefore recommend using a drill guide at all times to reduce the risk of viral transmission in the operative setting. Cite this article: Bone Jt Open 2021;2(9):752–756.

Cadaveric Simulation of Endoscopic Endonasal Procedures: Analysis of Droplet Splatter Patterns During the COVID-19 Pandemic

Objective The primary mode of viral transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is thought to occur through the spread of respiratory droplets. The objective of this study was to investigate droplet and splatter patterns resulting from common endoscopic endonasal procedures. Study Design Cadaver simulation series. Setting Dedicated surgical laboratory. Subjects and Methods After instilling cadaver head specimens (n = 2) with fluorescein solution, endoscopic endonasal procedures were systematically performed to evaluate the quantity, size, and distance of droplets and splatter following each experimental condition. Results There were no observable fluorescein droplets or splatter noted in the measured surgical field in any direction after nasal endoscopy, septoplasty with microdebrider-assisted turbinoplasty, cold-steel functional endoscopic sinus surgery (FESS), and all experimental conditions using an ultrasonic aspirator. Limited droplet spread was noted with microdebrider FESS (2 droplets, <1 mm in size, within 10 cm), drilling of the sphenoid rostrum with a diamond burr (8, <1 mm, 12 cm), and drilling of the frontal beak with a cutting burr (5, <1 mm, 9 cm); however, the use of concurrent suction while drilling resulted in no droplets or splatter. The control condition of external activation of the drill resulted in gross contamination (11, 2 cm, 13 cm). Conclusion Our results indicate that there is very little droplet generation from routine rhinologic procedures. The droplet generation from drilling was mitigated with the use of concurrent suction. Extreme caution should be used to avoid activating powered instrumentation outside of the nasal cavity, which was found to cause droplet contamination.

Controlling Shapes in a Coaxial Flow Focusing Microfluidic Device: Experiments and Theory

A coaxial flow focusing PDMS (polydimethylsiloxane) microfluidic device has been designed and manufactured by soft lithography in order to experimentally study a miscible inner flow. We studied a coaxially focused inner flow (formed by an aqueous fluorescein solution) which was fully isolated from all microchannel surfaces by an additional water outer flow. Different flow rates were used to produce a variety of flow ratios and a 3D reconstruction of the cross-section was performed using confocal microscope images. The results showed an elliptical section of the coaxially focused inner flow that changes in shape depending on the flow rate ratio applied. We have also developed a mathematical model that allows us to predict and control the geometry of the coaxially focused inner flow.

Study of Absorption Spectra, Fluorescence and Energy Levels of Fluorescein Dye

The absorption and fluorine spectra of dissolved fluorescein solution in ethanol and different concentrations were studied. The optical properties(absorbance, permeability, linear absorption, and refractive index, as well as time and fluoridation)were calculated. The results showed that a decrease in concentration leads to a decrease in absorption values and an increase in permeability values. This results in a decrease in the values of the absorption coefficient and refractive index. This is in accordance with Lambert's law. Also, the values of the fluorine are lower. The top of the emission spectrum is transferred to the longer wavelengths. The temporal age of fluoride decreases and the quantitative output increases, thus using this dye as an effective laser medium in liquid state lasers. The infrared spectroscopy of the dye was also studied using the (Gaussian 9) program.

Fluorescein effect on the vase life of calla (Zantedeschia aethiopica (L.) K. Spreng.) inflorescences

Calla (Zantedeschia aethiopica (L.) K. Spreng), is a cut flower which had obtained importance in recent years, but postharvest handling is limited. Thus, in order to know the fluorescein concentration effect and pH of pulse solution on inflorescences calla postharvest, were evaluated in Teotitlan de Flores Magon, Oaxaca-Mexico, four fluorescein concentrations (0, 20, 40 and 60 %, respectively) and two pH levels (acid and alkaline) in a completely randomized design with factorial arrangement, having a total of 24 experimental units, which was established by vase life and calla inflorescence with white spathe color, immersed in a fluorescein solution adjusted as appropriate at acidic or alkaline pH, where response variables were as follows: vase life, water consumption, stem diameter, absorption fluorescein stem base and fluorescein vertical absorption by floral scape. Results indicates the increased vase life is achieved at alkaline pH by fluorescein addition of 20, 40 and 60 %, respectively. Likewise, the higher water consumption is achieved at this pH. From this research, we can conclude fluorescein can affect the calla physiology for increasing vase life.

THE SPECIFIC FEATURES OF FLUORESCEIN ANGIOGRAPHY OF THE RETINA IN THE CHILDREN OF DIFFERENT AGE AND THE POSSIBLE COMPLICATIONS OF ITS APPLICATION

Purpose. The objective of the present study was the further adaptation of the fluorescence angiography technique for the examination of the children of different ages and the evaluation of the nature, severity, and frequency of complications likely to develop in the course of such examination as a result of intravenous administration of sodium fluorescein and its intake. Material and methods. A total of 957 children at the age varying between 1.5 months and 16 years were divided into two age groups. The first group consisted of 204 (21.3%) children under the age of 1.5 months and up to 5 years including premature babies in whom fluorescence retinal angiography was performed under general anesthesia with the use of the specially developed and improved methodology. The second group was comprised of 753 (78.7%) children at the age between 6 and 16 years. To 649 of these children (86.2%), the dye was injected intravenously whereas to 104 (13.8%) of them sodium fluorescein was given per os. Results. We have developed and further improved the method for fluorescence angiography in the children of various ages including premature infants. The fluorescence angiography of the fundus of the eye in the children at the age from 1.5 months and up to 16 years resulted in the complications of varying severity in 5.2% of the patients. Mild complications in the form of nausea or vomiting accounted for 3.8% of their total number. The moderately severe complications (1.0%) manifested themselves as the development of the collaptoid state or urticaria. The severe complications (0.2%) were apparent as bronchospasm and laryngospasm. No complications whatever were documented in the children after the oral intake of a 10% sodium fluorescein solution. Conclusion. The intravenous fluorescence angiography is a fairly safe method for the examination of the fundus of the eye in the children, however it can be accompanied in rare cases (3.8%) by the complications the majority of which (75%) are mild disorders. Both intravenous administration of sodium fluorescein under general anesthesia and its oral intake can be regarded as safe interventions.

Sinus Penetration of a Pulsating Device Versus the Classic Squeeze Bottle in Cadavers Undergoing Sinus Surgery

Objectives: Nasal irrigation is standard in the management of chronic rhinosinusitis both before and after surgical intervention. Numerous irrigation devices are commercially available. The aim of this study was to compare the efficacy of a handheld pulse irrigation device against the gold standard manual squeeze bottle after endoscopic sinus surgery (ESS). Methods: Five cadaveric specimens were prepared with video visualization ports into each sinus. Endoscopic sinus surgery was performed on each cadaver from minimal to maximal dissection. Sinuses were irrigated with fluorescein solution using both devices following each dissection. The irrigations were video recorded. A blinded independent observer scored each irrigation according to a defined scale. Results: Comparison of the 2 devices using an intraclass correlation coefficient (ICC = 0.39) showed the 2 systems differed. Observation of individual sinuses showed the squeeze bottle consistently provided greater irrigation in the maxillary ( P < .006), frontal ( P < .0001), and sphenoid ( P < .0001) sinuses. Pulse irrigation improved only in the maxillary sinus following ESS. Conclusion: The squeeze bottle consistently demonstrated superior irrigation in both native and operated conditions. Interestingly, saline penetration was not significantly improved after opening of the frontal and sphenoid sinuses. This is likely due to decreased backpressure in the nasal passage after opening the sinus cavities.

Optical Gain Coefficient Measurement Of Colloidal Solution Of Spasers

Optical gain coefficient of colloidal solution of spasers was measured by the variable stripe length method, where the intensity of the amplified spontaneous emission from the sample edge is measured as a function of excited volume. Spasers consist of gold core-silica (porous) shell nanoparticles penetrated with fluorescein. Under these conditions, we observed the exponential growth and narrowing of line and directivity of stimulated emission. The obtained optical gain coefficient of spaser colloids in fluorescein solution in ethanol is g = 16,2 cm–1. Separately, fluorescein solution in ethanol had g = 3,7 cm–1.