Alternative agents to prevent fogging in head and neck endoscopy

A Low-cost 3D Printed Telescopic Sleeve: A Technical Note

Background: Endoscopic nasal surgery is often a tedious process due to repeated removal of the Hopkins rod telescope from the nasal cavity for manual defogging of the tip due to the presence of blood, smoke, and secretions. Objective: To design and print a 3-dimensional (3D) low-cost telescopic sleeve to allow the defogging solution to clean the rigid telescope tip without removing it from the nasal cavity. In addition, the sleeve must also act as a conduit for suction and irrigation to provide a clear surgical field view intraoperatively. Results and conclusion: A 3D printed low-cost telescopic sleeve, when used in conjunction with other add-ons, can be a helpful and cost-effective adjunct during endoscopic nasal surgery.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12070-022-03281-0.

Fogging of Protective Eyewear in Intensive Care Unit and a Comparative Study of Techniques to Reduce It

Background

Fogging of protective eyewear (PEW) can hinder routine work in the intensive care unit (ICU). The prevalence of fogging impairing vision (FIV) and the technique that reduces fogging have not been evaluated previously.

Methods

After donning personal protective equipment (PPE) with an N95 mask, the healthcare workers (HCWs) sequentially tried plain PEW, soap-coated PEW, PEW worn at a distance over the PPE hood, and the use of tape over a mask. The vision (distant and near) was checked before wearing PEW and with each technique. The prevalence of fogging and FIV, that is, change in vision in either eye was estimated and compared among various techniques. Mixed-effects logistic regression was used to analyze factors affecting fogging and to compare techniques. Room temperature, room humidity, and lens temperature were measured during the study.

Results

A total of 125 HCWs participated (151 observations) and the prevalence of FIV was 66.7%. The fogging of PEW, as well as the extent of PEW fogging, was least with soap coating followed by a mask with tape and goggles worn at a distance. The FIV was significantly lesser only with the mask with tape with an odds ratio (OR) [confidence interval CI)] of 0.45 (0.25-0.82). The prevalence of fogging while at work in the COVID ICU was 38%.

Conclusion

The prevalence of FIV is 66%. Application of tape over the mask can avoid disturbances in vision best. Soap coating of the PEW and PEW worn at distance from the eyes are potential alternatives.

How to cite this article

Ravisankar NP, D'Silva CS, Varma MMKG, Sudarsan TI, Sampath S, Thomas T, et al. Fogging of Protective Eyewear in Intensive Care Unit and a Comparative Study of Techniques to Reduce It. Indian J Crit Care Med 2023;27(1):32-37.

The Diagnostic Value of Traditional Nasal Examination Tools in an Endoscopic Era

BACKGROUND

As the endoscope has become more common in the otolaryngologist's office, there is a need to reevaluate the value of traditional nasal examination methods. The objective of this study was to determine the sensitivity and specificity of traditional nasal examination tools compared to those of the rigid endoscope.

METHODS

A prospective diagnostic study was conducted. Eligible patients with nasal symptoms were recruited and examined using 4 tools: (1) a nasal speculum, (2) an otoscope, (3) a posterior rhinoscopy mirror, and (4) a rigid nasal endoscope. The diagnostic value of each tool was evaluated.

RESULTS

There were a total of 53 patients eligible for inclusion in the study. The mean age of all patients was 40.9 years. The most common nasal symptom was nasal obstruction (90.6%). With regard to the tools used in anterior rhinoscopy, the nasal speculum had a sensitivity of 54.69% (95% confidence interval [95% CI]: 41.75-67.18) and specificity of 88.10% (95% CI: 74.37-96.02); and the otoscope had a sensitivity of 57.81% (95% CI: 44.82-70.06) and specificity of 85.71% (95% CI: 71.46-94.57). After application of topical anesthesia and decongestant, the nasal speculum had a sensitivity of 67.19% (95% CI: 54.31-78.41) and specificity of 85.71% (95% CI: 71.46-94.57); and the otoscope had a sensitivity of 65.62% (95% CI: 52.70-77.05) and specificity of 83.33% (95% CI: 68.64-93.03). The posterior rhinoscopy mirror had a sensitivity of 12.50% (95% CI: 5.18-24.07) and specificity of 94.00% (95% CI: 83.45-98.75). All adverse events in this study were minor.

CONCLUSION

The traditional nasal examination tools exhibited excellent specificity. However, the sensitivity was only average, meaning that they may not be suitable for screening. We do not recommend routine use of topical anesthesia and decongestants when applying these tools, as the application of these agents did not improve the clinical sensitivity or specificity. The posterior rhinoscopy mirror had a lowest sensitivity. We thus do not recommend using a posterior rhinoscopy mirror to rule out pathologies of the posterior nasal cavity.

Water drop-surface interactions as the basis for the design of anti-fogging surfaces: Theory, practice, and applications trends

Glass- and polymer-based materials have become essential in the fabrication of a multitude of elements, including eyeglasses, automobile windshields, bathroom mirrors, greenhouses, and food packages, which unfortunately mist up under typical operating conditions. Far from being an innocuous phenomenon, the formation of minute water drops on the surface is detrimental to their optical properties (e.g., light-transmitting capability) and, in many cases, results in esthetical, hygienic, and safety concerns. In this context, it is therefore not surprising that research in the field of fog-resistant surfaces is gaining in popularity, particularly in recent years, in view of the growing number of studies focusing on this topic. This review addresses the most relevant advances released thus far on anti-fogging surfaces, with a particular focus on coating deposition, surface micro/nanostructuring, and surface functionalization. A brief explanation of how surfaces fog up and the main issues of interest linked to fogging phenomenon, including common problems, anti-fogging strategies, and wetting states are first presented. Anti-fogging mechanisms are then discussed in terms of the morphology of water drops, continuing with a description of the main fabrication techniques toward anti-fogging property. This review concludes with the current and the future perspectives on the utility of anti-fogging surfaces for several applications and some remaining challenges in this field.

A Randomized Controlled Trial Comparing Laparoscopic Lens Defogging Techniques through Simulation Model

Context

Current literature demonstrates a lack of comparative studies regarding effective techniques for reducing laparoscopic lens fogging.

Aim

Our primary objective is to determine the efficacy of various laparoscopic defogging techniques (LDT) through a randomized controlled trial that employs a novel simulation model of the abdominopelvic cavity.

Settings and Design

This study was conducted at academic community hospital. This study design was a randomized controlled trial through simulation.

Subjects and Methods

A chamber was constructed that simulated the abdominopelvic cavity. We used 5 and 10 mm 0° laparoscopes. A 10 cm visual analog scale was developed to assign visual clarity (VC) scores. The 10 cm mark indicated perfect VC. We employed the following LDTs: (1) glove warming (GLOVE), (2) surfactant solution (Fog Reduction and Elimination Device [FRED]), (3) chlorhexidine solution (SOAP), (4) warm saline (SALINE), and (5) control. Three observers were blinded to the LDT used. Primary outcomes included VC scores at designated time intervals (5, 30, and 60 s) for each LDT. A minimum of 10 observations per time interval were required to achieve adequate power based on a 2.5 cm difference in VC scores.

Results

For the 10 mm laparoscope, FRED, SOAP, and SALINE had a VC score at 60 s (VC60) higher than control (4.8 ± 2.2, 7.8 ± 0.8, 7.9 ± 0.7 vs. 2.4 ± 0.72, P < 0.05). Both SOAP and SALINE VC60 scores were higher than FRED (7.8 ± 0.8, 7.9 ± 0.7 vs. 4.8 ± 2.2, P < 0.05). No differences were noted in VC60 scores between control and GLOVE (2.4 ± 0.72 vs. 3.1 ± 2.2, P > 0.05) and between SOAP and SALINE (7.8 ± 0.8 vs. 7.9 ± 0.7, P > 0.05). Similar results were noted with the 5 mm laparoscope.

Conclusions

Common LDTs such as SALINE and SOAP were more effective than FRED, while GLOVE was no different than control. These results demonstrate that the use of effective LDTs can potentially translate into improved patient care and operative outcomes during surgery.

Quantifying Intraoperative Laparoscopic Visual Field Opacity

Background and Objectives:

Laparoscopic surgery can be complicated by condensation and debris on the lens obscuring the visual field, increasing the risk of surgical error and injury to the patient. Despite, development of possible solutions, little is known regarding the quantitative measure of time lost during surgery because of an obscured visual field. Without this knowledge, the cost of laparoscopic lens fogging cannot be quantified and compared to the cost of antifogging devices. In the present study, we investigated the amount of time a laparoscope is withdrawn for cleaning during surgery.

Methods:

This was a prospective, observational study of patients (n = 52) who underwent laparoscopic surgery at Florida Hospital Celebration Health. Patient's age, gender, and body mass index, operative time, wound class, estimated blood loss, type of procedure, and complication (if any) were collected. In addition, intraoperative information on the number of times and total amount of time the laparoscope was withdrawn because of obscured visual field were recorded.

Results:

Eighty-two percent (43) of the procedures required laparoscope withdrawal because of fogging. Increased operative time, increased blood loss, and patient age correlated with the number of times (P < .05) and amount of time (P < .05) the laparoscope was withdrawn.

Discussion:

There was a significant correlation between increased laparoscope withdrawal because of an obscured visual field with increased EBL, operative time, and patient age. Possible explanations include change in body composition with age, the increased viewing angles required for more complex procedures, and increasing intraoperative effect on the surgeon of the poor visual field caused by fogging and debris.

Prospective, randomized comparison of the use of FloShield Air System® versus the reference technique (water + povidone-iodine solution) during gynecologic endoscopic surgery to evaluate the operative lens vision quality

BACKGROUND

The FloShield Air System^® is a new device for laparoscopic surgery that utilizes a continuous dry CO₂ gas flow over the scope to defog the lens and protect it from condensation, debris and smoke. We set out to compare the performance and efficiency of the device in terms of operative lens vision quality (OLVQ) with the reference technique (water + povidone-iodine (PVI) solution) during gynecologic laparoscopic surgery.

MATERIALS AND METHODS

We conducted a single-center randomized prospective study between March and June 2016 (Trials Database Registration NCT02702531) including 53 patients undergoing gynecologic laparoscopic surgery with water + PVI solution and 51 patients who underwent surgical procedures with the FloShield Air System. The primary outcome measure was the number of laparoscope removals during surgery. Secondary outcome measures were the time to clean, assessment of the quality of vision, the correlation between the laparoscopic surgical complexity and outcomes, and cost effectiveness.

RESULTS

Overall, the mean patient age was 43.2 years (range 22-86) and body mass index 24.8 (range 16.8-42.7). The mean number of endoscope removals during surgery was 7.0 (range 0-37) in the water + PVI solution arm and 2.8 (range 0-12) in the FloShield Air System^® arm. The number of removals was significantly lower in the FloShield arm (p < 0.001). No difference in time to clean, quality of vision, level of laparoscopic procedure complexity, or cost was observed between the groups.

CONSLUSIONS

The FloShield Air System^® resulted in fewer laparoscopic lens removals than the water + PVI solution solution, but that there was no difference in quality of vision, cleaning time or cost, especially for the more complex surgery.