Laparoscopic Lens Defogging Using Anti-fog Solution, waRm Saline, and Chlorhexidine Solution

Randomized Comparison of Laparoscopic LEns Defogging Using Anti-fog Solution, waRm Saline, and Chlorhexidine Solution (CLEAR)

The aim of this study is to compare three popular methods of minimizing or reducing laparoscopic lens fogging (LLF) by heating lens using warm saline, applying anti-fog agent to lens, and rubbing lens with chlorhexidine in laparoscopic gynecologic surgery.

The physiology behind laparoscopic lens fogging (LLF) is well understood based on meticulous experiments outlining the role of temperature and humidity. Despite many efforts, including uses of warm saline, various anti-fog agents, chlorhexidine, betadine, and rubbing the lens on serosal surfaces, to reduce LLF, there remains no consensus as to which method is superior to prevent LLF. Furthermore, most previous studies were experimental trials conducted in a simulation model or a non-human in vivo model or an expert's commentary based on their clinical experiences , and there was no randomized controlled trial focusing LLF in human model. Therefore, this randomized trial aimed to compare three popular methods of minimizing or reducing LLF by heating lens using warm saline, applying anti-fog agent to lens, and rubbing lens with chlorhexidine in laparoscopic gynecologic surgery.

Inclusion Criteria:

• age between 18 and 65 years
• American Society of Anesthesiologists physical status (ASAPS) classification I-II
• the absence of pregnancy at the time of surgery

Exclusion Criteria:

• allergy to chlorhexidine or anti-fog solution
• anticipating cases of abrupt change in intra-abdominal humidity such as hemoperitoneum and profuse ascites
• extremely short or long operative time (<20 min or > 180 min) affecting the frequency of LLF
• unavailability of the surgical recording equipment for laparoscopic procedure.