A pilot study to determine medical laser generated air contaminant emission rates for a simulated surgical procedure

Chemicals in Surgical Smoke and the Efficiency of Built-in-Filter Ports

Background and Objectives:

Surgical smoke contains various malodorous and hazardous combustion byproducts. We aimed to analyze hydrocarbons accumulated in the abdominal cavity during laparoscopic gynecologic surgery and determine the efficiency of a built-in-filter port.

Methods:

We prospectively followed seven patients with benign uterine pathology. Surgical smoke was generated using laparoscopic or robotic electrocautery. The smoke was collected twice for each patient using a built-in-filter port and a conventional port. The concentrations of volatile organic compounds and aldehydes were determined using gas chromatography with mass spectrometry and high-performance liquid chromatography with ultraviolet visible light detection and compared using the paired-sample Wilcoxon signed-rank test.

Results:

Five volatile organic compounds and five aldehydes had toxic effects or unpleasant odors. The median concentration of formaldehyde before filtration (0.870 ppm) exceeded the time-weighted average concentration (0.75 ppm) of the Occupational Safety and Health Administration. Built-in-filter ports significantly reduced the concentration of five volatile organic compounds and two aldehydes but not that of formaldehyde, acetaldehyde, and propionaldehyde. Formaldehyde concentration decreased by 50% after filtration but remained above the recommended exposure limit (0.016 ppm) of the National Institute of Occupational Safety and Health.

Conclusions:

Surgical smoke in minimally invasive gynecologic procedures contains several hazardous hydrocarbons including formaldehyde. Built-in-filter ports have the potential to reduce the exposure of surgical smoke to surgeons and operating room personnel; nevertheless, development of built-in-filter ports is necessary to improve the filtering efficiency for highly concentrated formaldehydes.

Biomarkers of Human Cardiopulmonary Response After Short-Term Exposures to Medical Laser-Generated Particulate Matter From Simulated Procedures: A Pilot Study

OBJECTIVE

We conducted an exposure chamber study in humans using a simulated clinical procedure lasing porcine tissue to demonstrate evidence of effects of exposure to laser-generated particulate matter (LGPM).

METHODS

We measured pre- and post-exposure changes in exhaled nitric oxide (eNO), spirometry, heart rate variability (HRV), and blood markers of inflammation in five volunteers.

RESULTS

Change in pre- and post-exposure measurements of eNO and spirometry was unremarkable. Neutrophil and lymphocyte counts increased and fibrinogen levels decreased in four of the five subjects. Measures of HRV showed decreases in the standard deviation of normal between beat intervals and sequential 5-minute intervals.

CONCLUSION

These data represent the first evidence of human physiologic response to LGPM exposure. Further exploration of coagulation effects and HRV is warranted.

Modeled occupational exposures to gas-phase medical laser-generated air contaminants

Exposure monitoring data indicate the potential for substantive exposure to laser-generated air contaminants (LGAC); however the diversity of medical lasers and their applications limit generalization from direct workplace monitoring. Emission rates of seven previously reported gas-phase constituents of medical laser-generated air contaminants (LGAC) were determined experimentally and used in a semi-empirical two-zone model to estimate a range of plausible occupational exposures to health care staff. Single-source emission rates were generated in an emission chamber as a one-compartment mass balance model at steady-state. Clinical facility parameters such as room size and ventilation rate were based on standard ventilation and environmental conditions required for a laser surgical facility in compliance with regulatory agencies. All input variables in the model including point source emission rates were varied over an appropriate distribution in a Monte Carlo simulation to generate a range of time-weighted average (TWA) concentrations in the near and far field zones of the room in a conservative approach inclusive of all contributing factors to inform future predictive models. The concentrations were assessed for risk and the highest values were shown to be at least three orders of magnitude lower than the relevant occupational exposure limits (OELs). Estimated values do not appear to present a significant exposure hazard within the conditions of our emission rate estimates.