Exposure of operating room surgical staff to surgical smoke under different ventilation schemes

Surgical smoke: a matter of hygiene, toxicology, and occupational health

The use of devices for tissue dissection and hemostasis during surgery is almost unavoidable. Electrically powered devices such as electrocautery, ultrasonic and laser units produce surgical smoke containing more than a thousand different products of combustion. These include large amounts of carcinogenic, mutagenic and potentially teratogenic noxae. The smoke contains particles that range widely in size, even as small as 0.007 µm. Most of the particles (90%) in electrocautery smoke are ≤6.27 µm in size, but surgical masks cannot filter particles smaller than 5 µm. In this situation, 95% of the smoke particles which pass through the mask reach deep into the respiratory tract and frequently cause various symptoms, such as headache, dizziness, nausea, eye and respiratory tract irritation, weakness, and abdominal pain in the acute period. The smoke can transport bacteria and viruses that are mostly between 0.02 µm and 3 µm in size and there is a risk of contamination. Among these viruses, SARS-CoV-2, influenza virus, HIV, HPV, HBV must be considered. The smoke may also carry malignant cells. The long-term effects of the surgical smoke are always ignored, because causality can hardly be clarified in individual cases. The quantity of the smoke changes with the technique of the surgeon, the room ventilation system, the characteristics of the power device used, the energy level at which it is set, and the characteristics of the tissue processed. The surgical team is highly exposed to the smoke, with the surgeon experiencing the highest exposure. However, the severity of exposure differs according to certain factors, e.g., ventilation by laminar or turbulent mixed airflow or smoke evacuation system. In any case, the surgical smoke must be removed from the operation area. The most effective method is to collect the smoke from the source through an aspiration system and to evacuate it outside. Awareness and legal regulations in terms of hygiene, toxicology, as well as occupational health and safety should increase.

Escape of surgical smoke particles, comparing conventional and valveless trocar systems

BACKGROUND

During minimal access surgery, surgical smoke is produced which can potentially be inhaled by the surgical team, leading to several health risks. This smoke can escape from the abdominal cavity into the operating room due to trocar leakage. The trocars and insufflator that are used during surgery influence gas leakage. Therefore, this study compares particle escape from a valveless (Conmed AirSeal iFS), and a conventional (Karl Storz Endoflator) system.

MATERIALS AND METHODS

Using an in vitro model, a conventional and a valveless trocar system were compared. A protocol that simulated various surgical phases was defined to assess the surgical conditions and particle leakage. Insufflation pressures and instrument diameters were varied as these are known to affect gas leakage.

RESULTS

The conventional trocar leaked during two distinct phases. Removal of the obturator caused a sudden release of particles. During instrument insertion, an average of 211 (IQR 111) particles per second escaped when using the 5 mm diameter instrument. With the 10 mm instrument, 50 (IQR 13) particles per second were measured. With the conventional trocar, a higher abdominal pressure increased particle leakage. The valveless trocar demonstrated a continuously high particle release during all phases. After the obturator was removed, particle escape increased sharply. Particle escape decreased to 1276 (IQR 580) particles per second for the 5 mm instrument insertion, and 1084 (IQR 630) particles per second for 10 mm instrument insertion. With the valveless trocar system, a higher insufflation pressure lowered particle escape.

CONCLUSIONS

This study shows that a valveless trocar system releases more particles into the operating room environment than a conventional trocar. During instrument insertion, the leakage through the valveless system is 6 to 20 times higher than the conventional system. With a valveless trocar, leakage decreases with increasing pressure. With both trocar types leakage depends on instrument diameter.

Surgical smoke: A hidden killer in the operating room

Surgical smoke is a byproduct of aerosols containing several components produced by energy equipment. The characteristics of surgical smoke components produced by different types of tissues or using different kinds of energy devices vary. For example, the average diameter of smoke particles produced by electrocautery is smaller, and the possibility of viable cells and pathogens in surgical smoke produced by an ultrasonic knife is higher. According to the characteristics of its composition, surgical smoke may be an important risk factor affecting the health and safety of operating room staff and patients. The use of surgical masks, suction devices and portable smoke evacuation systems can reduce this risk to some extent. However, most operating room staff members do not implement corresponding measures to protect themselves. In this paper, the characteristics of surgical smoke and the research progress in protective measures are briefly reviewed.

Measurement and Control of Surgical Smoke to Enhance Surgical Team Safety

Amid the coronavirus disease 2019 era, concern about the safety of surgical teams related to surgical smoke (SS) is rising. As simple ventilation improvement methods (SVIMs), we replaced 4 of the 8 supply diffusers with a direction-adjustable louver-type, closed 2 of the 4 exhaust grills, and strengthened the sealing of the doorway. Dynamic changes in the concentration of particulate matter (PM) with sizes of < 1.0 μm (PM1.0) were measured using low-cost PM meters (LCPMs) at eight locations in the operating room (OR). SS concentration up to 4 minutes at the location of the surgeon, first assistant, and scrub nurse before and after SVIMs application decreased from 65.4, 38.2, 35.7 µg/m³ to 9.5, 0.1 and 0.7 µg/m³ respectively. A similar decrease was observed in the other 5 locations. SVIMs could effectively control SS and the LCPM was also effective in measuring SS in the OR or other spaces of the hospital.

Current Status and Factors Associated with Clean Operating Rooms: A Survey of Hospitals in China

Background

Indoor air quality is controlled in the clean operating room (OR) to reduce the risk of surgical-site infections (SSIs). The aim of this study is to assess the usage and management of clean ORs in China and to identify factors associated with the risk of SSIs.

Methods

An online survey was distributed to hospitals in China from August 5 to September 5, 2018 via the WeChat account of the Shanghai International Forum for Infection Control and Prevention. The questionnaire consisted of two parts: basic information (hospital type, level, and number of beds) and usage and management (number of ORs, usage time, maintenance mode, test frequency, compliance with current standards, and comfort of healthcare workers). The significance of factors associated with the cleanliness and maintenance of clean ORs was assessed by univariate and multivariate logistic regression analyses.

Results

Among 1,308 responding hospitals, 25.7% failed to comply with current standards. “Maintenance mode” had a significant effect on compliance with current standards for clean ORs (p < 0.0001) and “professional” maintenance was superior to “outsource or no” maintenance (odds ratio = 0.511, 95% confidence interval = 0.367–0.711). There was a significant difference in the comfort of healthcare workers in clean ORs that complied with current standards vs. those that did not (39.92% [388/972] vs. 64.28% [216/336], respectively, p < 0.0001). Humidity was the chief complaint among healthcare workers.

Conclusion

Maintenance of clean ORs was significantly associated with the compliance of current standards. Noncompliance with current standards was associated with greater risks of SSIs. Maintenance of ORs for prevention of SSIs should consider the costs and benefits.