Original Paper Received: October 14, 2009 Accepted after revision: November 17, 2010 Published online: $ $ $
Eur Surg Res 322855 DOI: 10.1159/000322855
Chemical Production in Electrocautery Smoke by a Novel Predictive Model Y.-C. Wu a C.-S. Tang b H.-Y. Huang c C.-H. Liu b Y.-L. Chen a D.-R. Chen a Y.-W. Lin b a
Department of General Surgery, Changhua Christian Hospital, Changhua City, b Department of Public Health, College of Medicine, Fu Jen Catholic University, and c Department of Statistics and Information Sciences, Fu Jen Catholic University, Sinjhuang City, Taiwan, ROC
Key Words Aromatic chemicals ⴢ Diathermy ⴢ Electrocautery smoke ⴢ Health risk assessment ⴢ Surgical plume
Abstract Objectives: The hazards of electrocautery smoke have been known for decades. However, few clinical studies have been conducted to analyze the responsible variables of the smoke production. This study collected clinical smoke samples and systematically analyzed all possible factors. Methods: Thirty diathermy smoke samples were collected during mastectomy and abdominal cavity operations. Samples were analyzed using a gas chromatographer with a flame ionization detector. Data were applied to construct prediction models for chemical production from electrosurgeries to identify all possible factors that impact chemical production during electrosurgery. Results: Toluene was detected in 27 smoke samples (90%) with concentrations of 0.003–0.463 mg/m3 and production of 176.0–2,780.0 ng. Ethyl benzene and styrene were identified in very few cases. General linear regression analysis demonstrates that surgery type, patient age, electrocautery duration and imparted coagulation energy explained 67.63% of the variation in toluene production. Conclusion: Surgery type and patient age are known prior to surgery. In terms of risk precaution, the operating team
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should pay close attention to exposure when certain positive factors of increasing the chemical production are known in advance. Copyright © 2011 S. Karger AG, Basel
Introduction
The US Occupational Safety and Health Administration estimates that 500,000 employees working in operating theaters are exposed to electrosurgical and laser smoke annually [1]. Electrocautery smoke is considered a toxin similar to cigarette smoke [2]. More than 80 chemicals, including volatile organic and inorganic compounds, have been identified in clinical and in vitro electrocautery smoke studies. The major organic compounds generated by the electrocautery include aliphatic and aromatic hydrocarbons, aldehydes, phenols, nitriles and fatty acids [3–9]. Carbon dioxide, carbon monoxide, ammonia and hydrogen cyanide are inorganic gases common in abdominal and breast electrocautery smoke [2, 6, 9]. A
A portion of this work was presented at the 2008 Chinese Environmental Analytical Society Annual Conference, Kaoshiung, Taiwan, May 2008.
Yu-Wen Lin, PhD Department of Public Health, College of Medicine Fu Jen Catholic University, 510 Jhongjheng Road Sinjhuang City 24205, Taiwan (ROC) Tel. +886 2 2905 2068, Fax +886 2 2905 6382, E-Mail 056416 @ mail.fju.edu.tw
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survey conducted in Wessex, England, demonstrated that most operating theater staff were concerned about exposure to surgical smoke and felt that precautions were inadequate [10]. Toluene, ethyl benzene, styrene, xylenes and furfural were identified as the primary respiratory irritants in electrocautery smoke [4, 6, 9, 11–13]. These chemicals have an unpleasant smell and are a health concern for the staff exposed to electrocautery smoke [10]. An in vitro study indicated that the chemical composition of electrocautery smoke varied with the applied technique, energy (watt), duration of electrocautery and pathology of treated tissue [8]. Applying a suction device during surgery can reduce exposure to smoke vapors and particulates [8, 10, 14]. Identifying the chemical composition of electrocautery smoke will prove to be a valuable reference when developing the efficient hazard control technologies. To date, however, the amount of systematic quantitative data for electrocautery smoke is limited, and no study has investigated the causal relationships between chemical production and factors affecting the smoke compositions. This study quantifies phenols, furfural, and aromatic hydrocarbons (ethyl benzene, toluene and xylene isomers) in mastectomy and abdominal cavity electrocautery smokes. Additionally, this study assesses the relationships between chemical production and possible influential factors – surgery type, imparted energy for cutting or coagulation, electrocautery duration, patient age and body mass index (BMI). The predictive regression model of chemical production is established using this systematic study design.
Materials and Methods Operating Theaters All smoke samples were obtained from 2 general operating theaters at a medical research center with an indoor atmosphere pressure of 769.2 mm Hg. The mastectomy operating room was 5 m2. The air flow volume of the laminar-flow ventilation system was 175 ft3/min. The abdominal cavity operating room was 6 m2 with an air flow volume of 211 ft3/min. The average operating room temperature and relative humidity were 20.65 8 0.52 ° C and 47.12 8 3.74%, respectively, during the sampling period. Dissection and resection during breast and abdominal surgeries were carried out using bipolar electrocautery units (FORCE 300, Valleylab, Boulder, Colo., USA). The application of electrocautery was intermittent during each procedure. The using time in each case was counted by the stopwatch and added up as the electrocautery duration of each procedure. The other parameters, the energy imparted during cutting or coagulation, patient demographic data and the surgical procedure were also recorded.
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Fig. 1. Sampling chamber scheme. (1) Outlet: connected to the suction system of the operating room. (2) Inlet: connected to the tip of the electrocautery knife. (3) Tygon tube to extend the gas flow from the tip of electrocautery knife. (4, 5) Active samplers (SKC ST226-95 XAD-7 and ST226-01). (6) Gilian low-flow air sampling pump.
Smoke Sampling and Analyses Seven aromatic compounds (ethyl benzene, phenol, styrene, toluene, xylene isomers) and 1 aldehyde (furfural) in electrocautery smoke were analyzed. The sampling apparatuses were arranged in a 2.5-liter acrylic chamber (fig. 1). The chamber inlet port was connected to the electrocautery pencil tip by a sterile Tygon tube. The open end of the tubing was fixed at about 2–3 cm from the pencil tip using surgical tape. The outlet port was connected to a wall-mounted suction system that drew surgical smoke into the lower portion of the chamber via the Tygon tube. A smoke tube (SKC Inc., Eighty Four, Pa., USA) was utilized to determine the air current inside the chamber and to confirm that the suction force was sufficient. The smoke diffused evenly at a suction pressure of –140 mm Hg and vacuum flow rate of 4,000 ml/min. The vacuum pump ran continuously during every sampling period. This sampling chamber was placed beneath the operating table. This design facilitated sample collection near the point where smoke was generated without interfering with surgical procedures and avoiding possible patient infection. The aromatic compounds were collected by the SKC ST226-01 active charcoal sampler (SKC Inc.) with a low-flow air sampling pump (Model LFS-113; Gilian Instrument Corp., West Cladwell, N.J., USA) at a sampling flow rate of 50 ml/min according to the methods of the US National Institute of Occupational Safety and Health [15, 16]. Phenol was trapped by the SKC ST226-95 XAD-7 sampler (SKC Inc.) with a Gilian low-flow air sampling pump (Model LFS-113; Gilian Instrument Corp.) at 100 ml/min according to the method of the US Occupational Safety and Health Administration [17]. The flow rates of sampling pumps were calibrated using an electronic primary standard calibrator (717510M; SKC Inc.).
Wu /Tang /Huang /Liu /Chen /Chen /Lin
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Table 1. Patient and operative data and composition of electrocau-
tery smoke Surgery type
Mastectomy
Gender (male/female) 0/15 Age, years Mean 8 SD 55.9814.0 Range 24.0476.0 BMI Mean 8 SD 25.0986.08 Range 18.43444.95 Operative time, min Mean 8 SD 119.0836.5 Range 65.04185.0 Electrocautery duration, min Mean 8 SD 40.9811.4 Range 22.0466.0 Cutting energy, W 1 (n = 14) 25 (n = 1) Coagulation energy, W Toluene Concentration, mg/m3 Mean 8 SD Range Production, ng Mean 8 SD Range Ethyl benzene Concentration, mg/m3 Mean 8 SD Range Production, ng Mean 8 SD Range Syrene Concentration, mg/m3 Production, ng Xylene Phenol Furfural
Abdominal cavity 10/5 57.9813.0 32.0477.0 25.9283.78 19.80432.68 143.3838.1 95.04235.0
15–30
24.388.3 9.5440.5 1 (n = 3) 20–30 (n = 5) 35–50 (n = 7) 25–50
0.08380.062a 0.03140.217
0.20580.139d 0.05640.463
342.68221.5 176.04862.0
1,144.08824.8 287.042,780.0
0.05980.015b 0.04840.069
