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echnology and Engineering

hemical Compositionf Gases Surgeons Are Exposed touring Endoscopic Urological Resections

obin Weston, Richard N. Stephenson, Paul W. Kutarski, and Nigel J. Parr

BJECTIVES To identify any potentially harmful chemical constituents of the gaseous plume produced fromurological endoscopic diathermy.

ETHODS Chemical analysis was performed on the gaseous plume produced from prostatic resections andvaporizations using gas chromatography with mass spectroscopy and high-performance liquidchromatography using ultraviolet and visible light detection. In addition, carbon monoxidelevels were analyzed using a portable catalytic flammable gas sensor.

ESULTS This study identified a cocktail of volatile organic hydrocarbons produced during these proce-dures, some of which are known carcinogens. The most significant finding being high levels ofcarbon monoxide.

ONCLUSIONS From this preliminary study, we advocate the use of smoke evacuator systems for all urologistsregularly performing these procedures, and suggest that further research is required to investigatepotential long-term complications to the urologist. UROLOGY 74: 1152–1155, 2009. © 2009

Elsevier Inc.

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he visible plume and associated unpleasant odorproduced from urological endoscopic electrosur-gical procedures will be familiar to all urologists.

he etiology of the gas produced has been previouslynvestigated with the aim of identifying the constituentsesponsible for intravesical explosions.1-3 As surgeons were familiar with the risks and complications that patientsre exposed to during surgical procedures; however, littlehought is given to potential hazards faced by the surgeonnd operating room staff during the course of an opera-ion. Until now, no study has quantitatively analyzed theaseous plume that the surgeon and theater staff arentermittently exposed to when the resected elements areithdrawn from the resectoscope.The aim of our study was to determine the chemical

omposition and quantify exposure to the surgeon of thisaseous plume from transurethral resection of prostatesTURP) using modern analytic techniques.

ATERIALS AND METHODS

or initial identification of constituents, gas samples were ob-ained during 3 TURP’s and 1 transurethral vaporization of therostate (TUVP), for benign prostatic enlargement. All proce-ures were performed by 2 consultant surgeons. For the TURP’s

rom the Department of Urology, Arrowe Park Hospital, Wirral, Cheshire, UKReprint requests: Robin Weston, M.B., Ch.B., F.R.C.S., 6 Rimmers Ave,

gormby, Merseyside L37 7AR. E-mail: robinweston@talktalk.netSubmitted: January 19, 2009, accepted (with revisions): April 18, 2009

152 © 2009 Elsevier Inc.All Rights Reserved

Stortz resectoscope with standard Stortz resecting loop wassed, powered by an ERBE ICC-350 electrosurgical unit set toutocut 210 W and monopolar coagulation 65 W. For theUVP the Gyrus PlasmaKinetic (bipolar) system was used, withlasma V electrode set to 160 W for cutting and 80 W foroagulation. Glycine (1.5%) was used for irrigation during theURP’s and 0.9% saline for the TUVP. Continuous samplingf the gas from 15 cm above the end of the resectoscope waserformed. Two sorbent tubes containing carbon filters foruantitative analysis of volatile organic hydrocarbons were at-ached to a suction pump at a rate of 100 mL/min. A furtherube containing dinitrophenylhydrazine for collecting alde-ydes was attached to a suction pump producing a flow of 200L/min. Sampling commenced when the resection began andas discontinued when the resectoscope was withdrawn from

he patient. The duration was recorded allowing us to calculatehe volume of gas sampled. Background theater air samples wereaken from the same operating theater during a period of 2ours while not in use, enabling background contamination toe discounted. Further, control sorbent tubes were transportedlong with the samples and remained unopened to excludeontamination during transit. All procedures were performed inhe same operating theater in which a positive pressure venti-ation system with 22 air exchanges per hour is used.

Analysis was carried out at the Health and Safety Laboratoryn Sheffield. The sorbent tubes were analyzed by gas chroma-ography (GC) using mass selective detection for identificationnd flame ionization detection for quantification. The dinitro-henylhydrazine tubes were analyzed by high-performance liq-id chromatography using ultraviolet visible light detection.The above technique does not detect carbon monoxide

CO), a gaseous constituent previously identified in electrosur-

ical gases; therefore, continuous monitoring for CO was also

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erformed using a GASMAN 2 portable CO monitor, againeld at 15 cm above the resectoscope. The CO levels wereontinuously digitally recorded throughout the operation andata were subsequently uploaded to a personal computer fornterpretation. A total of 11 TURP’s and 1 TUVP had contin-ous CO sampling.The TURP chippings were weighed before fixing in formalin

nd the samples were sent for pathologic examination. Regard-ng the TUVP no sample was obtained for pathologic exami-ation and the volume of the gland was assessed by digitalxamination. Transfer of the specimen into formalin was notone in the operating theater to avoid volatile gaseous contam-nation.

ESULTShe chemicals identified during the operations are shown

n Table 1. Maximum concentration is given in paren-heses for chemicals that were quantitatively analyzed byame ionization detection. Accurate determination ofhe concentration of the remaining chemicals in Table 1as not possible with the GC although estimated levelsre in the low parts per billion (ppb).

The mean resection time was 53 minutes (range 23-4), and the mean resection weight was 37 g (range8-67). The duration of the procedures, mass of tissueesected, and concentrations of the most common gasesroduced from the first 4 procedures are shown in Table. All histology was benign. Table 3 compares the con-entrations produced during the TUVP and a comparableized prostatic resection of 67 g, showing almost doublehe mean concentration of CO emitted from the TUVP.

Continuous CO monitoring allowed mean exposureuring the operation to be recorded and also variabil-ty. Peaks were recorded several seconds after with-

Table 1. Gaseous chemicals identified (maximum leveldetected)

Benzene (5 ppb) Styrene (2 ppb) Carbon monoxide(� 490 ppm)

Toluene (5 ppb) Di-t-butylbenzene(3.2 ppb)

Formaldehyde(5.8 ppb)

Ethylbenzene (2ppb)

Isooctane (1.3ppb)

Xylene (2 ppb)

Butene (3.2 ppb) Propene PenteneAcetone Hexene HepteneAcrylonitrile Isoflurane*

Maximum exposure limit: benzene 1 ppm, formaldehyde 2 ppm.* Anesthetic contaminant.

Table 2. Mean concentrations (�g/m3)

TURP1 TURP2 TURP3 TUVP(45 min) (43 min) (52 min) (50 min)(29 g) (31 g) (67 g) -

Benzene 4.1 7.0 12.8 16.0Toluene 7.9 9.4 15.0 18.8Ethylbenzene 1.7 1.7 4.3 8.7Styrene 0.9 7.2 4.3 8.5

rawal of the resectoscope and returned to baseline m

ROLOGY 74 (5), 2009

ndetectable levels usually within less than a minuteFig. 1). In 4 of 12 procedures, the peak CO level reachedhe maximum detectable level by the apparatus at 490 ppmparts per million), suggesting that levels higher than thisere reached. The mean CO level recorded throughout

he duration of the procedures was 7 ppm. The actualime-weighted average for CO will be slightly higherecause in 4 of the procedures the upper limit of the COetecting apparatus was reached.The control sample of theater air yielded very low

ackground levels of volatile organic components asould be expected in indoor ambient air. BackgroundO levels were undetectable. The anesthetic gas isoflu-

ane was detected as a background contaminant. Thereas no contamination of the sample tubes during transit.

OMMENThe results showed that numerous organic hydrocarbonsre emitted during endoscopic urological electrosurgicalrocedures. These compounds identified are similar tohose previously detected in standard electrocautery4-6

nd in closed gaseous environments.7,8 With regard torevious urological endoscopic diathermy gases: in 1935,ambleton et al1 presented a quantitative analysis of

ases obtained during electrosurgery on dog prostates;heodore et al,2 in 1975, used GC to analyze gasesollected at the dome of the bladder after transurethralesection of prostates. Both investigators found the pres-nce of hydrogen along with CO and several other low-

Table 3. Mean concentration TURP vs TUVP

TURP3 (67 g) (ppm) TUVP (ppm)

CO 9.8 mg/m3 (8.5) 19.3 mg/m3 (16.8)Benzene 12.8 �g/m3 (0.004) 16.0 �g/m3 (0.005)Toluene 15.0 �g/m3 (0.004) 18.8 �g/m3 (0.005)C3-C6

Alkenes64.5 �g/m3 (0.025) 464.4 �g/m3 (0.180)

Figure 1. Intra-operative carbon monoxide emissions

olecular-weight hydrocarbons. Davis3 confirmed these

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ndings in 1983, although in the analysis it was notossible to accurately quantify each constituent. In histudy, gas from raw meat fulgurated in 0.15% glycine wasollected and analyzed by GC. He identified hydrogen,arbon monoxide, carbon dioxide, and a range of hydro-arbons in which the most common was methane, al-hough he did not elaborate which other hydrocarbonsere produced. The aim of these studies was to detect theases collecting at the dome of the bladder, which areesponsible for intravesical explosion.9,10 Hydrogen washought to be the responsible constituent occupying be-ween 10% and 60% of the gas detected in Davis’ study.3

ombustion of hydrogen is only possible in the presencef oxygen, which in the case of intravesical explosions ishought to enter the bladder via the resectoscope whileithdrawing the elements, and not produced by pyrolysis.Surgical smoke has been shown to be mutagenic,11 and

n a study by Tomita et al,12 1 g of pyrolyzed tissueenerated the equivalent mutagenicity to 6 cigarettes. Inur study, benzene and formaldehyde were detected,hich are the known carcinogens, and were previouslyndetected in endoscopic diathermy gases. The exposureevels however are well below the maximum exposureimit of 1 and 2 ppm, respectively.13 The low-molecular-eight alkenes (propene, butene, etc.) are found in rel-tively higher concentrations and levels may reach a fewarts per million; however, these are not generally re-arded as harmful compounds, and have no occupationalxposure standards.

Carbon monoxide is produced in significantly higherevels than the other compounds detected. The cumula-ive CO levels during the procedures monitored wereelow toxic levels; however, they are produced in signif-cant quantities to potentially cause adverse side effectso the surgeon such as headache, fatigue, and nausea.ccording to the occupational safety and health admin-

stration the maximum exposure to CO should be � 35pm for no longer than 8 hours.14 The limit for short-erm exposure (15-min reference period) is 200 ppm. TheO levels of 800 ppm for more than 2 hours can be fatal.his study did not investigate adverse effects on theperating surgeon; however, with regard to CO it woulde possible in future studies to perform breath or serumests before and after the procedure.

The data suggest that TUVP may produce higher lev-ls of gaseous compounds than TURP, and that themount of harmful gases produced in resections is relatedo the mass of prostatic tissue resected. However, the aimf this study was to identify the chemical constituents ofhe plume from endoscopic resections and it was notowered to demonstrate a statistical difference betweenrostatic resections and vaporizations.

ONCLUSIONSe conclude from this study that the gaseous plumes

roduced from these procedures contain potentially

armful organic compounds, although with the excep- m

154

ion of CO, the quantities are insufficient to cause acutedverse effects on the surgeon. The levels of CO areufficient to cause side effects, and therefore steps shoulde taken to reduce the amount of plume inhaled whenithdrawing the resecting elements. At present, the

ong-term cumulative effects of the harmful hydrocar-ons, benzene, and formaldehyde are unknown. We woulddvocate the use of gas extraction systems for urologists whoegularly undertake these procedures.

eferences1. Hambleton BF, Lackey RW, Van Duzen RE. Explosive gases

formed during electrotransurethral resections. J Am Med Assoc.1935;105:645-646.

2. Theodore C, Ning JR, Atkins D, et al. Bladder explosions duringtransurethral surgery. J Urol. 1975;114:536-539.

3. Davis TR. The composition and origin of the gas produced duringurological endoscopic resections. Br J Urol. 1983;55:294-297.

4. Gatti JE, Murphy B, Noone RB. Analysis of electrocautery smokeproduced during reduction mammoplasty. Surg Forum. 1986;37:579-580.

5. Sagar PM, Meagher A, Sobczak S. Chemical composition andpotential hazards of electrocautery smoke. Br J Surg. 1996;83:1792.

6. Moot AR, Ledingham KM, Wilson PF, et al. Composition of volatileorganic compounds in diathermy plume as detected by selected ionflow tube mass spectrometry. ANZ J Surg. 2007;77:20-23.

7. Hensman C, Baty D, Willis RG, et al. Chemical composition ofsmoke produced by high-frequency electrosurgery in a closed gas-eous environment. Surg Endosc. 1998;12:1017-1019.

8. Ott D. Smoke production and smoke reduction in endoscopicsurgery. Endosc Surg. 1993;1:230-232.

9. Kretschmer HL. Intravesical explosions as a complication of trans-urethral electroresection: report of two cases. J Am Med Assoc.1934;103:1144.

0. Bobbitt RM. Intravesical rupture of bladder during transurethralprostatic resection. J Urol. 1950;64:338-340.

1. Gatti JE, Bryant CJ, Noone RB, et al. The mutagenicity of elec-trocautery smoke. Plast Reconstr Surg. 1992;89:781-784.

2. Tomita Y, Mihashi S, Nagata K, et al. Mutagenicity of smokecondensates induced by CO2 laser irradiation and electrocauteri-zation. Mutat Res. 1981;89:145-149.

3. Health & Safety Executive. EH40/2005 Workplace Exposure Limits2005. London: The Stationery Office; 2005.

4. NIOSH. Recommendations for occupational safety and health:compendium of policy documents and statements. National Insti-tute for Occupational Safety and Health, 1992; DHHS (NIOSH)Publication No. 92-100.

DITORIAL COMMENThis article is likely to be of interest, and perhaps some con-ern, to anyone who uses a resectoscope on a frequent basis.he authors have performed a relatively simple study analyzing

he production of carbon dioxide and several other noxiousases in 4 patients undergoing either TURP or TUVP. Allrocedures were performed under similar operating room con-itions, with positive pressure ventilation. An obvious criticisms the use of digital rectal examination to estimate resectedeight with TUVP. Given the associated inaccuracy, any com-arison between TUVP and TURP must be questioned. Addi-ionally, there was only a single TUVP performed, and many ofhe values recorded appear to lie within the range obtained atURP. The authors admit that their study was not powered to

ake such comparisons, but what they have demonstrated is

UROLOGY 74 (5), 2009