Chapter 32 Operating Room Fires and Personnel Injuries Related to Sources of Ignition P.908 Although flammable anesthetics have disappeared from operating rooms, perioperative fires continue to occur. They can have devastating consequences, precipitate legal action, and take a great psychological toll on everyone involved. They usually come as a complete surprise to the staff ( 1 , 2 , 3 , 4 ). Most operating room fires are of little consequence and are not reported, making the actual incidence difficult to determine ( 2 , 5 , 6 ). Approximately 10% to 20% of reported fires result in serious patient injury ( 7 , 8 ). Fuels present in the operating room include plastics that produce dense black smoke when ignited. The smoke may contain toxins and may hinder safe evacuation of the patient and staff from the room. Sudden ignition can present secondary problems ( 9 ). It can cause a startle reflex, causing the surgeon's hand to jerk and potentially cut into unintended tissue or set other areas of the surgical site on fire. The Fire Triangle For a fire to occur, there must be three factors (fire triangle or triad) present: an ignition source, a fuel, and an oxidizer to support combustion together in the proper proportions and under the right conditions ( Fig. 32.1 ).
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Chapter 32 Operating Room Fires and Personnel Injuries Related to Sources of Ignition P.908
Al though f lammable anesthet ics have disappeared from operating rooms,
perioperat ive f i res cont inue to occur. They can have devastat ing consequences,
precipi ta te legal act ion, and take a great psychological to ll on everyone involved.
They usua lly come as a comple te surprise to the staff (1,2,3,4).
Most operat ing room fi res are o f l i t tle consequence and are not reported, making
the actual inc idence dif f icul t to determine (2,5 ,6). Approx imately 10% to 20% of
reported f i res resu lt in serious patient injury (7,8). Fuels present in the operat ing
room include plast ics tha t produce dense black smoke when ignited. The smoke
may conta in toxins and may h inder safe evacuation of the pat ient and staff f rom the
room. Sudden igni tion can present secondary problems (9). It can cause a start le
ref lex , caus ing the surgeon's hand to je rk and potentially cut into unin tended t issue
or set other a reas of the surgical s ite on fi re .
The Fire Triangle For a f i re to occur, there must be three fac tors (f ire tr iangle or triad) p resent: an
igni tion source, a fuel , and an oxid izer to support combustion together in the proper
proport ions and under the right condi t ions (Fig. 32.1).
View Figure
Figure 32.1 Three things are necessary for a fire to occur: an ignition source, fuel, and an oxidizer.
Ignition Source There are a number of igni tion sources in the operat ing room. Most are under the
surgeon's control.
Lasers The acronym laser ( l ight ampl if ication by s timulated emission of radiat ion) def ines
the process by which a form of energy is converted into l ight energy
(10,11,12,13,14,15,16). The term can also refer to the device tha t produces the
l ight or to the l ight i tself .
Lasers use a col imated, coherent, monochromatic , intense beam of electromagnetic
radiation to cut, coagulate, or vaporize tissue.
The rate that the laser energy is delivered is ca lled power and is measured in
watts . The wattage is equal to the amount of energy, measured in joules, d iv ided by
the duration of exposure measured in seconds. Laser power density is the amount
of power d istr ibu ted wi thin an area and is indicated in watts per square cent imeter.
Components of a Laser System The basic components of a laser system are two parallel mirrors encompassing the
laser medium and a power source (Fig. 32.2). In add it ion, there may be an aiming
beam for de livering laser energy tha t is outs ide the v isible range.
Laser Medium
The medium (head) holds the subs tance energized to produce laser l igh t. The
medium, wh ich may be a solid, liquid, o r gas, determines the wavelength of the
emitted radiation . The laser is named for the material used as the medium.
Power Source The power (pumping, pump, exci ta tion) source supplies energy to the laser med ium
to c reate the l ight. When the power source is act ivated, energy is absorbed by
electrons of the atoms in the laser medium, which are e levated to energy levels
above their ground state. They then decay to lower energy levels and emit photons
that are not in phase with one another and travel in all di rections.
Optical Cavity The optical (resonator) cavi ty p rov ides the envi ronment in which the laser medium
is conf ined. Energy released from the medium travels in al l di rect ions. Mirrors are
used to ref lec t and increase the energy of emission. One of the mirrors is no t 100%
ref lec tive and allows a small port ion of the l ight to escape.
Light Guide A light guide (delivery system) di rec ts the laser beam to the surgical s ite (Fig.
32.3). Fiber-optic bundles are a convenient f lex ible condui t for some wavelengths .
Other lasers ut i l ize a hol low tube wi th mirrors aligned to reflect the beam f rom i ts
source through the focusing lens .
Aiming Beam With certa in lasers, it is necessary to use a low-powered v is ib le beam as a marker.
This is usua lly a helium-neon gas laser. I t passes th rough the same optical pa th as
the laser beam.
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View Figure
Figure 32.2 Components of a laser.
Laser Types Types of med ical lasers commonly used in surgery are shown in Table 32 .1.
Laser Hazards Lasers can cause s ignif icant damage to opera ting room personne l (inc lud ing the
anesthesia provider) and the pat ient. Hazards involv ing lasers include f ires ,
atmospheric contamination, eye damage, organ or vessel perforation, and embolism
(10). Figure 32.4 shows a s ign used to warn personne l that a laser is in use.
View Figure
Figure 32.3 This is a schematic representation of a CO2 laser guide as might be found in either an operating microscope or a handheld wand. The guide consists of hollow tubes with hinged, aligned mirrors that reflect the beam from its source through the focusing lens.
A recurrent problem wi th lasers is that they may be activated when not in use
(22,23). Often, a foot switch accidentally act iva tes the laser. The laser may be in a
posit ion where this is not no ticed for some time. When the laser is not actually in
use, i t should be p laced in the STAND-BY mode.
A f i re may resu lt when a laser beam hits a fuel or the laser f iber becomes
damaged. Ign ition can be almost ins tan taneous. Whi le mos t ignition sources must
be in contact with a material to cause ign it ion, a laser can supp ly heat to a fuel
f rom a few centimeters to severa l meters away, so i t can ignite material c lose to the
t ip, at some d istance from the tip , or under several layers of o ther material . A
surface drape can be penetrated by the laser but not igni te . Materials under the
drape may then igni te and burn wi thout being not iced for several minutes (24). The
laser beam can be ref lec ted f rom a metal surface, causing a burn or ign it ing
material in a remote loca tion.
Laser Risk Classification A classif ication system ref lecting laser risk to the patient and personnel has been
developed (25,26,27). The higher the c lass, the more stringent the protec tion
needed.
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TABLE 32.1 Commonly Used Lasers and Associated Personnel Hazards
Laser Medium
Features Potential Hazards to the Eye
Special Considerations
CO2 Readily absorbed by all biologic materials, independent of pigmentation. Tissue destruction is proportional to its water content. Produces a very superficial tissue effect.
Injury to the eye will be confined to the cornea. There is no risk to the retina. Since the laser is absorbed by plastic and glass, ordinary eyeglasses with sideguards can be used for eye protection.
Fires involving both tracheal tubes and supraglottic devices have been reported with this laser.
Nd-YAG
Can be transmitted through fiber-optic fibers. Poorly absorbed by water but well absorbed by pigmented tissue (11).
Retinal damage can occur. Opaque green eyewear or eyewear with clear lenses with a special coating should be worn.
Because it is taken up by pigment, colored markings on tracheal tubes are more likely to be damaged than clear portions (12). Blood or mucus on or in the tracheal tube makes the tube less resistant to the laser beam. Fires have been reported from an Nd-YAG laser passed through the channel of a flexible bronchoscope (17,18). The rigid bronchoscope is recommended for use with this laser, although the flexible scope may be needed to treat hard-to-reach areas (19).
KTP Passes through clear substances but is absorbed by hemoglobin and other pigments (11,20,22).
Retinal damage may occur. Special eyewear with red filter should be worn.
Argon Beam is selectively absorbed by red, orange, and yellow pigment and strongly absorbed by hemoglobin and
Retinal damage may occur. Special opaque orange goggles/eyewear should be worn.
melanin. Fiber-optic bundles can be used to transmit the laser beam.
From Klarr P. Laser complications. In: Atlee J, ed. Complications in Anesthesia. Philadelphia: WB Saunders, 1999:588β590.
Class 1 Lasers Lasers that are totally enclosed or that emit extremely low output fall into c lass 1.
These are safe to v iew.
Class 2 Lasers Low-risk lasers are in c lass 2. Their r isk is approximate ly equivalent to staring at
the sun or o ther brigh t lights that can cause centra l re tinal injury. These are not
hazardous unless someone overcomes their natura l aversion response to bright
l ight.
Class 3 Lasers Class 3 lasers operate at a power level above 1 mW. This is a hazard even if
v iewed only momentari ly . Class 3 lasers are subdiv ided into a and b subclasses .
The 3a subclass cons is ts of lasers in the 1 to 5 mw power range. These lasers pose
a moderate ocular hazard. Class 3b inc ludes lasers that emit between 5 and 500
mW of output power. Even momentary v iewing of these lasers is potential ly
hazardous to the eye. They may also be a hazard to skin.
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View Figure
Figure 32.4 Note that the laser class is on the sign.
Class 4 Lasers Any cont inuous wave laser wi th a power output above 500 mW is in c lass 4 . These
lasers pose serious skin, eye, and f i re hazards.
Igni tion risk is re lated to a number of fac tors beside the laser c lassif ication . Class
3b and 4 lasers are cons idered to be igni tion hazards. The igni t ion risk of other
c lasses of lasers wi l l depend on how they are focused, the t ime of exposure, and
the oxidizers and fuels tha t are present.
Metal instruments can become overheated with pro longed laser use and could
cause a burn (28).
Electrosurgery Unit Electrosurgery (radio frequency) apparatus is so widely used that there is of ten
complacency about reading the instruct ion manual or following safe pract ices
(29,30). Electrosurgery units are the mos t common igni tion source in surgica l f i res
(6). The instruction manua l should be s tudied at the beginning of a tra ining program
and reviewed periodica lly. A brief set of operat ing instruc tions should be readi ly
availab le on the instrument (31).
Terminology The vocabulary concerning electrosurgery is somewhat confusing (32). This chapter
wi l l def ine e lec trosurgery devices as those that employ a h igh-f requency (radio
f requency) electric current passing through t issues to cut, coagulate, or prov ide a
blend of cutting and coagu lat ion. Elec trocautery ut i l izes a heated wire or blade,
usual ly at the end of a probe fo r coagulation . Most elec trocautery devices are
battery-opera ted.
Physics There are three modes avai lable on modern electrosurgery devices .
Cutting Mode The cutt ing mode uses a continuous s ine wave. Heating is rap id and produces h igh
temperatures that explode cel ls that come in contact wi th the electrode. This
produces a cut in the tissue.
Coagulation Mode The coagu lat ion mode features short bursts of a dampened s ine wave. Less heat is
produced s ince the current is not cont inuous. Tissue desiccat ion occurs , and the
ends of blood vessels are thermally sealed .
Blend Mode The blend (cut-coagulation) mode employs a waveform and voltage between tha t of
the cutting and coagu la tion cycle . The rela tive amount of cutting or coagulat ion
depends on the lengths of the bursts of voltage. Severa l blend se tt ings may be
availab le on an elec trosurgical uni t (33).
Types Monopolar With monopolar (unipolar) electrosurgery un its , e lectrons f low f rom the genera tor to
the act ive electrode and through the patient to the dispers ive (return , inact ive)
electrode, sometimes incorrect ly called the grounding pad (Fig. 32.5). The curren t
disperses from high densi ty at the tip of the act ive electrode to a lower dens ity v ia
the lowest impedance pathway tha t it can f ind .
Generator The elec trically powered generator (power uni t) c rea tes a radio frequency current
that passes through the active electrode. The effect on tissue depends on the
current intensi ty, the type of current employed, the durat ion of exposure to the
current, the hand piece used, and the dispers ive electrode (34). Coagulat ion
requires longer contact wi th the probe than cutt ing. As electrica l energy is appl ied
to the t issue, char forms. Since char has h igher impedance, more current d iss ipates
di rectly to the dispers ive elec trode and the ef fect is reduced (34).
Active Electrode
The active elec trode has a handle and is connected to the generator by a f lex ible
wi re. It d irects current f low to the surgical si te. The tip of the act ive electrode may
be a blade, spatula, ball , lancet, loop, forceps , need le po int, or suct ion tip. I t may
be disposab le or reusable. The t ip
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configuration determines i ts abil i ty to desiccate tissue. A needle-tip electrode
concentrates more power on t issue contact than does a paddle or ba ll -shaped
electrode (34). At a given electrode vol tage, the paddle-shaped t ip p resents a
higher power at the edge than on the flat port ion. The electrode may be activa ted
by a hand contro l or foot switch. The control may also be used to switch f rom one
mode to another.
View Figure
Figure 32.5 Monopolar electrosurgery unit.
Dispersive Electrode The dispers ive (inactive, return) electrode (grounding or ground electrode, pla te, or
pad) col lects the current from the patient and returns it to the generator to
comple te the c i rcu it . The large contact surface of the pad provides low impedance.
Most pads present ly in use are prejel led. Reusab le metal p lates used in conjunct ion
wi th conduc tive ge l are rarely used today. With some electrosurgery uni ts , two
dispers ive e lec trodes should be used (35).
Safety System
Modern electrosurgical uni ts possess a return e lec trode (contac t quali ty) moni to ring
system. This ensures tha t the patient is connec ted to the return e lec trode (34,36).
Current f lowing to the ac tive electrode is measured and compared with current
returning f rom the d ispers ive electrode. If the curren ts are not ba lanced, the uni t is
deactivated. A more recent innovation is active electrode monitoring (AEM)
(37,38,39,40). This continuously moni tors the electrical c ircui t and automatically
shuts down the generator and sounds an ala rm if dangerous e lectrical leakage
occurs. Newer generators can sense dramatic changes in t issue impedance or
temperature changes at the return electrode (33,41). Some modern electrosurgery
machines are equipped wi th βspl i t padsβ (42). The uni t wi l l not func tion unless both
halves of the pad are in contact wi th the patient.
Bipolar The bipo lar electrosurgery unit is composed o f a generator and two electrodes
located wi th in mill imeters of each other. The energy f low is be tween the two
electrodes , and no current f lows through the patient 's body. This al lows the energy
to be local ized more precise ly. The current densi ty in the t issues surrounding the
ac tive electrode is substant ially less than that for monopolar elec trodes, and
deeper t issue layers are preserved wi th lower vol tage and power requirements. This
type of e lec trosurgery un it can coagulate even when the tip is immersed in b lood.
Bipolar units cannot be used fo r cutting .
Bipolar elec trodes are produced in a variety o f conf igurat ions: hooks , spatulas ,
sc issors, forceps , and needles (29 ,43). Of ten, these devices are batte ry-opera ted.
There are reports that the ON-OFF swi tch on one of these dev ices did not always
deactivate the dev ice when it was set aside (44 ,45). The hot t ip could then set
drapes on f i re. At least one device could be act ivated by another device's wire less
remote-control uni t or by f luorescent room l ights (46).
Hazards Associated with Electrosurgery Mishaps with the elec trosurgery uni t of ten involve faul ty re turn electrodes, improper
electrode placement, or al te rnate low-impedance outlets. Insuff ic ient contact wi th
the dispersive pad can resul t in pa tient burns and/or burns to others who are in
contact wi th the pat ient. Among the low-impedance al te rnatives are
electrocardiogram (ECG) monitoring elec trodes, temperature probes, urinary
ca theters, metall ic parts of surgica l tables, heating pads, and oximeters (47).
About 68% of reported surgical f i res involve e lectrosurgical equ ipment (48). Fires
associated wi th the electrosurgery unit are of ten associated with an oxidizer-
enriched atmosphere. When the electrosurgery uni t is used, heat vaporizes t issue
or expels tissue embers from the t ip. In room air, t issue vapors do not igni te, and
embers are quick ly extinguished. In an oxidizer-enriched atmosphere, the vapors
can ignite into a brief f lame, and embers can fly several inches and burn unt i l they
are consumed. A f la re of evolved gases can d irectly ignite any convenient fuel . The
electrical wires associa ted wi th the electrosurgery electrode may develop a short
c i rcui t, wh ich could resul t in a f ire (49).
During laparoscopic surgery, burns that are sometimes fatal can occur ou tside the
surgeon's v iew when using an elec trosurgery uni t (14,29,33,38,40,50,51,52). These
are usua lly caused by insu lat ion fai lure, di rect coupling, or capacit ive coup ling.
I f a defect occurs in the active electrode's insulation , current can f low through the
defec t. Defec ts can resul t f rom improper handling or damage to both reusable and
disposable electrodes . A number of devices are avai lable to detect insula tion
Of ten , the patien t is being given 100% oxygen in ant ic ipa tion of interrupted
venti lation and/or because of the underly ing c linical cond ition. If the tracheal tube
or cuff is contacted, an oxidizer wi l l be released. Current ly , there is no tracheal
tube that is safe for use wi th electrosurgical devices or electrocautery, al though
some are more resistant to igni tion than others (155).
Using Electrosurgery in the Mouth Using electrosurgery in the oral cavi ty may resul t in a f i re
(6,156,157,158,159,160,161,162). The tracheal tube is of ten the fuel , but o ther
i tems such as sponges or patient t issue may be involved. Of ten, wet gauze is used
in the throat to catch sec ret ions or to pro tect the tracheal tube. If there is a leak
around the tube, the gauze can becomes oxidizer-enriched and dry ou t more
quick ly.
Laser-induced Tracheal Tube Fires The l ikelihood that a laser wil l contact the tracheal tube during ai rway procedures
is high (163). Cuffed tubes are more l ikely to be contacted than noncuffed tubes.
The tube may be exposed to ei ther the di rec t or ref lec ted laser beam. Flaming
t issue in c lose proximity to the tube may cause it to ignite (164).
In addi tion to local damage in the larynx, injury can occur to the lower a irway and
the parenchymal t issue in the lung. The products of combustion may be b lown into
the lungs.
The cuff is the most vulnerable part of the tracheal tube. It cannot be wrapped, and
laser-resistan t tubes do not have laser-res is tan t cuffs .
Wet cotton sponges are of ten used around the tube to protect the cuff f rom the
laser beam. If these dry out, they can become fuel for a f ire (165). Tape that is
used to secure the tube can igni te.
During lower ai rway surgery using a laser, the cable may be passed through the
inside of a tracheal tube. The tracheal tube should be placed just below the vocal
cords so that the t ip is as fa r away f rom the operat ive s ite as possible.
Other Head and Neck Fires Head and neck f i res can occur during local anesthes ia procedures when
electrosurgery apparatus is used (6,49,56,126,166,167,168,169,170,171,172,173).
Of ten , oxygen is being administe red, and i t may diffuse into the surg ical area. Any
f lammable i tem in the v ic ini ty can catch f ire.
Fires Involving Pressure Regulators While no t a frequent occurrence, a f ire in a regulator can be d isastrous (174).
These fi res may resul t f rom adiabat ic compress ion or partic le ignit ion in which
debris is b lown f rom the cyl inder into the regulator wi th suffic ient energy to cause
igni tion. Improper pressure regulator assembly may also cause a f i re.
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Regula tors wi th aluminum components are more l ike ly to burn than other
regulators . The Food and Drug Adminis trat ion (FDA) and the National Ins ti tute for
Occupational Safe ty and Heal th (NIOSH) now recommend that aluminum regulators
be replaced wi th ones wi th brass components (64,66). A number of aluminum
oxygen regulators have been recalled (67).
Intraperitoneal Fires Severa l explosions have been reported during laparoscopy when nitrous oxide was
used as the insuff lating gas (122,175,176,177). Ni trous oxide in the inspired gases
wi l l dif fuse into the peritoneal cavi ty and may reach a high enough concentrat ion to
support combustion (178,179). Fires have also resul ted f rom inf lat ing the peri tonea l
cavity wi th an oxygen-CO2 mixture instead of pure CO2 (180,181). The Pin Index
Safety System (Chapter 1) wi l l not p revent this error, because the index ho les for
tanks wi th 100% CO2 are the same as for any tank wi th greater than 7% CO2 .
Fires during Defibrillation Oxygen is always used during resusci tation, and the source is of ten disconnected
and p laced near the head (58,182,183). This may allow oxygen to f low over the
defibri l la tion electrodes (184). A spark caused by placement of the def ibri l lato r
paddle or electrode close to an ECG elec trode or poor contact be tween the
patient 's sk in and the def ibri l lator paddle or electrode may ignite hair or other
combustible materials in the area (183,185).
Fires in Canisters Fires in CO2 absorbent canisters have been reported
(186,187,188,189,190,191,192,193). These are d iscussed in more detail in Chapter
9.
Personnel Risks
Smoke Hazards Potent ial ly hazardous ai rborne contaminants are formed from tissue vaporization
when a laser is used. These by-products have the potent ial to be mutagenic,
carc inogenic, teratogenic, or a vector for v iral infect ion (10,194). Elec trosurgery
devices and bone saws also produce vaporized f ragments that have the same
hazards (25).
Inhaling potent ia lly hazardous ai rborne contaminants can be kept to a minimum by
scavenging the smoke. This wi l l help to give the surgeon a c learer v iew o f the
surgical field and removes o ffensive and irrita ting odors. Various smoke evacuators
are avai lable (103,195). To be most effect ive, the evacuator nozzle should be
posit ioned as c lose as possible to the operative f ie ld and be func tiona l before,
during and for 30 seconds after t issue is vaporized (196).
Personnel masks should be removed and discarded as soon as poss ib le af te r use
(196). Standard surgical masks f i l ter ou t partic les down to about 3 microns in
diameter. The laser plume has partic les as small as 0.31 microns . High-eff ic iency
masks can f il te r partic les down to 0.30 mic rons, bu t they are dif f icul t to breathe
through and lose their eff iciency when wet (10,103).
Ocular Injuries The laser beam may be di rected over some distance. The area of hazard may not
be l imi ted to the immediate surgical area and may present risk to operating room
personnel (25). The surgeon is not highly susceptible to injury because of the
safety dev ices bui lt into the ins trument. However, if the ins trument is accidental ly
ac tivated, he is exposed to the same hazards as other personnel .
The eye is especially vulnerable to injury. Because CO2 laser beams are absorbed
wi th in the fi rs t 200 Β΅m of t issue, they are a hazard to the cornea (197). Argon, KTP,
and Nd-YAG lasers are more like ly to cause damage to the retina . The ex tent of
damage wil l depend on wh ich part of the retina is affected. Permanent v isual loss
may resul t (25).
All personnel in the area where a laser is used should wear appropriate protect ive
eyewear. This may inc lude goggles, face shields, spectacles , or presc ription
eyewear using special materials or reflec tive coatings (or a combination of both),
se lec ted to reduce the potent ial ocular exposure. The safety eyewear should be
marked according to the wavelength (laser type) (Fig. 32.6). I t should be noted that
laser safety eyewear is not des igned fo r looking di rectly at a laser beam (16). The
patient 's eyes should be c losed and covered wi th saline-soaked gauze or a
nonshiny metal shield . Awake patients should wear goggles specif ic for the laser
being used. Windows in the room should be covered and a warning sign placed
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on the operat ing room door at eye level (Fig. 32.4). Spare eyeware should be
availab le at a ll entrances.
View Figure
Figure 32.6 All laser-protective eyewear should be clearly and permanently labeled.
Electrical Shock Another concern is electrical shock from the e lec trosurgery device. A common
pract ice among surgeons is to al low an assistant to touch the dista l end of a
forceps wi th the act ive electrode f rom the electrosurgery apparatus. This act ion
makes the forceps the active electrode. A glove may not offer suffic ient p rotec tion
f rom the electrical c ircui t . Holes appear in as many as 15% of g loves.
There are ways to minimize the shock potential wh ile using electrosurgery. The
ac tive electrode should be f irmly in contact wi th the forceps before i t is energized.
The person holding the forceps should try to contact i t in as large an area as
possible to spread the concentration of the charge.
Fire Prevention The best way to deal with fi res is to prevent them f rom start ing (127,198). Fi res can
be avoided by not allowing the th ree elements of the f ire tr iangle to come together
at the same t ime.
Controlling Ignition Sources One way to reduce f ires is to properly use equipment that might ac t as an igni tion
source. I t is important to read instruct ion manuals and to alter techniques to f i t
these instructions.
Lasers
Personnel who use lasers should take a cert if ied laser course (6,23,26,103). They
should practice their techn ique on inanimate ob jec ts and gain experience a t the
hands of an experienced c linic ian. Specif ic personnel should be designated to
moni tor and prevent laser hazards.
A laser protocol should be developed and fo llowed. Lasers should be test f ired onto
a safe surface before use to ensure tha t the beams are properly al igned. Lasers
should always be kept in the standby mode except when needed. The lowest power
densi ty and shortest pu lse dura tion that wi l l do the job should be used. The laser
should be activated only when the tip is under the surgeon's d irect v is ion. The laser
should be placed in standby mode before removing i t f rom the surg ical s i te.
Laser f ibers should not be c lipped to drapes because the f ibers may be broken. The
laser fiber should be careful ly passed through an endoscope before in troducing the
scope into the pat ient to minimize the risk of f iber damage. The f iber's funct ionali ty
should be verif ied before insert ing the endoscope into the pat ient.
I f a laser contact t ip is used, the t ip wil l remain hot for several seconds. Bl ind entry
into cavi ties wi th this tip should be avoided (199). The risk of tracheal tube igni tion
wi l l be lowered if the laser is activated during the expiratory pause (200).
Electrosurgery Unit The elec trosurgery uni t should not be used during tracheostomy
(31,34,50,111,171,201,202,203,204). Bleeding should not be trea ted wi th
electrosurgery af ter f lammable dressings have been appl ied.
A bipolar electrosurgery uni t should be used whenever possible . This wi l l reduce
the curren t densi ty in the t issues surrounding the ac tive electrode and minimize the
potential for di rect coupl ing. Bipolar units work at lower voltages and are not
associated wi th insulation fai lure .
Monopolar un its should have a means to moni tor the return electrode or ac tive
electrode. Us ing active e lec trode monitoring wi l l min imize the risk of s tray
electrosurgical burns (38). Before each use, the electrosurgery uni t and assoc ia ted
safety features should be inspected for s igns of damage and tested to ensure that
the uni t is functioning correct ly. If i t is not work ing properly or is damaged, the
electrosurgical apparatus should be immediately removed f rom serv ice. The uni t
should be pro tec ted f rom sp il ls . Unintentional act ivation may occur i f f lu ids enter
the generator. The alarm system should be checked prior to applying the dispers ive
electrode. The act ive electrode should have a t ip that is secure, because a loose
t ip may cause a spark. Prejel led dispers ive electrode pads should be checked for
uniform gel dis tr ibution and absence of exposed wires before being applied to the
patient. Outdated or previously opened but unused dispers ive e lectrode pads
should not be used, because the gel can undergo electrolys is and/or desicca tion. If
a dispers ive elec trode pad requiring gel is used, the pad shou ld be checked
careful ly to identify any dry spots on i ts surface before it is placed on the patient.
Af ter the patient has been posi tioned, the connect ion between the pat ient and the
unit should be establ ished by p lac ing the dispers ive electrode on a nonhairy a rea of
c lean, dry sk in. The dispers ive electrode should be the appropria te s ize for a
patient ( i.e. , neonate, infant, ped iatric , adult) and never be cu t to reduce its size.
The dispers ive electrode should be app lied to c lean, dry skin over a large, wel l-
perfused muscle mass as c lose to the operative s i te as practica l, avoiding bony
prominences, scar t issue, skin over a metal prosthesis, o r dis tal to a tourniquet.
Excessive hair shou ld be removed before apply ing the dispers ive e lec trode,
because hair wil l insu late the pad from the patient. The pad's ent ire surface area
should main tain uniform body contact. There should not be any ten ting, gaping, o r
moisture under the pad. This wil l interfere with adhesion to the sk in and decrease
the contac t surface. The dispers ive electrode
P.918
should not be moved to another s i te a fter ini tial appl ication. The status of the
dispers ive e lec trode should be checked if any tension is applied to the cord or i f
the pat ient is reposi tioned after the pad is appl ied. A used dispers ive electrode
should not be reapp lied.
Electrocardiographic electrodes should be placed as far as possible from the
operative si te to minimize the alternate f low o f current through the electrodes and
moni tor to g round.
I f insulated electrosurgical elec trode probes are required, only commercial ly
availab le insulated probes should be used (9). Insulating s leeves cut f rom catheters
or o ther materials shou ld no t be used to sheathe probes.
The lowes t power settings tha t are effective for the surgical procedure , as
determined by the surgeon in conjunc tion wi th the manufacturer's recommendation,
should be used. The ent i re ci rcui t should be checked if the operator requests higher
power sett ings because of ineffectual results .
The elec trosurgery uni t should be act ivated only when the tip is under the
surgeon's direc t v ision and only by the person using i t . Cords shou ld no t be
c lamped with or wound around any objec ts . The electrosurgery probe should be
kept c lean to minimize the risk of adherent t issue incandescing or f laming. The
electrosurgical penc il should be placed in a holster when i t is not in act ive use. The
electrosurgical uni t should be placed in s tandby mode whenever i t is no t in active
use. Unnecessary foo t swi tches should be removed so that they are not
accidentally ac tivated .
During laparoscopic surgery, all-metal or a ll-p lastic cannulas should be used and
not a hybrid cannula system (i.e. , a combination of plastic and metal cannulas )
(37). Electrosurgery elec trodes should not be used ins ide metal suct ion i rrigators.
The elec trosurgica l uni t should be deac tivated before removing it f rom the surgical
s i te. Even after deact ivation , the probe t ip may retain enough heat for a few
seconds to mel t plast ics or igni te some fuels, so it shou ld be placed ins ide a c lean,
wel l -insulated holder or broken off . In addi tion to protecting the t ip, this makes i t
more dif f icult to acc identally ac tivate the switch . The t ip should be broken, and a
safety cover should be placed over the tip and act ivation swi tch before the device
is discarded (205).
Argon-enhanced Coagulation All safety measures observed for the electrosurgical unit shou ld be observed for
argon-enhanced coagulation (31). The electrode should not be placed in di rect
contact wi th t issue. The hand piece should be moved away f rom the pat ient's t issue
af te r each activation. The argon gas f low and the argon coagu lator should be
ac tivated simul taneously. The argon gas l ine should be purged of ai r before each
procedure and by act ivat ing the system after moderate delays between act ivat ions.
Fiber-optic Light Sources All connec tions should be made before the l ight source is activated, because the
end of the cable can cause a f i re (53). An act ive f iber-optic cable should not be
placed on flammable material . The l ight source shou ld be turned OFF before
disconnecting the cab le. The end of a f iber-optic cable can retain a signif icant
amount of heat after be ing disconnected from the l ight source (206). Therefore, i t is
importan t to be careful where one places the end of a f iber-op tic cord.
Heated Humidifiers Only a breath ing tube and heat ing ci rcu it labeled for use with a spec if ic humid if ier
should be used (207). Heated breathing c i rcui ts should not be covered wi th sheets,
blankets, towels, clothing, o r other material. They should not rest on surfaces such
as the patient, operat ing table, blankets, o r medical equipment. Instead, a boom
arm or tube tree shou ld be used to support them. A heated-wire breathing ci rcui t
should not be turned ON before f low has been ini tiated. I f there is no f low (as
during cardiopulmonary bypass ), the heater should be turned OFF (208).
Defibrillators When us ing a defibri l lato r, care should be taken to hold the paddles f i rmly and
posit ion them properly. Disposable conduc tive pads should be larger than the meta l
surface of the paddle and be wi thin their expiration date. This wil l prevent arc ing
when the paddles are activa ted (58). ECG electrodes should be appl ied as far as
possible f rom the def ibri l lat ion pads.
Electrical Faults All electrica l cords should be regularly inspec ted for cuts and nicks in the
insulat ion, f rayed insulat ion, and loose connections at the plug or receptac le ends
(209). Al l plugs should be pushed completely in to the receptacles to prevent p rong-
to-prong arc ing (210).
Managing Fuels Tracheal Tubes
Non-intubation Techniques Since the tracheal tube is of ten the fuel for the f i re , anes thetic techn iques that do
not require a tracheal tube wi l l el iminate one component of the f i re triad (92).
These inc lude apnea, jet vent i lat ion, and spontaneous breathing.
Apnea With the apneic technique, the pat ient is vent i lated by us ing a mask or tracheal
tube, and these are withdrawn as the laser is used (92,93,211). Af ter a period of
t ime, vent i lat ion is reinstated. This is repeated as long as needed to perform the
surgery.
Insufflation Patients may be al lowed to spontaneously breathe a combinat ion of oxygen and
anesthet ic agents whi le laser procedures are undertaken. The gases are
administered through a catheter or hook in the
P.919
corner of the mouth tha t is wel l out of the way of the laser beam. The suc tion
channe l of a laryngoscope may be used to insuff late oxygen. Operat ing room
pollut ion wi th anesthet ic agents may be high wi th this technique. Oxidizers should
be used as sparingly as possible s ince the insuff lated gas cou ld support
combustion.
Jet Ventilation Jet vent i la tion techniques ei ther v ia a metal bronchoscope or a catheter inserted
through the crico thyroid membrane may be used (212). A h igh-veloci ty jet of oxygen
or helium and oxygen can be di rec ted into the ai rway above or below the glo tt is by
us ing various apparatus (21,92,93,196,213,214).
There has been a f i re reported with th is technique (215). An errant laser strike
igni ted the surgeon's glove. The resul tan t burning vapors were entra ined into the
patient 's airway. The patient's mustache was also igni ted , and the pat ient suffered
fac ial burns .
Filling the Cuff with Saline The cuff is the most vulnerable part of the tracheal tube, regardless of the tube or
cuff materia l. If a laser beam penetrates an ai r-f i l led cuff , gas can leak in to the
operative field, and if the oxygen concentrat ion is high, the risk of f i re is great.
Fluid in a cuf f ac ts as a heat s ink and makes the cuff less easy to perforate
(216,217). Fi l ling the tracheal tube cuff wi th a l idocaine jelly-plus -saline mixture no t
only prevents the cuff f rom being igni ted but may plug small holes in the cuff
resul ting f rom a laser h it (218).
I f the cuff is perfora ted, a je t of f lu id may ex tingu ish the f ire. If perfo rated, fluid-
f il led cuffs reta in their shape longer than a ir-f i l led cuffs . Care must be taken to
remove all ai r f rom the cuff , because any remaining ai r wil l sett le in the most
superior part of the cuff , which is the part most l ikely to be h it by the laser beam.
Addit ion of methylene blue or o ther biocompatible and highly v isible dye to the
sa line wi l l help the surgeon to recognize a perforated cuff . Some surgeons object to
the addi t ion of methylene blue because if the cuff is punc tured, the color of the
t issues is al tered, making it dif f icu lt to recognize pathology.
Protective Wrappings The tube can be covered wi th a protective wrapping. These are discussed in
greater de tai l in Chapter 19.
Merocel wrap (Laser-GuardTM) was found to be acceptable for surg ical levels of
CO2 , KTP, and Nd-YAG lasers (219,220,221,222). Merocel-wrapped tubes are not
more combus tible if they are coated with blood (223). Reflec ted laser beams have
not been a problem with th is wrap (224). This product is easier to apply than
metall ic tapes (225).
Aluminum and copper tapes are effective for use with the CO2 and Nd-YAG lasers if
the tube is meticulously wrapped (226,227,228). However, a f i re can occur if the
laser contacts part of the tube that is not wrapped (229,230). A wrapped red rubber
tube does not offer protection f rom the KTP laser (86). The adhesive backing or
surface coating of some tapes can be ign ited by laser beams (92). The presence of
blood on the surface of foi l-wrapped tubes makes combustion more l ikely to occur
(223). Tape-wrapped tubes may unravel, leaving portions of the tube exposed. I f
the wrapping is dislodged, i t could obstruct the airway. A wrapped tube may catch
f ire (231,232). Meta ll ic tapes may ref lect the laser to nontargeted areas (224).
Spiral wrappings may cause the tube to k ink . Any wrapping adds thickness to the
tracheal tube, which could be a problem for the surgeon.
Protecting the Cuff with Wet Covers As a fu rther p recaut ion, moist cottono ids, sponges, or pledgets can be placed on
the cuff (92,233,234). Cotton gauze is a good choice because i t s tays wet longer
than other covers and has low energy transmission (235). Wet gauze wi l l also
protect the shaft (236). These have been found to be especial ly help ful with the
CO2 laser (234). The Nd-YAG, KTP, and argon lasers may allow some energy to
penetrate the pledget and rup ture the cuff (235).
I t is important that wet covers be kept moist. Laser beam h its may dry them, and if
that happens, they lose their protect ive effect. Further hi ts can cause the
co ttonoids and/or cuff to ign ite. Al l these must be retrieved af ter surgery.
Special Tracheal Tubes Ready-to-use laser-resis tant tubes are discussed in Chapter 19. Laser res istant
means tha t the material can wi thstand l imi ted laser energy wi th l i tt le o r no damage.
The use of a special laser tube does not necessari ly prevent a f ire during laser
surgery (237). Even though the tube is labeled laser-resistant, the cuff wi l l not be
resistant, and special p recautions need to be taken to protect it . A fi re may occur i f
the pro tec tive wet gauze over the cuff dries or is displaced.
No laser-resistant tracheal tube is completely safe f rom all types of lasers under all
condi tions . All of these tubes can be damaged or igni ted by lasers for which they
are not intended or by high laser energies (238,239). Some are made more
combustible by blood (223). Tubes sold for use with lasers should indicate the type
of laser fo r which they are sui ted as we ll as the condi tions (power, power densi ty,
spot s ize, oxygen concentra tion) under which the tube is safe to use. Stric t
adherence to manufacturer's warnings and d irections is essential .
I f the Nd-YAG laser is used through a f iber-optic bronchoscope passed th rough a
tracheal tube, i t is best to use an unmarked PVC tube (240). The tracheal tube
should be placed just below the vocal cords so tha t the t ip is as far away from the
operative si te as possible. I t should be remembered tha t the cover on the f iber-
optic endoscope is plast ic and can burn.
Some laser-res is tan t tubes are more resistant to f i re than conventiona l tracheal
tubes when contacted by elec trosurgical instruments (155).
P.920
When laser contac t tips are used, there is an even greater opportuni ty for igni tion .
They can get hot enough to melt and burn plast ics even when the laser is inac tive
(241).
Double-cuff tubes are not more resistant to leaks that wil l occur af ter cuff puncture
but do al low a sea l to be maintained if one cuff remains intact. The second cuff is
s t i l l vulnerable to puncture (239).
There are disadvantages assoc ia ted wi th laser-resis tant tubes . They are more
expensive than PVC and red rubber tubes. Since these tubes are often used for
patients who have had previous laryngeal surgery, the anatomy may be dis to rted,
making intubat ion diff icult . Some laser-resistant tubes are so st if f that i t is dif f icult
to pass a stylet or use wi th a specia lized laryngoscope such as the Bu llard
laryngoscope (Chapter 18). Therefore , a diff icult intubation may become even more
challenging when these tubes are needed.
Using Smaller Tracheal Tubes Smal l -diameter trachea l tubes require higher power densit ies fo r ignit ion than
large-d iameter tubes because the higher gas f low cools smaller tubes more quick ly
than larger tubes. Also, the smal le r the tracheal tube, the less l ikely i t is to be hi t
by an igni t ion source.
Making the Tracheal Tube Easy to Remove The tube should be f ixed so that it can be removed rapidly, if necessary. If the tube
is to be removed, th is should be done immediately after igni tion to minimize
damage to the ai rway and lungs. If the tube continues to burn, i t may be very
diff icul t to remove. Some tracheal tubes break apart as they burn . If the tube is
wrapped, the wrapping may break in to pieces tha t could lodge in the airway.
Some tubes are easier to remove than others (91). PVC tubes wi th sal ine-f il led
cuffs are more diff icult to remove than red rubber tubes . The fastest way to deflate
a fluid-f i l led cuff is to remove the contents wi th a syringe rather than cu tt ing the
pi lot bal loon. Unclamping the inf lation tube on a red rubber tube wi l l result in rapid
release of the cuff contents.
Wetting Fuels The use of wet towe ls , packers, or sponges around the surgical s ite can prevent
igni tion of materials near the s i te . Gauze or sponges used with uncuffed tracheal
tubes to minimize gas leakage in to the pharynx and sponges , gauze, and pledges
(and their s tr ings) used to protec t the tracheal tube cuff should be moistened and
not allowed to dry.
Hair that is near the opera tive si te (e.g., eyebrows, beards , and moustaches)
should be made nonflammable by coating i t thoroughly wi th a water-soluble
lubricating jelly .
Proper Preparation Practices Water-based solut ions should be used to decontaminate the skin prior to surgery
whenever possible . If a lcohol-containing solut ions must be used, a minimum of the
agent should be used and appl ied l ike paint, no t in a thick, runny coat. The so lu tion
should not be applied in a manner tha t allows dripping, pooling, or wicking. I f
so lut ion drips away from the surgica l s i te , it should be immediate ly blotted with a
gauze sponge before it can soak into any absorbent material . Any soaked materials
should be removed. Daubing of p rep pooled on skin (in the umbil icus or c ricoid
notch) may be needed. Draping should be delayed to al low the solution to fully
vaporize and become d iluted in room air. Th is could take 10 minutes or longer
(1,117). Incise (adhesive, occ lus ive) drapes should be used, if possible, to iso late
head and neck inc is ions from oxygen-enriched atmospheres and from flammable
vapors beneath the drapes (120). I f the incise material does not adhere to the
patient, the prep is l ikely s ti ll wet, and the pat ien t should be redraped once the
prep is ful ly d ry.
Correct Product Choices I t is important to consider the f i re potent ial when choosing equipment. The
anesthesia provider should be aware of the c i rcumstances under which a f i re can
occur and strive to use the product that wi l l have the lowest flammabil ity under
condi tions where i t wi l l be used.
Fi re /laser-res is tan t drapes should be used when exposure to igni tion is poss ib le. It
is important that the drape is tested with the type of ignit ion source that is to be
used. A standard for testing drapes using the CO2 laser has been published (242).
Laser-resistant anesthes ia c i rcui t protectors and drapes are available. These are
aluminized to def lec t the laser beam. There is sti l l the possibi l i ty tha t the beam may
be reflec ted onto a flammable surface and start a f ire (243).
The use of a metall ic Y-piece and elbow wi l l ensure tha t tracheal tube combus tion
wi l l not spread to the anes thesia breathing system (244).
Other Measures A number of other measures may be benef ic ial in preventing a f ire. The tracheal
tube should be withdrawn to above the s i te of surgery during tracheotomy. The use
of posi tive end-expira tory pressure (PEEP) may decrease the risk of a irway f i re in
some cases (245,246). Nurs ing personnel can reduce the combustible load in the
room by removing disposable paper wrappers and covers before the start of the
case. Not only does this reduce the fuel in the room, bu t it a lso reduces the waste
that mus t be disposed as βred bagβ wi th i ts higher disposal costs (2).
Minimizing Oxidizer Concentrations The f ire risk can be reduced by remov ing or iso la ting the oxidizer f rom the surgical
area or minimizing i ts concentrat ion.
P.921
During def ibri l lat ion, all sources of oxygen should be comple tely removed f rom the
area around the pat ient.
Oxygen should be adminis te red only when indicated and in no h igher concentration
than is needed (as gu ided by oxygen saturat ion monitoring).
There are several ways of supp ly ing a gas with an oxygen concentra tion greater
than 21% but less than 100% to the pat ient. An oxygen and an ai r f lowmeter can be
connec ted by using a Y-piece (Fig. 32 .7), or a blender can be used. If the machine
has an a ir f lowmeter, a mixture of oxygen in a ir can be set and del ivered to
common gas outlet (247). If the common gas outlet can be accessed, a nasal
cannula can be mated to the outlet by using a 5-mm tracheal tube connector. I f the
common gas outlet cannot be accessed, a ci rc le sys tem can be attached to the
machine, the adjustable pressure l imi ting (APL) va lve c losed, and the selector
swi tch set to BAG. A nasal cannula can then be attached to the Y-piece. This
arrangement may cause the cont inuous positive pressure alarm to be activated. A
forced-air convect ion machine can be used to prov ide a high f low o f ai r around the
patient 's head whi le a nasal cannu la delivers a low f low of 100% oxygen to the
patient.
View Figure
Figure 32.7 Gas from an oxygen flowmeter and an air flowmeter can be connected to produce a gas with an oxygen concentration of less than 100%.
I f possible , the oxygen flow should be discont inued for at leas t 1 minute before
heat-produc ing surg ical instruments are used (248,249). When the heat source is
no longer used and any t issue embers are ext inguished, oxygen administra tion can
be resumed.
During head and neck surgery, a barrier should be established between the oxygen-
enriched atmosphere beneath the drapes and the surgica l field, if possible. Th is
can often be accompl ished wi th an adhesive (incise, occlusive) drape (2,117).
When gas is used to venti late the area under the drapes and prevent CO2
accumulat ion, the lowest acceptab le concentrat ion of oxygen should be used (250).
Forming an open tent wi th the drapes wil l prevent gases from collecting and allow
oxygen to diss ipate (56 ,170). Since oxygen is s light ly heav ier than room air as long
as there is some way for the oxygen to get in and out of a space, i t wi l l tend to f low
toward the f loor. Actively scavenging the space beneath drapes wi th a suct ion
device wil l lower oxygen concentrat ions s ign if icant ly (251). Dev ices that combine
oxygen de livery wi th suction to prevent oxygen bui ldup under the drape have been
described (252,253). A fan can be used to blow the accumulated oxygen away f rom
the pat ient. Direct ing the f low o f nasa l oxygen through a nasal ai rway wil l lower the
oxygen concentration a t the sk in (254).
Hea lth care ins ti tu tions should consider purchasing anesthesia workstat ions tha t
include internal pipel ines and f lowmeters for ai r (248). This makes it easy to switch
patient venti lat ion beneath the drapes f rom oxygen to air before the use of heat-
producing surgical instruments. An ex ternal f lowmeter can be added to an
anesthesia mach ine if piped air is available (Fig. 32.7).
Ni trogen, ai r, o r hel ium may be used to reduce the inspired oxygen concentrat ion to
the lowest level that wi l l provide acceptable patien t oxygenation. Nitrous oxide
supports combus tion and should not be used as the di luent gas (255,256,257).
Helium is a good heat conduc tor and may offe r a s ligh t pro tective effect wi th the
CO2 bu t not the KTP laser (258,259). The use of hel ium may decrease the
resistance of the gases passing through the tracheal tube (260,261).
P.922
Ni trogen insuff lation can s ignif icantly reduce the inc idence of laser-induced
tracheal tube cuff f i res (262). This can be accompl ished by attaching a catheter
covered with a laser-resistant wrap to the tracheal tube. Ni trogen is then insuff lated
through the catheter. This technique should be undertaken wi th caut ion, as a
hypoxic mix ture may possibly be adminis te red.
Al though using lower inspired oxygen concentrat ions wi l l reduce the risk of igni t ion ,
i t wi l l not tota lly prevent it . If there is a s igni ficant leak around the tracheal tube
cuff , the anes thesia prov ider may f i l l the reservoir bag by pushing the oxygen f lush .
This wi l l result in an elevated oxygen concentra tion. A more appropria te response
wou ld be to inc rease the f resh gas f low wh ile main ta ining the same inspired oxygen
concentration or to replace the tracheal tube.
When elec trosurgery is used in the oral cavity , the use of a cu ffed tracheal tube wi l l
minimize the oxidizer level . Leaks around the tube may result in f ires (161,263). I f
an uncuf fed tube mus t be used, an occlusive pharyngeal pack moistened with a
nonf lammable l iquid wi l l reduce the gas f low into the oral cavi ty (264). Insuff la ting
the mouth with gases such as helium, CO2 , or n itrogen wi l l reduce the oxidizer
concentrat ion . The oropharynx can be scavenged wi th separate suct ion.
Pneumatic power tools shou ld be opera ted wi th n itrogen or ai r. Inf latable
tourniquets should be inf la ted wi th ai r or nitrogen but not oxygen or ni trous oxide
(56,79,265). Ni trous ox ide should not be used for insuff la ting the abdominal cav ity
during laparoscopy (266,267,268).
Preventing Pressure Regulator Fires Fires in regulators can be minimized by not al lowing them to become contaminated
wi th oi l , grease, or other combus tible materials o r c leaned with a f lammable agent
such as alcohol (122,269). Before a regula tor is f it ted to a cyl inder, partic les should
be cleared f rom the cylinder ou tlet by remov ing the protect ive cap or seal and
s lowly and briefly opening (βcrackingβ) the valve wi th the port pointed away f rom
the user and any other persons . A cyl inder valve should always be opened slowly to
al low heat to be dissipated as the gas is recompressed. Consideration should be
given to rep lacing aluminum regulators with those made f rom brass. Rules for
handling cylinders are discussed in Chapter 1.
Fire Plan Each heal th care fac il i ty should formulate a plan for deal ing quickly wi th an
operating room f ire (1 ,6,56,58,127,171,202,206,240,270,271,272,273,274). Surgica l
teams should be trained in and prac tice dri l ls for keeping minor f i res f rom gett ing
out of control and manag ing f ires that do get out of control . They should know the
locat ion and proper use of a larm boxes, gas shut-o ff valves, and fi re extinguishers.
Evacuation procedures should be reviewed periodically.
I t is important to immediately cal l for help, decide who is going to f ight the fi re ,
when i t wi l l be appropriate to leave the room, and how to care for the pat ient during
the f i re .
Burning material on or in the pat ient of ten can be ex tingu ished effec tively and
safely by hand or wi th a nonflammable liqu id (e .g ., saline f rom a bas in on the scrub
table) or wet c loth. With laser surgery in the a irway, a t least two syringes f il led with
sodium chloride should a lways be available to ex tingu ish the f ire (275). Larger
areas can be smothered with a blanket or wet towe l. Fi re b lankets are not
recommended (8 ,276). If the drape is water-resis tant, water poured on i t wi l l be
ineffective (277). The f ire wi l l burn on the unders ide. The only effect ive technique
is to pul l the burning materials from the patient.
Fires tha t involve electrica l components are best handled by disconnect ing the
device from i ts electric power supply and removing the dev ice f rom the room.
The f low o f oxygen, n itrous oxide, or ai r to any involved equipment should be
turned OFF, if this can be accompl ished wi thout injury to personnel or the pat ient.
Most pat ients can tolerate short periods of oxygen deprivation . The patient should
be venti lated with ai r and intravenous agents used to mainta in anesthesia unt i l all
possible sources of f i re or reigni t ion are suppressed. It may be necessary to c lose
the oxygen and ni trous oxide shut-off valves to the affected room (58,278,279).
Cyl inder valves should be c losed and all cylinders removed from the area. If
supplemental oxygen is necessary to oxygenate the pat ient, the patient should be
moved to the nearest area where oxygen can be safely used (56).
I f an ai rway f i re occurs, the breath ing system shou ld be disconnected from the
tracheal tube to stop gas f low. If this s i te is not easi ly accessible or the operator
may be burned in the process o f disconnecting the tube, the breathing system can
be disconnected at the absorber (280).
The trachea l tube should no t be unduly secured so that i t can be removed quick ly.
Al though immediate removal of the tracheal tube and protective devices is usua lly
recommended wi th an ai rway f i re , th is may not always be the bes t course of act ion
(148,281). The risk:benefi t ratio of extubat ion needs to be considered. A stylet or
ai rway exchange catheter can be used to subst i tute a new tube the burned tube for.
I f the decis ion to remove the tube has been made, sal ine-f i lled cuffs on plast ic
tubes can be def la ted faster by aspira ting the f luid than by cutt ing the p ilot tube
(91). With red rubber tubes, unclamping the pilot tube is fastest.
P.923
The airway should be re-establ ished and the patient vent ilated wi th ai r unt i l i t is
certain that nothing remains burning . Then, 100% oxygen should be administered.
A search for f ragments tha t remain in the trachea and assessment of damage to the
larynx and tracheobronchial tree shou ld be made.
Extinguishing a Fire Although mos t operat ing rooms have a sprink ler system, sprinklers are frequently
not effec tive wi th operat ing room f ires (206). This is because the sprink le rs are
rare ly located over the operating room table and are heat ac tivated. Operating room
f ires tend to give off a lot of smoke and tox ic produc ts bu t not necessarily enough
heat to immediately activate the sprinklers . Therefore, i t is important the all
operating room personnel are fami liar wi th f i re extinguishers .
Location Strategically placed portable fi re ext inguishers are an important part of any f ire
protect ion program (1 ,282,283). They shou ld be located in conspicuous, readi ly
access ib le loca tions that a re known by al l operat ing room staff (F ig. 32.8).
Hands-on experience with f i re ex tingu ishers is essent ial to a f ire safety education
program (284). Sett ing up real f i res in a park ing lot and prov iding practice wi th
ex tinguishers can have valuable payoffs during an actual f i re.
Use Use of any f ire extinguisher can be recalled by the acronym, pass . Pul l the p in. Aim
the horn or nozzle a t the base of the f ire. Squeeze the trigger o r handle wh ile
holding the ext inguisher upright. Sweep the ext inguisher from side to side, covering
the area of the f i re. Ins truct ions are found on the f ire ext inguisher (F ig. 32.9). The
pin and hose are shown in F igures 32.10 and 32.11.
Choice of Extinguisher The choice of ex tingu isher should be based on the pred ic ted f ire risk for that
locat ion (282,285,286). Fi res are c lassif ied according to their fuel. Class A f i res
include small masses of ordinary combus tiblesβ-c lo th, paper, and most plas tics.
Fi res involv ing f lammable l iqu ids or grease are in c lass B. Electrical ly energized
f ires are c lass C. Two standard sets of f i re c lass labels exist: a tradi tional le ttering
system and a newer universal pictograph system tha t does not require the user to
be famil iar wi th the alphabet f ire c lass codes (F ig. 32.9).
View Figure
Figure 32.8 Fire extinguishers should be in conspicuous locations, well known to all operating room staff.
Halogenated Agents Halogenated ext inguishing agents are l iquids that upon discharge under relatively
high pressure surround a f ire with a combinat ion of vapor and l iquid droplets (mist).
Halogenated agents are ideal ly sui ted for f ighting f ires involv ing electronic
equipment and f i res in areas where electrical or electronic equipment is nearby.
Halon was the agent of choice fo r operating room f ires fo r many years (202). I t has
the abi li ty to penetrate burning material and to smother and cool the chemical
react ion of the fi re . While usual ly marked for c lass B and C f ires, i t is also effec tive
against class A f ires found in the opera ting room. Unfortunately, because of
environmental concerns, halon ext inguishers are no longer avai lable . If present in
an opera ting room, they may be used but cannot be recharged. The National Fi re
Protect ion Association requires that nonrechargeable
P.924
P.925
ex tinguishers be removed from serv ice 12 years from the date of manufacture
(287). In response to the prohibi tions on the use of ha lon , a number of
ex tinguishing agents have been developed to rep lace it (282,288,289) (Fig. 32 .12).
View Figure
Figure 32.9 The instructions for using the fire extinguisher are printed on the extinguisher.
View Figure
Figure 32.10 The pin that needs to be pulled to activate the extinguisher is in the handle at the top of the extinguisher. The hose is normally attached to the side of the extinguisher. This figure also shows the pressure gauge, which indicates that the extinguisher is usable, and the monthly checkout list, which shows that the extinguisher has been checked, the extinguisher and hose is undamaged, and the pressure is in the use range.
View Figure
Figure 32.11 Close-up of pin and pressure gauge at top of extinguisher.
View Figure
Figure 32.12 There are several substitutes for halon available.
Carbon Dioxide CO2 ex tinguishers emit a fog of CO2 gas with l iquid and solid partic les that rapidly
vaporize to cool and smother a f i re. Although they carry a B and C rat ing, they can
be used to ex tinguish small class A fi res. CO2 f ire ext inguishers are heav ier and
bulk ier than halon-type devices . CO2 ext inguishers do not leave a residue but do
emit l iquid and sol id components that rap idly vaporize . This causes rapid cool ing
that might cause f reezing i f i t comes into contact wi th exposed skin or internal
organs (283,290).
Water Pressurized-water ext inguishers are chiefly ef fec tive against c lass A f ires . They are
more dif f icult to use than CO2 and halon-type extinguishers. To put ou t fi res on
water-repel lant d rapes, a f inger mus t be placed over the nozzle to produce a f ine
spray. A s tream or splash of water could fan the f i re (1). A non-magnetic water mis t
ex tinguisher is avai lable for use in the MRI unit magnet room.
View Figure
Figure 32.13 All operating room personnel must know where the fire alarm is located. The instructions for activating it are printed on the fire alarm.
I f the f i re starts to get out of control , the f i re alarm (Fig . 32.13) should be sounded,
and the f ire department should be not if ied to give f iref igh ters ample time to respond
(1). F iref igh ters would ra ther f ind that a small f i re has been ext inguished than see
smoke bil lowing out of a bui ld ingβespecially in a health care faci l i ty .
The patient and staff should be evacuated if the f i re and smoke are excessive
(210). In some s i tua tions , however, it may be more hazardous to move the pat ient
than to a ttempt to ext inguish or contain the f i re. The attending physician must
determine which would present the lesser hazard .
The doors should be c losed to contain the smoke and isola te the f i re . Wet sheets or
towels can be stuffed under the doors to reduce the spread of smoke f rom the
room.
Whatever steps are necessary should be taken to protect or evacuate pat ients in
adjacent a reas.
Af ter the f ire, involved materials and dev ices should remain in place for the f ire
department invest igators . Notes should be made as soon as poss ible af te r the f ire
and an inc ident report comple ted.
P.926
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3. Anonymous. JCAHO warns about surgical f ires . Outpat ien t Surgery Magazine
2003;4:8 .
4. Nationa l Fi re Protect ion Association. Fi re safety in heal th care fac il i t ies. Quincy,
MA: Author, 2003.
5. Rodriguez JG, Satt in RW. Injuries as an adverse react ion to c l inical ly used laser
devices. Lasers Surg Med 1987;7:457β460.
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35.
9. Anonymous. E lec trosurgica l fi res sti l l a hot topic. Technol Anesth 1996;17(4):1β
2.
10. Rampi l IJ . Anesthet ic considerat ions for laser surgery. Anesth Analg
1992;74:424β435.
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anesthesia. Cancer Bul le tin 1989;441:219β223.
12. Sosis MB. Hazards of laser surgery. Seminars in Anesthesia 1990;9 :90β97.
13. Van Der Spek AFL, Spargo PM, Norton ML. The physics of lasers and
implica tions for their use during ai rway surgery. Br J Anaesth 1988;60:709β729.
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Technol 2002;36:203β207.
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fac i li t ies (ANSI Z-136.3). New York: Author, 2005.
17. Denton RA, Dedhia HV, Abrons HL, e t al . Long-term surv ival af ter
endobronchial f i re during trea tment of severe malignant ai rway obs truct ion with the
Nd:YAG laser. Ches t 1988;94:1086β1088.
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23. Brodman M, Port M, Friedman F, et al. Opera ting room personne l morbidity from
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286. Nat ional F ire Protect ion Associat ion . Standard fo r portab le f ire ext inguishers
(NFPA 10), 2002 ed. Quincy, MA: NFPA, 2002.
287. Anonymous . 10 quest ions about NFPA 10. What you might want to know about
maintaining and using portable fi re ex tingu ishers. NFPA J 2001;95:26, 92 .
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P.929
Questions For the fol lowing quest ions, select the correct answer
1. The percentage of operating room fires that result in patient injury is A. 10% to 20%
B. 20% to 30%
C. 30% to 40%
D. 40% to 50%
E. 50% to 75%
View Answer2. Which of the following is most commonly involved in operating room fires? A. Lasers
B. Elec trosurgery equipment
C. Argon beam coagula tors
D. Fiber-opt ic i l luminat ion systems
E. Def ibri l la tors
View Answer3. Which type of tracheal tube will cause the most severe damage to the tracheobronchia l tree if i t catches fire?
A. Red rubber
B. Si l icone
C. Laser resistant
D. PVC
View Answer4. In order to filter out potentia l airborne contaminants, the surgical mask must be able to fi lter particles of which size? A. 30 microns
B. 3 microns
C. 0.3 mic rons
D. 0. 03 mic rons
E. 0.003 microns
View Answer5. Wet cotton gauze will protect the shaft and cuff of a tube best w ith which laser?
A. Argon
B. KTP
C. Nd-YAG
D. CO2
View Answer6. A clear, unmarked PVC tube is relatively resistant to be used with which laser?
A. Argon
B. KTP
C. Nd-YAG
D. CO2
View AnswerFor the following quest ions, answer
β’ i f A, B, and C are correct
β’ i f A and C are correct
β’ i f B and D are correct
β’ i f D is correct
β’ i f A, B, C, and D are correct.
7. The factors necessary to start a fire include
A. Igni tion source
B. Fuel
C. Oxidizers
D. Lasers
View Answer8. The characteristics of laser l ight inc lude
A. Coherency
B. Monochromatic i ty
C. Coll imated
D. Ul trav iolen t
View Answer9. Which factors determine the ignition risk with a laser? A. Laser medium being used
B. How the laser is focused
C. Class of laser
D. Exposure t ime
View Answer10. Common errors when using e lectrosurgical equipment include A. Improper p lacement of dispers ive elec trode
B. Insuff ic ient dispers ive elec trode contact
C. Faulty re turn electrode
D. Insu lat ing the patien t from the opera ting room table
View Answer11. Measures to minimize the risk of a tracheal tube fire from a laser include A. Fil l ing the cuf f wi th saline
B. Minimiz ing the laser power densi ty and durat ion
C. Us ing a laser-resis tan t tube
D. Us ing low oxygen concentrations in the inspired gas
View Answer12. Concerning laser-induced tracheal tube fires A. The tube may be contacted by a ref lec ted laser beam
B. The cuff is laser-resis tant
C. Cotton sponges that p rotect the cuff may dry ou t
D. Use of an uncuffed tube increases the risk
View Answer13. Which laser(s) is (are) l ikely to damage the retina?
A. KTP
B. Nd-YAG
C. Argon
D. CO2
View Answer14. Which laser(s) is (are) l ikely to damage only the cornea? A. KTP