1. International Laser
Safety Conference
Albuquerque, New Mexico
March 23 – 26, 2015
Review of Endotracheal
Tube Fires
Presented by
Kevin B. Frey, CST, MA
Director of Education
Association of Surgical Technologists
2. Disclosures
• I have no disclosures to make &
therefore, do not have any financial
relationships and/or interest with any
commercial interests that could pose
a conflict of interest with this
presentation.
• Additionally, my presentation will
include discussion of commercial
products that will be referenced in
generic terms except for those
products no longer commercially
available or used.
3. Learning Objectives
• Compare various types of ET tubes.
• Describe the causes of ET tube fires.
• Methods for preventing ET tube fires.
• Empowering the surgical patient
4. Lockheed Martin 30-Kilowatt Fiber Laser
Weapon System “Athena”: James Bond
Fans Are Cheering
• Ford F150 blasted 1 mile away
5. ET tube used on elephants. Internal diameter of 45 mm. The
guy holding it is about 6’ tall to give estimate of length of
tube.
6. Brief Review of Types of Laser ET Tubes
• Difference between laser proof &
laser resistant ET tube
– Laser proof: Cannot catch fire
– Laser resistant:
• Provides some degree of protection
• Tube used outside of it limits or laser
strike on unprotected area between
distal tube shaft & cuff or cuff itself
there will be problems
7. • ET tubes no longer used
– Norton laser ETT: Was the only laser
proof ETT on the market; may still exist
in some hospitals4
– Laser-Shield I: No longer manufactured –
thankfully.
– Bivona laser ETT: No longer available
Brief Review of Types of Laser ET Tubes
8. Brief Review of Types of Laser ET Tubes
• Stainless steel ET tube
– Used only for CO2 & KTP laser
– Steel tube is flexible, smooth surface
with a Magill curve
– Single-use
9. Brief Review of Types of Laser ET Tubes
• Stainless steel ET tube con’t
– Double cuff design; distal cuff can be
used if proximal cuff is damaged by laser
– Adult tube: Distal end including
Murphy’s eye is combustible PVC
– One study stresses the importance of
slowly aspirating the saline from the cuff2
– Matte finish to defocus reflected
laser beams
10. Brief Review of Types of Laser ET Tubes
• Red rubber w/ embossed copper foil
wrap
– Spiral-wrapped from cuff to proximal end
of tube; wrap diffuses laser energy
– Single-use
– CO2 & KTP lasers
11. Brief Review of Types of Laser ET Tubes
• Red rubber w/ embossed copper foil
wrap
– Atraumatic fabric outer covering must be
saturated with saline & kept saturated
– Outer covering reduces heat buildup; it
has to be vaporized to get to the copper
– Outer covering adds size to the internal
diameter
12. Brief Review of Types of Laser ET Tubes
• Polyvinyl alcohol (PVA) sponge &
silver foil ETT
– Soft white rubber tube w/ PVA sponge,
reinforced w/ corrugated copper foil, &
double cuff
– H20 from sponge “soaks” up the laser
energy; prevents “hot tube”
effects common with
metal tubing
– Argon, CO2, Nd:YAG
13. Brief Review of Types of Laser ET Tubes
• Polyvinyl alcohol (PVA) sponge &
silver foil ETT con’t
– One study identified issues with
crimping of this ETT3
– Crimping occurred with a patient w/
complete obstruction of airflow
– Researchers then experimented by
bending an unused tube – weakness in
wall of tube identified predisposing to
crimping & causing airflow obstruction
14. Short Review: What Happens
• Initially fires located on surface of
ETT; causes thermal injury to tissues
• Blow-torch effect: Fire burns to
interior of ETT; 02,positive
pressure ventilation, laser
heat, & combustible
materials create the effect
15. Case Study: FiO2
5
• Triple endoscopy w/ laser
vaporization lesion L. vocal cord
– Intubation was successful; cuff filled w/
air during endoscopy & replaced w/
saline before laser vaporization
– Patient would rapidly desaturate when
circuit disconnected to move OR bed
– So Fi02 kept at 50% – 90%; anesthetic gas
was desflurane
– Tube ignition occurred about 45 minutes
into the procedure
16. Case Study: FiO2 con’t
• Brief review of FiO2
– The “fraction” of the “inspired” air that
consists of O2 or other words, if you took
the air that someone breathes in & find
out how much is O2 you have the FiO2
– Air around us is 78.1% nitrogen, 20.9%
O2,0.9% argon, 0.1% carbon dioxide; so
FiO2 is 21%
– Patient receives 100% O2 then FiO2 is
100%
17. Case Study: FiO2 con’t
• In this procedure FiO2 played a major
role.
– When combustion occurred FiO2 was
50% & desflurane 5.2%. Since level of
FiO2 was > than room air (21%) an
oxidizer-enriched atmosphere was
present.
– The correlation being high level of
inspired O2 & tube combustion.
– Keep FiO2 as low as possible that
adequately oxygenates the patient
19. Case Study: Thyroglossal Cystectomy1
• 7-yr. old male presents w/ cyst at the
posterior aspect at the base of the
tongue
• Throat was packed with saline
soaked gauze; removed due to
obstructing vision of surgeon;
surgeon assured the team extra
precautions would be taken to avoid
diode laser delivery handle tip not
contacting ETT
20. Case Study: Thyroglossal Cystectomy
• You guessed it right – the tip
“accidently” slipped & came into
contact w/ the ETT; fortunately
occurred after cyst was removed
• Flexible laryngopharyngoscope
performed – tissue was normal
21. Case Study: Thyroglossal Cystectomy
• So what happened:
– Packing removed; most likely could have
been repositioned; smaller packing
– Assurance by surgeon that Murphy’s law
would not occur
– Report revealed used a PVC ETT that did
not have laser-resistant wrapping
23. Empowering the Patient
• AHA Patient Care
Partnership
–Involvement In Your
Care
–AST is in process of revising
its SOP for Laser Safety& will
include this empowerment
recommendation1
24. References
1. Association of Surgical Technologists. 2010. Standards
of Practice for Laser Safety.
http://www.ast.org/uploadedFiles/Main_Site/Content/Ab
out_Us/Standard%20Laser%20Safety.pdf. Accessed
February 28, 2015.
2. Bhat AG, Ganapathi P. “Blow-torch phenomenon”
during laser assisted excision of a thyroglossal cyst at
the base of the tongue. Journal of Anesthesiology
Clinical Pharmacology. 2012; 28(2): 247-248.
3. Heyman DM, Greenfeld Al, Rogers JS, McCarthy BS,
Tucker J. Inability to deflate the distal cuff of the laser-
flex tracheal tube preventing extubation after laser
surgery of the larynx. Anesthesiology. 1994; 80(1): 236-
25. References con’t
3. Jacobs JS, Lewis MC, DeSouza GJ, TerRiet MF.
Crimping of a laser tube resulting in hypoxemia.
Anesthesiology. 1999; 91(3): 898.
4. Patel A. Anesthesia for laser airway surgery. In: Hagberg
CA, ed., Benumof & Hagberg’s Airway Management. 3rd
ed. Philadelphia, PA: Saunders; 2012: 824-858.
26. References con’t
5. Stein E, Subramaniam B. PBLD 23 Burning
issues – cautery, skin prep and airway fires.
https://www.scahq.org/sca3/events/2011/a
nnual/syllabus/pbld/submissions/wed/PB
LD%2023%20Burning%20issues%20-
%20cautery,%20skin%20prep%20and
%20airway%20fires%20-
%20Subramaniam-Stein.pdf. Accessed
February 28, 2015.
