Jace's Flashcards: Laser Airway Surgery and Airway Fires Flashcards

What is the fire triad?

Fuel + O₂ + Ignition source

During facial or head procedures, oxygen can pool under the drapes and increase fire risk. What two actions can help prevent this?

1. Turn down the oxygen 1-2 minutes before and after using the bovie

2. Place suction under the drapes to remove trapped oxygen

What type of endotracheal tube should be used during laser airway surgery to prevent ignition from the laser beam?

A laser-resistant endotracheal tube matching the specific laser wavelength

What are the advantages of using lasers?

1. Dry field

2. Good hemostasis

3. Rapid healing and minimal scarring

4. Surgical accuracy

5. Preservation of normal tissue

6. High degree of sterility

7. Decreased post-op edema and pain

8. Shorter surgical time/recovery

Why is teamwork and communication important during laser airway surgery?

→ Because of sharing the airway with the laser

→ Team members must communicate and work together

CO₂ Laser

1. Wavelength

2. Absorber

3. Typical Applications

1. Wavelength:

→ 10,600

→ Invisible - Far infrared

2. Absorber:

→ All tissues

→ Water

3. Typical Applications:

→ General surgical cutting

→ Precise surgical cutting

Nd: YAG

1. Wavelength

2. Absorber

3. Typical Applications

1. Wavelength:

→ 1064

→ Invisible - Near infrared

2. Absorber:

→ Darkly pigmented tissues

3. Typical Applications:

→ General coagulation (via fiber optics)

→ Tumor debulking

Nd: YAG-KTP

1. Wavelength

2. Absorber

3. Typical Applications

1. Wavelength:

→ 532

→ Visible - Emerald green

2. Absorber:

→ Blood

3. Typical Applications:

→ General lesions

→ Pigmented lesions

Argon

1. Wavelength

2. Absorber

3. Typical Applications

1. Wavelength:

→ 488-514

→ Visible - Blue-Green

2. Absorber:

→ Melanin

→ Hemoglobin

3. Typical Applications:

→ Vascular lesions

→ Pigmented lesions

Krypton

1. Wavelength:

2. Absorber:

3. Typical Applications:

1. Wavelength:

→ 400-700

→ Visible - Blue-Red

2. Absorber:

→ Melanin

3. Typical Applications:

→ General lesions

→ Pigmented lesions

What color protective goggles are used for each laser type:

1. CO₂ laser

2. Nd:YAG laser

3. Argon laser

1. CO₂ laser → Clear goggles

2. Nd:YAG laser → Green goggles

3. Argon laser → Orange goggles

How does laser wavelength affect absorption and penetration in tissue?

Longer wavelengths:

→ Higher absorption

→ Shallower tissue penetration

Shorter wavelengths:

→ Lower absorption

→ Deeper tissue penetration

What determines the type of laser to use?

1. Procedure

2. Type of surgery

3. Location

4. Requirements of the physician

What are the different ANSI laser classifications?

1. Class 1

2. Class 2

3. Class 3R

4. Class 3B

5. Class 4

Which class is considered safe with no risk when viewed by the naked eye?

Class 1

Which class uses low-power visible radiation?

Class 2

What is the wavelength range for Class 2 lasers? Example of a Class 2 laser?

→ 400-700 nm

→ Example: Laser pointer

Which laser class relies on the blink or aversion reflex for eye protection?

Class 2

For which laser class is restricted beam viewing generally safe?

Class 3R

In which class is direct eye exposure hazardous?

Class 3B

For which class is protective eyewear required if direct viewing may occur?

Class 3B

Which classes require a key switch for operation?

1. Class 3B

2. Class 4

Which laser class do most medical and surgical lasers belong to?

Class 4

True or false: Class 4 lasers pose danger to eyes, skin, and combustible materials

True

Which type of tissues absorb CO₂ laser energy?

All tissues and water

What happens to water and blood vessels when hit with a CO₂ laser?

1. Water instantly vaporizes

2. Blood vessels are sealed

In which type of procedures are CO₂ lasers commonly used?

1. ENT

2. OMF

3. GYN

Intraepithelial neoplasms

What is the most commonly used laser for airway surgery?

CO₂

Why is the CO₂ laser beam not visible to the naked eye?

CO₂ lasers emit infrared light, which is invisible to human eyes

If CO₂ laser is invisible, how do surgeons aim it?

A visible He-Ne (helium-neon) laser beam is coaxially aligned with the CO₂ beam to guide aiming

Why must a CO₂ laser be calibrated?

Because it typically uses a line-of-sight delivery system

What modification allows a CO₂ laser to be flexible? What risk does this introduce?

1. Pressurized helium gas tube

2. Gas embolism with direct tissue contact

What can CO₂ laser be mixed with to enhance excitation energy?

N₂

What are the hazards/disadvantages of lasers in the operating room?

1. Retinal or corneal damage

2. Laser plume of smoke

3. Airway fires and OR fires

What ocular injuries can occur from a misdirected laser beam?

Retinal or corneal damage

What are the potential pulmonary effects of inhaling the laser plume?

1. Interstitial pneumonia

2. Bronchiolitis

3. ↓Mucociliary clearance

4. Inflammation

5. Emphysema

What infectious risk can a laser plume of smoke pose?

Act as a vector for viruses

→ HPV from condyloma vaporization

What should you use to protect against smoke plumes?

1. Evacuator

2. +/- Laser mask N95

Why are drapes a risk for fires?

1. Drapes ignite quickly

2. Allow oxygen to pool

3. Waterproof

→ H₂O rolls off instead of absorbing laser energy

What precaution should be taken regarding surgical prep solutions during laser surgery?

Avoid alcohol prep if possible

What personal protection from retinal damage should be used?

Laser specific protective eyewear/goggles with sideguards

True or false: Standard contact lenses provide adequate protection against laser exposure in the OR

False

→ They do not protect against laser injury

What should be on the door of laser cases in the OR?

A sign and extra goggles for staff entering

What is used for patient optical protection?

1. Protective goggles per laser in use

2. Moist eye patches, moist towels, or gauze

3. Laser-protected ETT

→ If working in the airway

What is the only laser proof ETT ever made?

Norton Laser Endotracheal Tube

→ No longer manufactured

What are the 4 laser resistant endotracheal tubes?

1. Xomed Laser-Shield II

2. Mallinckrodt Laser-Flex

3. Sheridan Laser-Trach

4. Lasertubus

Which laser-resistant ETT resists all types of medical lasers?

Rusch Lasertubus ETT

Which ETT has a laser-resistant overwrap of aluminum foil tape and a Teflon cover?

Xomed Laser Shield II

Which ETT has a dry methylene blue in the cuff

Xomed Laser Shield II

→ Seeps out if cuff is punctured

Which ETT has stainless steel shafts?

Mallinckrodt Laser-Flex ETT

Which ETT is used only with CO₂ and KTP lasers?

Mallinckrodt Laser-Flex ETT

Which laser-resistant ETT has a proximal and a distal cuff?

Mallinckrodt Laser-Flex ETT

Which ETT is made of a red rubber tube with copper foil?

Sheridan Laser-Trach ETT

Which ETT is made of soft white rubber and has a laser guard?

Rusch Lasertubus

Which ETT contains Merocel sponge and a silver foil?

Rusch Lasertubus

Which ETT has a cuff in cuff design?

Rusch Lasertubus

What is the incidence of OR fires?

100-200 per year - Reported

Ignores near misses such as a fiberoptic cable scorching a "bullet" hole in the drapes with no flames and virtually no smoke

What percentage of reported fires result in serious injury?

20%

How many deaths a year are caused by airway fires?

1-2

What is the definition of an OR fire?

A fire that occurred on or near patients who are under anesthesia care

Includes:

→ Surgical fires

→ Airway fires

→ Fires within the airway circuit

What is the definition of an airway fire?

Special type of surgical fire that occurred in a patient's airway

→ May or may not include fire in the attached breathing circuit

What is an Electrosurgical Unit (ESU)?

1. Provides electrical energy that is used to cut and coagulate tissue

2. Energy delivered to the tissue through an active electrode controlled by the surgeon

What is an Oxygen Enriched Atmosphere (OEA)?

1. O₂ rich environment

2. Highly combustible

How does an OEA affect fire behavior in the OR?

It can transform a flame into an instantaneous flash or explosion

How small of an increase in O₂ concentration can accelerate fire risk?

An increase from 21% (room air) to 25% can significantly accelerate fire spread

What is a commonly overlooked source of oxygen in general anesthesia?

N₂O

Why does the use of O₂ and N₂O increase the risk of fire?

1. Support combustion

2. Reduce the amount of energy needed to ignite flammable substances

→ Energy: Current, heat, or friction

How is an OEA created in the oropharynx during airway surgery?

O₂ and N₂O leak around the ETT, its cuff, or packing = Creation of an OEA

True or false: Some fuels that will not burn in the 21% concentration of oxygen found in room air will burn vigorously in an OEA

True

What are the major sources of ignition in the OR?

1. Electrosurgical units (ESU)

2. Lasers

To prevent surgical fires, where should the Bovie be kept when not in use?

In its holster

→ Not on the drapes

True or false: Any piece of electrical equipment can short out and lead to sparks and arcing

True

What are sources of fuel in the OR?

1. Linens

Ex: Gowns, drapes, blankets, paper goods

2. Prep agents

Ex: Alcohol, aerosols, tinctures, degreasers

3. Dressings

Ex: Stockinet, tape, sponges, gauze

4. Ointments

Ex: Wax, benzoin, petroleum, aeroplast

5. Equipment/Supplies

Ex: Anesthesia components, insulation material around cables and wires, gloves, cuffs, hoses

6. Patient

Ex: Hair around the face, GI tract gases like methane

After applying DuraPrep or Chloraprep, how long should you wait before draping to prevent ignition risk?

At least 3 minutes

Why can drapes be dangerous during fires?

1. Hang vertically which allows flames to spread rapidly

2. Can obscure flames, smoke, and heat

3. Flame-retardant feature can cause fires underneath drapes to go undetected

Why is the upside-down U configuration of the drapes the worst of the four scenarios?

→ Fires beneath drapes are difficult to detect

→ Once fire reaches the bottom edge, it spreads explosively

Body hair is extremely flammable, particularly when saturated with?

O₂

What type of body hair easily ignites?

Fine hair covering most body surfaces and on the face.

After ignition, the fire can spread _________ feet per second.

2-10

What should surgeons and anesthesiologist be aware of to prevent fires?

The hazards of using ESUs in OEAs are commonly present in the oropharynx and trachea

What safety precautions should be taken during airway surgery with a laser or electrosurgical unit (ESU)?

1. Avoid using ESUs to cut tracheal rings

→ Use scissors or a scalpel instead

2. Keep all sponges, gauze, or pledgets in the airway wet

3. Use laser-appropriate ETTs

4. Fill the ETT cuff with methylene blue tinted NS

→ To detect cuff rupture

How can communication reduce the risk of fire?

Allow for turning off the oxygen at certain times and switching to air

→ Oxygen tends to pool under the drapes and may take some time to disperse when switched off

What FiO₂ level should be maintained during tracheostomy or airway procedures using Bovie to reduce fire risk?

FiO₂ ≤ 30%

What is the protocol for airway fires?

1. Remove the ETT

2. Stop the flow of all airway gases

→ VAA

→ O₂

→ Turn up the air

3. Remove all other flammable material from the airway

4. Extinguish flames with saline or water, and pour saline into the airway

5. Care for the patient

Step 5 of the protocol for airway fires is to care for the patient. What does this entail?

1. Ventilate with air only until confirmed no residual fire, then switch to 100% O₂

2. Inspect the airway with fiberoptic bronchoscopy to assess damage

3. Reintubate if needed and manage airway injury appropriately

4. Assess patient’s status and plan for ongoing care

During airway fire management, what anesthetic can be given to prevent patient awareness once VAA is stopped?

Propofol

What are the specific fire prevention steps for the AA?

1. Pay special attention to ESU because of risks

2. During MAC cases, discontinue O₂ use during ESU or laser use

→ Reduces ambient O₂ level

3. Stop O₂ use 1 minute prior to ESU usage and wait 1 minute after ESU usage before resuming O₂

What should the surgeon do to prevent fires with the ESU?

Keep it in the non-conductive holster

→ Protects drapes from inadvertent discharge of the ESU

Fire prevention for surgeons during ESU, Light Cables, and Laser use

1. Activate only when the tip is visible

2. Deactivate before the unit is removed from the surgical site

3. Place in "stand-by" mode when not in use

Fire prevention for surgeon during bowel procedures

1. Be aware that methane may be present in bowel and use caution with ESU

2. Similar care must be exercised with body cavities containing O₂ or N₂O

Why do surgeons need to clean ESU electrodes often?

Carbonized tissue can contribute to:

1. Arcing

2. Increased resistance

3. Less effective units

4. Requests to "increase the bovie"

Fire prevention for surgeon with use of ESU

1. Use care with ESU Wires

2. Use hand-activated ESUs

→ Avoid foot-activated units

3. Avoid the ESU when cutting tracheal rings

4. Use lowest ESU power setting and activate for short periods of time

→ Avoid long periods of use on high settings

5. Evacuate gaseous products of ESU

Why should the surgeon use care with ESU wires?

To avoid kinking and coiling of ESU wires which can lead to induction currents or shorts

Why should surgeons use hand-activated ESUs instead of foot-activated?

Lowers the risk of inadvertent discharge of ESU

Why should surgeons avoid the ESU when cutting tracheal rings?

Reduces the risk of airway fire

Why should the gaseous products of the ESU be evacuated?

Reduces the one potential source of fuel or ignition of the triad

What is an important nursing precaution to prevent surgical fires when using an ESU?

Place the return pad over a large muscle mass near the surgical site

What is important to remember about fire prevention after the case?

Turn off O₂ after the case

→ Leaving O₂ on over the weekend greatly increases O₂ concentration and risk of OR fire

What is the typical O₂ percentage in the OR?

22%

P.A.S.S.

Pull

Aim

Squeeze

Sweep