ANES 501 Week 7: Lasers in Anesthesia MASTERY GUIDE 2025 – 37 Expert-Curated Q&A with Detailed Rationales, Laser-Tissue Interaction, and Surgical Safety Protocols

what is a laser?

light amplification with stimulated emission of radiation

what happens when the lasing medium is stimulated by electricity?

the electrons change orbital patterns and emit light

what is the light emitted by a laser?

coherent, columnated, and monochromatic

what does the way a laser react depend on?

its wavelength

CO2 laser?

absorbed by water and hence all tissues; has limited penetration to a depth of <0.5 mm

Nd: YAG laser?

transmitted through clear tissues and materials- absorbed by dark tissues- deep penetration 2-6 mm

argon laser?

selectively absorbed by hemoglobin and melanin- penetration is 0.5-2 mm

what is a KTP laser?

potassium titanyl phosphate

what does a KTP laser do?

weakly absorbed by water and strongly absorbed by Hgb- penetrated 0.5-2 mm

dye lasers?

wavelength can be changed from hemoglobin absorption or phototherapy

how are laser hazards classified?

by ANSI- 1 to 4 with 4 being the most dangerous

what are most medical lasers?

class 4 hazard

Laser exposure can cause what?

eye damage- location depends on depth on the wavelength

Argon and YAG lasers damage what part of the eye?

retina- the lens will focus the laser emission on the fovea and increase the intensity up to 100,000 times

what lasers damage the retina?

argon and YAG

what do CO2 lasers damage?

the cornea

what lasers damage the cornea?

co2 lasers

what are rooms using lasers required to have?

a sign specifying laser type

what blocks the co2 laser?

all types of glasses and goggles

what types of lasers need special goggles?

Argon, KTP, YAG - to absorb the laser emission

what can the laser plume cause?

bronchial irritation, produce mutagenic chemicals- viral particles can also be released- special masks are used as well as evacuation system

what is needed with a laser plume?

special mask and a surgical evacuation system

how do airway fires occur?

from ignition of the ETT or surgical packing

what type of ventilation is used for insufflation?

jet ventilation

what happens with jet ventilation/?

laser plume is still a problem, hypoventilation is possible, OR pollution from anesthetic agent not returned to scavenger

laser surgery of the airway and ET TUBES?

reduced FIo2 of 30% or less

how can a reduced fio2 be accomplished?

with helium or nitrogen induction- n2o is oxidating and not effective is reducing fire hazard

where should fio2 be if using laser during airway surgery?

less than 30%

what can ignite if hit with laser?

PVC, red rubber, and silicone

combustion materials from an ET tube are?

highly toxic

how are ET tube protected from airway fires?

with metallic coating- laser ready tubes are commercially available

what can be done to the airway around the tube to decrease fire risk?

airway can be packed with saline soaked sponges

what are 7 ways of surgical fire prevention?

1. avoid open air supplemental oxygen administration 2. coat facial hair with water soluble lubricant 3. use flame retardant drapes 4. use suctioning below drapes to avoid build up of oxygen 5. avoid pooling of prep solutions 6. have 2 syringes of saline available to extinguish fires (containers for burning materials) 7. educate staff as to causes and management and locations of extinguishers

how do you avoid open air supplemental oxygen?

administer only through ETT or LMA- if given through a nasal cannula or mask, discontinue oxygen at least 1 minute before laser use

what three conditions must be met for a fire to occur?

fire triangle 1. source of fuel 2. source of oxidizing agent (o2 n20) 3. source of ignition (heat)

what is the primary response to an airway fire? (4)- how quickly?

1. remove ETT tube and any burning material 2. stop FGF 3. pour saline into airway/mouth 4. ventilate with lo2 fio2 to reduce incidence of smoldering and rekindling

within 6 seconds

what is the secondary response to an airway fire (5)

1. inspect removed tube to assess for possible remaining burning material 2. flexible or rigid bronchoscopy 3. steroids/antibiotics 4. ventilatory support 5. 24 hours observation at least