This document discusses anaesthetic considerations for laser surgery. It begins by outlining the objectives which are to discuss the types of lasers used, preoperative assessment and preparation, airway management and ventilation options, laser hazards and prevention, and crisis management for airway fires. It then provides details on the types of lasers used clinically, biological effects of lasers, and clinical applications of lasers. The role of anesthesiologists is to maintain oxygenation, remove carbon dioxide, keep the patient anesthetized, and reduce risks. Various airway management techniques and their advantages/disadvantages are discussed such as intubation, spontaneous ventilation, insufflation, and jet ventilation. Laser hazards like atmospheric contamination, perforation
2. OBJECTIVES
• TYPES OF LASERS IN AIRWAY SURGERY
• PREOPERATIVE ASSESSMENT , PREPARATION
AND INDUCTION
• AIRWAY MANAGEMENT AND VENTILATION
OPTIONS
• LASER HAZARDS AND PREVENTION
• CRISIS MANAGEMENT IN AIRWAY FIRES
3. LASER
LIGHT AMPLIFICATION by STIMULATED
EMISSION of RADIATION
Lasers provide the ability to transfer large quantities
of energy rapidly and precisely to remote
location,achieved with the use of coherent
collimated and monochromatic light focussed with
the use of resonating mirrors or fibre optic
bundles.
Laser power density is the amount of power
distributed within an area and is indicated in Watts
per sq. cm.
4. ESSENTIAL COMPONENTS OF LASER
LASER MEDIUM-GAS/SOLID WHOSE ELECTRONS CREATE LASER LIGHT
RESONATING MIRRORS-TO BOOST LASER EFFICIENCY
ENERGY SOURCE-TO EXCITE ATOMS OF LASER MEDIUM INTO PRODUCING
LASER LIGHT
PROPERTIES-
COHERENCE-ELECTROMAGNETIC FIELDS OF ALL PHOTONS OSCILLATE
SYNCHRONOUSLY IN SAME PHASE
COLLIMATED-NARROW BEAM
MONOCHROMATICITY-WAVELENGTH IS LIMITED
5. CLINICAL APPLICATIONS
Used commonly for ocular, fissure
surgery, genitourinary,oropharyngeal and
endoscopic laryngeal surgeries.
• Provides good haemostasis.
• Rapid healing and minimal scarring.
• Surgical precision and preservation of normal
tissue.
• Lesser post‐op oedema and pain.
6.
7. SOLID-RUBY/YAG
GAS-CO2 ,HELIUM
EXCIMER(DIMERS IN EXCITED STATE)-XE,ARGON,BROMINE,FLOURINE
DYE-ORGANIC DYE(CARCINOGENS)
DIODE(EXCITATION WITH LIGHT/ELECTRICAL SOURCE)-LASER
POINTERS/DVD/CD
TYPES OF LASERS IN CLINICAL
PRACTICE
8. I KNOW IT IS BORING ,PLZ GET UP AND BEAR WITH ME
FOR SOMETIME.
9. DIFFERENT WAVELENGTHSOF LASER LIGHT CAUSE DIFFERENT
PATTERNS OF TISSUE DESTRUCTION DEPENDING ON LASER
PARAMETERS AND TISSUE FACTORS.(eg CO2 long wavelength
superficially absorbed)
Image
10. h t i l d ith
Nd‐YAG NEAR 1060 ‐Transmitted through fibre ‐Can cause retinal
LASER
MED
IUM
COLOUR WAVE
LENGTH
(nm)
FEATURES HAZARDS AND
PREVENTION
CO2 FAR
INFRA
10,600 ‐invisible, needs aiming laser
‐requires operating microscope
‐large amount of
laser plume
RED ‐highly water absorbent
‐vapourises superficial layers
‐precision cuts, good
‐OT contamination
‐Ocular injury to
cornea. Can be
haemostasis, less oedema with
almost no injury to
surrounding tissue
prevented with use
of clear plastic or
glass eyewear.
Ho‐YAG
INFRA
RED
INFRA 2060
optic bundles.
‐Penetrates up to 2 to 6 mm
‐Readily absorbed by
pigmented tissue
‐Excellent absorption in water
damage. Protect
with opaque green
eyewear.
‐Delayed oedema
and bleeding
‐Can cause venous
embolisation in
RED rich tissues. Used for nasal and
tonsillar surgeries.
tracheal surgeries.
11. BLUE 488 ‐ Strongly absorbed by Use special
KTP GREEN 532 ‐Used with flexible fibre
optic
‐Retinal
damage can
‐Absorbed by pigmented
tissues.
‐Used for highly vascular
areas such as tongue, nose
and deep structures in
trachea.
occur. Use
special glasses
with red filter.
ARGON GREEN 515 ‐Transmitted with fibre
optic bundles.
‐ Can cause
retinal damage.
pigmented tissues like
haemoglobin and melanin.
opaque orange
eyewear.
12. BIOLOGICAL EFFECTS
ELECTROMAGNETIC EFFECT-E .g, LITHOTRIPSY
THERMAL EFFECT-ELECTROCAUTERY,HARMONIC
PHOTOABLATIVE-EG CORNEAL SX,PROSTATE SX
PHOTOCHEMICAL EFFECT-LEAST STUDIED , EFFECT ON
ETC,ENZYME SYSTEMS,OXIDATION STATES ETC.
13. granulomas
S
.
INDICATIONS
• Benign growth‐ nodules, polyps, cysts,
• Vocal cord dysfunction
• Malignant growths
• Recurrent respiratory papillomatosis
Laryngeotracheal surgeries involves a SHARED
AIRWAY and thus cooperation
between surgeon and
anesthesiologist is must.
14.
15. ROLE OF ANAESTHESIOLOGISTS
MAINTAIN OXYGENATION.
REMOVAL OF CO2
KEEP PATIENT ANAESTHETISED PROVIDING
GOOD DEPTH OF ANAESTHESIA
THROUGHOUT PROCEDURE
REDUCE RISK OF AIRWAY FIRE
DEAL WITH CRISIS AND REDUCE
POST OPERATIVE COMPLICATIONS
17. DETAILED HISTORY
‐ difficulty in breathing, swallowing, snoring, stridor,
wheezing, difficulty in clearing secretions, change
in voice, best breathing position and breathing
pattern during sleep.
‐ Try to get an idea of the location, size, extent,
mobility of lesion and the extent of airway
compromise.
‐ Older debilitated patients with long standing
airway compromise are likely to have CVS and RS
involvement and should be evaluated for same.
‐Obesity, history of acid reflux and hiatus
should also be noted as it increases risk of
aspiration.
18. EVALUATION
• PREVIOUS AIRWAY ASSESSMENT WITH DIRECT
OR INDIRECT LARYNGOSCOPY
• IMAGING WITH CHEST RADIOGRAPHY, CT
SCAN OR MRI OF SITE OF LESION
Before providing anaesthesia, determine the
possibility airflow obstruction post
induction and site of lesion whether
supraglottic, glottic or subglottic.
19. PREOPERATIVE PREPARATION
• Avoid sedative premedication. In very anxious
patients consider titrated doses of midazolam with
monitoring. Assurance and counselling is best.
• Can consider antisialogouge like glycopyrrolate for
drying up secretions and to counter vagal
bradycardia due to DL or ML scopy
• Always have a difficult airway cart ready, with rigid
bronchoscope, jet ventilator and tracheostomy tray
on stand by.
• Other standard precautions for LASER surgeries.
20. INDUCTION OPTIONS
IV PROPOFOL
/SEVOFLURANE
+/- MUSCLE
RELAXATION
SHORT ACTING
OPIODS
INDUCTION
CAN BE INHALATIONAL OR INTRAVENOUS
IV with propofol, short acting opioid and muscle relaxation if
reqd
23. CLOSED VENTILATION WITH INTUBATION
HOW TO SECURE AIRWAY?
1. small growth‐ routine tracheal intubation
after induction with small size tubes
2. moderate growth with possibility of
worsening of airway obstruction‐ awake
intubation/tracheostomy under LA with
limited premedication
3. large growth, impinging on airway‐
preoperative tracheostomy electively, no
premedication
24. MAY BE NEEDED DUE TO
• ADEQUATE MAINTAINANCE
• HIGHER RESISTANCE,AGENTS
PROS AND CONS OF INTUBATION
ADVANTAGES DISADVANTAGES
• ROUTINE TECHNIQUE • LIMITS SURGICAL ACCESS
• AIRWAY PROTECTION AND VISIBILITY
• CONTROL OF VENTILATION HIGH AIRWAY PRESSURES
OF DEPTH WITH VOLATILE SMALLER TUBE SIZE
• MONITOR ETCO2 DIFFICULT SUCTIONING,
OCCLUSION
• RISK OF AIRWAY FIRE
25. SPONTANEOUS VENTILATION
INDUCTION‐ Inhalational with sevoflurane or IV with
propofol and short acting opioids.
VENTILATION‐ 100% O2 by face mask
Topical LA applied to VC by Dlscopy
Once adequate depth ‐ procedure is done
ADVANTAGES- excellent visualisation of field, can evaluated
VC function
DISADVANTAGES‐ only for short procedures, depth of
anaesthesia not consistent, risk of aspiration, surgical
field not immobile
26. INSUFFLATION TECHNIQUE
ROUTES‐ small catheter in nasopharynx,
nasopharyngeal airway, sidearm or channel of
laryngoscope
ADVANTAGES‐ allows us to provide continuous
O2 supply to patient. Can also be used to
provide volatile agents.
DISADVANTAGES‐ no control over ventilation,
risk of aspiration, gastric distension, OT
pollution, inconsistent depth
27. • Induction followed by endotracheal tube insertion.
INTERMITTENT APNOEA TECHNIQUE
Patient ventilated till SpO2 100%
• ETT removed from airway‐ surgeon takes over for
procedure.
• Watch O2 sats‐ when it falls to predetermined level,
ETT reinserted and patient ventilated till SPO2 back
to 100%
• PROS-excellent visibility of field and safety in laser
• CONS‐ limits surgical time, aspiration risk,
inconsistent depth, inadequate ventilation, trauma
due to multiple intubations, can’t be used in
debilitated patients or those with cardio‐respiratory
compromise and decreased FRC
28. • Always monitor chest wall motion
JET VENTILATION
• Gas under high pressure
supplied to airway via a 16 G
catheter aligned with the
laryngoscope, that is open to
ambient air
• Ventilatory rate of 6‐7/min at 15‐
20 psi for adults and 5‐10 psi for
children. I:E ratio of 1.5:6 sec
for adequate inspiration and
expiration.
29. inadequate ventilation
surgicalblown distal
Depth to be maintained by IV
barotraumaLess risk of barotrauma
SUPRAGLOTTIC V/S SUBGLOTTIC
Most commonly used Delivery of gas directly into
Malalignment can lead to trachea‐more efficient
Blood, debris or tissue can be No vocal cord motion
Movement of vocal cords No time constraints for surgery
Cant monitor ETCO2 100% O2 at 15 psi
drugs But higher risk of pulmonary
30. TRANSTRACHEAL JET VENTILATION
• Percutaneous transtracheal
catheters through the
cricothyroid membrane or
trachea
Problems
• Greatest risks of barotrauma of
all ventilation(>copd)
pneumothorax/mediastinum.
• Blockage & Kinking
Infection
• Bleeding
31. HIGH FREQUENCY JET VENTILATION
• Ventilatory rates : about 100‐150 b/minute used
• Tidal volume : <2 ml/kg
• Allows a continuous expiratory flow of air,
enhancing the removal of fragments of blood and
debris from the airway.
• Reduced peak and mean airway pressures with
improved hemodynamic stability
• Enhanced diffusion and interregional mixing
within the lungs resulting in more efficient
ventilation
32. PROBLEMS WITH JET VENTILATION
• Cannot be used in obese, COPD and Restrictive
lung disease patients
• Avoided in severe obstructive pathologies in
which egress of exhaled air is not possible
• Cannot use volatile agents for anaesthesia
• Not possible to monitor ETCO2
• Intraoperative arrhythmias, aspiration, seeding of
polyp into trachea.
• Postoperative laryngospasm, laryngeal oedema,
stridor, pneumothorax and pneumomediastinum.
36. ATMOSPHERIC CONTAMINATION
• Plume of smoke and fine particulates (mean size
0.31μm) ‐deposited in the alveoli
• Sensitive individuals: headaches, tearing, and nausea
after inhalation. May be vector for viral infections
• Animal study: interstitial pneumonia, bronchiolitis,
reduced muco‐ ciliary clearance, inflammation,
emphysema
Prevention
• smoke evacuator
• high‐efficiency masks.
37. may a LASER system
Use Coolant gas‐• CO2( cant coagulate vessel
several days later when
of ventilation to wash
out CO2 when used inmaximal, with Nd‐YAG
Laser hazards
PERFORATION VENOUS AIR EMBOLISM
• Misdirected laser energy • Associated with Nd‐YAG
Perforate a large blood vessel
>5mm) lasers preferred.
• LASER‐induced Absorbed faster from
pneumothorax vessels
• Perforation may occur • Keep higher frequency
oedema and necrosis are
Lasers laparoscopic and GU.
38. INAPPROPRIATE ENERGY TRANSFER
• Incidentally pressing the LASER control trigger
• Tissue damage outside of surgical site
• Also‐Drape fires
‐Eye damage (patient or other medical staff)
‐Endotracheal tube‐damage, fires
PRECAUTIONS: WARNING SIGN OUTSIDE OT
1. Use lasers in short bursts and low power.
2. Cover eyes with opaque saline soaked knits or metal shields.
Special eyewear for OT personnel
3. Wet drapes to cover head and chest.
4. Saline soaked pledgets to be placed around tube and area of
surgery.
5. Windows to be covered with opaque drapes
39. finish.wrap and outer Teflon coat.
Small uncuffed and large sizes
Cuff contains methylene blue
crystals.
SPECIAL LASER TUBES
LASER SHIELD II LASER FLEX TUBE
Stainless steel with smooth
Silicone with inner aluminium plastic surface and matte
For CO2/KTP For CO2 and KTP LASERS.
with 2 cuffs available.
40. NORTON TUBE BIVONA FOAM CUFF LASER TUBE
foam sponge with silicone
Uncuffed, external
attached.
cuff can be
Retains shape when ruptured but
SPECIAL LASER TUBES
Spiral wound metal tube with Aluminium and silicone spiral
stainless steel connector. with silicone covering.
Reusable flexible and thick. Self inflating cuff of polyurethane
envelope.
For CO2, KTP and Nd‐YAG can no longer be deflated for
Flexible coils not airtight‐ can removal.
cause leak Only for CO2 LASERS.
41. TUBE WRAPS:TUBE
1. MEROCEL WRAP‐LASER GUARDcopper foil and water absorbent
sponge.For CO2 and KTP LASERS
SPECIAL LASER TUBES
SHERIDAN LASER TRACHEAL
Can be used with CO2, KTP and Nd‐
Red rubber tube wrapped with YAG
fabric. FDA approved‐ metal foil
Thick wall and high pressure cuff laminated to a synthetic
2. Aluminium and copper foils.
LASER TUBUS
White rubber tube with cuff within
cuff design.
Inner cuff is filled with air and outer
cuff with saline.
42. • Trauma to mucosa• Paint the tube
benzoin.
with
• No protection of cuff
60 degree.
• Add thickness to tube
junction tube
it adds 2 mm to tube
• Wrapping in spiral with
of the cuff
SPECIAL LASER TUBES
METHOD OF WRAPPING DISADVANTAGES OF TUBES
medical adhesive such as • Reflect laser beam
• Cut the end of the tape at Expensive
• Start wrapping from • Airway obstruction
proximal end of cuff • Limited surgical access as
30% -50% overlap thickness.
• It includes inflation tube
43. SPE
SPECIAL LASER TUBES
COVIDIEN LASER ORAL/NASAL TUBE WITH TWO
CUFFS(LASER FLEX) CO2/KTP LASER.
OTHER FACTS-
TO SAVE ETT REFLECTIVE TAPE TO REFLECT LIGHT
CUFF FILLED WITH METHYLENE BLUE TO DETECT LEAK
CU/AL-NOT FDA APPROVED,MEROCEL-FDA APPROVED
CHOOSE TUBE 1-2MM SMALLER IN SIZE .
44. LASER RISK CLASSIFICATION
• CLASS 1 : Considerably safe. Lasers that are
completely enclosed or emit extremely low output.
• CLASS 2 : Low risk. Equivalent risk to staring for long
directly at the sun or at bright lights, which can lead
to central retinal injury.
• CLASS 3 : Lasers with power above 1 mW
3A : 1‐5 mW. Moderate hazard
3B : 5‐500 mW . Even momentary viewing can be
hazardous to eyes and skin.
• CLASS 4 : Continuous wave laser with power output
above 500 mW . Serious skin, eye and fire hazard.
45. WARNING SIGNS OUTSIDE OT
EYE PROTECCTION-FOR PATIENT AND WORKING PERSONNEL.
LASER PLUME-EVACUATOR MACHINES AND HIGH EFFECIENCY MASKS.
INSTRUMENTS –MATT FINISH TO AVOID REFLECTION.
MUCOUS MEMBRANE ADJACENT TO SX SITE SHOULD BE COVERED WITH
SALINE SOAKED GAUZE.
SURGICAL DRAPES SHOULD BE FLAME RESISTANT
PREVENTIVE MEASURES AGAINST FIRE MUST BE READY LIKE CO2
EXTINGUISHER,WATER.
SAFETY MEASURES IN LASER SURGERIES
46.
47. power and in short pulses
AIRWAY FIRE PROTOCOL
• Use lowest FiO2 ‐less than 40 %
• Air preferred to N2O
• Avoid tubes for short
procedures
• Limit laser output to lowest
• Activate only when laser fibre tip
is visible and clear of ETT
• Use wet drapes to cover patients
hair and chest
• saline filled 50 cc syringe to be
kept ready
• nearest source of cold water and
fire extinguisher should be known.
48. AIRWAY FIRE PROTOCOL-4 E’S
Extract / Eliminate/ Extinguish
• Put out fire – flood field with saline
• Remove energy source – stop LASER
• Remove oxidant source – disconnect circuit, stop ventilation &
gases
• Remove fuel source (blowtorch effect)– extubate and remove
burning fragments
Evaluate
• Review airway – ensure no burning fragments
• Oxygenate – 100% oxygen by bag and mask
•Review damage flexible or rigid bronchoscopy,chestXray
may be needed, bronchial lavage for fragments
• Establish airway – re‐intubate, laryngeal mask airway or jet
• Severe airway damage – tracheostomy or oral intubation, ICU
admission, controlled ventilation and high dose steroids.
49. AND PREVENTION PROTOCOL
TO SUMMARISE
PROTOCOL
TYPES OF LASERS
AND EFFECTS
ASSESSMENT
PREPARATION
E.g.. CO2, KTP, Nd‐YAG, Argon INDUCTION
LASER HAZARDS AIRWAY FIRE
AND PREVENTION
AIRWAY MANAGEMENT WITH TYPES
OF VENTILATION
(SPECIAL MENTION OF LASER TUBES)