BY Azza Lotfy Ass. Lect. Of Anesthesia & ICU

1. Anesthesia for Laser surgery BY Azza Lotfy Ass. Lect. Of Anesthesia & ICU

2. Light Amplification of Stimulated Emission of Radiation LASER

3. Physical principles of laser Production of laser (Laser system hardware):

4. Physical principles of laser Characters of Laser beam : Monochromatic: one wave length) Coherent: (oscillate in the same phase) Collimated: (exist as a narrow, parallel beam)

5. Effect of Laser on tissues: • Laser factors: • Wavelength • Power density • Duration • Tissue factors: • Absorption • Thermal conductivity • Local circulation • Scatter

6. Types of medical Laser:

7. Advantage and clinical uses of laser: • Scalpel and electro coagulator. • Allow precise microsurgery. • Relatively dry field. • Less postoperative edema and pain with lower infection rate.

8. Disadvantages of laser (hazard of laser) • Atmospheric contamination ” laser plume” • Misdirection of laser energy • Gas embolism • Energy transfer to an inappropriate location • Fire and explosion

9. Disadvantages of laser (hazard of laser) Atmospheric contamination ” laser plume”: • Interstitial pneumonia. • Bronchiolitis. • Reduced mucociliary clearance, inflammation. • Emphysema. • Plume can be mutagenic, teratogenic or vector of viral infection.

10. Disadvantages of laser (hazard of laser) Misdirection of laser energy: perforation of viscous or large blood vessels. Gas embolism: Venous gas embolism when laparoscopic or hysteroscopic laser surgery are reported. Energy transfer to an inappropriate location: Eye damage(corneal opacities, retinal damage); Skin damage(from erythema to blisters or charring). Fire and explosion: Laser contact with flammable material such as rubber or plastic may cause fire and explosion.

11. Airway Fire • Incidence; 0.5% - 1.5% • Predisposing factors; • Flammable materials (ETT). • Source of ignition (Laser beam). • Gas support combustion (O2).

12. Airway Fire • Fire may be: • On external surface of ETT cause local thermal destruction. • Blowtorch like fire.

14. Airway Fire Approaches to reduce the incidence of airway fire: • Reduction of the flammability of ETT. • Removal of flammable material from the airway by using : • Venturi jet ventilation; • Intermittent extubation with or without apnea. • Reduction of the available oxygen content to the minimum required for reasonable arterial saturation.

15. Reduction of the flammability of ETT • The use of special type of laser resistant tracheal tube. • Wrapped standard tubes.

16. Reduction of the flammability of ETT • The use of special type of laser resistant tracheal tube; • These tubes resist laser beams ,more bulky, stiffer • Disadvantage: Traumatic (mucosal abrasion) Reflect laser beam and transfer heat No Cuff protection Expensive

17. Laser resistant tracheal tube • The Norton tube: • Reusable • Stainless steel • Flexible tube • No cuff

18. Laser resistant tracheal tube • The Laser Flex tube (Mallinckrodt laser tube): • Airtight stainless steel tube • Flexible • Uncuffed or with two cuffs

19. Laser resistant tracheal tube • The Laser-Shield II (Xomed-laser shield II tube): • Silicone tube • Inner aluminum wrap • Outer Teflon coating

20. Laser resistant tracheal tube • The Bivona Fome-Cuff laser tube: • Designed to solve the perforated-cuff-deflation-problem. • It consists of an aluminum wrapped silicone tube with unique self inflating foam sponge filled cuff which prevent deflation after puncture.

21. Reduction of the flammability of ETT: • Wrapped standard tubes: • Standard tracheal tubes (rubber, silicon, and PVC). • Wrapped with laser resistant material (except the cuff). • the wrapped material may be: • Aluminum or copper foil tape with adhesive back. • Merocel laser guard (merocel wrap).

22. Wrapped standard tubes • Disadvantage of wrapping: • No cuff protection. • Add thickness to the tube. • Not an FDA approved device. • May reflect laser beam to non target tissue. • Protection varies with the type of the metal foil used. • Air way obstruction. • Rough edges may cause damage to mucosal surface.

23. Wrapped standard tubes • Mechanism of wrapping: • Paint the tube with medical adhesive such as benzoin. • Cut the end of the tape with scalpel to approximately 60 degree. • Start wrapping from the junction of the tube and the proximal end of the cuff • Wrapping in spiral with 30% to 50% overlap layer. • Wrapping include the inflation tube of the cuff.

25. Wrapped standard tubes • Protection of the cuff: • Filling the cuff with saline colored with methylene blue. • Place the cuff distally in the trachea and covered visible cuff with moistened cotton pledgets.

26. Approaches to reduce the incidence of airway fire: • Removal of flammable material from air way: • Jet ventilation: • Use high pressure oxygen source directed at the glottis through small metal tube such as ventilating bronchoscope or 12 gauge blunt needle. • it permit entrainment of oxygen enriched air during inspiration and escape of carbon dioxide and exhaust gases during expiration.

27. Removal of flammable material from air way Advantage: • Adequate ventilation without introducing flammable material. • No obstacle to the surgical field. Disadvantage: • Barotrauma • Pneumothorax • Restriction to only anesthetic intravenous agents • Gastric distention • Relative requirement for compliant lungs

28. Removal of flammable material from air way • Intermittent extubation with or without apnea: • Intermittent extubation by the surgeon. • Combined with spontaneous ventilation or intermittent apnea. • General anesthesia provided by nasal insufflations of potent inhaled anesthetic or by use of intravenous anesthetic agent.

29. Approaches to reduce the incidence of airway fire: • Reduction of the available oxygen content: • Oxygen and nitrous are powerful oxidizer. • Reduce the inspired oxygen concentration to less then 0.40. • Avoiding diluting oxygen with nitrous . • Dilute with helium.

30. Airway fire protocol(Management of airway fire) • Communication and recognition. • Stop ventilation, remove ETT and disconnect breathing circuit from anesthesia machine to: • Remove flame • Remove the retained heat in the tube • Stop flow of enriched gas • Flood the surgical field with water. • Ventilate the patient with 100% oxygen via face mask.

31. Airway fire protocol(Management of airway fire) • Assess the damage: • Examine the patient face and oropharynx • Rigid bronchoscope. • Direct laryngoscope. • Monitor the patient with pulse oximetry, serial ABG and chest X ray. • Reintubate the patient or perform trachestomy as needed. • Use ventilatory support, steroid and antibiotic as needed.

32. Protective safety measure during laser surgery • Warning signs • Eye protection: • For the patient: eye should be taped closed and covered with opaque saline swabs or metal shield. • For the working personals: wear safety goggles or lens specific for the laser wave length in use. • For laser plume: • use efficient smoke evacuator at the surgical site. • Use special high efficiency mask.

33. Protective safety measure during laser surgery • Skin protection: The patient ‘skin, mucous membrane and teeth adjacent to operative field should be covered with saline soaked gauze. • Surgical drapes made of flame resistant or waterproof material. • Preventive measures against fire and explosion must be ready.

34. FINALLY • Never are cooperation and communication between surgeon and anesthesiologist more important than during LASER surgery, it is the key to managing a crisis such as air way fire

35. Thank you

36. High pressure oxygen source • Venturi effect (entrainment of air). • Active insipration • Passive expiration