Microlaryngeal surgery Microlaryngeal surgery Microlaryngeal surgery

Microlaryngeal surgery

1. Anesthetic Management For M icrolaryngeal Surgery Presenter – Dr. Mohit Jagga Moderator – Dr. Naresh / Dr. Shridevi

2. Introduction MLS includes diagnostic & therapeutic interventions on larynx using an operating microscope for various lesions Includes endoscopic & laser procedures It is a laryngoscopy aided by an operating microscope Provision of clear, free & unobstructed airway is the principal concern of anesthesiologist.

3. Microlaryngeal surgery encompasses a wide range of laryngeal procedures that can be organized in two broad categories: Phonomicrosurgery ( i.e., Benign and malignant vocal cord lesions, laser laryngeal surgery, and vocal cord augmentation) Laryngeal framework surgery (i.e., Vocal cord paralysis and motion disorders, scarring, stenosis of the glottic, subglottic, and tracheal areas, and laryngeal trauma).

4. Preoperative Evaluation and Preparation Comorbidities contributing to their voice symptoms and affecting anesthetic management COPD Various rheumatological and neuromuscular disorders Endocrine disorders (hypothyroidism)

5. Silent laryngopharyngeal reflux Long history of heavy smoking and drinking  Elderly and have cardiovascular disease Postradiation changes in the neck large tongue or intraoral masses that can be exophytic and mobile

6. The rate of difficult endotracheal intubation is high among patients presenting for ear, nose, or throat cancer surgery, which is on average six times higher than among the general surgical patient population It is prudent to assess the laryngeal mobility, the degree of tracheal deviation, and the location of the cricothyroid membrane (CTM). Stridor indicates significantly narrowed airway (<4-5 mm) .

7. PRE-OP ASSESSMENT Indicators of Difficult Airway Changes in the voice H/o dyspnea, dysphagia or inability to handle oro-nasal secretions Radiation to head and neck H/o difficult airway Previous head and neck surgery Tumors and edema of pharynx and hypopharynx A DETAILED AND COMPLETE AIRWAY EXAMINATION

8. PRE-OP ASSESSMENT Preoperative optimization Stop Smoking Nebulization with bronchodilator and steroid Chest Physiotherapy Incentive Spirometry Steam Inhalation Consent For tracheostomy For post op. ventilation and ICU

9. Investigations Routine CBC , blood glucose, RFT, LFT, S.Electrolyte Urine routine, ECG Specific: to assess extent, invasion, destruction Chest X–ray PA X–ray neck – AP / Lateral Indirect laryngoscopy PFT (COPD) Laryngogram filling defect CT scan MRI

10. GOALS OF ANAESTHESIA To control ventilation with adequate oxygenation & CO2 elimination. Protect airways with no risk of aspiration. Keep patient anesthetized. Provide clear motionless surgical field Allow safe emergence. Pain-free, alert patient with intact airway reflexes at conclusion. Close cooperation & communication between surgeon & anesthetist – essential

11. Anticipated anesthetic problems Patients with upper airway problems. Sharing of airway with surgeons. Need of Profound muscle relaxation. Special attention should be directed to adequately protecting the patient’s eyes and arms to prevent accidental injury or compression by heavy surgical instrumentation. Oxygenation and ventilation. CVS instability. Postoperative spasm or edema.

12. I.  Awake airway surgery (conscious sedation) II. Asleep airway surgery (general anesthesia) II.1. Endotracheal intubation (cuffed microlaryngeal tracheal [MLT] tube) II.2. Tubeless techniques a. Spontaneous ventilation Inhalational anesthesia (insufflation) Total intravenous anesthesia b. Apneic intermittent ventilation c. Jet ventilation Supraglottic Subglottic Low frequency High frequency Superimposed high frequency INTRAOPERATIVE VENTILATION TECHNIQUE AND STRATEGIES FOR MLS

13. Advantages Prevent soiling of lower airways. Controlled ventilation Minimal environment pollution Disadvantages Poor surgical access High pressures. High resistance due to small diameter tubes Endotracheal Intubation with Microlaryngeal Tracheal Tubes

14. ETT'S used in Microlaryngeal Surgeries 1. Micro laryngeal tracheal tube : Most commonly used. Can be used orally or nasally. It is 4, 5 or 6 mm I.D, But with the same adult length (31 cm) and is stiffer (less prone to compression).

15. Micro-Laryngeal tracheal tube Advantages: Its small size will not impede the surgeon´s view. Its cuff will prevent aspiration of blood or debris. It allows introduction of inhalational agents It allows monitoring of ET C O2 . Limitations Restricts visibility & surgical access High inflation pressures required Risk of laser induced airway fire

16. Conventional E.T.T. of small size: Use one size smaller in children. Use size 4, 5 or 6 mm I.D in adults. Disadvantages: It is too short for the adult trachea. It is with low volume cuff that will exert high pressure against the trachea. Pollards Tracheal Tube: It is formed latex reinforced with nylon spiral. Its proximal end size is 10 mm ID and distal end size is 5-7 mm ID.

17. Tubeless Techniques METHODS Insufflation of high flow O2 Intermittent apnea technique Venturi (manual) jet ventilation HFJV ADVANTAGE Good surgical access DISADVANTAGES Barotrauma Variable levels of anesthesia Risk of aspiration

18. 1 . Insufflation of high flow O2 : Via a small catheter placed in the trachea. Patients should breathe spontaneously otherwise ventilation will be inadequate for longer procedures Limitations Lack of control over ventilation. Unprotected airway. Pollution - volatile agents. Unsuitable for large floppy lesions obstructing airways.

19. 2. Intermittent Apnea technique: The ventilation and anesthesia are maintained with O 2 a potent volatile agent by a face mask or E.T.T. for periods which alternate with periods of apnea during which the surgery is performed, usually 2-3 min. Advantages: Immobile unobstructed surgical field. Safe use of laser surgery. Disadvantages: There is risk of hypoventilation Risk of aspiration of blood and debris. Variable levels of anesthesia. Interruption to surgery for reintubation. Potential trauma through repeated intubation

20. 3. Manual jet ventilation It is connected to a side port of the laryngoscope. During inspiration ( 1-2 sec ), the jet pressure starting with 15-20 psig in adults. 5-10 psig in infants and children. Then increase the pressure gradually until adequate chest rise While the O 2 source is directed through the glottic opening it entrains room air into the lung ( venturi effect ) . Expiration is allowed passively in 4-6 seconds. It is important to monitor the chest wall motion constantly for proper tidal volume assessment and to allow sufficient time for exhalation to avoid air trapping. TIVA necessary for jet ventilation as vaporizers are bypassed.

21. Wei nasal jet tube - regular nasopharyngeal airway with two modified nozzles. One is the jet nozzle connected to the manual jet ventilator. Another nozzle is used to monitor breathing connected to a PaCO2 monitor.

22. Jet Ventilation with TIVA Standard induction with propofol, sevoflurane Turn off sevoflurane, Start 100-300 mcg/kg/minute propofol 0.1-0.5 mcg/kg/minute remifentanil infusion Maintain BIS 40-60

23. 4. High-frequency jet technique Variation of manual jet ventilation. It utilizes a small cannula or tube in the trachea through which gas is injected at high frequency. TIVA is needed for induction and maintenance 1. HFPPV (freq. From 60 to 200 b/min.) 2. HFJV (freq. 80 – 600 b/min ) 3. HFOV (freq. ≥600 b/min.) High-frequency jet ventilation (HFJV) has the most application modes at present. Supraglottic, subglottic, transtracheal jet ventilation

24. INTRAOPERATIVE ANAESTHETIC MANAGEMENT MONITORING Close observation & monitoring throughout the procedure necessary to maintain correct depth of anesthesia , prevent movement, coughing & laryngospasm. ECG NIBP SpO2 EtCo2

25. PREMEDICATION: Sedatives are avoided if any degree of airway obstruction is suspected. Glycopyrrolate 0.2 - 0.3 mg IM 1 hour before surgery Anticholinergics are used to decrease secretions and to avoid bradycardia. Acid aspiration prophylaxis :- H2 blocker , PPI

26. INDUCTION AND MAINTAINANCE: Propofol (2mg/kg), Fentanyl (1-2mcg/kg) Remifentanyl (0.5-1mg/kg) – potent, rapid recovery profile Topical anesthesia of larynx Appropriate muscle relaxation – succinylcholine & intermediate acting NDMR Ensure adequate depth of anesthesia Thorough suction before extubation .

27. MUSCLE RELAXATION: Intraoperative muscle relaxation can be achieved by intermittent boluses or infusion of intermediate duration NDMRS (rocuronium, vecuronium, cis-atracurium), or with a succinylcholine infusion. Profound degrees of non-depolarizing block may delay return of protective airway reflexes and extubation. Given that profound relaxation is often needed until the very end of the surgery, endoscopy remains one of the few remaining indications for succinylcholine infusions.

28. INTRAOPERATIVE COMPLICATIONS 1. Cardiovascular instability BP and HR fluctuate markedly during laryngoscopy and may need invasive BP monitoring because: Many patients are heavy smokers or alcoholic which predisposes them to CVS disease. The procedure resembles a series of stress-filled laryngoscopies and intubations separated by varying periods of minimal surgical stimulation. So, CVS stability should be , maintained by Supplementation with short acting anesthetics e.g. propofol or sympathetic antagonist e.g. esmolol ( during periods of stimulation). Regional laryngeal nerve block e.g. Glosso-pharyngeal nerve ( at the posterior tonsillar pillar). Topical anesthesia of the larynx with lidocaine.

29. 2. Bleeding 3. Desaturation 4. Laryngospasm 5. Bronchospasm 6. Trauma 7. Delayed recovery

30. Postoperative Management Laryngeal edema can occur in the early postoperative period, manifested by retractions and respiratory stridor in the recovery room. Laryngospasm can develop because of laryngeal hyperactivity. treated with positive pressure mask ventilation with 100% O 2 . More severe cases of laryngospasm may require the use of a small, sub apneic dose of sch ( 0.1 to 0.2 mg/Kg IV ). Pneumothorax should be considered after jet ventilation Pulmonary complications as a result of retained secretions and subsequent atelectasis.

31. LASER MICROLARYNGEAL SURGERIES

32. Light Amplification by Stimulated Emission of Radiation Laser works on several principles in quantum physics Characteristics : - coherence (one phase) - collimation (parallel direction) - Monochromaticity (same wavelength)

33. Applications of Laser Surgery Lasers have been utilized in almost every surgical specialty and allow precise microsurgery Lasers allow the surgeon to focus enormous heat on small area of tissue Utilizing laser also allows instantaneous sealing of small vessels and lymphatics with minimal damage to surrounding tissues

34. Advantages of laser surgery Precise lesion targeting Minimal bleeding Minimal edema/tissue reaction Preservation of surrounding structures and normal tissues ( Selective absorption) Rapid healing Easy transmission through endoscopes Minimal postop pain, scarring

35. Hazards of Laser Surgery Atmospheric contamination by laser plume Perforation of a vessels or structure Airway fire Venous air embolism Inappropriate energy transfer ( Drape fire ,Eye damage , ET Tube‐ damage, fires)

36. Atmospheric contamination Plume of smoke and fine particulates efficiently transported and deposited in the alveoli These have the potential to transmit microbiological diseases. Sensitive individuals: headaches, tearing, and nausea after inhalation Prevented by using smoke evacuator Respiratory filter masks compliant with Occupation Safety and Health Administration standards should be worn by all OT persons

37. Safety considerations OT warning signs for LASER use. Restrict entry into OT Wear protective eye glasses Avoid flammable materials (drapes, plastic tubes etc.). Patient's eyes – taped closed & cover with wet pads Wet towels to drape. Competent person for equipment use Avoid misdirection of beam

38. Fire triangle

39. Management of Airway Fires Prevention and Preparation Keep the O2 concentration 30%, or less if possible. Use an O2/air mixture. Avoid N2O. Use a “laser-safe” endotracheal tube. Inflate the endotracheal tube cuff with dyed (methylene blue) normal saline to provide an early indicator of cuff rupture. Use a pre-prepared 50-mL syringe of saline to extinguish any fire, and flood the surgical field if a fire occurs. Have an extra endotracheal tube available for reintubation in case a fire occurs. Inform the surgical team working on the airway of any situation in which high concentrations of O2 are being used.

40. In the Case of an Airway Fire 1. Stop laser. Stop ventilation. Turn off O2 2. Inform the surgical team, and assign someone to call the control desk for help. 3. Remove the burning endotracheal tube and drop it in the bucket of water, if available. 4. Put out the fire with your improvised fire extinguisher. 5. The area should be flushed with saline.

41. When the Fire Is Extinguished 1. Ventilate the patient with 100% O2 by facemask . 2. When the patient is stable, assess the extent of airway damage., debris and foreign bodies should be removed. 3. Re-intubate the patient if significant airway damage is found. 4. When appropriate, arrange for admission to an ICU. 5. Provide supportive therapy, including ventilation and antibiotics, and extubate when appropriate. 6. Tracheotomy may be needed.

42. 1. Laser-shield II Tracheal Tube : It is designed for use with CO2 and KTP lasers. Made from silicone with an inner aluminum wrap and a smooth Teflon outer coating. The cuff is not laser resistant & contains methylene blue crystals as a marker to identify perforation. It should be inflated with water or saline solution. ENDOTRACHEAL TUBES DESIGNED FOR LASER SURGERIES

43. Cottonoids for wrapping around the cuff are supplied with each tube. These must be moistened and kept moist during the entire procedure Disadvantage : Exposure of unprotected parts of the tube proximal & distal to cuff can result in rapid combustion. The methylene blue crystals may not fully dissolve & may obstruct the pilot tube, making it impossible to deflate.

44. 2. Laser-Flex Tubes Laser flex tube is a flexible stainless steel tube with a smooth plastic surface and matte finish to reflect a laser beam. Designed for CO2 and KTP lasers Adult version has two PVC cuffs and PVC tips with Murphy eye. Cuffs are inflated by two separate inflation tubes. Distal cuff should be filled first until sealing occurs then proximal cuff is filled with saline colored with methylene blue. The distal cuff can be used if proximal one is damaged by laser. Disadvantage: stiffness, roughness, cannot be trimmed. The double cuff adds to the time of intubation and extubation.

45. 3. Sheridan laser tracheal tube This is a red rubber tube wrapped with copper foil tape. This is overwrapped with water-absorbent fabric that should be saturated with water prior to use. It is designed for use with a CO2 or KTP laser. Disadvantage : it has a thick wall . high-pressure cuff. 4. Norton tube The norton tube is a reusable, flexible, uncuffed Spiral wound metal tube Stainless steel connector & has a thick wall. Not affected by any laser Disadvantage : air leak Tissue damage

46. 5. Lasertubus: Made of white rubber & has a cuff-within-a cuff design. If the outer cuff is perforated by a laser beam, the trachea will still be sealed by inner cuff. The inner cuff is filled with air & outer with water or saline. It is recommended for use with argon, NdYAG, CO 2 lasers.