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Airway Endoscopy and Laser Anesthetic considerations Dr. Abdul-Hamid Samarkandi, FFARCSI,KSUF Chairman Anaesthesia Department King Saud University Hospitals King Khalid University Hospital Objectives: 1- Airway assessment and patient examination. 2- Mapping a plane for the perioperative sequlae. 3- Requirements for save endoscopy. 4- Selection for reasonable anesthetic technique. 5- Intraoperative challenges. 6- Postoperative recommendations. 7- Considerations for Laser surgery. 1- Airway assessment and patient examination. Must be able to assess or anticipate the degree of difficulty Then select method most likely to succeed . Clinical Airway Assessment Airway examination: - Indirect laryngoscope. Radiographic studies Lung reserves: flow-volume loop. Reserving ICU bed for postop.respiratory care. * Discusse the perioperative plan with the surgeon Historical features ( prior AW difficulty): – Anesthesia record in old chart. – Medical alert bracelet. – Tracheostomy scar. Anatomical features: – C-spine mobility – External dimensions ( 3-3-2 rule) * Mouth opening 3 fingers (TMJ). * Mandible large enough to accommodate tongue. * 3 fingers from tip of chin to hyoid. – Length of neck/position of larynx - 2 fingers between top of thyroid and floor of jaw Teeth – large or protruding incisors obstruct vision – jagged teeth can lacerate balloon Oral dimensions – narrow facial features and high arched palates (decreased lateral space) – Mallampatti classification Mallampatti Classification (Tongue to Pharyngeal Size) I - soft palate, uvula, tonsillar pillars visible – 99 % have grade I laryngoscopic view. II - soft palate, uvula visible. III - soft palate, base of uvula. IV - soft palate not visible – 100% grade III or grade IV laryngoscopic views. Mallampatti Classification Predictors of Difficult Laryngoscopy Direct laryngoscopy intubation is difficult in 1% - 4% and impossible in 0.05% - 0.35% of patients who have seemingly normal airways. The unanticipated difficult laryngoscopy intubation places patients at increased risk of complications ranging from sore throat to serious airway trauma. Moreover, in some cases we may not be able to maintain a patent airway, leading to severe complications such as brain damage or death. Predictors of Difficult Laryngoscopy Short, thick, muscular neck. Receding mandible. Protruding maxillary incisors – “Buck teeth” Poor TMJ mobility/ limited jaw opening Limited head and neck movement – ( including trauma ) High, arched palate Predictors of Difficult Laryngoscopy Tumor, abscess or hematoma Burns Angioneurotic edema Blunt or penetrating trauma Rheumatoid arthritis, ankylosing spondylitis Congenital syndromes Neck surgery or radiation Response to Unanticipated Difficulty Difficult laryngoscopy and intubation – Can’t intubate but Can ventilate – Can’t intubate and Can’t ventilate Difficult Mask Ventilation Response to Unanticipated Difficulty Bag the patient. Maximize neck flex/ head extension. Move tongue out of line of site. Maximize mouth opening. ID landmarks and adjust blade. BURP maneuver – (Backwards Upwards Rightwards Pressure on Thyroid Cartilage) Increasing lifting force. Consider Miller blade. Bag the patient. Response to Unanticipated Difficulty An optimal or best attempt at difficult laryngoscopy should consist of : – use of optimal sniffing position – no significant muscle tone – use of optimum external laryngeal manipulation (BURP) – one change in length of blade – one change in type of blade – a reasonably experienced laryngoscopist Response to Unanticipated Difficulty Remember, the first response to failure to intubate should always be to Bag-MaskVentilate the patient. The first response to failure of bag-maskventilation is always better bag-maskventilation Algorithm for Difficulty “Bagging” Remove FB - Magill forceps. Triple maneuver if c-spine clear – Head tilt, jaw lift, mouth opening Nasal (NP) or oropharyngeal (OP) airways. two-person, four-hand technique. Generate as much positive pressure as possible without inflating the stomach Do not abandon bagging unless it is impossible with two people and both an OP and NP airway The Failed Intubation: Definition Three failed attempts to intubate – by an experienced anesthetist. Inability to ventilate with BMV (Bag-Mask-Ventilation) Inability to oxygenate The Failed Intubation If can’t intubate but can ventilate with BMV have time to consider options – – – – – – Light guided technique (Lighted stylet) Combitube LMA Fiberoptic techniques Retrograde intubation Cricothyrotomy Awake Oral Intubation Prepare patient psychologically Pre-oxygenate Topical anesthesia if time permits Titrated sedation - avoid obtundation Reassure patient throughout procedure Difficult Airway Kit • Multiple blades and ETTs • ETT guides (stylets, bougé, light wand) • Emergency nonsurgical ventilation ( LMA, Combitube, TTJV ) • Emergency surgical airway access ( cricothyroidotomy kit, cricotomes ) • ETT placement verification • Fiberoptic and retrograde intubation The Failed Intubation If can’t intubate, can’t ventilate , must act immediately – – – – – Cricothyrotomy Urgent Tracheotomy Percutaneous Transtracheal Jet Ventilation Combitube LMA The last three are temporizing measures and not definitive airway management Awake Oral Intubation Consider for anticipated can’t intubate, can’t ventilate situation distorted upper airway anatomy (i.e., penetrating neck trauma) Avoids ‘burning bridges” maintains ventilation maintains patient’s ability to protect airway May use to take quick look to assure that you can see enough for RSI Difficult Airway Maxims “It is preferable to use superior judgment -- to avoid having to use superior skill”. Difficult airway due to upper airway pathology Plan for tracheostomy before going to surgery (under LA) Awake fibroptic laryngoscope ,either nasal or oral Anesthetic management of operative endoscopies Preoperative preparation Psychological preparation of patients and /or his relatives . Arrangement for ICU bed. Consent for tracheostomy. Avoid sedation. Anti-sialagouge : Glycopyrrolate IV or IM (Quaternary ammonium compound) Atropine , Scopolamine (Tertiary ammonium compounds) Nebulizing racemic epinephrine Nebulizing bronchodilators. Intravenous corticosteroid. Intraoperative considerations 1- Maintaining surgical anesthesia levels: - Continuous infusion of short acting anesthetics (TIVA) : Propofol ,Alfentanil,Remifentanil. - Supplementary volatile anesthetics . - Supplementation with: * -antagonists e.g.; Esmolol. * -agonist e.g.; Dexemedotomidine. Intraoperative considerations 2-The use of muscle relaxants: * Continues infusion of SUX.or Intermittent boluses of short and intermediate durations relaxants. VS * TIVA plus volatile anesthetics 3-Methods of ventilation 1- Conventional ETT anesthesia using size 4.0-6.0 micro-laryngeal tube. 2- Insufflation's ventilation with high flows of oxygen through a small catheter placed in the trachea. better with spontaneously breathing patients. 3- Intermittent apnea technique : Periods of controlled ventilation via face mask or ETT alternated with periods of apnea. 4- Manual Jet Ventilation : The jet injector is connected to a high pressure source of oxygen and to the side port of the laryngoscope. It ventilate the lungs during inspiration and allow period for passive expiration. 5-High -Frequency Jet Ventilation: Utilizes a tube in the trachea to inject small volume of gas at a rate of 80-300 times/min. Manual intermediate- frequency jet ventilation: Use small bag (0.5 l) for delivering small volume high rate , jet like ventilation (60150). Uneventful course during endoscopy Difficulty to maintain ventilations. - As a complications during airway surgery: - Laryngeal stenosis (edema, bleeding) - Laser surgery (fire, small size ETT) - As a complications after airway surgery. - Bleeding, edema. - Pneumothorax. Endoscopy under local anesthesia 1-Rigid bronchoscope: - As rigid bronchoscopy requires straight line between object and operator for visualization. - It always done under GA. Endoscopy under local anesthesia 2- Fiberoptic Bronchoscope - It Does not require straight line for image visualization. - It could be done under LA: I. Topical Application of LA II. Nerve block III. Nebulization of LA I. Topical Application of LA Step 1: Prepare the nose with vasoconstrictor and ribbon gauze soaked with LA . Step 2: Apply LA to the base of the tongue, posterior pharyngeal wall anterior tonsillar pillars & tonsils Step 3: With the help of tongue depressor apply LA to side walls of pharynx and each pyriform fossa Step 4: Do Laryngoscopy and apply LA to Vallecullae,epiglottis and keep soaked gauze to each pyriform fossa for 30 seconds to block superior laryngeal nerve Step 5: SAYGO (Spray As You GO) to lower airway II. Nerve block 1- Glossopharyngeal nerve block Inject 2 ml of Lignocaine 2% to the anterior pillar of the tonsil at site 1 cm above the lower pole of the tonsil at the depth of 8mm (on each side) II. Nerve block 2- Superior Laryngeal Nerve block Infiltrate 2ml of Lignocaine 2% into the thyro-hyoid membrane at site in between the greater cornu of hyoid bone and superior cornu of thyroid cartilage. II. Nerve block 3- Transtracheal block : (Recurrent laryngeal nerve block) Insert 22 gauge canula into trachea through cricothyroid membrane or in between tracheal rings, remove the trocar, aspirate air for .Forcefully Inject 4 ml of Lignocaine 2% at the end of inspiration. Post-endoscopy care Oxygen by face-mask. Close monitoring for homodynamic and respiratory parameters (PACU) before shifting. NPO for 4 - 6 hrs. Good hydration ( IV fluids). Racemic epinephrine or normal saline Nebulization. Post bronchoscopy X-Ray chest. Non-narcotics pain killers. Lidocaine added to a tracheostomy tube cuff reduces tube discomfort Tracheostomy tube cuffs were inflated with 5 ml lidocaine 4% solution and air at 20 cmH2O . Lidocaine diffusion across the tracheostomy tube cuff reduces tube discomfort e.g.: patients undergoing oral cancer surgery Laser surgery and precautions Characteristics: - Monochromatic. - Coherent. - Collimated. Advantages: pain. - Excellent hemostasis. - Minimal edema and Laser Hazards: It depends on the medium in which laser beam is generated ( wavelength). CO2 Laser (10.600 nm ).is more localised,less penetrated YAG Laser (1.060 nm ).less absorbed by water ,deep penetration Laser A. Anesthetic precautions: Suction of Laser fumes. Eye protection for all members inside the theatre including the patient's eye. Avoidance of ETT fire: - Use of inflammable ETT . e.g.; Metal, red rubber, silicon rubber - Use intermittent apnea technique or jet ventilation. Laser 4-Use low inspired O2 concentration. 5-Replace N2O by air or Helium. 6-Inflate ETT cuff with mixture of lidocaine and saline( 1:2). Laser B-Surgical precautions: 1- Limit the duration and intensity of the Laser beam as possible. 2-Saline soaked pledgets to be placed in the airway to limit risk of ignition. 3-A 60 ml syringe filled with water to be standby for fire control. Airway-fire protocol 1- Stop ventilation, Remove ETT, Turn off O2, and disconnect the circuit from the machine. 2-Submerge the ETT in water. 3-Ventilate with Ambu bag and reintubate with regular ETT. 4-Assess the airway damage (bronchoscope, ABGs). 5- Consider steroids and bronchial lavage. Thank You