Lesson 8 Alternative Airway Devices.docx

- Difficult Airway: Clinical situation in which a trained anesthetist experiences difficulty with facemask ventilation, laryngoscopy, intubation, or all of these - Difficult laryngoscopy: the inability to visualize any portion of the vocal cords - Difficult endotracheal intubatio...

- Difficult Airway: Clinical situation in which a trained anesthetist experiences difficulty with facemask ventilation, laryngoscopy, intubation, or all of these - Difficult laryngoscopy: the inability to visualize any portion of the vocal cords - Difficult endotracheal intubation: the inability to intubate despite multiple attempts - Failed intubation: occurs in about 1 in 2000 patients in an elective setting - Difficult BVM = BOOTS - Difficult SGA = RODS - Difficult intubation = LEMON - Difficult cricothyrotomy = SHORT - Airway plan - Must consider patient factors and procedure factors - Preop airway assessment findings? - Anticipated difficulties? - Aspiration risk? - Awake vs. Asleep? - Airway devices? - Backup Plan if Plan A fails? - Preparation - Ambu, suction, stethoscope (ASS) - SOAP = suction, oxygen, airway/ancillary equipment, pharmacy - MSMAIDS = machine, suction, monitor, airway, IV drugs, special - Preoxygenation/denitrogenation = 100% FiO2, 10-12 L/min for 3-5 mins - Patient positioning - Head extended, neck flexed - Align OA, PA, LA axes - Higher height might be better -- bed between xiphoid and nipple - Direct laryngoscopy, Video laryngoscopy are both used to perform tracheal intubation - Standard intubation procedure 1\. Preoxygenation\ 2. Administer Induction Agent\ 3. Verify loss of consciousness\ 4. Attempt PPV\ 5. Administer muscle relaxant\ 6. Continue PPV while waiting for muscle relaxant effect\ 7. Laryngoscopy\ 8. Intubation\ 9. Verify ETT Placement - RSI = indicated when immediate control of the airway is desired in pts with increased risk of aspiration 1\. Preoxygenation\ 2. Administer Induction Agent AND muscle relaxant\ 3. CRICOID PRESSURE (aka Sellick maneuver) at 30 Newtons\ 4. Verify loss of consciousness\ 5. NO PPV\ 6. Laryngoscopy\ 8. Intubation\ 9. Verify ETT Placement\ 10. Release Cricoid Pressure AFTER placement is confirmed - Modified RSI 1\. Preoxygenation 2\. Administer Induction Agent 3\. CRICOID PRESSURE 4\. Verify loss of consciousness 4\. Attempt PPV to confirm ability to ventilate 5\. Administer muscle relaxant 6\. Laryngoscopy 7\. Intubation 8\. Verify ETT Placement 9\. Release Cricoid Pressure AFTER placement is confirmed - Difference between modified RSI and RSI is that in modified RSI, you verify you can ventilate by giving one breath before giving muscle relaxant - Most treacherous time of airway management is extubation - Oral airways - Only for unconscious pts - Can cause vomiting, dental injury/trauma, soft tissue ischemia, laryngospasm - OPA pulls tongue and epiglottis away from the posterior pharynx - NPAs - Use in conscious pts - Rests above epiglottis - Contraindicated in basilar skull fracture, facial trauma, nasal fracture, disruption of midface, nasopharynx or roof of mouth, prior transsphenoidal hypophysectomy, prior Caldwell-Luc procedure, anticoagulated patients - **Microlaryngeal tubes** - Used for head and neck procedures - Smaller diameter, longer length to give more room in oral cavity - More proximal adult-sized cuff - **RAE Tubes** - Preformed bend to prevent kinking - Used to facilitate surgical access in facial procedures, oral procedures, mandibular procedures - **Check bilateral breath sounds** - If too deep, tip can rest at or below carina - If too shallow, can get in way of surgeon - North facing points up and is nasal RAE - South facing points down and is oral RAE - Direct Nasal Intubation Procedure - Standard induction - Vasoconstrictor bilateral nares - Slowly, sequentially insert lubricated nasal trumpets of increasing size to dilate nares - Introduce nasal ETT and gently insert past turbinates - DL method - Insert laryngoscope with or without forceps and visualize ETT passing through cords - ­­ - Nasal intubation indirect intubation procedure - Main difference is that pt is spontaneously breathing - Administer vasoconstrictors - Sedate pt - Anesthetize posterior oropharynx, pharynx, larynx - Slowly, sequentially insert nasal trumpets - Gently insert NETT until past turbinates - Listen for breath sounds while advancing - Le Fort fractures -- can't use nasal airways in Le Fort fractures 2 and 3 - Armored ETT - Reinforced tubes with embedded coiled metal or plastic wire - Useful when extreme angles are needed - Can be occluded if pt bites down - NIM (neural integrity monitor) Tubes - Used for intraoperative nerve monitoring of vocal cords - Precise tube placement is critically important -- use VL - Laser surgery -- special tubes designed to decrease risk of airway fire - Cuff filled with saline or methylene blue to allow for prompt detection of cuff rupture -- does not decrease fire risk, but makes rupture easier to detect - Wrapping with standard ETT with reflective tape is not an alternative - Double lumen tubes - One tube with 2 lumens, bronchial and tracheal - Ability to isolate lung ventilation for thoracic procedures i.e. one lung ventilation - Size based on height - Not appropriate for children or for extended postop use - One lung ventilation in children? Just purposefully mainstem or use fiber optic guidance - One lung ventilation options on adults? Use double lumen tubes or bronchial blockers - VL - Channeled = integrated place where you pass an ETT through a channel - Non-channeled = pass ETT separately i.e. not through a channel e.g. Glidescope, McGrath - Disadvantage - Cost - Blood, secretions, and fog can obscure view - Risk of dental and pharyngeal injury by hyper-focusing on screen - Factors associated with difficult VL - Neck immobility - Restricted mandibular protrusion - Restricted mouth opening, jaw mobility, and oropharyngeal space - Obesity - Hyperangulated blade in VL helps visualize anterior airway structures that you wouldn't normally be able to see via DL - SGA placed blindly - King Laryngeal Tube - Single lumen with 2 cuffs - Combitube - Have 2 lumens (esophageal and trachea) - LMA = laryngeal mask airway - Used as a primary airway device and rescue device - Used with or without muscle relaxation - Less coughing and bucking on emergence/removal - Preserved laryngeal competence and mucocilliary function - Less laryngeal trauma and less stimulating than ETT - Less likely to cause bronchospasm than ETT, but you can still have laryngospasm - Has aperature bars to prevent the epiglottis from blocking the airway - Sizing 3 female adults, 4-5 male adults - Disadvantages - Aspiration risk - Non-supine position - Obesity, pregnancy - Long surgical duration - Intraabdominal or airway procedures - Procedures involving insufflation - Most common problems with LMA use are - Wrong size - The distal tip folded over and occluded airway - Other common problems with LMA use - "Poorly seated"- poor seal & difficulty with PPV - Airway not protected as with ETT - Complications: bronchospasm, postop swallowing difficulties, respiratory obstruction, laryngeal nerve injury, edema, hypoglossal nerve paralysis, aspiration, larymgospasm - Laryngospasm after LMA extubation - Suction if secretions are visualized - PPV - Consider succs and reintubate - 1^st^ generation vs 2^nd^ generation LMAs - Reusable when made from silicone. Disposable when made from plastic - Having higher pressures to ventilate can cause gastric distention increased risk of vomiting - I-gel vs regular LMA - Coiled vs regular LMA - LMAs designed for intubating through e.g. Fastrach LMA and Air-Q - Fastrach LMA - Has handle - Helpful in CICV situations - Can accommodate ETTs up to 7 or 8 - LMA limitations - Airway is not protected -- aspiration risk - Laryngospasm can still occur - Don't work as well with PPV - Can lose fit with position change - Max recommended cuff pressure is 60 cmH2O - Maintain peak airway pressure at 20 cmH2O or less - Articulating stylet = stylet that moves and is typically used with VL; bronchoscope can be used as articulating stylet - Lighted stylet = transluminates the neck to delineate correct position of ETT - Bougie - Used when glottis opening is difficult to visualize (Class IIb or III) - Use with high angle blades - If no tracheal clicks, look for "hold-up" sign as Bougie reaches carina (35-40 cm) - Airway exchange catheters - Used to change ETTs - Can be left in airway after extubation to facilitate reintubation if needed - Can be used for jet ventilation or oxygen insufflation - Flexible fiberoptic bronchoscope (FOB) - Gold standard for managing the difficult airway in an awake, spontaneously breathing patient - Hold scope cord with DOMINANT hand, manipulate lever with NON-DOMINANT hand - Used to confirm double lumen tube placement