Anatomy of an Airway Disaster: Lessons from the School of Hard Knocks Why things go wrong

1. Anatomy of an Airway Disaster: Lessons from the School of Hard KnocksWhy things go wrong D. John Doyle MD PhD

2. Objectives Understand the special problems that may occur in some “difficult airway” patients.

3. Objectives Understand how the ASA difficult airway algorithm may help deal with “difficult airway” patients.

4. Objectives Understand the special issues in the “difficult extubation” patient.

5. Airway Horror Stories Jaws wired shut after maxillofacial surgery (and then patient has an epileptic seizure and vomits).

6. Airway Horror Stories ETT cuff won’t deflate (pilot line sealed shut as patient bites on it).

7. Airway Horror Stories ETT sutured into place by oral surgeon. (PACU story)

8. Airway Horror Stories Fetal distress in a parturient with a known difficult airway.

9. Airway Horror Stories Epiglottitis in a child with an parent known to have malignant hyperthermia.

10. Airway Horror Stories Severe epistaxis following extubation after maxillofacial surgery (jaw wired shut).

11. Airway Horror Stories Ankylosing spondylitis so severe that the patient’s nose is in contact with her chest.

12. Case of Dr. A. Ovassapian

13. http://www.burnsurgery.org/Modules/initial/images/page_19b.jpghttp://www.burnsurgery.org/Modules/initial/images/page_19b.jpg

14. Laryngeal Edema Laryngeal edema. Courtesy of L. Baijens. Wittekamp et al.Critical Care 2009 13:233   doi:10.1186/cc8142

15. WHY AIRWAY DISASTERS OCCUR 1. Incomplete assessment 2. No plan 3. No preparation 4. No trained assistance 5. Overconfidence/Ego 6. Fear of calling for help 7. Getting the wrong help (story) 8. No experience with LMA or Combitube 9. Fear of trying a surgical airway

16. The Morbidly Obese Man Scheduled for Gastroplasty Anesthetic #1 • Pentothal / Succinylcholine • Couldn’t intubate • Couldn’t ventilate well • Succinylcholine wore off • Patient woke up

17. Anesthetic #2 • Pancuronium used for “improved relaxation” • Couldn’t intubate • Couldn't ventilate • Bradycardia • Cardiac arrest • Coroner’s inquest

18. THE MORBIDLY OBESE WOMAN for post-gastroplasty repair • Fentanyl / thiopental / succinylcholine induction • Couldn’t incubate; couldn’t ventilate • Experienced head and neck surgeon in the room • Decision to have surgeon do surgical airway • Surgeon decided to attempt a formal tracheostomy • Difficulty finding trachea in layer after layer of fat • Patient died (eventually)

19. More Airway Disasters • Facial trauma • Unrecognized esophageal intubation • Too many attempts at laryngoscopy/intubation (too much help) • Failed TTJV http://www.onlinejets.org/articles/2009/2/1/images/JEmergTraumaShock_2009_2_1_51_44685_u1.jpg

20. ASA Recommendations for Known or Suspected Difficult Airway 1. Inform the patient about the special risks 2. Make sure another individual is available to assist 3. Give supplemental oxygen while managing the airway (e.g. nasal prongs during fiberoptic intubation)

21. Three Basic Management Choices...to be made for each airway situation 1. Nonsurgical vs surgical airway for the initial approach to intubation 2. Maintenance of spontaneous breathing vs breathing for the patient 3. Awake intubation vs intubation after induction of general anesthesia

22. Three Basic Situations You Must Always Have a Plan for 1. Awake intubation 2. The patient who is difficult to intubate but easy to ventilate 3. The patient who cannot be intubated or ventilated

25. THE SITUATION... • Can’t intubate • Can’t ventilate well • Want to “bail out”

26. THE OPTIONS... • Reposition head • Airway adjuncts oral airway nasopharyngeal airway • Laryngeal mask airway • 2 man - 2 hand technique person 1: 2- handed jaw thrust person 2: ventilates • Surgical airway TTJV cricothyroidotomy

27. How Many Attempts at Elective Intubation? 1. First attempt 2. Second attempt • reposition head • external laryngeal manipulation • use stylet / airway introducer 3. Third attempt If no success after 3 attempts, wake up the patient and try awake intubation or alternate plan (?insert LMA ?regional anesthesia, etc.)

28. Techniques for Difficult Intubation • Alternative laryngoscope blades • GlideScope • Awake intubation • Blind intubation (oral, digital, nasal) • Fiberoptic intubation (awake, asleep) • Intubating stylet / tube changer • Light wand • Retrograde intubation • Surgical airway (Modified from ASA Guidelines for Management of the Difficult Airway)

29. Difficult Airway Box 1. Extra nasopharyngeal and oropharyngeal airways 2. Selection of supraglottic airways (e.g., LMA. i-Gel) 3. ETTs of assorted sizes, including narrow diameter tubes 4. Video laryngoscope (e.g., GlideScope) 5. Equipment for awake intubation (drugs, sprayers, airways) 6. Equipment for fiberoptic intubation 7. Equipment for cricothyrotomy 8. Exhaled CO2 detector 9. Airway introducer (“gum elastic bougie”) (Modified from ASA Airway Management Guidelines)

30. Difficult Mask Ventilation

31. Langeron O, Masso E, Huraux C, Guggiari M, Bianchi A, Coriat P, Riou B: Prediction of difficult mask ventilation. Anesthesiology 2000; 92:1229–36

32. Techniques for Difficult Ventilation • Esophageal-tracheal Combitube • Intratracheal jet stylet • Laryngeal mask airway • Nasopharyngeal airway • Oropharyngeal airway • Rigid ventilating bronchoscope • Surgical airway • Transtracheal jet ventilation • Two-person mask ventilation (Modified from ASA Guideline for Management of the Difficult Airway)

33. ASA DAA

36. Extubation Extubation is the process of removing an endotracheal tube (ETT) from the patient's trachea. This should ordinarily only be done with the patient awake and obeying verbal commands. Even so, catastrophes on extubation can occur, such as total collapse of the airway in a patient with tracheomalacia. Sometimes it is wise to extubate over an ETT exchange catheter (as in any patient who would be difficult to reintubate).

37. Difficult Extubation

38. Difficult Extubation Extubation is the process of removing an endotracheal tube (ETT) from the patient's trachea. This should ordinarily only be done with the patient awake and obeying verbal commands. Even so, catastrophes following extubation can occur, such as total collapse of the airway in a patient with tracheomalacia. Sometimes it is wise to extubate over an ETT exchange catheter, such as in any patient who would be very difficult to reintubate. Such a device can be left in place and later used to facilitate reintubation should a trial of extubation end in failure. If reintubation becomes necessary the exchange catheter can then be used as a guide to direct the new ETT through the cords. Some exchange catheters can also be used to administer low flow oxygen deep into the lungs (eg. 2 liters/min flow rate) as well as for capnography or even emergency jet ventilation in a manner similar to transtracheal jet ventilation (TTJV) [1-3]. References [1] Cooper RM. The use of an endotracheal ventilation catheter in the management of difficult extubations. Can J Anaesth 1996; 43:90-3. [2] Cooper RM. Extubation of the difficult airway. Anesthesiology 1997;87:460. [3] Benumof JL. Airway exchange catheters for safe extubation: the clinical and scientific details that make the concept work. Chest 1997;111:1483-6.

39. LMA as a “bridge to full extubation” GENERAL IDEA • Extubate ETT and replace with LMA or ILMA • Remove LMA some time later • Can reintubate via LMA if needed

40. Tube Exchange Catheters

41. Airway Exchange Catheters These can be left in place and later used to facilitate reintubation should a trial of extubation end in failure. If reintubation becomes necessary the exchange catheter can then be used as a guide to direct the new ETT through the cords. Some exchange catheters can also be used to administer low flow oxygen deep into the lungs (eg. 2 liters/min flow rate) as well as for capnography or even emergency jet ventilation in a manner similar to transtracheal jet ventilation (TTJV) [1-3]. References [1] Cooper RM. The use of an endotracheal ventilation catheter in the management of difficult extubations. Can J Anaesth 1996; 43:90-3. [2] Cooper RM. Extubation of the difficult airway. Anesthesiology 1997;87:460. [3] Benumof JL. Airway exchange catheters for safe extubation: the clinical and scientific details that make the concept work. Chest 1997;111:1483-6.

42. Extubation of the Difficult Airway: An Algorithm 1. Ensure leak around ETT cuff exists 2. Place tube changer (TE). 3. Ensure oxygenation and ventilation are adequate and that patient is fully awake and reversed. Then pull ETT. 4. Employ “rescue strategy” if airway unstable or lost after pulling the ETT

43. One of Several Tube Exchange Catheter Extubation Algorithms http://crashingpatient.com/wp-content/images/part3/extubation.jpg

44. Cook Tube Exchange Catheter

46. Post-Extubation Airway Obstruction • Often due to apposition of tongue and soft palate against posterior pharyngeal wall(oral airway often helpful) • But often due to laryngospasm(oral airway may worsen situation)

47. Airway Edema • Mechanical trauma • Impeded venous drainage (eg. SVC syndrome) • Airway instrumentation • Pregnancy (esp with preeclampsia) • Head & neck injury

48. Vocal Cord Paralysis • Usually secondary to RLN injury, resulting in an unopposed SLN mediated cord adduction • Causes: • Thyroidectomy • IJ line placement • ETT related (ETT cuff compression of RLN against lamina of thyroid cartilage)

49. Extubation Wisdom • Don’t take out anything out of the patient you can’t put back in . • If in doubt, extubate wide awake. • A person who is bucking on the tube may not necessarily be safe to extubate. • You can get into trouble even when extubating the awake patient. • Always have a backup (rescue) plan

50. More Wisdom (Warning!) “Reintubation over a tube exchanger is not uniformly successful. Success rate can be enhanced by rotation of the ETT and simultaneous bronchoscopy...”(Miller et al., 1995)