DIFFICULT AIRWAY MANAGEMENT

1. DIFFICULT AIRWAY MANAGEMENT Tools and Tactics for Success

2. First Case of the Day

3. ASA Definition The Difficult Airway- is defined as the clinical situation in which a conventionally trained Anesthesiologist experiences difficulty with facemask ventilation of the upper airway, difficulty with tracheal intubation, or both Difficult to Ventilate- is when signs of inadequate ventilation could not be reversed by mask ventilation or oxygen saturation could not be maintained above 90% Difficult to Intubate- is when a trained Anesthetist using conventional laryngoscope take’s more than 3 attempts

4. DISCUSSION • 4th National Audit Project NAP4 • Causes of difficult intubation • Basic airway evaluation (Lemon Law ) • Airway Management A-B-C • Gallery of tools • Extubation of the Difficult Airway • ASA Difficult airway algorithm

5. Degrees of Airway Difficulty

6. Overlap Difficult Mask Ventilation

7. Overlap Difficult Mask Ventilation Difficult SGA

8. Triple Failure Difficult SGA Difficult Mask Ventilation Difficult Intubation DANGER ZONE

9. An Emergent Surgical Airway is Not Always Assured Difficult Mask Ventilation Difficult surgical airway Difficult Intubation Danger Zone

10. 4th National Audit Project NAP4 • Sept 2008-Sept 2009 estimated 2,900,000 GA performed in the UK • Data collected on 114,904 GA’s from 309 hospitals over a 2 week period • 184 serious airway complications, including: • -Death (14) • -Brain Damage • -Emergent Surgical Airway • -Unexpected ICU admission

11. NAP4 Lessons Learned PRIMARY PROBLEMS • Aspiration #1 • Extubation Problems • Tracheal Intubation • Delayed Intubation • Failed Intubation • Can’t Intubate Can’t Ventilate

12. NAP4 Lessons Learned Poor Airway Assessment & Poor Planning contributed to Poor Outcomes • Failure to match strategy to assessment (technique) • Failure to have prepared strategy (plan B and C)

13. NAP4 Lessons Learned Emergency Percutaneous Cricothyrotomy failed 60% of the time

14. NAP4 Lessons Learned A common theme was “failure to plan for failure” • In some cases when airway management was unexpectedly difficult the response was unstructured. In these cases outcomes were generally poor. • The project identified numerous cases where awake fiber-optic intubation was indicated but not used

15. NAP4 Lessons Learned • Aspiration was the single most common cause of death in anesthesia events • Importantly most aspirations occur due to failure to recognize risk factors and failure to adjust the anesthetic technique accordingly • Aspiration remains the most frequent cause of airway related deaths during anesthesia.

16. NAP4 Lessons Learned One third of the events occurred during emergence or in recovery. Obstruction was the common cause in these events Recommendations: • Nasal Trumpets • Oral Airway • Airway exchange catheter • SGA prior to removal of ETT (Bailey Maneuver) • Awaken patient with SGA in place

17. Predictors of Difficult Mask Ventilation • Beard • OSA • Obesity • Male Gender • Mallampati class III or IV • Neck Circumference

18. Predictors of Difficult Intubation • Inadequate Preoperative Assessment. • History of difficult intubation • Inadequate equipment • Experience not enough. • Poor technique. • Increased Age • Mallampati III or IV

19. Anatomical Factors Affecting Laryngoscopy • Neck Circumference (Single Major Predictor in Obese) • Short Neck. • Protruding incisor teeth. • Long high arched palate. • Increase in either anterior depth or Posterior depth of the mandible decrease in Atlanto Occipital distance • Limited cervical range of motion • Small mouth opening • Temporomandibular joint pathology

20. Basic Airway Evaluation in All Patients • Previous anesthetic problems • General appearance of the neck, face, maxilla and mandible • Jaw movements • Head extension and movements • The teeth and oropharynx • The soft tissues of the neck • Recent chest and cervical spine x-rays

21. Think L-E-M-O-N When Assessing a Difficult Airway Look externally. Evaluate the 3-3-2 rule. Mallampati. Obstruction? Neck mobility.

22. L:Look Externally • Obesity or very small. • Short Muscular neck • Large breasts • Prominent Upper Incisors (Buck Teeth) • Receding Jaw (Dentures) • Burns • Facial Trauma • Stridor • Macroglossia (Lg Tongue)

23. E-Evaluate the 3-3-2 Rule • 3 fingers fit in mouth • 3 fingers fit from mentum to hyoid cartilage • 2 fingers fit from the floor of the mouth to the top of the thyroid cartilage

24. E-Evaluate the 3-3-2 Rule

25. Class-I Class-II M-Mallampati classification soft palate, fauces; Uvula, pillars. the soft palate, fauces and uvula Class-III Class-IV soft palate and base of uvula Only hard palate

26. Mallampati ?

27. Cormack & Lehane Grading

28. O-Obstruction Blood Vomit Teeth Dentures Epiglottis Tumors Foreign Body (piercings)

29. N-Neck mobility -Measurement of Atlanto-Occipital Angle

30. Atlanto-Occipital Angle Estimates the angle traversed by the occluded surface of the upper teeth Grade I --- > 35° Grade II –- 22-34° Grade III – 12-21° Grade IV -- < 12°

31. Thyromental Distance • Measure from upper edge of thyroid cartilage to chin with the head fully extended. • A short thyromental distance equates with an anterior larynx • Greater than 7 cm is usually a sign of an easy intubation • Less than 6 cm is an indicator of a difficult airway • Relatively unreliable test unless combined with other tests

32. Thyromental Distance

33. MANAGEMENT PLAN OF ANTICEPATED DIFFICULT AIRWAY • Discussion with colleagues in advance • Equipment tested before • Senior help backup • Definite initial plan (A) for ventilation and intubation • Definite plan (B) than option of awake intubation • Ideal situation surgery team standby

34. Preoxygenation Two Techniques Common in Use: • Tidal volume breathing (TVB) of 100% oxygen via a tight-fitting face mask for 5 minutes (Preferred Method) • Deep breaths/Vital Capacity 4 times within 0.5 min (Time to desaturation is consistently shorter then preferred method) Why Preoxygenate? • O2 Consumption Vo2=250ml/min and 2500ml O2 in FRC (after preO2) = 10 minutes to use this O2

35. Airway Management A-B-C Start with Plan A If plan A fails- Go to plan B If plan B fails- Go to plan C

36. Plan “A”: (ALTERNATE) • Different Length of blade • Different Type of Blade • Different Position • Different Equipment

37. Plan “B”: (BVM and BLIND INTUBATION Techniques ) • Mask Ventilation • Bougie • Combi-Tube? • LMA an Option? • Fiberoptic?

38. Plan-C Can’t Intubate.. Can’t Ventilate • Needle Cricothyrotomy • Transtracheal Jet Ventilation • Retrograde Wire Intubation

39. Failure.. Why does it happen • No critical discussion with colleagues about proposed management plan • No request for experienced help • Exaggerated idea of personal ability • Ill-conceived plan A and/or plan B • Poorly executed plan A and/or plan B • Persisting with plan A too long, starting the rescue plan too late • Not involving, and preparing, surgical colleagues

40. GALLERY OF TOOLS

41. Rigid Laryngoscope Blades Of Alternate Design And Size Mc Coy Macintosh Magill Miller Polio

42. Video Laryngoscopy Airtraq McGrath C-Mac

43. Video Laryngoscopy • VL Calls on a Alternative Skill Set • In Critical Situations Unpracticed Techniques may not be Helpful

44. Video Laryngoscopy • Use a stylet and shape it to match your VL Blade • Watch the patient not the monitor when • inserting the VL Blade • Trouble passing tube • -Withdraw • -Lift Less • -Drop your angle

45. Video Laryngoscopy Versus Direct Laryngoscopy • Improved Glottic View • Experienced vs Inexperienced • Cost • Standard of the future? • Picture Confirmation?

46. Bullard Rigid FiberopticLaryngoscope • Time • Experience • Limited Maneuverability

47. Stylet Devices Optical Stylet Lighted Stylet • No Nasal Intubation • No Suction • Limited to above Cords

48. GUM ELASTIC BOUGIE (GEB) • First used in England • Cheap • Good in patients in whom only epiglottis is visualized

49. Supraglottic Airways SGA Combitube LMA

50. The Esophageal-Tracheal Combitube • Useful as emergency airway • Two lumens allow function whether place in esophagus or trachea • Esophageal balloon minimizes aspiration