Airway Management

1. Airway Management Aric Storck PGY-5 Dr. Mike Betzner July 20, 2005

2. Objectives • Crash course in ED airway management: • Indications • Who do you intubate • Who do you not intubate • What type of airway is it • easy, difficult, failed, crash • RSI • Pediatric Airways • Hands on procedural skills station

3. Practical skill stations • Gum elastic bougie • LMA & I-LMA • Trachlight • Needle cricothyrotomy / surgical cricothyrotomy

4. Case • 78F • Acutely SOB • Alert • Talking one word sentences • JVP up • Diffuse wheeze • Sats 84% • ABG 7.25 / 60 / 50 / 19 • Does she need intubation?

5. Step 1Who needs intubation?

6. Indications for Intubation • ABCDE • A - Airway protection • aspiration, obstruction • B – Breathing • Failure to oxygenate • Failure to ventilate • C – Circulation (Shock) • D – Disability / neuro (GCS <9 or drop by 2) • E - Expected clinical course

7. Does our patient have a reason to intubate? • Airway – not a concern right now • Breathing • Failure to oxygenate • Failure to ventilate • Circulation – not a concern right now • Disability – not a concern right now • Expected Course – likely to get worse

8. Crash Airway Does our patient need to be intubated immediately?

9. APPROACH TO THE AIRWAY

10. THE CRASH AIRWAY

11. You have decided to intubate. How do you assess her airway?

12. Predicting a Difficult Airwaythe LEMON law • L = Look • E = Examine • M = Mallampatti • O = Obstruction • N = Neck mobility

13. Obesity Micrognathia High arched palate Narrow face Short or thick neck Neck trauma Large tongue Presence of facial hair Dentures Large teeth Easy intubation Call anesthesia LEMON - Look

14. LEMON –Evaluate 3-3-2 • Evaluate 3-3-2 • 3 fingers of mouth opening • 3 fingers between front of chin and hyoid • 2 fingers from mandible to thyroid cartilage

15. Mallampati score Grade 1: entire post. Pharynx, visualized to tonsillar pillars No difficulty Grade 2: hard palate, soft palate and top of uvula only No difficulty Grade 3: hard and soft palate only Moderate difficulty Grade 4: no visualization post pharynx or uvula (hard palate only Severe difficulty LEMON – Mallampati score

16. LEMON -Obstruction • Upper and lower airway obstruction • Foreign body aspiration • Epiglottitis • Croup • Abscesses • Trauma • Others

17. LEMON –Neck Mobility • C-spine collar • Rheumatoid arthritis • Spinal surgery

18. Is this likely a difficult airway?

19. RSI(Rapid Sequence Intubation) • What is it? • Preoxygentation + Induction agent + NMB + Sellicks maneuver • Why do we do it? • To minimize risk of aspiration in unfasted pts i.e. almost anybody in the ED • Whom do you do it in? • Pts w/ anticipated easy airways & no contraindications to RSI (~80% of ED intubations)

20. Steps of RSI Sellicks maneuver = key concept in RSI • 7 P’s • Preoxygenation -10 to -5 min • Preparation • Premedication -3 min • Paralysis & Induction 0 min • Protection & Positioning +20 sec • Pass the tube w/ Proof + 45-60 sec • Post-intubation care +60 – 80 sec

21. Preoxygenation • Why do we do it? • Replace nitrogen portion of FRC w/ 100% O2, creating a O2reservoir for delaying desaturation during apneic period • How do we do it? • Ideally 5 min of 100% O2 via BVM or alternatively 8 VC breaths • Pearls • NRB delivers only 70% O2 – need to use BVM w/ good seal • Spontaneous breaths only -- DON’T BAG THE PT (unless clinically indicated) • DON’T BREAK SEAL – single RA breath sets you back to step 1

23. Preparation • Even SIMPLE BOB can do it… • S – Suction • I – IV • M – Meds & Monitors • P – Personnel • L – Laryngoscopes • E – ETT’s (3 sizes) • B – BVM • O – Oxygen • B – Backups / alternative devices

24. Pretreatment • LOAFD – given 3 min before Induction • L – Lidocaine • 1.5 mg/kg IV (tight heads, tight lungs) • O – Opiates (Fentanyl) • 2-3 ug/kg IV – blunts sympathetic response • A – Atropine 0.02 mg/kg IV • Kids ≤ 10 or 2nd dose Sux • F – Fluid bolus • D – Defasiculating agent • Rocuronium 0.1 mg/kg – blunts rise in ICP

25. Paralysis & Induction • Induction agent • Etomidate 0.15-0.30 mg/kg IV push • Midazolam 0.1-0.2 mg/kg IV push • Ketamine 1-2 mg/kg IV push • Thiopental 1-5 mg/kg IV push • NMB • Succinylcholine 1.5 mg/kg IV push • Rocuronium 0.6 – 1.0 mg/kg IV push

26. Protection…. • Sellicks Maneuver • Gentle (10 lb) pressure on cricoid ring – compresses esophagus & prevents passive regurgitation • Initiate 10-20 sec after NMB – don’t release until cuff inflated & ETT position confirmed • Release if vomiting occurs (rare once NMB in) • Key part of RSI but frequently done wrongly, poorly, or forgotten altogether

27. … & Positioning • Key to successful intubation – don’t neglect • Age & Body habitus dependent – goal is “sniffing” position • Neonates & infants – towel under shoulders • Children – towel under neck • Adolescents & Adults – towel under head • Obese – towels under head, neck, & shoulders

28. Pass the tube w/ Proof • Confirmation of ETT position • Watch it go through cords • ETCO2 monitors – gold standard • Colorimetric – Yellow = Yes / Purple = Poor • Portable digital – gives reading • Quantitative – good waveform • Esophageal detector devices • Bulb or syringe aspiration • Clinical methods – least reliable • Auscultation, chest rise, misting

29. Post-intubation Management • Right insertion depth? • Adults: TT = TT (tip-teeth = 22 cm) • Kids: ETT size x3 = cm mark at teeth • Confirm w/ portable CXR • Secure ETT • Ventilator settings • different talk but hugely important! • Continued sedation +/- paralysis • Rule of 1/3’s – give 1/3 of intubation doses prn

30. Case • You have just intubated your patient • Suddenly they becomes difficult to bag • What is your approach to dealing with post-intubation complications?

31. Approach to post-intubation complications • G-DOPE • G – gastric distention (peds) • D – Displacement of ETT • O – Obstruction of ETT • P – Pneumothorax • E – Equipment failure • Pearls • Bradycardia = esophageal intubation until proven otherwise • When in doubt, take it out (change everything)

32. Case 4 • 45M • Morbidly obese, big beard • Sudden collapse and grand mal seizure • Vomiting as EMS rolls them in • What kind of airway is this?

33. Difficult Airway • Anesthesia literarture: • 1-3% of intubations will be difficult • 0.1-0.4% of anticipated “easy” intubations end up failing intubation • ~1/10,000 will be “can’t intubate, can’t bag” • ED airways likely more difficult • NEAR data indicates 1% cricothyrotomy rate • Important to try and anticipate but often cannot

34. Approach to the Difficult Airway • Anticipate • thorough evaluation when possible • Call for help • 2nd EP, anesthesia, ENT, surgery, etc. • Evaluate ability to bag the patient • Make an intubation strategy • Triple set-up • Topical anesthesia / awake laryngoscopy • Adjuncts / Alternatives / Backups

35. Predictors of the Difficult Airway • COMATOSE • C – C-Spine mobility limitations • O – Obstructed, OSA • M – Mallampati grade 3 or 4 • A – Anatomy • dysmorphic features, retrognathia, short or thick neck, large incisors, facial hair • T – Trauma (head, neck) • O – Obesity • S – “Soon to be moms” (pregnant) • E – Evaluate 3-3-2 rule

36. Predictors of Difficult BMV • Age > 55 yo • Obesity (BMI > 26 kg/m2) • Facial Hair • Lack of teeth • Hx of snoring • Identified as independent predictors of difficlut BMV ventilation in prospective analysis of 1502 pts • Anesthesiology 2000; 92:1229–36

37. Difficult Airway Algorithm Anticipated Difficult Airway Time (sats OK) No Time (desats) BNTI Anticipate easy to Bag Anticipate hard to bag BMV works BMV Fails Triple Set-up Awake Look +/- RSI Backups Ready 2 Cric Topical Anesthesia Mild Sedation Awake Laryngoscopy Consider: I-LMA Trachlight Fiberoptic Cricothyrotomy Failed Airway Failed Airway

38. Triple Set-Up • Awake laryngoscopy • topical anaesthesia • may go to RSI if looks easy • Rapid Sequence Induction • 2-3 backups immediately at hand: • Bougie • Trachlight • I-LMA • Fiberoptic • McCoy blade • Cricothyroidotomy preparation • Neck prepped & draped, Cric kit open, 2nd person gloved & gowned w/ scalpel in hand

39. Awake Laryngoscopy • Mild sedation • Small doses of midazolam (1-2 mg) +/- fentanyl (25-50 mcg) • Titrate q3-5 min to effect • Want pt able to follow instructions, w/ spont resps • Topical anesthesia • 4% viscous lidocaine on gauze to pharynx, or • Lidocaine spray (10-20 sprays), or • Lidocaine neb • 5 cc 2% lido + 5 cc 2% lido w/ epi in nebulizer • Laryngoscopy or Fiberoptic • 2 options if can see cords: • Dynamic airway (e.g. anaphylaxis)  tube right there • Stable airway (e.g. Pierre Robin)  do RSI

40. Pre-medications L-O-A-D Lidocaine Fentanyl Atropine Defasiculation Neuromuscular Blockers Succinylcholine Rocuronium Induction Agents Etomidate Midazolam Ketamine Thiopental Airway PharmacologyDrugs you need to know

41. SuccinylcholinePharmacology • Depolarizing NMB • Binds to Ach-R, depolarizes it (fasiculations), and stays bound preventing further depolarization • Dose: • Adults: 1.5 mg/kg IV, 3.0 mg/kg IM • Kids <1 yo: 3.0 mg/kg IV • Kids >1 yo: 2.0 mg/kg • Onset: 45-60 sec • Duration of Action: ~10 min

42. SuccinylcholineSide Effects • Bradycardia – vagotonic effect • Kids <8 -- prevent w/ atropine • 2nd dose – Tx w/ atropine • Fasiculations • ↑ IOP – questionable clinical significance • ↑ ICP – prevent w/ defasiculating dose of Roc • Hyperkalemic arrest in at risk pts • Pre-existing hyperK e.g. CRF • Burns: 24 hrs post – 1-2 yrs after healing • Crush injuries: 7d post – 2-3 months • Denervation injuries (CVA, spinal cord): 7d – 6 mo • Neuromuscular Dz (MS, Muscular dystrophies, ALS etc): indefinite • Malignant Hyperthermia – rare but 60% mortality • Trismus / masseter spasm – usually transient

43. SuccinylcholineContraindications • Absolute • Personal or FHx of Malignant Hyperthermia • Burns >24 hrs old • Crush or denervation injuries >7d old • Neuromuscular Dz • Relative • Lack of experience w/ drug • Anticipated difficult airway

44. RocuroniumPharmacology • Non-depolarizing NMB • Competes with ACh & binds to ACh-R • Doesn’t cause depolarization (no fasciculations) • Dose: • Intubation dose: 0.6-1.0 mg/kg • Defasiculation dose: 10% of intubation dose • Onset: 60 sec • Duration of Action: 40-60 min

45. Can you reverse it? • Sort of… • Neostigmine • Blocks Ach breakdown – thus increases [ACh] at receptor to compete with rocuronium • Won’t work until [Roc] ↓’s to ~40% therefore slow onset (~30 min) making it clinically useless as such in the ED • Cholinergic side effects

46. Induction Agents • ALL induction agents can potentially cause myocardial depression & hypotension • Individualize agent & dose to clinical situation • Inadequate induction (i.e. light pt) increases risk of laryngospasm

47. EtomidatePharmacology • Imidazole derivative w/ hypnotic effects • Appears to work at GABA receptor • Trauma drug of choice • Most hemodynamically stable agent we have • Cerebroprotective • Blunts ↑ in ICP, ↓’s cerebral O2 demand • Dose • 0.15 – 0.3 mg/kg (use lower dose if unstable) • Onset: 20-30 secs • Duration of Action: 7-14 mins

48. EtomidateSide Effects • Vomiting SPAM • N & V • occurs in 30-40% • S – Seizures • Conflicting data, but appears to lower Sz threshold in pts w/ focal seizures • P – Pain on injection • A – Adrenal surppression • Reversible & not associated w/ worse outcomes after single dose • M – Myoclonus • Not associated w/ Sz activity on EEG • Occurs in 30-65% -- can ↓ incidence w/ fentanyl pre-Tx

49. EtomidateContraindications • 4 p’s • Prior Seizures • Pregnancy • Category C: animal evidence of harm • Poor Adrenal function • Pediatrics • Likely to change; several studies documenting use for RSI & PSA in kids • Used by 70% of US ED’s

50. KetaminePharmacology • PCP deriviative • Analgesic, amnestic, anesthetic • Bronchodilator • Drug of choice in Asthma / COPD • Catecholamine release  ↑ HR & BP • Good in hypovolemic, hypotensive pts • Does not supress respiratory drive • Dose: 1-2 mg/kg IV or 4-6 mg/kg IM • Onset: 15-30 Sec • Duration: 10-15 min