1 Airway Management in the Critically IllDr. CHAN King-chung June 7, 2006

2 Learning Airway Management

3 Case Scenario M/65 Admitted for COAD exacerbation Put on BiPAPFound to be unresponsive SpO2 = 87%. BP = 160/90. HR = 120 What would you do ?

4 Indication for Airway Obstruction Assisted Ventilation AspirationSecretion Clearance

5 Airway Obstruction

6 Opening Airway Head tile, Chin lift Jaw thrust

8 Insertion of Oral Airway

9 Nasopharyngeal Airway

10 Mask Ventilation 1-Person: difficult, less effective2-Person: easier, more effective

11 Difficult Mask VentilationLeak around the mask No clear chest expansion during ventilation Ventilation possible only with 2-person

12 Prediction (MOANS) Mask seal Obese / Obstruction Age No teethBeard, facial injury Obese / Obstruction BMI >26 Age >55 years No teeth Stiff lung

13 Complications Gastric distension AspirationPressure injury to eyes, nose or lips Facial nerve palsy

14 Bag-Mask Ventilation

15 Rapid Sequence IntubationVirtually simultaneous administration, after preoxygenation, of a potent sedative agent and a rapidly acting neuromuscular blocking agent to facilitate rapid tracheal intubation without interposed mechanical ventilation

16 Why RSI ? Minimize risk of aspiration Optimal intubating conditionHigh success rate

17 Success Rate Medical Trauma RSI 99.8% 97.7% No med 94.7% 96.3%Sedation only 95% 93.7% Nasal 97% 98.1%

18 7 Ps Preparation Preoxygenation PretreatmentParalysis with induction (Time Zero) Protection and positioning Placement with proof Postintubation management

19 7 Ps Preparation (Time -10mins) Preoxygenation PretreatmentParalysis with induction (Time Zero) Protection and positioning Placement with proof Postintubation management

20 Preparation (T -10mins) Assess for possible difficult airwayAssemble equipments and prepare drugs Attach monitors Establish IV access

21 Preparation (T -10mins) Assess for possible difficult airwayAssemble equipments and prepare drugs Attach monitors Establish IV access

22 Difficult Intubation Intubationist with >2 years of experienceMore than 3 attempts Intubation time >10 minutes

23 Chances of Difficult AirwayProbability Difficult mask ventilation Uncertain Difficult intubation 1 - 4% Failed intubation % Difficult ventilation & Difficult intubation 1.5% Cannot Ventilate & Cannot Intubate %

24 Assessment of Airway The LEMON rule Look externally Evaluate 3-3-2Mallampati score Obstruction Neck Mobility

25 Look Externally Receding mandible (Micrognathia)Large tongue (Macroglossia) Protruding teeth Short neck Obese Head & neck injury

27 Evaluate 3-3-2 Mouth opening Hyoid-Mental distance Thyrohyoid distanceAccommodate 3 fingers Hyoid-Mental distance 3 fingers Thyrohyoid distance 2 fingers (Thyromental distance >6 cm)

28 Mallampati Score I II III IV Faucial pillars + - Uvula Soft palateHard palate Grade 4 Larynx 0% 10% 33%

29 Assess this Lion

31 Neck Mobility Necessary for a good laryngoscopy viewSternomental distance <12.5cm (normal 15cm)

32 Preparation (T= -10mins)Assess for possible difficult airway Assemble equipments and prepare drugs Attach monitors Establish IV access

33 Equipments for IntubationAirway Oral / Nasl Airway Oxygen & Ventilation Oxygen Source Mask (Various Size) Manual Resuscitator Endotracheal Tube 7-9mm ETT Malleable Stylet / Bougie Syringe K-Y Jelly Fixation Adhesive Tape Laryngoscopy Laryngoscope Blade (Size 3 first) Suction Small Pillow Magill Forceps Drugs Sedative Muscle Relaxant Confirmation Stethoscope End-tidal CO2 Oesophageal Detector

34 Shape of ETT Hockey Stick To manoeuvre within oral cavityExpect some resistance in removing stylet Lubricate stylet

35 McCoy Laryngoscope

36 Sedation for IntubationEtomidate 0.2mg/kg More CV stable Adrenal suppression Midazolam 0.1mg/kg Convenient Infusion for sedation Less clear end point of induction Propofol 0.5mg/kg More hypotension Thiopentone 1.5mg/kg Standard for neurosurgical patient Ketamine 1mg/kg Increase BP

37 Muscle Relaxant Suxamethonium Rocuronium 1.5mg/kg30-45s to full action Last 10 mins Fasciculation Increase K Hyper K to start with Burn >24hrs Spinal injury >24hrs Increase ICP Rocuronium 1mg/kg 60s to full action Last 1 hour No fasciculation

38 7 Ps Preparation (Time -10mins) Preoxygenation (Time -5mins)Pretreatment Paralysis with induction (Time Zero) Protection and positioning Placement with proof Postintubation management

39 Preoxygenation (T= -5mins)100% oxygen for 5 minutes 8 vital capacity breath (Not 100% on SpO2) Provide store of oxygen during intubation

40 Time to Desaturation

41 Pretreatment (T= -3mins)Lignocaine 1.5mg/kg Raised ICP Bronchospasm Opioid Fentanyl 1-3ug/kg Coronary heart disease Atropine 0.01mg/kg Age < 10years Defasciculation 10% paralysis dose Rocuronium 0.06mg/kg Raised ICP

42 Paralysis with Induction (T= 0s)Ascertain everyone is ready Sedative → Relaxant → NS flush As quickly as possible Don’t flush between sedative & relaxant

43 Protection & Positioning (T= +30s)Cricoid Pressure Position patient Do not bag unless SpO2<90 Increase risk of aspiration

44 Cricoid Pressure Cricoid: cartilage with a complete ringAlso called Sellick’s Manoeuvre Firm pressure to prevent regurgitation

46 Positioning Sniffing position Head Extended, Neck Flexed

49 Laryngoscopy Grading Complete glottis visibleAnterior glottis not seen Only epiglottis Epiglottis not seen

50 Signs of Successful IntubationNon-fail-save signs Breath sound in chest No breath sound over stomach Chest rise and fall Moisture condensation on tube in expiration ‘Normal’ compliance on bagging CXR Hearing air exit from tube on chest compression Feeling of cartilage with Bougie Resistance upon passing Bougie / Suction catheter

51 Signs of Successful IntubationNear-fail-save signs ETCO2 (6 breaths / 1min) False negative in cardiac arrest False positive after carbonated drinks Oesophageal Detector Gastric distension

53 Postintubation ManagementSecure Tube CXR Sedation +/- paralysis Set ventilator

54 7 Ps Preparation (Time -10mins) Preoxygenation (Time -5mins)Pretreatment (Time -3mins) Paralysis with induction (Time Zero) Protection and positioning (Time +30s) Placement with proof (Time +45s) Postintubation management

55 Failed Intubation Summon Help Mask ventilation Think about whyChange blade or intubator Optimize patient ?? Impossible to intubate

56 Maintain Ventilation Patient die not from failed intubation but failed ventilation Rescue from failed intubation is bagging Rescue from failed bagging is ‘better’ bagging Another dose of relaxant often KILLS

57 Endoscopy Mask Able to pass bronchoscope and ETTFor bronchoscopic intubation if mask ventilation effective

58 Fiberoptic IntubationCut tube to 26cm before use Fix the tube to the top end with tape Open the airway with jaw thrust

59 Difficult Bagging Insertion of oral / nasal airwayOther Airway adjuncts Laryngeal Mask Airway Intubating Laryngeal Mask Combitube Laryngeal Tube

60 Laryngeal Mask Airway

62 Selection of LMA Size Weight Max Cuff Volume Pass ETT FOB Size 1<6.5kg 4mL 3.5 2.7mm 2 6.5-20kg 10mL 4.5 3.5mm 2.5 20-30kg 15mL 5 4mm 3 30-60kg 20mL 6 (cuff) 5mm 4 >60kg 30mL 6.5 (cuff)

63 Insertion of LMA 1 2 3 4 Keep neck in flexionInsertion difficult with Cricoid Pressure Move out 1 to 2cm upon inflation

64 Advantage of LMA High success rate No muscle relaxation required87-94% with only brief training No muscle relaxation required Conduit for subsequent intubation Fiberoptic / Bougie / 6mm ETT

65 Disadvantage of LMA Risk of Aspiration Failure Rate 1 to 5%Partially reduced with the newer Proseal Failure Rate 1 to 5% Improve with training Airway obstruction with over inflation

66 LMA Insertion

67 Intubating Laryngeal MaskEasier insertion Rigid handle Designed for intubation Blind FOB guided

68 Inserting ILMA

69 Inserting ETT via ILMA

70 Combitube Combitube Adult > 5ft Combitube SA (Small Adult) 4 - 5ft

72 Advantage of CombitubeCan be inserted in any position Minimized risk of aspiration No fixation needed after inflating oropharyngeal balloon IPPV at higher pressure Neck movement not necessary Little training Work in either tracheal or oesophageal position No preparation necessary

73 Problem with CombitubeClearance of airway secretion no possible No conduit to change to ETT

74 Contraindication Intact gag reflex Under 4 feetCentral airway obstruction Known oesophageal pathology Caustic ingestion

76 Laryngeal Tube Similar to CombitubeConduit available for tracheal access

77 Sizes of Laryngeal TubePatient Patient Size Colour Volume Newborn <5kg Transp. 10mL 1 Infant 5-12kg White 20mL 2 Child 12-25kg Green 35mL 3 Teenage <155cm Yellow 60mL 4 Adult cm Red 80mL 5 Large Adult >180cm Pruple 90mL

78 Cannot Intubate / VentilatePatient will DIE in minutes Continue with mask ventilation despite difficulties Call Surgeon for surgical airway ?Trial of of Combitube Prepare for Cricothyrotomy

79 Cricothyrotomy Last resort for cannot-intubate, cannot-ventilateSurgical Cricothyrotomy Needle Cricothyrotomy Require jet ventilation

80 Needle Cricothyrotomy

81 Needle Cricothyrotomy

82 Difficult CricothyrotomySurgery of neck Haematoma, infection, or other neck swelling Obesity Radiation distortion Tumour of the neck

83

84 Percutaneous TracheostomyElective procedure At least 2 doctors Surgeon Anaesthetist / Airway management Usually under LA & sedation

85 Advantage Lower risk of infection Lower incidence of bleedingOR = 0.28 ( ) Lower incidence of bleeding OR = 0.29 ( ) Lower mortality OR = 0.71 ( ) Similar major peri-procedural complications Similar long-term complications Crit Care Apr 7;10(2):R55

86 Contraindications Emergency airway Infection of the neckObesity with short neck Bleeding diatheses PT/APTT > 1.5x normal Platelet count <50 Bleeding time > 10mins Tracheomalacia PEEP > 15cmH2O Age <15 years Distortion of the neck anatomy Hematoma Tumor Thyromegaly High innominate artery Scarring from previous neck surgery

87 Procedure ETT withdrawn before starting Dilation methodsSerial Blue Rhino Giggs Forceps Percutwist Bronchoscopic monitor for beginners 1 2 3 4

88 Complications Immediate Early Post-op Late Post-op (>6m) Death 0.4%Haemorrhage (2.5%) Hypoxia False Passage (0.8%) Posterior Tracheal Wall Perforation Surgical Emphysema Tension Pneumothorax Accidental Extubation Early Post-op Haemorrhage Stomal Infection (1%) Excessive Granulation tissue Tracheal Arterial Fistula Late Post-op (>6m) Tracheal Stenosis (2%) Tracheocutaneous Fistula Voice Change (up to 50%) Disfiguring scar (4%)

89 Dislodged TracheostomyConfirm dislodgement Cannot pass suction catheter No ETCO2 Remove Tracheostomy tube Do not re-insert tracheostomy if track is not formed (< 1 to 2 weeks) Start mask ventilation Reintubate trans-laryngeally

90 Changing ETT Adequate fasting Sedation + paralysisCook’s Airway Exchange Catheter NOT Bougie as it has to be at least twice the length of ETT

91 Cook’s Catheter

92 Procedure

93 Procedure

94 Procedure

95 Procedure

96 Reference Video on the use of various adjuncts Use of LMA Use of LMA Percutaneous Tracheostomy General airway management

97 Reference BLS Provider Manual (2006) by American Heart AssociationACLS Provider Manual (2003) by American Heart Association Airway Management: Principles and Practice (1995) by Benumof et. al. Manual of Emergency Airway Management (2004) by Walls et. al.