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intubation

emergency intubation

Introduction

  • emergency intubation is endotracheal intubation outside of theatre environments
  • induction of anaesthesia and attempted intubation may result in a Can't Intubate, Can't Oxygenate (CICO) event which mandates immediate surgical airway
    • although difficult intubations are relatively common, fortunately, CICO events are rare - perhaps 1 in 10,000 to 1 in 50,000 of routine general anaesthetics in theatre but perhaps up to 10x more frequent than this in EDs and ICUs.
    • unless there are no alternatives, patients should not have intubation attempted unless at least one operator is trained not only in advanced airway techniques but also in surgical airway technique

Contra-indications to intubation

  • a current advanced care directive stating request not to be intubated
  • intubation is likely to be impossible and an emergent surgical airway is required
  • patient is at high risk of adverse event in intubation and patient's condition allows intubation to be deferred or avoided
  • patient is having a terminal event and resuscitation is futile and decision has been made to palliate

Potential indications for emergent intubation outside of theatre

  • failure to maintain an airway despite other measures
  • failure to protect the airway despite other measures
  • failure to oxygenate despite other measures
  • failure to ventilate despite other measures
  • procedure or transport requiring a protected airway
  • anticipated deterioration - eg. airways burns, heavily sedated tricyclic overdose, etc

High risk patients

  • difficult airway which may make intubation difficult, prolonged or impossible
    • LEMON algorithm for airway check:
      • Look for blood, facial trauma
      • Evaluate 3-3-2 rule: 3 fingers mouth opening, 3 fingers under the jaw, 2 fingers from jaw to thyroid
      • Mallampati - less useful in ED intubations
      • Obstruction - anticipated difficulty ventilating for anatomic reasons
      • Neck mobility - suspected cervical spine fracture, etc
  • intolerance to apnoea or induction agents which shorten the available time to achieve intubation safely or cause catastrophic cardiovascular failure:

a modified 7 P's for safer intubation

Plan

  • what is the safest approach for this patient?
    • what are the risks for this patient?
      • assess airways
      • assess cardiorespiratory reserve
        • do they need IV fluids or inotropes?
        • if the patient is not likely to tolerate induction agents, consider calling anaesthetics team to perform an awake intubation
        • do they need PEEP to pre-oxygenate?
      • bariatric issues
      • are any pharmacologic agents contra-indicated?
        • propofol will cause hypotension
        • suxamethonium may be lethal in hyperkalaemia
    • is intubation appropriate?
    • should you call for help from anaesthetics?
    • allocate your team
    • do you have the resources if not, can the intubation be delayed?
    • can you safely manipulate the neck or will you need to use in-line cervical traction (eg. head and neck trauma)?
    • do you need to perform a delayed sequence induction to allow better pre-oxygenation in a combative, hypoxic patient?
    • should you just be embarking upon a surgical airway rather than attempting intubation (eg. upper airway obstructed patient who stops breathing and intubation is likely to be very difficult)?
  • outline YOUR PLAN FOR FAILURE at intubation attempts
    • DEFINE and COMMUNICATE a patient-specific STOP POINT for each plan level
    • PLAN A: your initial plan of how you will attempt intubation aiming for success on 1st attempt
      • eg. DSI or RSI drugs, video laryngoscopy and intubation using a bougie or introducer
      • failure STOP POINT may be after 3 attempts or SpO2 falls below 93%
      • if Plan A fails but Plan B or C succeeds, then consideration may be given to either waking the patient up, or, if this is not possible, having an anaesthetist re-attempt PLAN A
    • PLAN B: your initial backup procedure if Plan A fails
      • eg. call for help and start 2-person BVM ventilation with oropharyngeal airway or if severe facial trauma, Plan B may be surgical airway
      • failure STOP POINT may be after various steps to improve ventilation have failed or SpO2 falls below 90%
    • PLAN C: if Plan B fails, and you can't wake the patient up, then your plan C may be insertion of a supraglottic device such as a LMA or iGel
      • failure STOP POINT may be 2nd device of either different size or type has failed or SpO2 falls below 90%
    • PLAN D: when all else fails and you can't wake the patient up and have them breathing, DECLARE Can't Intubate, Can't Oxygenate and resort rapidly to a surgical airway to save their life

Position

  • suspected cervical spine injury
    • in-line cervical traction
    • consider a small folded towel under head to prevent hyperextension of the neck and maintain neutral alignment
    • elevate head by tilting bed 30deg in reverse Trendelenberg position
  • no cervical spine injury
    • elevate head 30deg by using a ramp under the upper body or similar
    • ear-to-sternal-notch position

Pre-oxygenation

  • prongs for intranasal oxygen set at 4L/min, PLUS,
  • non-rebreather mask with flush rate oxygen (40-70L/min using a high-flow flowmeter)
    • if this is not available, use a tightly applied, well sealed BVM with PEEP set to 5cm H2O at 15L/min oxygen flow - confirm seal with waveform capnography
  • if inadequate pre-oxygenation cannot be achieved (SaO2 > 98%)
    • apply CPAP using either:
      • BVM with PEEP as above, or,
      • proprietary CPAP, or,
      • the ventilator
    • increase nasal prong oxygen flow to 15L/min or as tolerated
  • combative patients may require delayed sequence induction with premed of ketamine in titrated 10-20mg doses
    • WARNING: when using ketamine be prepared to take over the airway as it does not always remain protected

Preparation

  • preferably use a checklist which the scribe can go through with you
  • SALTMINED mnemonic
    • Suction and oxygen - check wall suction is working and Yankauer suction is placed near head of bed, and just prior to intubation increase nasal prong oxygen flow to 15L/min
    • Airways sized and checked (Guedel's and nasopharyngeal)
    • Laryngoscopes x 2 checked and lights functional and video laryngoscopy working
      • Mac blade sizes - 1: <10kg; 2: < 30kg; 3: medium/small adults; 4: tall adults
    • Tubes and bougie - check ETT cuff, and prime with lubricant, have BVM, bougie, LMA and scalpel available
      • ETT size for adults: 7.0: very short/small; 7.5: medium; 8.0: most adults as allows easier suctioning
    • Monitoring including 12 lead ECG, BP, and SaO2, with ET CO2 calibrated and ready to use
    • IV access (preferably x 2), fluids running, RSI drugs drawn up and labelled
    • Need help?
    • Everyone ready and knows their roles - scribe nurse, airway nurse, airway Dr, drug Dr
    • Difficult intubation plan discussed with team such as the Vortex model
      • always be prepared to resort to emergency cricothyroidotomy using scalpel/finger/tube (6.0 size ETT) if can't intubate and can't oxygenate
      • communicate YOUR PLAN to the team

Pharmacology

  • have metaraminol (Aramine) drawn up in case of hypotension from induction agents
  • for patients with hypotension:
    • if severe, consider awake intubation or address the hypotension with fluids or inotropes
    • if mild, consider ketamine 0.5-1mg/kg and rocuronium 1.5mg/kg
  • for normotensive patients:
    • iv induction agent such as:
    • immediately followed by muscle relaxant such as suxamethonium 1.5mg/kg OR rocuronium 1.2-1.5mg/kg followed by a flush
  • for severe hypertensive patients or patients with head injury or intracranial bleeds
    • pre-med such as fentanyl 50-100mcg iv whilst pre-oxygenating
    • further fentanyl 100mcg iv 1-2 minutes pre-induction
    • propofol 1-1.5mg/kg followed by usual muscle relaxant as above
  • ensure i/nasal oxygen flow increased to 15L/min at induction
  • await muscle relaxation (~45secs) then attempt intubation

Placement of the tube

  • video laryngoscope C-MAC
  • ETT
    • consider using introducer inside ETT, or if difficult airway, insert bougie first instead of ETT
    • hold blade at bottom with left hand, thumb on rear handle and elbows tucked in so blade and elbow are aligned (holding blade higher up on handle makes you work harder with less control and stresses wrist)
    • visualise anatomy, insert blade in right of mouth and sweep tongue to left (patients with large chests, you may need to have blade rotated 90deg to your right, then inset lade into mouth 1cm then re-orientate blade to normal), suction prn, visualise epiglottis, re-position head if difficult seeing it or use video laryngoscope
    • place blade in vallecula and lift blade so that it lifts the head, may need external laryngeal manipulation to help to see vallecula
      • bimanual ELM
      • BURP: Backward, Upward, Rightward and Pressure - not as effective as bimanual
    • insert tube or bougie with it rotated to right so it does not obstruct your view and so you can just use fingers to rotate it to place it anterior or posterior as needed
      • if using bougie, hold it firmly and just need to see post. arytenoid cartilage and posterior notch and insert bougie anterior to these (can feel clicks on the tracheal rings and “hold-up” at carina (~40cm in adults))
    • if using a stylet, lubricate stylet, and have it straight until cuff then bend it 25-35deg angle at the cuff (60-70deg for video laryngoscopy then rotate RIGHT not left if hold up beyond the glottic inlet), ensure stylet does not pass through end of tube, lubricate cuff and attach a full 10mL syringe to pilot balloon.
    • pass tube or bougie through the cords - insert horizontally from corner of patient's mouth
    • if using bougie, keep blade in place and railroad tube over bougie, may need to pull back a touch and rotate tube counterclockwise if it hangs up on arytenoid cartilage, then remove bougie and confirm position
  • check ETT position - distance (eg. 21-22cm at lips for most adults), equal air entry, chest expansion
  • inflate cuff and attach ventilation circuit with ETCO2
  • secure ETT
  • CXR to confirm depth of tube (not whether in trachea) - should end 2cm above carina

Post-intubation care

intubation.txt · Last modified: 2019/10/28 11:38 (external edit)