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Showing posts with label Airway. Show all posts
Showing posts with label Airway. Show all posts

Sunday, October 1, 2017

Intubation basics

"By failing to prepare, you are preparing to fail"

One cannot emphasised the importance of the preparation phase when intubating a patient. The insertion of the tube is only 1/7th of the process... of the 7 big steps for intubation. It was only in the ER, when faced with all sorts of difficult airways, from the anatomically difficult ones to the physiologically difficult ones, did I learn to appreciate the value of the preparation phase before intubation.

Terminology

    • Rapid sequence intubation
      • requires emergency intubation, but not a crash intubation
      • on a patient who is not fasted and hence at risk of aspiration
      • hence involves a fast acting muscle relaxant and avoid using the BVM to prevent the risk of aspiration
    • Crash intubation
      • patient is near-death or near collapse

Why intubate?

    • Failure to oxygenate
    • Failure to ventilate
    • Anticipated clinical deterioration
    • Unable to protect their own airway

Planning phase

    • Intubation is only 1/7th of all the steps involved in safely intubating a patient.
    • It may not always be successful; hence we needs back up plans.
    • A sample from Kangaroo Island SA
      • Melbourne launched the concept of VORTEX, to reinforce the 3 pillars of BVM-LMA-ETT before deciding to plunging into surgical airway. It also represents the steps taken and the difficulty level of each step when faced with a difficult airway


How to intubate?




1) Preparation
→ Assess patient’s airway
  • 4D
    • Dentition
    • Dysmotility
    • Distortion
    • Disproportion
  • Difficult BVM & LMA
    • NOMADS
      • N: no teeth
      • O: obese
      • M: mask fit
      • A: age
      • D: distortion
      • S: stiff lungs
  • Difficult DL & intubation
    • LEMON
      • L: look externally (jaw, teeth, neck, obesity, face)
      • E: evaluate 3:3:2
      • M: Mallampati score (erect)
      • O: obstruction
      • N: neck immobility

  • Difficult cricothyroidotomy
    • AIR
      • A: access
      • I: injury
      • R: radiation
  • Physiological difficult airway
    • HOPA
      • H: hypotension
      • O: hypoxia
      • P: pH (metabolic acidosis)
      • A: agitation

→ Prepare staff & checklist
Example of a checklist from HCMC

→ Difficult airway team
→ Prepare equipment
  • Suction
  • NP/OP airway
  • ET tube
  • Laryngoscope
    • Direct
    • Video
      • Glidescope: hyperacute angulated laryngoscope blade allows visualisation of the vocal codes with less head & neck movement
      • The C-MAC® video laryngoscope is available in the original MACINTOSH blade shapes (sizes 2, 3 and 4), the MILLER shape (sizes 0 and 1), and in the blade shape for difficult airways – the D-BLADE™
  • Airway adjuncts
    • Bougie
  • Failure plan equipment
    • LMA
      • Silicon
      • LMA with port for gastric suction
      • Intubating LMA
    • Cricothyroidotomy set
2) Pre-oxygenation
  • Mechanism: Nitrogen washout- replace alveolar nitrogen with oxygen
  • Purpose: to maximise the time available to perform intubation before desaturation occurs
  • Time to desaturation to less than 90% is:
    • Healthy adults: 8mins
    • Moderately ill adults: 5mins
    • Obese adults: 2.7mins

  • Methods:
    • 3-5 mins with NRM
    • 8 vital breaths
    • Apneic oxygenation
      • Nasal cannula with high flow oxygen
    • NIV
    • DSI
3) Pre-treatment
  • Children:
    • Atropine to reduce secretions
    • Atropine to prevent bradycardia
  • Head injury
    • Fentanyl 2-3mcg/kg
    • Lidocaine
4) Paralysis with induction
  • Use of either depolarising or  non depolarising paralytic
    • Suxamethonium or
    • Rocuronium found in ED
5) Position
Prepare the patient’s position
  • Align tragus with the sternal notch horizontally
    • This aligns the oral axis, pharyngeal & laryngeal axis
  • Ramp position if very obese to achieve the above
6) Placement of tube
  • Confirm placement by:
    • End tidal capnography
    • Watching the black line past the vocal cord
    • Misting of the tube
    • Chest rise bilateral
    • 5 pt auscultation
    • Colour change on colorimetric capnograph (purple→ yellow)
7) Postintubation management
  • ECG, BP
  • Ionotropes, targetted temperature management
  • CXR
  • Urinary catheterisation