Intubation

This page is for adult patients. For pediatric patients, see: intubation (peds)

Indications

Oral cavity and oropharynx.
Sagittal section through the head and neck showing the subdivisions of the pharynx.
External views of the larynx: (a) anterior aspect; (b) anterolateral aspect with the thyroid gland and cricothyroid ligament removed.
The cartilages and ligaments of the larynx seen posteriorly.
Larynx as visualized from the hypopharynx.
  • Failure to ventilate
  • Failure to oxygenate
  • Inability to protect airway
    • Gag reflex is absent at baseline in ~1/3 of people[1], so lack of gag reflex is inadequate in determination of ability to protect airway.
    • If a patient is able to tolerate placement of an oropharyngeal airway, they likely require intubation for airway protection
    • GCS <8 generally an indication for intubation in trauma patients
  • Anticipated clinical course (anticipated deterioration, need for transport, or impending airway compromise)
  • Combative patient who needs imaging (suspicion of intracranial process, etc)

Considerations

  • 2015 AHA ACLS guidelines deemphasize placement of advanced airway placement in initial resuscitation
  • Out-of-hospital arrest data suggests lower survival of those intubated in field[2]
  • 108,000 patients examined in U.S. registry of inpatient hospital arrests, with 95% of intubations occurring within 15 min of resuscitation[3]
    • Patients intubated were significantly less likely to survive to discharge, 16% vs. 19%
    • Also less likely to be discharged with good functional status, 11% vs. 14%

Absolute Contraindications

  • No absolute contraindications when performed as an emergent procedure
    • Exception: cannot ventilate and anticipate near impossible orotracheal intubation, strongly consider awake fiberoptic intubation (if possible) and also performing a surgical airway as a back up plan

Relative Contraindications

See Predicting the difficult airway

Difficult BVM (MOANS)

  • Mask seal
  • Obesity
  • Aged
  • No teeth
  • Stiffness (resistance to ventilation)

Difficult Intubation (LEMON)

  • Look externally (gestalt)
  • Evaluate 3-3-2 rule
  • Mallampati
  • Obstruction
  • Neck mobility

Equipment Needed

Normal larynx.
Normal intubation view.
  • Medications
    • Induction agent
    • Paralytic agent
  • Pre-oxygenation devices (nasal cannula, non-rebreather, bag valve mask, etc.)
    • Oropharyngeal/nasopharyngeal airway for difficult to ventilate patients
    • Leave nasal cannula on for apneic oxygenation if possible
  • Laryngoscope (type based on clinical indication and provider preference)
  • Endotracheal tube
  • End-tidal CO2 device (colorimetric or quantitative)
  • Ventilator
  • Suction
  • Intubation adjuncts (bougie, lighted stylet, etc)
    • Ensure you have correct stylet for type of laryngoscope you are using
      • Direct or Mactintosh-blade videolaryngoscopes require malleable stylets
      • Hyperangulated videolaryngoscopes require rigid stylets
  • Bag valve mask

SOAP-ME Checklist Mnemonic

  • Suction
  • Oxygen
    • Nasal cannula
    • Non-rebreather
    • Bag-valve mask
  • Airways
    • Endotracheal tube
    • Rescue devices
    • Adjuncts
  • Positioning
  • Medications
  • Equipment

Procedure

Macintosh Blades 1-5, from bottom to top
The Macintosh blade is inserted into the vallecula (left) while the Miller blade is inserted under and lifts the epiglottis (right)

Direct laryngoscopy (with Macintosh blade)

  1. Place patient into sniffing position
  2. Use "scissor" technique with right hand to open mouth
  3. Insert laryngoscope blade into right side of mouth
  4. Slowly advance blade into mouth while performing "tongue sweep"
  5. Identify epiglottis
  6. Advance tip of blade into vallecula
  7. Lift upward and away from operator to expose glottis
  8. Deliver tube through vocal cords

Video laryngoscopy

  • Hyperangulated video laryngoscope
    • Patient ideally in neutral spine position (as opposed to "sniffing" position for direct laryngoscopy)
    • After induction, use right hand to "scissor" mouth open
    • Place hyperangulated blade midline and slowly advance with progressive identification of airway landmarks
    • Advance blade into vallecula
    • When cords fill entire screen (Cormack-Lehane Grade I), slightly retract laryngoscopy so that cords only occupy upper 1/3 of screen (CL Grade II, allows for passage of ETT with rigid stylet)[4]
      • If intubation is attempted with the best view possible, operators often have difficulty advancing the tube around the tongue and hypopharyngeal soft tissues
  • Standard geometry video laryngoscope
    • Same technique utilized with direct laryngoscopy
    • Can either visualize directly or utilize video screen for tube delivery

Post-Procedure

  • Confirm tube placement with auscultation and end tidal CO2[5]
  • Secure tube
  • Place OG to decompress stomach
  • Provide sedation and analgesia
  • Head of bed to at least 30°
  • Obtain CXR
    • Tube should be 3-5 cm from the carina
  • Check ABG ~30 minutes after intubation
  • Check cuff pressures - should be between 20-30 cm H2O
  • Check plateau pressure using "inspiratory hold" - should be less than 30 cm H2O
An endotracheal tube in good position on CXR. Arrow marks the tip.
An endotracheal tube not deep enough. Arrow marks the tip.

Initial ventilation settings

Disease Tidal Volume (mL/kg^) Respiratory Rate I:E PEEP FiO2
Traditional 8 10-12 1:2 5 100%
Lung Protective (e.g. ARDS) 6 12-20 1:2 2-15 100%
Obstructive (e.g. bronchoconstriction) 6 5-8 1:4 0-5 100%
Hypovolemic 8 10-12 1:2 0-5 100%

^Ideal body weight

Complications

Special Situations

Severe Metabolic Acidosis

Further drop in pH during intubation can be catastrophic

  • NIV (SIMV Vt 550, FiO2 100%, Flow Rate 30 LPM, PSV 5-10, PEEP 5, RR 0)
    • SIMV on ventilator, not NIV machine
    • "Pseudo-SIMV" mode
  • Attach end-tidal CO2 and observe value
  • Push RSI medications
  • Turn the respiratory rate to 12
  • Perform jaw thrust
  • Wait 45sec
  • Intubate
  • Re-attach the ventilator
  • Immediately increase rate to 30
  • Change Vt to 8cc/kg
  • Change flow rate to 60 LPM (normal setting)
  • Make sure end-tidal CO2 is at least as low as before

Active GI Bleed

  1. Empty the stomach
    • Place an NG and suction out blood
      • Varices are not a contraindication
    • Metoclopramide 10mg IV
      • Increases LES tone
  2. Intubate with HOB at 45°
  3. Preoxygenate!
    • Want to avoid bagging if possible
  4. Intubation meds
    • Use sedative that is BP stable with lower dose (etomidate, ketamine)
    • Use paralytics with higher dose (actually increases LES tone)
  5. If need to bag:
    • Bag gently and slowly (10BPM)
    • Consider placing LMA
  6. If patient vomits
    • Place in Trendelenberg
    • Place LMA
    • Use meconium aspirator
  7. If patient aspirates anticipate a sepsis-like syndrome
    • May need pressors, additional fluid (not antibiotic!)

See Also

Airway Pages

Mechanical Ventilation Pages

External Links

Videos

References

  1. Davies AE, Kidd D, Stone SP, MacMahon J. Pharyngeal sensation and gag reflex in healthy subjects. Lancet. 1995 Feb 25;345(8948):487-8.
  2. Hasegawa K et al. Association of prehospital advanced airway management with neurologic outcome and survival in patients with out-of-hospital cardiac arrest. JAMA 2013 Jan 16; 309:257.
  3. Angus DC.Whether to intubate during cardiopulmonary resuscitation: Conventional wisdom vs big data. JAMA 2017 Feb 7; 317:477.
  4. Gu Y, Robert J, Kovacs G, et al. A deliberately restricted laryngeal view with the GlideScope® video laryngoscope is associated with faster and easier tracheal intubation when compared with a full glottic view: a randomized clinical trial. Une vue laryngée délibérément restreinte à l'aide du vidéolaryngoscope GlideScope® est associée à une intubation trachéale plus rapide et plus aisée qu'une vue glottique totale: une étude clinique randomisée. Can J Anaesth. 2016;63(8):928-937. doi:10.1007/s12630-016-0654-6
  5. Scott Weingart, MD FCCM. Podcast 84 – The Post-Intubation Package. EMCrit Blog. Published on October 16, 2012. Accessed on January 16th 2021. Available at [1].