Intubation: Tracheal and Nasotracheal

Rapid sequence intubation (RSI) is the preferred method of emergency airway management. It involves the near simultaneous administration of fast-acting induction and neuromuscular blocking agents to achieve optimal intubating conditions without the need for bag-mask ventilation. The following discussion of orotracheal intubation refers to RSI. Techniques for gum-elastic bougie insertion and nasotracheal intubation are also discussed.


imagesFailure to protect the airway

imagesFailure to maintain the airway

imagesFailure of ventilation

imagesFailure of oxygenation

imagesPredicted deterioration or anticipated clinical course requiring intubation


imagesOrotracheal and Nasotracheal Intubation

   imagesTotal upper airway obstruction

   imagesTotal loss of facial landmarks

imagesNasotracheal Intubation


   imagesBasilar skull or facial fracture

   imagesNeck trauma or cervical spine injury

   imagesHead injury with suspected increased intracranial pressure (ICP)

   imagesNasal or nasopharyngeal obstruction

   imagesCombative patients or patients in extremis


   imagesPediatric patients


imagesViewing the oropharynx from above, the tongue is the most anterior structure

imagesThe pouchlike vallecula separates the tongue from the epiglottis, which sits above the larynx (FIGURE 1.1)

imagesThe vocal cords sit as an inverted “V” within the larynx

imagesThe larynx is anterior to the esophagus


imagesGeneral Basic Steps




   imagesParalysis and induction


   imagesPlacement of tube

   imagesProof of placement

   imagesPostintubation management


FIGURE 1.1 Larynx visualized from the oropharynx. Note the median glossoepiglottic fold. It is pressure on this structure by the tip of a curved blade that flips the epiglottis forward, exposing the glottis during laryngoscopy. Note that the valleculae and the pyriform recesses are different structures, a fact often confused in the anesthesia literature. The cuneiform and corniculate cartilages are called the arytenoid cartilages. The ridge between them posteriorly is called the posterior commissure. (Reused with permission from Redden RJ. Anatomic considerations in anesthesia. In: Hagberg CA, ed. Handbook of Difficult Airway Management. Philadelphia, PA: Churchill Livingstone; 2000:9.)


   imagesAssess airway: Use LEMON mnemonic to predict difficulty of airway

      imagesLook externally: If you sense that an airway appears difficult, it likely is

      imagesEvaluate anatomy: The “3-3-2 rule” (FIGURE 1.2)

        imagesThyromental distance: Should be approximately 3 finger widths. Significantly more or less suggests a difficult airway.

        imagesMouth opening: Less than 3 finger widths predicts poor visualization on laryngoscopy and a difficult airway

        imagesHyomental distance: More or less than 2 finger widths predicts a difficult airway

      imagesMallampati score: Roughly correlates the view of internal oropharyngeal structures with intubation success. Graded as class I to IV (FIGURE 1.3).

      imagesObstruction/Obesity: Any evidence of upper airway obstruction heralds a difficult airway. Obesity is also associated with difficult laryngoscopy.

      imagesNeck mobility: Crucial to obtaining the optimum view of the larynx. Hindrance to neck extension, including cervical spine immobilization, predicts difficulty in intubation.


      imagesEndotracheal tube (ETT) and smaller backup (often 7.5 or 8.0 and 7.0)

      images10-cc syringe

      imagesLaryngoscope blade

      imagesLaryngoscope handle


      imagesRescue airway devices, including oral airway, gum-elastic bougie, and laryngeal mask airway

      imagesRSI pharmacologic agents


FIGURE 1.2 A: The second 3 of the 3-3-2 rule. B: The 2 of the 3-3-2 rule. (From Walls RM, Murphy MF. Manual of Emergency Airway Management. The 4th edition, 2012 version of the Walls Emergency Manual as well. Philadelphia, PA: Lippincott Williams & Wilkins; 2012:77, with permission.)

   imagesCheck integrity of ETT cuff

   imagesEnsure that laryngoscope light source is working properly

   imagesMake sure IV is functioning

   imagesEnsure patient is appropriately monitored

   imagesPosition patient and adjust bed height

   imagesAssign team roles

   imagesPrepare for possible surgical airway


   imagesTheoretically, deliver 100% oxygen for 3 minutes via nonrebreather mask. (In reality, it delivers approximately 70% oxygen.)

      imagesThis fills the functional residual capacity with oxygen, replacing nitrogen and allowing for a longer apneic period before desaturation

   imagesWhen time is critical, preoxygenation can be achieved in eight vital capacity breaths

   imagesNasal cannula should be placed to augment preoxygenation and facilitate apneic oxygenation


This refers to the administration of medications to attenuate the potential adverse side effects of intubation. Medications are given 3 minutes prior to intubation. While evidence supporting pretreatment is not conclusive, it should be considered in the following groups of patients:

   imagesElevated ICP: To mitigate ICP increase with laryngoscopy and intubation

      imagesLidocaine 1.5 mg/kg

      imagesFentanyl 3 μg/kg

   imagesCardiovascular disease: To decrease sympathetic response

      imagesFentanyl 3 μg/kg

   imagesReactive airway disease: To reduce bronchospasm

      imagesLidocaine 1.5 mg/kg

      imagesAlbuterol 2.5 mg nebulized

imagesParalysis and Induction

   imagesGive the induction agent, as a bolus, in sufficient dose to produce immediate loss of consciousness. Common agents are propofol (1.5–3 mg/kg) and etomidate (0.3 mg/kg).

   imagesPush the paralytic agent immediately following the induction agent. Succinylcholine (1.5–2 mg/kg) is the common first choice in RSI because of its rapid onset.

      imagesFasciculations will occur 20 to 30 seconds after the administration of succinylcholine

      imagesApnea and paralysis will occur almost uniformly by 1 minute


FIGURE 1.3 The Mallampati Scale. (From Walls RM, Murphy MF. Manual of Emergency Airway Management. 4th edition, 2012 version of the Walls Emergency Manual as well. Philadelphia, PA: Lippincott Williams & Wilkins; 2012:78, with permission.)

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Aug 9, 2016 | Posted by in EMERGENCY MEDICINE | Comments Off on Intubation: Tracheal and Nasotracheal
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