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.


INDICATIONS



imagesFailure to protect the airway


imagesFailure to maintain the airway


imagesFailure of ventilation


imagesFailure of oxygenation


imagesPredicted deterioration or anticipated clinical course requiring intubation


CONTRAINDICATIONS



imagesOrotracheal and Nasotracheal Intubation


   imagesTotal upper airway obstruction


   imagesTotal loss of facial landmarks


imagesNasotracheal Intubation


   imagesApnea


   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


   imagesCoagulopathy


   imagesPediatric patients


LANDMARKS



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


TECHNIQUE FOR OROTRACHEAL INTUBATION




imagesGeneral Basic Steps


   imagesPreparation


   imagesPreoxygenation


   imagesPretreatment


   imagesParalysis and induction


   imagesPositioning


   imagesPlacement of tube


   imagesProof of placement


   imagesPostintubation management



images


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.)


imagesPreparation


   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.


   imagesEquipment


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


      images10-cc syringe


      imagesLaryngoscope blade


      imagesLaryngoscope handle


      imagesSuction


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


      imagesRSI pharmacologic agents



images


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


imagesPreoxygenation


   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


imagesPretreatment


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



images


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.)

Only gold members can continue reading. Log In or Register to continue

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