Description

• Oral and nasopharyngeal airways:
  • Lift tongue off hypopharynx
  • Facilitate bag-valve-mask (BVM) ventilation
  • Insert oral airway when gag reflex is absent
• Rapid Sequence Intubation (RSI):
  • Preferred method for ED oral intubation (minimizes aspiration risk)
  • Rapid induction of anesthesia and paralysis
  • Contraindicated in complete upper airway obstruction and when there is complete loss of facial/oral landmarks
  • A preformulated backup strategy with alternative airway techniques is essential
  • Use of video laryngoscopy maximizes success
  • Video laryngoscopes:
    • Fiberoptic camera on the tip of laryngoscope blade (eg, GlideScope, C-MAC) to visualize tube placement
• Oral awake intubation:
  • Oral intubation with sedation only
    • Use when paralysis is contraindicated
  • Ketamine is most commonly used
    • Use with benzodiazepines
• Gum elastic bougie:
  • May increase first-pass success when used as part of initial intubation strategy
  • Airway adjunct used when vocal cords are not well visualized
  • Placement confirmed by feeling bougie bump against tracheal rings
  • Slide endotracheal tube (ET) over bougie, then remove bougie
• Alternative airway devices:
  • Extraglottic devices:
    • Inserted blindly into oropharynx and inflated
    • Laryngeal mask airway (LMA) forms a seal around glottic structures in hypopharynx
    • LMA offers less protection against aspiration than ET tube
    • Intubating LMA can be used to place an ET tube
    • Esophageal–tracheal tubes (eg, Combitube, King LT) occlude the esophagus and ventilate the hypopharynx
• Fiberoptic intubation:
  • Fiberoptic intubating stylets:
    • Fiberoptic camera on the tip of a stylet which holds ET tube (eg, Shikani)
  • ET tube placed over bronchoscope
  • Nasotracheal or orotracheal approach
  • Indications:
    • Anatomic limitations to glottis visualization
    • Limited mobility of mandible or cervical spine
    • Unstable cervical spine injury
  • Contraindications:
    • Need for immediate airway management
    • Significant oropharyngeal blood
• Nasotracheal intubation:
  • Indications:
    • Oral access impaired
    • Unsuccessful oral intubation
    • Paralysis is contraindicated
    • Limited cervical mobility
  • Contraindications:
    • Apnea (only absolute contraindication)
    • Anticoagulation
    • Massive facial, nasal, or head trauma
    • Upper airway abscess
    • Epiglottitis
    • Penetrating neck trauma
• Cricothyrotomy:
  • Definitive treatment for a failed airway
  • Incision in cricothyroid membrane
  • Tracheostomy or 6.0 or smaller ET inserted percutaneously into the airway
  • Indications:
    • Crash airway when other airway attempts fail
    • Massive facial trauma
    • Total upper airway obstruction
  • Contraindications:
    • Age <12 yr old
    • Laryngeal crush injury
    • Tracheal transection
    • Relative: Expanding zone II or III hematoma
• Bougie-guided cricothyrotomy
  • Incision through skin and cricothyroid membrane
  • Insert bougie through the incision
  • Faster than traditional cricothyrotomy
• Noninvasive positive pressure ventilation (NPPV):
  • Ventilatory support without use of an invasive artificial airway
  • Typically via facemask or nasal piece
  • Indications:
    • Preoxygenation before RSI with NPPV results in lower incidence of hypoxemia
    • Prehospital undifferentiated dyspnea
    • Most effective for conditions which respond quickly to treatment (COPD and CHF)
  • Contraindications:
    • Intractable emesis
    • Upper airway obstruction
    • Inability to protect airway or clear secretions
    • Hemodynamic instability
    • Altered mental status or coma
    • Cardiac or respiratory arrest
• High-flow nasal oxygen:
  • Heated, humidified high-flow oxygen provides increased comfort vs conventional nasal cannula
  • Provides FiO₂ up to 1.0 at 60 L/min
  • Provided minimal positive end-expiratory pressure
  • Indications:
    • Hypoxemic respiratory failure without hypercapnia
  • Contraindications:
    • Epistaxis
    • Nasal obstruction
    • Basilar skull fracture
    • Recent surgery to nares or aerodigestive tract
• Percutaneous translaryngeal ventilation (PTV):
  • Percutaneous placement of 12G or 14G catheter through cricothyroid membrane
  • Intermittent ventilation via high-pressure oxygen source
  • Indications:
    • Failed oral or nasal intubation until cricothyrotomy is complete
  • Contraindications:
    • Upper airway obstruction preventing expiration

Signs And Symptoms

Oral Clinical conditions requiring airway management:

• Failure to maintain or protect the airway
  • Oropharyngeal swelling
  • Absent gag reflex
  • Inability to clear secretions, blood
  • Stridor
• Hypoxia or ventilatory failure
  • Shortness of breath
  • Altered mental status
  • Status epilepticus
• Anticipated clinical course
  • Ventilatory control for head injury or tricyclic overdose
  • Sedation for diagnostic or therapeutic procedures
  • Early management if the airway might become compromised

Essential Workup

Recognition of a difficult airway (LEMON):

• Look:
  • Short mandible
  • Thick neck
  • Narrow mouth
  • Large tongue
  • Protruding teeth
  • Congenital syndromes, acromegaly
  • Obesity
• Evaluate
  • 3-3-2 rule (difficult airway if met)
  • Mouth opens <3 fingerbreadths
  • Horizontal length of mandible <3 fingerbreadths
  • Thyromental distance <2 fingerbreadths
• MALLAMPATI criteria (increasing difficulty):
  • Class I: Soft palate, uvula, pillars visible
  • Class II: Soft palate, uvula visible
  • Class III: Soft palate and base of uvula visible
  • Class IV: Hard palate only
• Obstruction from underlying disease states:
  • Angioedema
  • Goiter
  • Laryngeal–tracheal tumors
  • History of radiation therapy to the neck
  • Infections (epiglottitis, supraglottitis, croup, intraoral or retropharyngeal abscess, Ludwig angina)
  • Profuse upper gastrointestinal hemorrhage
  • Trauma (facial, neck, cervical spine, laryngeal–tracheal, burns)
• NECK mobility limitation:
  • Rheumatoid arthritis and other arthropathies that decrease cervical spine mobility
  • Spinal immobilization for trauma

Verification of correct tube placement:

• Visualization of tube passing through the vocal cords
• Tracheal tube depth (tube tip to upper incisors):
  • 21 cm (women)
  • 23 cm (men)
  • Age (yr)/2 + 12 (children)
• End-tidal CO₂ colorimetric device:
  • Changes color if CO₂ is present, indicating tracheal placement
  • Color change may not be seen in cardiac arrest
• Auscultate over stomach, axillae, and anterior lung fields
• Observe chest wall movement
• Condensation in the tube during ventilation

Diagnostic Tests And Interpretation

Differential Diagnosis

• Esophageal intubation
• Right or left mainstem bronchus intubation
• Extratracheal placement through tear in pyriform sinus or trachea
• Pneumothorax

Prehospital

Options for patients in respiratory arrest for advanced life support (ALS) providers:

• Bag-valve management (BVM) ventilation followed by definitive airway management in the ED
• Orotracheal intubation
• Esophageal-tracheal tubes
• LMA

Initial Stabilization/Therapy

• Maintain inline cervical spine immobilization in trauma
• Oxygen, monitor, IV

Ed Treatment/Procedures

Rapid Sequence Intubation

• Prepare equipment:
  • Suction, BVM, various sizes of ET tubes and laryngoscope blades, stylets, medications, and backup devices
• Preoxygenation:
  • 100% FiO₂ for 3 min prior to induction and paralysis
  • Non-invasive ventilation reduces incidence of hypoxemia when used pre-intubation
  • Apneic oxygenation after paralysis via nasal cannula
• Pretreatment:
  • Prevents physiologic sequelae of intubation
  • Performed 3 min prior to paralytic
  • Fentanyl 3–5 mcg/kg may minimize ICP rise and hemodynamic response to intubation in head-injured patients
  • Lidocaine 1.5 mg/kg (suppresses cough reflex) and albuterol in reactive airway disease
• Paralysis with induction:
  • Administration of induction agent (eg, etomidate, midazolam, ketamine)
  • Rapidly followed by administration of paralytic agent (eg, succinylcholine, rocuronium):
    • Relative contraindications to Succinylcholine
    • Anticipated difficult oral intubation,
    • Open globe injury
    • Organophosphate poisoning
    • Burns >3 days old
    • Denervation syndromes
    • Myopathies
    • Suspected hyperkalemia
  • Nondepolarizing agents like rocuronium can replace succinylcholine if contraindicated.
  • Sugammadex provides immediate reversal of nondepolarizing agents if need to restore breathing after a failed airway
• Positioning:
  • Head extension, with midline cervical stabilization in trauma patients
  • Cricoid pressure (Sellick maneuver) is controversial
• Placement of tube:
  • After muscle tone is lost (45–60s after succinylcholine)
  • Use a stylet with the ET tube
  • Place the cuff through vocal cords and inflate
  • Ventilate and confirm correct ET tube placement
• Postintubation:
  • Continued sedation with benzodiazepines, opiates, and/or propofol
  • Vecuronium if continued paralysis needed

Medication

• Atracurium: 0.4–0.5 mg/kg IV
• Atropine: 0.02 mg/kg IV
• Diazepam: 2–10 mg (peds: 0.2–0.3 mg/kg) IV
• Etomidate: 0.3 mg/kg IV
• Fentanyl: 3 mcg/kg IV
• Ketamine: 1–2 mg/kg IV or 4–7 mg/kg IM
• Lidocaine: 1.5 mg/kg IV
• Midazolam: 1–5 mg IV (0.07–0.30 mg/kg for induction)
• Propofol: 2–2.5 mg/kg IV
• Pancuronium: 0.1 mg/kg IV
• Rocuronium: 1 mg/kg IV
• Succinylcholine: 1.5 mg/kg (peds: 2 mg/kg) IV; 2.5 mg/kg IM/SC
• Suggamadex: 16 mg/kg
• Thiopental: 3 mg/kg IV
• Vecuronium: 0.1 mg/kg IV

Disposition

See Also (Topic, Algorithm, Electronic Media Element)

Rapid Sequence Intubation