Rosen & Barkin's 5-Minute Emergency Medicine Consult (38 page)

• Failure to ventilate is a life-threatening condition
  
• Assess every patient for the possibility of difficult mask ventilation or intubation
  
• Always formulate a back-up plan in case of a failed attempt
  
• Do not fixate on intubation but rather successful ventilation and oxygenation
  
• Move to alternate airway management techniques and consider surgical airway if unable to intubate or ventilate despite use of airway adjuncts
  

• Oro- and nasopharyngeal airways are available in infant+ sizes
  
• LMAs are available in infant+ sizes
  
• Combitube is only designed for patients >48 in in height
  
• Nasotracheal intubation is contraindicated in children under 10 yr of age
  

• Murphy MF. Airway management. In: Wolfson AB, Hendey G, Ling L, et al., eds.
  Harwood-Nuss’ Clinical Practice of Emergency Medicine
  . 5th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2009.
  
• Walls RM (ed).
  Manual of Emergency Airway Management
  . 4th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2012
  

CODES

• 96.01 Insertion of nasopharyngeal airway
  
• 96.02 Insertion of oropharyngeal airway
  
• 96.05 Other intubation of respiratory tract
  

BASICS

• Techniques that ensure adequate oxygenation and ventilation
  
• Oral and nasopharyngeal airways:
  
  • Lift tongue off hypopharynx
    
  • Facilitate bag-valve-mask (BVM) ventilation
    
  • Insert when gag reflex is absent
    
• RSI:
  
  • Preferred method for ED oral intubation (minimizes aspiration risk)
    
  • Rapid induction of anesthesia and paralysis
    
  • Contraindicated in patients who should not be paralyzed
    
  • A preformulated backup strategy with alternative airway techniques is essential
    
  • Use of fiberoptic techniques maximizes success
    
• Oral awake intubation:
  
  • Oral intubation with sedation only
    
    • Use when paralysis is contraindicated
      
  • Ketamine is most commonly used
    
    • Use with benzodiazepines
      
• Gum elastic bougie:
  
  • 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 (e.g., Combitube, King LT) occlude the esophagus and ventilate the hypopharynx
      
  • Video laryngoscopes:
    
    • Fiberoptic camera on the tip of laryngoscope blade (e.g., Glidescope, C-MAC) or LMA to visualize tube placement
      
  • Fiberoptic intubating stylets:
    
    • Fiberoptic camera on the tip of a stylet which holds ET tube (e.g., Shikani)
      
• Classic fiberoptic intubation:
  
  • 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 tube inserted percutaneously into the airway
    
  • Indications:
    
    • Crash airway when other airway attempts have failed
      
    • Massive facial trauma
      
    • Total upper airway obstruction
      
  • Contraindications:
    
    • Laryngeal crush injury
      
    • Tracheal transection
      
    • Relative: Expanding zone II or III hematoma
      
• 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
      

DIAGNOSIS

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
    

• Always be prepared with a difficult airway algorithm prior to beginning the procedure.
  
• Recognition of a difficult airway (LEMON)
  
  • LOOK for anatomic considerations:
    
    • Short mandible, thick neck, narrow mouth, large tongue, and 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, fauces, pillars visible
      
    • Class II: Soft palate, uvula, fauces visible
      
    • Class III: Soft palate 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 CO
    ₂
    colorimetric device:
    
    • Changes color if CO
      ₂
      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
    

• Pulse oximetry should rise after tracheal intubation
  
  • Continuous capnography used as adjunct
    
• Arterial blood gas to manage ventilator settings after intubation
  

CXR:

• To exclude mainstem bronchus intubation or pneumothorax
  
• Does not rule out esophageal intubation
  

Direct visualization of the ET tube through the cords is gold standard.

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

TREATMENT