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Airway Management, Emergency Medicine

Basics

Description

- 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

- 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

- 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

- 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)

- Auscultate over stomach, axillae, and anterior lung fields - Observe chest wall movement - Condensation in the tube during ventilation

- Placement of tube: - After muscle tone is lost (45-60 sec after succinylcholine) - Use a stylet with the ET tube - Place tube through vocal cords - Inflate cuff - Begin ventilation - Confirm correct ET tube placement

  • Techniques that ensure adequate oxygenation and ventilation
  • Oral and nasopharyngeal airways:Lift tongue off hypopharynxFacilitate bag-valve-mask (BVM) ventilationInsert when gag reflex is absent
  • RSI:Preferred method for ED oral intubation (minimizes aspiration risk)Rapid induction of anesthesia and paralysisContraindicated in patients who should not be paralyzedA preformulated backup strategy with alternative airway techniques is essentialUse of fiberoptic techniques maximizes success
  • Oral awake intubation:Oral intubation with sedation onlyUse when paralysis is contraindicatedKetamine is most commonly used
  • Gum elastic bougie:Airway adjunct used when vocal cords are not well visualizedPlacement confirmed by feeling bougie bump against tracheal ringsSlide endotracheal tube (ET) over bougie, then remove bougie
  • Alternative airway devices:Extraglottic devices:Inserted blindly into oropharynx and inflatedLaryngeal mask airway (LMA) forms a seal around glottic structures in hypopharynx.LMA offers less protection against aspiration than ET tubeIntubating LMA can be used to place an ET tubeEsophageal-tracheal tubes (e.g., Combitube, King LT) occlude the esophagus and ventilate the hypopharynxVideo laryngoscopes:Fiberoptic camera on the tip of laryngoscope blade (e.g., Glidescope, C-MAC) or LMA to visualize tube placementFiberoptic intubating stylets:Fiberoptic camera on the tip of a stylet which holds ET tube (e.g., Shikani)
  • Classic fiberoptic intubation:ET tube placed over bronchoscopeNasotracheal or orotracheal approachIndications:Anatomic limitations to glottis visualizationLimited mobility of mandible or cervical spineUnstable cervical spine injuryContraindications:Need for immediate airway managementSignificant oropharyngeal blood
  • Nasotracheal intubation:Indications:Oral access impairedUnsuccessful oral intubationParalysis is contraindicatedLimited cervical mobilityContraindications:Apnea (only absolute contraindication)AnticoagulationMassive facial, nasal, or head traumaUpper airway abscessEpiglottitisPenetrating neck trauma
  • Cricothyrotomy:Definitive treatment for a failed airwayIncision in cricothyroid membraneTracheostomy tube inserted percutaneously into the airwayIndications:Crash airway when other airway attempts have failedMassive facial traumaTotal upper airway obstructionContraindications:Laryngeal crush injuryTracheal transectionRelative: Expanding zone II or III hematoma
  • Percutaneous translaryngeal ventilation (PTV):Percutaneous placement of 12G or 14G catheter through cricothyroid membraneIntermittent ventilation via high-pressure oxygen sourceIndications:Failed oral or nasal intubation until cricothyrotomy is completeContraindications:Upper airway obstruction preventing expiration

Diagnosis

Signs and Symptoms

Clinical conditions requiring airway management:

  • Failure to maintain or protect the airway:Oropharyngeal swellingAbsent gag reflexInability to clear secretions, bloodStridor
  • Hypoxia or ventilatory failure:Shortness of breathAltered mental statusStatus epilepticus
  • Anticipated clinical course:Ventilatory control for head injury or tricyclic overdoseSedation for diagnostic or therapeutic proceduresEarly management if the airway might become compromised

Essential Workup

  • 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 teethCongenital syndromes, acromegalyObesityEVALUATE 3-3-2 rule (difficult airway if met):Mouth opens <3 fingerbreadthsHorizontal length of mandible <3 fingerbreadthsThyromental distance <2 fingerbreadthsMALLAMPATI criteria (increasing difficulty):Class I: Soft palate, uvula, fauces, pillars visibleClass II: Soft palate, uvula, fauces visibleClass III: Soft palate visibleClass IV: Hard palate onlyOBSTRUCTION from underlying disease states:AngioedemaGoiterLaryngeal-tracheal tumorsHistory of radiation therapy to the neckInfections (epiglottitis, supraglottitis, croup, intraoral or retropharyngeal abscess, Ludwig angina)Profuse upper gastrointestinal hemorrhageTrauma (facial, neck, cervical spine, laryngeal-tracheal, burns)NECK mobility limitation:Rheumatoid arthritis and other arthropathies that decrease cervical spine mobilitySpinal immobilization for trauma
  • Verification of correct tube placement:Visualization of tube passing through the vocal cordsTracheal 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 placementColor change may not be seen in cardiac arrestAuscultate over stomach, axillae, and anterior lung fieldsObserve chest wall movementCondensation in the tube during ventilation

Diagnosis Tests & Interpretation

Lab

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

Imaging

CXR:

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

Diagnostic Procedures/Surgery

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

Differential Diagnosis

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

Treatment

Pre-Hospital

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 in-line cervical spine immobilization in trauma
  • Oxygen, monitor, IV

Ed Treatment/Procedures

  • RSISimultaneous administration of sedation (induction agent) and paralysis to provide optimal conditions for emergency airway management
  • Prepare equipment:Suction, BVM, various sizes of ET tubes and laryngoscope blades, stylets, medications, and backup devices.
  • Preoxygenation:
  • Pretreatment:Prevents physiologic sequelae of intubationPerformed 3 min prior to paralyticDefasciculating dose of nondepolarizing agentFentanyl and lidocaine may minimize ICP rise and hemodynamic response to intubation in head-injured patientsLidocaine and albuterol in reactive airway disease
  • Paralysis with induction:Administration of induction agent (e.g., etomidate, thiopental, midazolam, ketamine)Rapidly followed by administration of paralytic agent (e.g., succinylcholine, rocuronium)Succinylcholine is relatively contraindicated with anticipated difficult oral intubation, open globe injury, organophosphate poisoning, burns >3 days old, denervation syndromes, myopathies, and suspected hyperkalemiaNondepolarizing agents (e.g., rocuronium) can be used as an alternative to succinylcholine
  • Positioning:Head extension, with midline cervical stabilization if trauma patientCricoid pressure (Sellick maneuver) is controversial and optional
  • Placement of tube:After muscle tone is lost (45-60 sec after succinylcholine)Use a stylet with the ET tubePlace tube through vocal cordsInflate cuffBegin ventilationConfirm correct ET tube placement
  • Postintubation:Benzodiazepines, opiates, or propofol used for continued sedationVecuronium may be used for continued paralysis
  • Estimation of ET tube size: 4 + age/4
  • Uncuffed ET tubes may be used in patients <8 yr old
  • Straight Miller blade is preferred in patients <3 yr old
  • Cricothyrotomy contraindicated in patients <12 yr old; PTV is preferred
  • Use atropine as pretreatment to reduce secretions and attenuate vagal effect
  • A defasciculating neuromuscular blocking agent not necessary for children <5 yr old

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 μg/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: 0.01 mg/kg IV (defasciculating dose); 0.1 mg/kg IV (paralyzing dose)
  • Rocuronium: 1 mg/kg IV
  • Succinylcholine: 1.5 mg/kg (peds: 2 mg/kg) IV; 2.5 mg/kg IM/SC
  • Thiopental: 3 mg/kg IV
  • Vecuronium: 0.01 mg/kg IV (defasciculating dose); 0.1 mg/kg IV (paralyzing dose)

Follow-Up

Disposition

Admission Criteria

Almost all intubated patients should be admitted to an ICU.

Discharge Criteria

Rarely, certain ED patients who have been intubated for airway protection or to facilitate diagnostic workup may be extubated in the ED after a period of observation and then discharged.

Pearls and Pitfalls

Respect the airway. Failure to intubate and ventilate is a life-threatening condition:

  • Assess each patient for the possibility of difficult intubation.
  • Prepare and familiarize yourself with all needed equipment and medications (including contraindications and side effects).
  • ALWAYS formulate your backup plan in the case of a crash airway or failed standard orotracheal intubation before beginning the procedure.

Additional Reading

  • 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, 2010.
  • Reardon RF, Mason PE, Clinton JE. Basic airway management and decision-making. In: Roberts JR, Hedges JR, eds. Clinical Procedures in Emergency Medicine. 5th ed. Philadelphia, PA: Saunders Elsevier, 2010.
  • Walls RM. Airway. In: Marx JA, Hockberger RS, Walls RM, et al., eds. Rosens Emergency Medicine: Concepts and Clinical Practice. 7th ed. Philadelphia, PA: Mosby Elsevier; 2010.

See Also (Topic, Algorithm, Electronic Media Element)

Rapid Sequence Intubation

Codes

ICD9

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

ICD10

0CHY7BZ Insertion of Airway into Mouth and Throat, Via Natural or Artificial Opening

SNOMED

  • 426153007 insertion of artificial airway (procedure)
  • 7443007 insertion of oropharyngeal airway (procedure)
  • 182692007 nasopharyngeal airway insertion (procedure)