II. Background

  1. Preoxygenation is critical to maximizing time to attempt intubation
    1. "Only contraindication to preoxygenation is that the patient is on fire"
    2. Baro (2012) APLS, HCMC, Minneapolis
  2. Oops Mnemonic (Levitan)
    1. Oxygen On
      1. Apply 15 lpm by Nasal Cannula for Apneic Oxygenation
    2. Pull Mandible forward
    3. Sit patient up (to 20 degrees)
  3. Nasal oxgenation
    1. Dr. Levitan describes the nose as the neglected orifice
    2. Vomit and plastic via the mouth
    3. Oxygen and ventilation via the nose
      1. More efficient Oxygen Delivery
      2. Nasal oxygen is much more comfortable than full masks
  4. Resources
    1. http://www.epmonthly.com/features/current-features/the-neglected-orifice-/

III. Technique: Patient positioning

  1. Alveolar ventilation and oygenation improves with head of bed elevated
    1. Semi-recumbent position with head of bed elevated 20 degrees or
    2. Head of bed elevated in reverse trendelenburg position if spine precautions

IV. Technique: Apneic Oxygenation (Levitan Technique)

  1. Continue oxygen throughout intubation to prolong period of safe apnea
  2. Passive Apneic Oxygenation increases oxygen reservoir in lungs by 6 fold
    1. Oxygen continues to be absorbed passively at a rate of 250 ml/min during apnea
    2. Carbon dioxide slowly accumulates during apnea
      1. Increases at a rate of 10 ml/min (3-5 mmHg increased pCO2/minute)
    3. Apneic Oxygenation has sustained patients at 98-100% Oxygen Saturation for up to 55 minutes
      1. Severe acidosis resulted (due to hypercarbia), but no Hypoxia occurred
      2. http://www.rtjournalonline.com/apneic oxygenation in man-Frumin Anesthes 1959.pdf
      3. Frumin (1959) Anesthesiology 20:789-98 [PubMed]
    4. Allows for significant increase in safe intubation time
    5. Oxygen carrying capacity and delivery is dependent on 3 factors
      1. Requires patent alveoli, patent upper airway and adequate Hemoglobin
  3. Technique
    1. Consider delivery via Nasal Trumpet once patient sedated
    2. Oxygen by Nasal Cannula at 15 L/min (in addition to oxygen face mask)
    3. Children: Use 5 L/min by Nasal Cannula until sedated and then increase
    4. Awake patients: Start with 5 L/min and titrate to 15 L/min by Nasal Cannula
  4. Efficacy
    1. Without Apneic Oxygenation, one third of intubations desaturate to <90% (median time 80 seconds)
      1. Bodily (2016) Ann Emerg Med 67(3): 389-95 +PMID:26164643 [PubMed]
    2. Apneic Oxygenation improves Endotracheal Intubation first pass success
      1. Sakles (2016) Acad Emerg Med 23(6): 703-10 +PMID:26836712 [PubMed]

V. Technique: Preoxygenation

  1. Standard pre-oxygenation
    1. Deliver oxygen with standard reservoir face mask
    2. Oxygen flow rate on regulator set to maximum (typically 15-60 L/min)
    3. Preoxygenate for at least 3 minutes
  2. Rapid pre-oxygenation (if alert)
    1. Deliver oxygen with tight fitting mask at FIO2 90% or higher
    2. Patient takes 8 breaths of full Tidal Volume (maximal inhalation and exhalation)

VI. Technique: Positive Pressure Ventilation

  1. Indicated if pre-oxygenation methods above do not increase Oxygen Saturation greater than 93-95%
    1. Suggests shunting with under-oxygenated alveoli
    2. Consider induction dose of Ketamine if patient cannot tolerate CPAP or BIPAP
  2. Delivery options
    1. CPAP
      1. Typical positive pressure pre-oxygenation method
      2. May be used for positive-pressure pre-oxygenation regardless of mental status
        1. Assumes a setting of impending intubation
    2. BIPAP
      1. May be preferred over CPAP if respiratory effort is inadequate
    3. Non-Invasive Positive Pressure Ventilation
    4. Bag Valve Mask with PEEP valve (5-15 cm H2O)

VII. Technique: Delayed Sequence Intubation or Dissociative Awake Intubation (Weingart and Levitan)

  1. Indications
    1. Unable to preoxygenate a severely hypoxic COPD or Asthma patient
    2. Unable to preoxygenate an uncooperative, angry, aggitated or innebriated patient
  2. Sedation
    1. Ketamine 1 mg/kg IV push
    2. Consider a second Ketamine dose at 0.5 mg/kg IV push
  3. Apply High Flow Oxygen
    1. Nasal Cannula at 15 L/min AND
    2. Bag-valve-Mask with PEEP Valve at 5-15 cm H2O (or CPAP or BIPAP)
      1. Positive End-Expiratory Pressure is required for technique
      2. Alveoli will otherwise close and not allow oxygenation
  4. Reposition patient
    1. Upright or semi-upright (head of bed at 20 degrees)
  5. Evaluate if oxygenation adequate with above High Flow Oxygen (Oxygen Saturation 95% or greater)
    1. Oxygen Saturation 95% or greater
      1. Preoxygenate for 2-3 minutes
    2. Oxygen Saturation <95%
      1. Suggests shunt pathology (Atelectasis or airway with blood or other fluid)
      2. Use Positive Pressure Ventilation methods (CPAP, BiPAP, BVM with PEEP Valve) as described above
  6. Intubation (if still needed for persistent Hypoxia or respiratory distress)
    1. Follow Rapid Sequence Intubation Algorithym with paralytic (using Ketamine above as the induction agent)
  7. References
    1. Braude and Weingart in Herbert (2014) EM:Rap 14(6): 12-13
    2. Weingart (2012) Ann Emerg Med 59(3): 165-75 [PubMed]

VIII. Precautions: Conditions with fast desaturation on intubation attempts (mnemonic: POPS)

  1. Mechanisms
    1. Low Functional Residual Capacity
    2. Increased oxygen consumption
  2. Pediatrics
  3. Obesity
  4. Pregnancy (consider upright intubation)
    1. Fetal Hemoglobin is oxygen avid
  5. Smoke Inhalation
    1. Carbon Monoxide Poisoning
    2. Cyanide Poisoning

IX. References

  1. Braude and Levitan in Majoewsky (2012) EM:RAP 12(4): 1
  2. Levitan (2013) Practical Airway Management Course, Baltimore
  3. Delay (2008) Anesth Analg 107(5): 1707-13 [PubMed]
  4. Weingart (2012) Ann Emerg Med 59(3):165-75 [PubMed]

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