Airway management

Last updated: August 9, 2022

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Airway management is the practice of evaluating, planning, and using a wide array of medical procedures and devices for the purpose of maintaining or restoring a safe, effective pathway for oxygenation and ventilation. These procedures are indicated in patients with airway obstruction, respiratory failure, or a need for airway protection (e.g., for general anesthesia or due to an aspiration risk).

Basic airway maneuvers are the most important first step and consist primarily of positioning, supplemental oxygen, and bag-mask ventilation with or without adjuncts. Patients with serious or persistent airway compromise typically require advanced airway devices, which consist of supraglottic devices, endotracheal tubes, and surgical airway devices.

In endotracheal intubation, a tube is inserted orally (or nasally) into the trachea to allow gas exchange, often via mechanical ventilation. The tube can be placed under direct visualization with the help of a laryngoscope or with video-assisted laryngoscopy. Correct placement is established based on multiple measurements, including exhaled CO2 and evidence of bilateral breath sounds on auscultation. Common complications of endotracheal intubation include hypoxia, hypotension, airway trauma, accidental esophageal intubation, and aspiration.

Surgical airways may be performed in an emergency, particularly as part of a cannot intubate, cannot ventilate (CICV) scenario, or placed for long-term mechanical ventilation. Patients with surgical airways are vulnerable to a sudden loss of the airway due to displacement or blockage of the tubes with secretions.

Airway management is used for patients with signs of airway obstruction and for patients whose airway is considered at-risk due to a potential loss of protective airway reflexes.

Clinical features of partial airway obstruction [1]

Clinical features of complete airway obstruction [1]

Red flags for an at-risk airway [2][3]

Urgently manage acute or rapidly-progressive stridor as it can indicate > 50% airway obstruction with a high risk of respiratory failure and difficult intubation. [2][8][9]Continuously monitor patients with red flags for an at-risk airway and exercise caution when transporting these patients away from a supervised setting, (e.g., for imaging studies). [3]

Definition

Respiratory arrest is the complete cessation of breathing in patients with a pulse. [10]

Etiology

Clinical features

Diagnostics

Management

Complications

References:[10][11][12]

These maneuvers may be used alone or combined with basic airway adjuncts and bag-mask ventilation.

Head-tilt/chin-lift maneuver [13]

  • Description: repositioning the head and neck to open the airway
  • Technique
    1. Tilt the patient's head posteriorly to 15–30° of atlantooccipital extension.
    2. Lift the chin with the fingers to pull the tongue and oropharyngeal soft tissue anteriorly.
    3. Use the thumb of the same hand to apply pressure below the lip, slightly opening the mouth.
    4. Maintain this “sniffing position” to align the oral, pharyngeal, and laryngeal axes.
  • Contraindication: suspected cervical spine injury

Jaw-thrust maneuver

After airway opening maneuvers have been performed, observe for signs of adequate ventilation and oxygenation (e.g., chest rise, audible air movement, positive waveform on capnography, SpO2 in target range).

Recovery position

Used only in spontaneously breathing patients

Definition [14][15]

Delivery of positive pressure ventilation to patients with absent or impaired respiratory effort using a bag-valve-mask unit

Indications [14][15]

Procedure

Create a mask seal

  • EC-clamp technique (one-person technique): commonly used in elective perioperative situations when the provider is alone
    1. With the patient supine, lift the jaw towards the mask using the 3rd, 4th, and 5th fingers of one hand, forming an E-shape.
    2. Squeeze the mask onto the face with the thumb and index finger of the same hand, forming a C-shape.
    3. Deliver breaths with the second hand.
  • Two-person bag-mask-ventilation technique: used in emergency settings in which the patient is deteriorating or ventilation is difficult, since it is more effective [16][17][18]
    • One provider makes a seal and opens the airway with both hands:
      • Press the mask firmly against the face with both thumbs.
      • Simultaneously perform a jaw thrust maneuver with all 4 fingers of both hands.
      • A two-handed EC-clamp technique may also be used. [19]
    • The second provider delivers breaths.

Initiate ventilation

  • Goal [10][20]
    • Adults: 500–600 mL (6–7 mL/kg) tidal volume at 10–12 breaths/minute
    • Children: 20–30 breaths/minute
  • Technique
    • Compress bag over approx. 1 second then allow it to fully reinflate.
    • Repeat every 5 seconds in adults and 2–3 seconds in children.
    • Adjust based on clinical situation (e.g., a compression-to-breath ratio of 30:2 if the patient is receiving chest compressions)

Confirm adequacy of BMV

Ensure oxygen is attached to the bag-mask apparatus!

Pitfalls and troubleshooting

Efficacy of BMV may be affected by provider technique or patient factors (such as obesity, reduced lung compliance, or craniofacial abnormalities).

Pitfalls and troubleshooting of bag-mask ventilation

Challenge Recommendations
Poor mask seal or difficulty opening airway
Poor chest rise
Inadvertent hyperventilation
  • Commonly occurs in stressful resuscitation scenarios. Can lead to:
  • Prevention
    • Maintain steady pressure and depth of bag compression.
    • Count seconds between breaths delivered.
Hypoxia during apneic period
Obese patient
  • Place patient in ramp position: pillow or rolled blanket under shoulders and extra pillows under head
Bearded patient
  • Apply lubricating gel or a transparent occlusive dressing to the beard to create a better mask seal
Edentulous patient
  • Leave removable dentures in for BMV to prevent air leak around sunken cheeks
  • If no dentures: Move mask cranially, placing the lower edge of the mask behind the lower lip (upon the lower gingival surface) or place an oropharyngeal airway.

Factors that contribute to difficult BMV can be remembered with the MOANS mnemonic: Mask seal, Obstruction/Obesity, Age > 55 years, No teeth, Stiff lungs/Sleep apnea.

These devices may be used in combination with airway opening maneuvers to improve airway patency.

Oropharyngeal airway (OPA) [13]

  • Description: a rigid curved device placed in the mouth to prevent the tongue from occluding the airway
  • Indications
  • Contraindications: conscious patient with intact gag reflex
  • Sizing rule: from the incisors to the angle of the mandible, or corner of the mouth (oral commissure) to the earlobe
  • Insertion technique
  • Further management: Toleration of an oropharyngeal airway indicates an at-risk airway; preparations should be made for intubation.

Nasopharyngeal airway (NPA) [13]

  • Description: a soft flexible tube inserted through the nares into the nasopharynx to prevent the tongue from occluding the airway
  • Indications: current or potential oropharyngeal obstruction
  • Contraindications [3][21]
  • Sizing rule: nostril to the ipsilateral tragus
  • Insertion technique
    1. Lubricate the tube.
    2. Consider topical decongestant to decrease the risk of epistaxis (e.g., oxymetazoline ). [22]
    3. Select the wider nostril.
    4. Insert gently without forcing.
    5. Aim posteriorly, not superiorly.
    6. Twist the tube back and forth for ease of passage.
    7. If resistance is encountered, stop and attempt on the contralateral nostril.

Definition

Advanced airway devices that occlude the distal oropharynx to facilitate positive pressure ventilation in the absence of an endotracheal tube

Indications

Contraindications

SGAs offer less protection against aspiration than ET tubes.

Options [15][23]

  • Laryngeal mask airway (LMA): a supraglottic device consisting of an inflatable mask attached to the end of a tube
    • Second-generation LMAs have safety adaptations such as bite blocks and gastroesophageal drainage ports.
    • Intubating LMAs (ILMAs) have adaptations that allow passage of an ET tube through the LMA.
  • i-gel®: A type of supraglottic airway; similar to the LMA, but the mask is anatomically-molded, noninflatable, and made of a soft gellike material.
  • Laryngeal tube airway (LTA)
    • An airway device consisting of a tube with two inflatable cuffs and ventilation holes between them.
    • Intubating LTAs feature additional adaptations to allow the passage of an ET tube through the LTA. [24]

Procedure [2][15]

  1. Choose the appropriate size for the patient:
    • Small adult: size 3
    • Medium adult: size 4
    • Large adult: size 5
  2. LMAs and LTAs: inflate cuffs fully to check for leaks before deflating.
  3. Lubricate the tip of the device, being careful not to block ventilatory openings.
  4. Place the patient in the sniffing position.
  5. Open the patient's mouth wide.
  6. Hold the device firmly (at the junction of the tube and mask for an LMA, at the bite block for an i-gel®, or at the connector for an LTA).
  7. Insert the device.
    • LMA and i-gel®: Insert smoothly along the hard palate and downwards with the outlet facing caudally.
    • LTA: Insert the tube rotated at 45–90° from midline (towards concave lateral) until past the base of the tongue, where it should be rotated back to midline (towards concave up).
  8. Stop when the device has passed the base of the tongue and resistance is felt (LMA or i-gel®) or the connector reaches the teeth (LTA).
  9. LMAs and LTAs: Inflate the cuff.
  10. Confirm supraglottic tube placement.

Confirmation of correct placement [25]

  • Air movement heard on auscultation of chest
  • Visible chest rise and fall
  • Continuous CO2 waveform on capnography
  • Stable or improving oxygenation

The distal end of the LTA may pass blindly into the trachea. Confirmation of correct placement is always necessary.

Troubleshooting the LMA [25]

Difficulty ventilating the patient through a supraglottic airway suggests the device is malpositioned.

  • Reposition the patient's head and neck and/or perform airway opening maneuvers.
  • Deflate and reinflate mask (cuff may be hyperinflated or hypoinflated).
  • Withdraw, advance, or rotate the device.
  • Remove and reinsert the device or change size (a larger size may be required).
  • Switch to a different airway adjunct.

Definitions [2][15]

Indications for endotracheal intubation [2]

Contraindications

Preassessment [2][30]

Before attempting intubation, remember to review the SOAP ME checklist: Suction, Oxygen, Airway equipment, Pharmacy, Monitoring, and Equipment for resuscitation.

If red flags for a difficult airway are present, call for help, consider using adjuncts for difficult airway, or proceed to a surgical airway.

Preoxygenation [31]

  • Definition: administration of 100% oxygen prior to induction [32]
  • Goals
    • Lengthen safe apnea time: the period during which patients can safely go without spontaneous breathing, i.e., between induction and successful ET tube placement [31]
    • Prevent critical desaturation and subsequent organ dysfunction or death
  • Target SpO2: as close to 100% as possible
  • Methods [33]

Once preoxygenation has begun, keep the mask firmly applied to the face in order to obtain the maximum benefit.

Preoxygenation is vital for patients with risk factors for rapid desaturation during the apneic period (e.g., critical illness, obesity, preexisting lung disease).

Intubation medications [2][15]

Typically two classes of medication are given prior to intubation, a sedating (induction) agent and neuromuscular blocking agent to paralyze the patient.

Induction agents for intubation [2]

  • Sedates the patient, thereby reducing airway reflexes and facilitating intubation
  • Commonly used agents include propofol, etomidate, and ketamine.
  • The choice of induction agent depends on patient characteristics and operator experience.
  • The duration of bolus doses is typically short (∼ 10 minutes) and infusions or repeat bolus dosing are required for ongoing sedation (see “Adjunctive care of ventilated patients” for suggested medications and doses).
Induction agents for intubation
Drug and dose Common applications Advantages Disadvantages
Propofol
Etomidate
  • Can reduce ICP
  • Minimal effect on blood pressure
Ketamine

Midazolam and fentanyl are not routinely recommended for intubation due to their unpredictable effectiveness and high risk of adverse events.

Paralytic agents for intubation [2]

Avoid succinylcholine in at-risk patients (i.e., those with renal impairment, burns, crush injuries, denervation, neuromuscular disease, prolonged abdominal sepsis) because it can cause life-threatening hyperkalemia! [2]

Direct laryngoscopy is the traditional first-line approach to intubation, however, in many centers, videolaryngoscopy is preferred and performed routinely.

Intubation via direct laryngoscopy [15]

  • Positioning: Place patient in sniffing position unless C-spine injury is suspected.
  • Technique: The majority of patients should have received induction agents and been preoxygenated.
    1. Wear appropriate PPE.
    2. Choose the correct ET tube size. [38]
    3. Gently open the patient's mouth.
    4. Insert the laryngoscope blade , using the groove to sweep the tongue aside.
    5. Advance steadily until the tip is at the vallecula and the epiglottis is visible below it.
    6. Lift gently forward and upward to raise the epiglottis and reveal the arytenoid cartilages and vocal cords.
    7. Insert the styleted ET tube.
    8. Once the tip is at the glottis, remove the stylet and gently advance until the cuff is past the cords.
    9. Inflate the cuff.
    10. Secure the tube once proper placement is confirmed.

Avoid rocking the laryngoscope on the teeth; it can cause dental injury and aspiration of tooth fragments.

Ensure equipment to manage a failed intubation is available at all times.

Intubation via videolaryngoscopy [15][39]

Confirmation of ET tube placement [42][43]

  • Direct visualization of endotracheal tube markers
    • Distal tube markers should be seen advancing past the vocal cords.
    • Proximal numbered tube markers should read approx. 21–23 cm at the patient's teeth.
  • Auscultation: breath sounds audible over both lung fields
  • Condensation: consistently visible in the tube during exhalation
  • CO2 detection: gold standard of successful endotracheal intubation [44]
    • Colorimetric capnometer: a qualitative CO2 detector connected between the tube and the BMV equipment
      • A visual indicator changes color from purple to yellow upon contact with CO2.
      • Consistent color changing with each breath > 3 times correlates with tracheal placement.
    • Capnometry: real-time quantitative EtCO2 level displayed numerically on the monitor
    • If capnometry is inconclusive: bronchoscopy or esophageal detector device [43]
    • Capnography: real-time quantitative EtCO2 displayed as a waveform
  • Imaging (e.g., CXR)

Intubation is an aerosol-generating procedure that carries a high risk of transmission of respiratory pathogens to healthcare workers. Appropriate PPE for all participating providers is essential. [45]