Airway management

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.

See also “Cricothyrotomy.”

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]

• Noisy breathing
• Snoring
• Stridor
• Hoarse voice
• Gurgling from secretions
• Hypoxia or hypercarbia
• Signs of increased work of breathing

Clinical features of complete airway obstruction ^[1]

• Inability to speak or cough
• Inaudible breath sounds
• Paradoxical movement of the chest and abdomen
• Profound hypoxia

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

• Loss of airway protective reflexes
  • Reduced level of consciousness (traditionally GCS ≤ 8) ^[4][5]
  • Ability to comfortably tolerate an oral airway
  • Inability to swallow secretions
  • Procedural sedation and/or general anesthesia
• Airway obstruction
  • Facial trauma
  • Burn injury and/or inhalational injury ^[6]
  • Progressive angioedema ^[7]
  • Known or suspected foreign body aspiration
  • Known laryngeal or pharyngeal cancer

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]

• Basic airway maneuvers are used:
  • To relieve partial airway obstruction in obtunded but spontaneously breathing patients
  • As a temporary measure prior to placement of a definitive airway in apneic patients or those with profound respiratory failure
• All patients require monitoring with pulse oximetry.
• Most patients should receive supplemental oxygen (see “Oxygen therapy”).
• Patients requiring basic airway maneuvers are at high risk of further airway deterioration; prepare for an advanced airway for most patients.

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

Head-tilt/chin-lift maneuver ^[10]

• 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

• Description
  • Displacing the mandible and tongue anteriorly to open the airway
  • May be used in conjunction with head-tilt/chin-lift or alone in patients with suspected C-spine injury
• Technique
  1. With the patient supine, place fingers behind the angles of the lower jaw.
  2. Move the jaw anteriorly to pull the base of the tongue and soft tissues away from the airway.
  3. Use the thumbs to open the mouth slightly.

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

• Description: positioning of the patient in a lateral decubitus position with slight neck extension
• Goal
  • Prevention of airway occlusion by the tongue and soft tissues
  • Reduction in the risk of aspiration the patient regurgitates
• Indication: temporary airway compromise that can be reversed with positioning (e.g., due to procedural sedation or acute alcohol intoxication)
• Contraindications
  • C-spine immobilization
  • Anticipated worsening of airway compromise
  • Transportation outside of a monitored environment

Definition ^[11][12]

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

Indications ^[11][12]

• Rescue ventilation: cardiac arrest, respiratory failure, accidental oversedation, failed intubation attempt (i.e., when safe apnea time has been exceeded)
• Bridge to intubation: following induction of apnea by administration of sedatives and muscle relaxants

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 3^rd, 4^th, and 5^th 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 ^[13][14][15]
  • 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. ^[16]
  • The second provider delivers breaths.

Initiate ventilation

• Goal ^[17][18]
  • 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

• Clinical
  • No audible air leak around mask
  • Bilateral chest rise
  • Air entry on auscultation of bilateral lung fields
• Monitor
  • SpO₂ in target range (may be above normal if preoxygenating)
  • Normal capnometry (waveform and EtCO₂ value)

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).

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) ^[10]

• Description: a rigid curved device placed in the mouth to prevent the tongue from occluding the airway
• Indications
  • Unconscious patient with airway obstruction (e.g., due to a large tongue, excessive nasopharyngeal tissue, copious secretion)
  • Typically used as a bridge to intubation
• 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
  • Adults: Insert concave up or concave lateral until past the tongue and then rotate until concave down.
  • Children: Using a tongue depressor to move the tongue down, insert carefully concave down.
  • Ensure OPA has bypassed the tongue and is not pushing it backwards.
• Further management: Toleration of an oropharyngeal airway indicates an at-risk airway; preparations should be made for intubation.

Nasopharyngeal airway (NPA) ^[10]

• 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][19]
  • Facial fractures, basilar skull fractures
  • Coagulopathy
• 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 ). ^[20]
  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

• Prehospital advanced airway management, e.g., out-of-hospital cardiac arrest
• Failed endotracheal intubation
• Surgical procedures requiring general anesthesia but not endotracheal intubation

Contraindications

• Epiglottitis
• Avoid in conscious patients with an intact gag reflex.

SGAs offer less protection against aspiration than ET tubes.

Options ^[12][21]

• 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. ^[22]

Procedure ^[2][12]

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 ^[23]

• 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 ^[23]

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][12]

• Endotracheal tube (ET tube): a flexible hollow tube designed to enter the trachea via the oropharynx or the nasopharynx, facilitate gas exchange, and protect the airway from aspiration
• Endotracheal intubation: placement of an ET tube in the trachea below the vocal cords
  • Orotracheal intubation: most common
  • Nasotracheal intubation: used in select conditions
  • Insertion usually assisted by direct laryngoscopy, video laryngoscopy , or flexible fiberoptic laryngoscopy
  • Typically requires sedation and paralysis ^[24]
  • Often preceded by BMV in fasting patients (e.g., elective surgery)
• Rapid sequence intubation/induction (RSI): commonly used when patients are at risk of aspiration
  • Goals: maximize first-pass success, reduce the risk of aspiration
  • Technique: rapid induction of anesthesia and paralysis followed by immediate intubation without intervening attempts at ventilation ^[25][26]
  • Differences from traditional intubation
    • Weight-based bolus doses of short-acting intubation medications are used without titration.
    • BMV is not performed

Indications for endotracheal intubation ^[2]

• Airway obstruction: e.g., anaphylaxis, peritonsillar abscess, angioedema
• Airway protection
  • Loss of airway protective reflexes: e.g., general anesthesia, persistent causes of AMS or coma
  • High risk of aspirating blood or secretions: e.g., hematemesis, massive hemoptysis, posttonsillectomy hemorrhage, uncontrollable vomiting
  • Anticipated deterioration: e.g., smoke inhalation injury, overdose
• Indications for invasive mechanical ventilation: : e.g., respiratory failure, respiratory arrest, multisystem trauma, septic shock

Contraindications

• Absolute: Presence of a valid do-not-intubate order and/or DNAR order
• Relative
  • Avoid RSI in certain types of difficult airways where rapid induction could precipitate a CICV scenario.
  • Avoid nasotracheal intubation in patients with facial and basal skull fractures. ^[27]

Complications

Mainstem intubation

• Definition: the placement of the distal end of an endotracheal tube into either the right or left main bronchus
• Etiology: inadvertent placement during intubation
• Clinical features
  • Hypoxia
  • Asymmetric breath sounds
  • High peak pressures
• Management: repositioning of the endotracheal tube

Preassessment ^[2][28]

• Identify any red flags for difficult airway management, e.g., using the LEMON assessment.
• Call an airway management expert if a difficult airway is anticipated.
• Ensure necessary equipment is available and functioning (see “Equipment checklist for intubation”).

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 ^[29]

• Definition: administration of 100% oxygen prior to induction ^[30]
• 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 ^[29]
  • Prevent critical desaturation and subsequent organ dysfunction or death
• Target SpO₂: as close to 100% as possible
• Methods ^[31]
  • First line: High flow O₂ (10–12 L/min) via NRB for 3 minutes
  • Alternative (if 3 minutes of preoxygenation is not possible): 8 breaths (vital capacity inspirations)

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][12]

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).

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]

• Benefits
  • Better visualization of glottic opening
  • Decreased risk of airway injury
• Classes of neuromuscular junction blockers (NMJ blockers)
  • Depolarizing NMJ blockers (e.g., succinylcholine )
    • Commonly used because of rapid onset and offset time (spontaneous respirations normally return within 10 minutes)
    • May precipitate severe hyperkalemia in patients with contraindications to succinylcholine
    • Rarely, prolonged paralysis occurs in patients with limited cholinesterase activity.
  • Nondepolarizing NMJ blockers: e.g., rocuronium
    • Indicated in patients with contraindications to succinylcholine
    • May be used as a first-line muscle relaxant in all patients.
    • Typically avoided in patients with a suspected difficult airway because they have a longer duration of action (risk of deterioration to a CICV scenario). ^[35]
• If ongoing paralysis is required, an infusion is necessary (see “Adjunctive care of ventilated patients” for suggested medications and doses).

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 ^[12]

• Positioning: Place patient in sniffing position unless C-spine injury is suspected.
  • Head elevated to a height of 10 cm
  • The neck is mildly flexed at the lower cervical vertebrae and extended at the atlanto-occipital joint.
• Technique: The majority of patients should have received induction agents and been preoxygenated.
  1. Wear appropriate PPE.
  2. Choose the correct ET tube size. ^[36]
  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 ^[12][37]

• Description
  • A laryngoscope that allows indirect fiberoptic visualization of the glottic opening without head and neck manipulation ^[38]
  • Video from the distal end of the blade is delivered to an external video screen.
• Indications
  • Routine intubations ^[37][39]
  • Known or suspected difficult airway
  • Failed intubation with direct laryngoscopy
  • Teaching endotracheal intubation
• Technique is similar to direct laryngoscopy except for the following:
  • Sniffing position is not always required.
  • Use a matching rigid stylet OR mold a flexible stylet to match the curvature of the blade.
  • Insert the blade along the patient's tongue until the vocal cords are centered on the screen.
  • Confirm passage of the ET tube past the vocal cords on the screen.

Confirmation of ET tube placement ^[40][41]

• 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 ^[42]
  • 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 ^[41]
  • Capnography: real-time quantitative EtCO₂ displayed as a waveform
• Imaging (e.g., CXR)
  • CXR: The distal tip of the endotracheal or tracheal tube should be 2–6 cm above the carina (reposition if necessary).
  • Trained practitioners only: Ultrasound may be used to confirm tube position.

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. ^[43]