What is the recommended technique for tracheal intubation in an adult patient with no significant anatomical abnormalities?

How to Intubate an Adult Patient

Pre-Intubation Preparation

The patient must be optimally positioned, preoxygenated, anesthetized, and fully paralyzed before attempting laryngoscopy. 1

Patient Positioning

• Position the patient head-up with alignment of the oral, pharyngeal, and laryngeal axes to optimize laryngeal view and prevent rapid desaturation. 2
• In obese patients (BMI >30 kg/m²), use the ramped position which increases intubation success rates. 1
• For cervical spine injury, perform manual in-line stabilization with removal of at least the anterior cervical collar to facilitate mouth opening. 1

Preoxygenation

• Administer preoxygenation with noninvasive ventilation (NIV) or high-flow nasal oxygen (HFNO) to prevent hypoxemia during intubation. 3
• In obese patients or those at high aspiration risk, use head-up positioning with CPAP/NIV or HFNO for thorough pre- and peroxygenation. 1
• Continue apneic oxygenation throughout the procedure to extend safe apnea time. 2

Anesthesia and Paralysis

• Use intravenous induction with full neuromuscular blockade as this is optimal in most critically ill patients. 1
• For rapid sequence induction (RSI), administer 0.6 mg/kg succinylcholine IV for adults, with effective dosing ranging from 0.3 to 1.1 mg/kg. 4
• Achieve complete neuromuscular blockade before attempting laryngoscopy to optimize intubating conditions. 2

Laryngoscopy Technique

Limit laryngoscopy attempts to a maximum of three to prevent airway trauma and progression to cannot-intubate-cannot-oxygenate (CICO) situations. 1

Equipment Selection

• Use videolaryngoscopy as the primary technique as it increases first-attempt success rates and may prevent esophageal intubation. 3, 5
• Choose a videolaryngoscope with which you are most familiar and trained. 1, 2
• Have second-generation supraglottic airway devices (SGAs) immediately available for rescue (e.g., i-gel, ProSeal LMA). 1

Laryngoscopy Execution

• One blade entering the oral cavity constitutes one attempt at laryngoscopy. 1
• Use a bougie or stylet when the laryngeal opening is poorly seen (Grade 2b or 3a views) or when using hyper-angulated videolaryngoscopes. 1, 2, 3
• Avoid blind efforts to pass a tracheal tube in Grade 3b and 4 views as this is potentially traumatic. 1

Optimizing Failed Attempts

After a failed first attempt, ensure the front-of-neck airway (FONA) set is immediately available and summon senior help. 1

Between attempts, optimize by:

• Using a different device or blade 1
• Changing operators 1
• Applying suction 1
• Reducing or releasing cricoid force 1
• Using optimal external laryngeal manipulation (OELM) or backward-upward-rightward pressure (BURP) 1

Confirmation of Intubation

It is mandatory to use waveform capnography to confirm intubation. 1, 2

• Absence of a recognizable waveform trace indicates failed intubation unless proven otherwise. 1
• During cardiac arrest, effective CPR produces an attenuated but recognizable capnograph trace. 1
• Auscultation and chest wall movement observation are unreliable in critically ill patients. 1, 2
• Bronchoscopy via the tracheal tube can also confirm tracheal placement. 1, 2

Rescue Strategies After Failed Intubation

Plan B: Supraglottic Airway Device

• Insert a second-generation SGA as it is preferable to facemask ventilation because SGAs frequently enable oxygenation and provide some aspiration protection. 1
• A single attempt at fiberoptic-guided intubation through the SGA is recommended if oxygenation is adequate. 1
• Proceed directly to FONA if oxygenation is marginal, aspiration is occurring, ventilation is difficult, or fiberoptic intubation is not possible. 1

Plan C: Facemask Ventilation

• Use facemask ventilation with CPAP between airway instrumentation attempts. 1
• Optimize with proper head, mandible, and body positioning. 1

Plan D: Front-of-Neck Airway

• Do not wait for life-threatening hypoxemia before transitioning to FONA. 1
• In obese patients where the cricothyroid membrane is impalpable, use preinduction ultrasound identification. 1
• Use a scalpel technique with vertical incision in obese patients. 1

Special Populations

Obese Patients (BMI >30 kg/m²)

• Obesity doubles complication risk (BMI >30) and quadruples it (BMI >40). 1
• Do not attempt multiple intubation attempts, SGA rescue, or prolonged facemask ventilation due to rapid refractory hypoxemia—proceed promptly to FONA. 1
• Consider securing the airway awake with fiberoptic or videolaryngoscopy technique. 1

Cervical Spine Injury

• Perform RSI using manual in-line stabilization as early airway securing is beneficial. 1
• Use a bougie during direct laryngoscopy as manual in-line stabilization worsens laryngeal view. 1
• Videolaryngoscopy increases success with minimal cervical movement. 1

Critical Pitfalls to Avoid

• Never exceed three laryngoscopy attempts as repeated attempts cause trauma and airway deterioration. 1
• Never rely on auscultation or chest rise alone to confirm tube placement—always use waveform capnography. 1
• Never delay FONA when facing progressive hypoxemia after failed intubation and SGA attempts. 1
• In obese patients, never persist with multiple rescue attempts—transition early to FONA. 1