What type of intubation blade is recommended for adult patients?

Intubation Blade Selection for Adult Patients

For adult patients requiring intubation, the Macintosh curved blade should be used as the primary laryngoscope blade, with videolaryngoscopy recommended as first-line in anticipated difficult airways or as a rescue device after failed direct laryngoscopy. 1

Primary Blade Selection

Direct Laryngoscopy

• Macintosh curved blade is the standard first-line blade for adult patients
  • Provides good visualization by inserting into the vallecula and indirectly elevating the epiglottis
  • Size 3 Macintosh blade appears to offer better first-pass success than size 4 in critically ill adults 2
  • Familiar to most clinicians, which is an important consideration for successful intubation

Special Circumstances

• Miller straight blade may be considered as an alternative when:
  • Direct elevation of the epiglottis is needed
  • After failed attempt with Macintosh blade 1
  • Note: While straight blades may provide better laryngeal visualization, curved blades generally offer better intubating conditions 3

Videolaryngoscopy Recommendations

When to Use Videolaryngoscopy First-Line:

• Anticipated difficult airway (MACOCHA score ≥3) 1
• History of difficult intubation 1
• Signs of upper airway obstruction 1
• Suspected or confirmed cervical spine injury (Grade A recommendation) 1

When to Use Videolaryngoscopy as Rescue:

• After failed direct laryngoscopy (Cormack-Lehane grade III or IV) 1
• When mask ventilation is possible but direct laryngoscopy has failed 1

Adjuncts to Improve Success

• Bougie/stylet: Should be readily available, particularly when using videolaryngoscopy 1, 4
• External laryngeal manipulation: Consider BURP (Backward, Upward, Rightward Pressure) maneuver to improve glottic view 1
• Alternative blade: If first attempt fails with one blade type, switch to another blade type 1

Contraindications for Videolaryngoscopy

• Mouth opening <2.5 cm
• Cervical spine fixed in flexion
• Upper airway tumors with stridor 1

Practical Considerations

• Ensure availability of difficult airway equipment including multiple blade types and sizes
• Capnographic confirmation of intubation is necessary in the intensive care environment 1
• Metal blades are preferred over plastic disposable blades for anticipated difficult intubations 1
• Regular training in videolaryngoscopy techniques is essential, especially for those who perform intubations in patients with cervical spine concerns 1

Common Pitfalls

• Persisting with the same blade after failed attempt rather than switching to an alternative
• Inadequate positioning before laryngoscopy
• Failure to have rescue devices immediately available
• Prolonged intubation attempts leading to desaturation (stop attempts if SpO2 <95% and prioritize oxygenation) 1
• Overlooking the importance of operator familiarity with equipment (use blades that clinicians are experienced with) 1