What is the hook technique in bag-mask ventilation?

The Hook Technique in Bag-Mask Ventilation

The hook technique is a novel bag-mask ventilation method that achieves significantly higher success rates (93.3%) compared to traditional techniques like the E/C (89.6%) and thenar eminence (87.2%) methods by providing better mask seal and airway patency. 1

Technique Description

The hook technique involves:

1. Positioning: Provider stands at the head of the patient
2. Hand placement:
   • Uses a chin lift maneuver while simultaneously securing the mask
   • Creates a tight seal between the mask and face
   • Allows for better airway patency maintenance

Comparison with Traditional Techniques

Traditional Techniques

• E/C technique: Uses the thumb and index finger in a "C" shape to hold the mask while the other fingers form an "E" shape on the mandible
• Thenar eminence technique: Places thenar eminences on the mask while fingers grasp the mandible

Advantages of the Hook Technique

• Higher success rate in ventilation (93.3%) compared to E/C (89.6%) and thenar eminence (87.2%) 1
• Particularly beneficial for providers with smaller hands
• Reduces provider fatigue during prolonged ventilation
• Minimizes finger discomfort during extended use
• Maintains better airway patency through effective chin lift

Best Practices for Bag-Mask Ventilation

Regardless of technique used, effective bag-mask ventilation requires:

• Two-person method whenever possible (one maintaining seal, one squeezing bag) 2
• Using an adult (1-2 L) bag for adult patients 2
• Delivering approximately 600 mL tidal volume (sufficient to produce visible chest rise) 2
• Delivering each breath over approximately 1 second 3
• Watching for visible chest rise as the primary indicator of effective ventilation 2
• Using supplementary oxygen (concentration >40%, flow rate 10-12 L/min minimum) when available 3

Common Challenges and Solutions

• Poor mask seal: Reposition hands using hook technique for better seal
• Inadequate ventilation: Ensure proper airway opening with head tilt-chin lift
• Provider fatigue: The hook technique may reduce fatigue compared to traditional methods
• Difficult airway: Consider oropharyngeal airway insertion to prevent tongue obstruction 3

Clinical Considerations

• For patients with suspected COVID-19 or other respiratory infections, use a tight-fitting mask with a heat and moisture exchange (HME) filter between the catheter mount and circuit 3
• In cardiac arrest scenarios, a two-person technique with a VE-grip improves seal, particularly in obese patients 3
• Avoid excessive ventilation during CPR as it can increase intrathoracic pressure, decrease cardiac output, and increase risk of regurgitation 2

Pitfalls to Avoid

• Excessive ventilation rate: Can impede venous return and decrease cardiac output
• Inadequate mask seal: Results in air leakage and insufficient ventilation
• Improper cricoid pressure: May impede ventilation; adjust or release if ventilation is difficult 3
• Gastric inflation: Can lead to regurgitation and aspiration; maintain appropriate ventilation volumes and pressures 3

The hook technique represents an important advancement in bag-mask ventilation that may improve outcomes in emergency airway management by providing more effective ventilation with less provider fatigue.