What PEEP (Positive End-Expiratory Pressure) setting is recommended for an AMBU (Artificial Manual Breathing Unit) bag in Neonatal Resuscitation Program (NRP)?

PEEP Setting for AMBU Bag in Neonatal Resuscitation

When using a self-inflating bag (AMBU bag) for neonatal resuscitation, approximately 5 cm H₂O PEEP is recommended for preterm infants, though achieving reliable PEEP with self-inflating bags requires adding a PEEP valve and remains technically challenging. 1

Guideline Recommendations by Infant Type

For Preterm Infants (<35 weeks gestation)

• The 2015 American Heart Association NRP Guidelines recommend approximately 5 cm H₂O PEEP when administering positive pressure ventilation to preterm newborns (Class IIb recommendation, Level of Evidence B-R) 1
• This recommendation was repeated from 2010 guidelines and reaffirmed in 2015 despite limited evidence showing only modest benefits (slight reduction in maximum oxygen concentration needed) 1

For Term Infants

• No specific PEEP recommendation can be made for term infants due to insufficient data 1
• The evidence base for term infants is inadequate to support or refute PEEP use during resuscitation 1

Critical Technical Limitations of Self-Inflating Bags

PEEP Delivery Challenges

• Self-inflating bags cannot deliver CPAP and may not achieve PEEP reliably even with a PEEP valve attached 1
• Research shows self-inflating bags with PEEP valves deliver significantly less PEEP than target settings (mean 3.6 cm H₂O when set at 5 cm H₂O) 2
• PEEP delivery is rate-dependent: at 20 inflations/minute, measured PEEP averages 3.6 cm H₂O; at 60 inflations/minute, it improves to 4.8 cm H₂O when targeting 5 cm H₂O 3

Device-Specific Performance

• The Ambu brand self-inflating bag with Ambu PEEP valve can deliver more consistent PEEP levels close to operator-set values compared to other brands 3
• Performance varies significantly by manufacturer, and the Laerdal brand (most commonly studied) shows inconsistent PEEP delivery 3, 2
• PEEP delivery is also lung compliance-dependent, with better performance in more compliant lungs 3

Alternative Devices for Reliable PEEP

T-Piece Resuscitator

• T-piece resuscitators (e.g., Neopuff) deliver PEEP more reliably and consistently than self-inflating bags (4.4 cm H₂O vs 3.6 cm H₂O when targeting 5 cm H₂O) 2
• These devices require a compressed gas source, limiting use in resource-limited settings 1

Flow-Inflating Bags

• Flow-inflating bags can deliver reliable PEEP (4.4 cm H₂O when targeting 5 cm H₂O) but require significant operator skill and a compressed gas source 2, 4

Practical Implementation Algorithm

When PEEP is indicated (preterm infant requiring PPV):

1. If compressed gas available: Use T-piece resuscitator or flow-inflating bag set to 5 cm H₂O PEEP 1

2. If only self-inflating bag available:

   • Attach manufacturer-specific PEEP valve (preferably Ambu brand if available) 3
   • Set PEEP valve to 5 cm H₂O 1
   • Maintain ventilation rate of 40-60 inflations/minute to optimize PEEP delivery 3
   • Recognize that actual delivered PEEP will likely be 3-4 cm H₂O rather than target 5 cm H₂O 3, 2

3. Monitor for adequate response: Improvement in heart rate and chest rise are primary indicators of effective ventilation 1

Important Caveats and Pitfalls

Safety Considerations

• Avoid excessive PEEP (>8-12 cm H₂O) as this may reduce pulmonary blood flow and increase pneumothorax risk 1, 5
• The evidence for PEEP benefit is weak, showing no improvement in mortality, intubation rates, or major morbidities—only a modest reduction in oxygen requirements 1

Mask Leak Impact

• Mask leak significantly reduces delivered PEEP—ensure proper mask seal 6
• Self-inflating bags provide no feedback about mask leak, unlike T-piece resuscitators 4

Resource-Limited Settings

• The evidence is not compelling enough to recommend against using self-inflating bags without reliable PEEP capability in settings where compressed gas sources are unavailable 1
• Novel PEEP valves that function without external gas sources are under development and may achieve 4-5 cm H₂O PEEP 6