What is the role of Positive End-Expiratory Pressure (PEEP) in term newborns with respiratory distress?

Role of PEEP in Neonatal Resuscitation

PEEP should be used during initial ventilation of premature newborns in the delivery room at approximately 5 cm H₂O, but there is insufficient evidence to recommend routine PEEP use in term infants. 1

Evidence-Based Recommendations by Gestational Age

Preterm Infants

• The International Liaison Committee on Resuscitation recommends using PEEP for initial ventilation of premature newborns during delivery room resuscitation (weak recommendation, low-quality evidence). 1
• The recommended PEEP level is approximately 5 cm H₂O when administering positive pressure ventilation to preterm infants. 2
• Animal studies demonstrate that PEEP during initial stabilization improves functional residual capacity, oxygenation, lung compliance, and reduces lung injury in immature lungs. 1
• One small human trial showed no benefit in reducing intubation rates in the delivery room, though the evidence base remains limited. 1

Term Infants

• No recommendation can be made for routine PEEP use in term infants due to insufficient data. 1
• There is no evidence to support or refute the value of PEEP during resuscitation of term infants. 1
• If using a device capable of delivering PEEP in term infants, approximately 5 cm H₂O is reasonable based on extrapolation from preterm data, though this lacks direct evidence. 3

Physiological Mechanisms

PEEP provides continuous low positive pressure to the airway that prevents lung collapse at end-expiration. 1

Key physiological effects include:

• Prevents alveolar collapse in lungs that are not supported by a stiff chest wall, particularly when breathing efforts are weak. 1
• Maintains lung volume during positive pressure ventilation, which is critical in surfactant-deficient or immature lungs. 1
• Improves functional residual capacity establishment at birth. 1
• Enhances oxygenation and lung compliance in animal models. 1
• Recent animal data shows PEEP of 8 cm H₂O improves lung function in near-term rabbits with elevated airway liquid volumes (as occurs with cesarean delivery). 4

Critical Safety Considerations

Avoid excessive PEEP levels (8-12 cm H₂O) as these may cause harm: 1, 3, 5, 2

• Reduces pulmonary blood flow. 1, 5, 2
• Increases risk of pneumothorax. 1, 5, 2
• May decrease cardiac output and superior vena cava flow, potentially increasing intraventricular hemorrhage risk. 6

Device Selection for Reliable PEEP Delivery

The choice of ventilation device significantly impacts PEEP delivery reliability:

T-piece resuscitators:

• Deliver target PEEP more consistently and reliably than bag-mask devices. 5, 2
• Require a compressed gas source. 2
• Preferred when PEEP is indicated and compressed gas is available. 2

Self-inflating bags:

• Cannot deliver CPAP and may not achieve PEEP reliably even with a PEEP valve attached. 2
• If this is the only available device, attach a manufacturer-specific PEEP valve set to 5 cm H₂O. 2
• The American Academy of Pediatrics notes evidence is not compelling enough to recommend against self-inflating bags in resource-limited settings where compressed gas is unavailable. 2

Flow-inflating bags:

• Can deliver PEEP when set appropriately with compressed gas source. 2

Common Pitfalls and How to Avoid Them

Starting with excessive PEEP: Begin at 5 cm H₂O for preterm infants; do not start at 8-12 cm H₂O. 1, 3, 5, 2

Assuming all devices deliver PEEP equally: Recognize that self-inflating bags are unreliable for PEEP delivery; use T-piece resuscitators when possible. 5, 2

Applying term infant protocols to preterm infants: The evidence and recommendations differ substantially between these populations. 1

Ignoring device limitations in resource-limited settings: While T-piece resuscitators are preferred, effective resuscitation with available equipment takes priority over ideal PEEP delivery. 2

Integration with Other Ventilation Parameters

When using PEEP during initial resuscitation:

• Start with initial peak inspiratory pressures of 20-25 cm H₂O for preterm infants. 1, 5
• Monitor for adequate heart rate increase and chest rise as indicators of effective ventilation. 3
• Avoid excessive chest wall movement during ventilation of preterm infants. 1, 5
• If pressure monitoring is available, use it to provide consistent inflations and avoid unnecessarily high pressures. 1, 3

Strength of Evidence and Knowledge Gaps

The recommendation for PEEP in preterm infants carries a weak recommendation with low-quality evidence. 1 The evidence shows:

• No improvement in mortality, intubation rates, or major morbidities in human studies. 2
• Only modest reduction in maximum oxygen concentration requirements. 2
• Strong animal data supporting physiological benefits. 1
• Insufficient human trial data to have confidence in effect estimates. 1

For term infants, the evidence gap is even more substantial, with no human trials available to guide practice. 1