What is the oxygen hood principle in pediatric oxygen therapy?

Oxygen Hood Principle in Pediatric Oxygen Therapy

The oxygen hood is a high-flow oxygen delivery device that provides a controlled oxygen environment for infants by enclosing the head in a clear plastic chamber, allowing for precise FiO2 delivery greater than 0.80 while maintaining access for feeding and care. 1

Mechanism and Function

• Oxygen hoods create a consistent oxygen-rich environment around the infant's head, delivering higher concentrations of oxygen than nasal cannulas can provide 1
• The hood allows for humidification of oxygen, which is recommended for flow rates above 1 L/min 1
• Unlike nasal cannulas, hoods avoid direct contact with the infant's face, reducing irritation and pressure injuries 2
• Oxygen hoods can achieve FiO2 levels greater than 0.80, comparable to what might be needed in severe respiratory conditions 1

Clinical Applications

• Most commonly used for neonates and infants with chronic lung disease of infancy (CLDI) or bronchopulmonary dysplasia (BPD) 1
• Particularly useful for infants who cannot tolerate nasal cannulas or face masks 2
• Provides a means to deliver precise oxygen concentrations while allowing for feeding and handling 1
• Often used in hospital settings before transitioning to home oxygen therapy with nasal cannulas 1

Physiological Benefits

• Helps maintain oxygen saturation between 90-95%, which is the ideal range for:

  • Promoting growth and lung development 1
  • Reducing pulmonary artery pressure and vascular resistance 1
  • Decreasing the frequency of central apnea 1
  • Improving exercise tolerance 1

• Studies show that maintaining adequate oxygenation can reduce the risk of pulmonary hypertension and right ventricular hypertrophy 1

Limitations and Considerations

• Oxygen hoods are primarily used in hospital settings and are less practical for home use compared to nasal cannulas 1
• They limit mobility and access to the infant compared to other oxygen delivery methods 3
• Monitoring is essential as oxygen concentrations can fluctuate with movement or if the hood is not properly positioned 3
• Carbon dioxide can accumulate if flow rates are inadequate (typically need minimum 5-7 L/min to prevent CO2 retention) 4

Transitioning from Hood to Other Delivery Methods

• For discharge planning, infants typically transition from oxygen hood to nasal cannula before going home 1
• Nasal cannulas at flow rates of 0.25 to 3 L/min can achieve similar pulmonary artery pressure reductions as hood oxygen therapy with FiO2 greater than 0.80 1
• When transitioning, careful monitoring of oxygen saturation during different activities (sleep, feeding, handling) is essential 1

Monitoring Effectiveness

• Pulse oximetry is the primary method for monitoring effectiveness of oxygen therapy 1
• For infants younger than 1 year, hypoxemia is defined as SpO2 ≤90% for ≥5% of recording time or three separate measurements 1
• Multiple determinations should be made during rest, sleep, feeding, and high activity to ensure adequate oxygenation across all states 1

The oxygen hood remains an important tool in the management of hypoxemia in infants, providing a reliable method for delivering high concentrations of oxygen while maintaining access for care and minimizing direct contact with the infant's face 2, 3.