Oxygen Therapy in Neonatal and Pediatric Care

Oxygen Therapy: Definition and Principles

Oxygen therapy is defined as the administration of O₂ with an elevated fraction of inspired oxygen (FiO₂) above the ambient air concentration (0.21). This process promotes:

• Increasing alveolar O₂ pressure;
• Creating a larger pressure gradient between the alveoli and capillaries;
• Ideal delivery: Oxygen that is heated and humidified.

Clinical Indications for Oxygen Therapy

• Reversal of hypoxemia:
  • Newborns: PaO₂ < 50 mmHg or O₂ saturation < 88%;
  • Young Infants (up to 6 months): PaO₂ < 60 mmHg or O₂ saturation < 92%;
  • Children (> 6 months): PaO₂ < 80 mmHg or O₂ saturation < 96%.
• Reduced labored breathing;
• Resorption of air cavities;
• Reduced pulmonary vascular resistance.

Modes of Administration

Common methods include the incubator, halo or hood, oxygen tent (Oxitenda), nasal cannula, various masks, and the T-tube.

Oxygen Delivery in the Incubator

FiO₂ is often not strictly controlled because the incubator opens frequently. Settings include:

• Horizontal Red Flag: Allows the entry of ambient air;
• Vertical Red Flag: Prevents the entry of ambient air.

A heated humidifier can be used with a "trachea" (corrugated tubing) inserted inside the incubator.

Oxygen Halo or Hood

An acrylic helmet that involves the head of the newborn. The FiO₂ calculation is:

FiO₂ = [(Liters of compressed air × 21) + (Liters of O₂ × 100)] / [Total liters of compressed air + O₂]

High flows range from 7 to 15 liters per minute. Disadvantages include cooling of the newborn, feeding difficulty, CO₂ rebreathing, and excess noise.

Oxygen Tent or Oxitenda

An acrylic box that involves the upper half of the infant's body. The FiO₂ calculation is:

FiO₂ = [(Liters of compressed air × 21) + (Liters of O₂ × 100)] / [Total liters of compressed air + O₂]

High flows are typically greater than 12 liters per minute. It shares the same disadvantages as the halo.

Nasal Catheter and Cannula

A simple and low-cost method. The FiO₂ calculation is: FiO₂ = 21 + (Number of liters of O₂ × 4). Low flows range from 0.5 to 5 liters per minute. This method is widely used for chronic administration.

Oxygen Masks

Masks are less frequently used in children. Flows range from 6 to 15 liters per minute. Types include:

• Simple mask;
• Oxygen reservoir mask;
• Venturi mask;
• Mask tube.

T-Tube Administration

Used for children with a tracheostomy who no longer depend on mechanical ventilation.

Oxygen Toxicity and Complications

Metabolites formed during oxygen oxidation are highly corrosive free radicals (superoxide and hydroxyl anions) that may cause cell destruction. Complications related to O₂ include:

• Absorption atelectasis;
• Bronchopulmonary dysplasia;
• Retinopathy of prematurity;
• Necrosis of white and gray matter.