Pediatric Acute Respiratory Distress Syndrome and Mechanical Ventilation

Clinical Note: Because pARDS is a restrictive lung disease, ventilator management must focus on lung protection to prevent further injury while ensuring adequate gas exchange.

Mechanical Ventilation and Lung Protection

When a child requires mechanical ventilation (MV), the primary goals are safety, comfort, and liberation. Safety involves ensuring adequate gas exchange while simultaneously providing "lung protection"—a strategy aimed at minimizing mechanical trauma to the lung tissue.

Types of Ventilation

• Conventional Mechanical Ventilation (CMV): Provides breaths at a rate of 150 per minute or less.
• High-Frequency Ventilation (HFV): A specialized mode providing more than 150 breaths per minute.

Complications of Invasive Ventilation

While mechanical ventilation is life-saving, it carries significant risks. These complications can be categorized into pulmonary, airway/infectious, and systemic issues.

Pulmonary Complications

Mechanical forces applied during ventilation can cause direct structural damage to the lungs:

• Barotrauma: Injury caused by excessive pressure applied to the airways.
• Volutrauma: Injury caused by overdistension of the alveoli due to excessive tidal volumes.
• Atelectrauma: Injury resulting from the repetitive opening and closing of collapsed alveoli during the respiratory cycle.
• Pneumothorax: An air leak disorder where air escapes from the lung into the pleural space.
• Patient-Ventilator Asynchrony: A lack of coordination between the patient's spontaneous breathing efforts and the ventilator's delivery, which can increase the work of breathing and cause discomfort.

Airway and Infectious Complications

The presence of an artificial airway (such as an endotracheal tube) introduces specific risks to the upper respiratory tract:

• Glottic/Tracheal Erosion or Stenosis: Physical damage or narrowing of the airway caused by the presence of the tube.
• Ventilator-Associated Pneumonia (VAP): A serious infection that develops in patients receiving mechanical ventilation.

Obstructive and Other Underlying Conditions

The management of a patient on a ventilator is often dictated by their underlying disease. For instance, patients with obstructive lung diseases—such as Cystic Fibrosis, Bronchopulmonary Dysplasia (BPD), or Severe Asthma—require different strategies than those with the restrictive patterns seen in pARDS.

Study Tip: When differentiating between lung injuries, remember that pARDS is a restrictive process (characterized by collapse and stiffness), whereas conditions like Asthma or Cystic Fibrosis are obstructive processes (characterized by airway resistance).

Summary Table of Complications