What are the different modes and types of mechanical ventilation for pediatric patients?

Different Modes and Types of Mechanical Ventilation for Pediatric Patients

The Paediatric Mechanical Ventilation Consensus Conference (PEMVECC) provides comprehensive recommendations for mechanical ventilation strategies in critically ill children, with approaches tailored to specific disease patterns and severity to optimize outcomes and minimize complications. 1

Non-Invasive Ventilation Options

• High Flow Nasal Cannula (HFNC): Delivers heated and humidified oxygen at flow rates exceeding patient's inspiratory flow, providing mild PEEP effect; appropriate for mild respiratory distress across various disease patterns 1, 2

• Continuous Positive Airway Pressure (CPAP): Maintains constant positive pressure throughout respiratory cycle, preventing alveolar collapse; useful in obstructive airway disease and as post-extubation support for patients at risk of stridor 1

• Non-Invasive Ventilation (NIV): Particularly beneficial for neuromuscular patients to prevent intubation and as a bridge during weaning from mechanical ventilation 1, 2

Invasive Ventilation Modes

Conventional Modes

• Pressure Control Ventilation (PCV): Most commonly used mode (60% of pediatric cases) where a set pressure is delivered with variable tidal volumes; allows better control of peak pressures 2, 3

• Volume Control Ventilation (VCV): Delivers consistent tidal volumes regardless of compliance changes; used in approximately 19% of pediatric cases 3

• Pressure-Regulated Volume Control (PRVC): Hybrid mode combining pressure control with volume targeting; used in 18% of pediatric cases to minimize barotrauma while ensuring adequate ventilation 3

Advanced Modes

• High-Frequency Oscillatory Ventilation (HFOV): Delivers very small tidal volumes at rapid rates (3-15 Hz); considered for severe cases with refractory hypoxemia despite conventional ventilation 1, 2

• Airway Pressure Release Ventilation (APRV): Maintains elevated airway pressure with intermittent releases; may be beneficial in severe ARDS but lacks systematic pediatric studies 4

• Extracorporeal Life Support (ECLS): Reserved for the most severe cases with refractory hypoxemia despite optimized conventional ventilation strategies 1

Setting the Ventilator Based on Disease Pattern

Healthy Lungs (e.g., post-operative)

• Tidal Volume: ≤10 mL/kg ideal body weight 1
• PEEP: 5-8 cmH2O 1
• Peak Pressure: Keep ≤28 cmH2O 1
• Target SpO2: ≥95% when breathing room air 1
• Target PCO2: 35-45 mmHg 1

Restrictive Disease (e.g., ARDS, pneumonia)

• Tidal Volume: ≤10 mL/kg ideal body weight, potentially lower in lung hypoplasia syndromes 1, 2
• PEEP: Higher levels based on disease severity, with titration and consideration of lung recruitment 1
• Peak Pressure: ≤28 cmH2O, or ≤29-32 cmH2O with increased chest wall elastance 1
• For PARDS: Target SpO2 92-97% when PEEP <10 cmH2O and 88-92% when PEEP ≥10 cmH2O 1
• Permissive Hypercapnia: Higher PCO2 accepted with target pH >7.20 1

Obstructive Airway Disease (e.g., asthma, bronchiolitis)

• Tidal Volume: ≤10 mL/kg ideal body weight 1
• PEEP: Add PEEP when air-trapping is present to facilitate triggering 1
• Peak Pressure: ≤30 cmH2O 1
• Respiratory Rate: Lower rates to allow for complete exhalation 1
• I:E Ratio: Extended expiratory time to prevent air trapping 1

Special Considerations

• Cardiac Patients: Require careful PEEP titration with hemodynamic monitoring 1, 2
• Neuromuscular Disease: Consider non-invasive ventilation and cough-assist devices 1
• Upper Airway Malacia: Use PEEP to stent airways 1

Monitoring Parameters

• Gas Exchange: Measure PCO2 in arterial or capillary blood samples; consider transcutaneous CO2 monitoring 1
• Oxygenation: Continuously measure SpO2; measure arterial PO2 in moderate-to-severe disease 1
• Ventilator Parameters: Monitor peak inspiratory pressure, plateau pressure, mean airway pressure, and PEEP 1
• Waveforms: Monitor pressure-time and flow-time scalars to optimize ventilator synchrony 1

Weaning Strategies

• Timing: Start weaning as soon as the patient's condition allows 1
• Assessment: Perform daily extubation readiness testing 1
• Post-Extubation Support: Consider non-invasive ventilation, particularly in neuromuscular patients 1
• Stridor Prevention: Use preventive measures in patients at increased risk for post-extubation stridor 1

Common Pitfalls and Caveats

• Inappropriate Tidal Volumes: Studies show actual practice often deviates from recommended tidal volumes, with median values of 9.2-10.3 mL/kg, potentially increasing risk of ventilator-induced lung injury 3

• Inadequate PEEP Titration: PEEP is often limited at ~10 cmH2O as oxygenation worsens, which may be lower than optimal for severe disease 3

• Practice Variability: Significant variation exists in ventilator management for pediatric patients, with clinicians making changes similar to protocol recommendations only 29% of the time 3

• Adult Protocol Adaptation: Most pediatric ventilation practices are adapted from adult protocols without sufficient evidence, neglecting differences in lung pathophysiology and response to injury 4

• Home Ventilators: Should not be used during the acute phase in the intensive care unit 1

• Hand Ventilation: Avoid unless specific conditions dictate otherwise 1