Overview
Definition:
Noninvasive ventilation (NIV) provides ventilatory support without an endotracheal tube, utilizing a tight-fitting mask interface
Continuous Positive Airway Pressure (CPAP) delivers a constant positive pressure throughout the respiratory cycle
Bilevel Positive Airway Pressure (BiPAP) delivers two distinct pressure levels: a higher pressure during inspiration (IPAP) and a lower pressure during expiration (EPAP)
Both aim to improve gas exchange and reduce the work of breathing in pediatric patients with respiratory compromise.
Epidemiology:
NIV use in pediatrics has steadily increased, particularly in neonates for conditions like respiratory distress syndrome (RDS) and apnea of prematurity
In older children, it's employed for acute exacerbations of asthma, bronchiolitis, pneumonia, neuromuscular weakness, and post-extubation support
Incidence varies widely based on underlying condition and hospital setting, with significant utility in PICUs and NICUs.
Clinical Significance:
NIV is a cornerstone in managing pediatric respiratory distress, offering a less invasive alternative to mechanical ventilation
It reduces the risks associated with intubation, such as VAP, airway trauma, and prolonged ICU stays
Effective application of CPAP and BiPAP can prevent progression to invasive ventilation, improve oxygenation, reduce work of breathing, and enhance patient comfort, directly impacting outcomes and resource utilization.
Indications And Contraindications
Indications:
Respiratory distress with adequate spontaneous breathing
Hypoxemic respiratory failure (e.g., pneumonia, pulmonary edema, ARDS)
Hypercapnic respiratory failure (e.g., neuromuscular disease, COPD exacerbation)
Post-extubation support to prevent re-intubation
Apnea of prematurity (CPAP)
Bronchiolitis
Asthma exacerbations.
Contraindications:
Inadequate spontaneous respiratory effort
Inability to protect airway or clear secretions
Vomiting or gastrointestinal issues with aspiration risk
Facial trauma or recent facial/upper airway surgery
Untreated pneumothorax
Severe hemodynamic instability
Upper airway obstruction proximal to mask
Patient refusal or intolerance.
Cpap Setup And Management
Interface Selection:
Nasal prongs or masks are common
Nasal prongs are generally preferred in neonates and infants to minimize air leak and nasal injury
Masks (nasal or oronasal) are used in older children, requiring good seal and patient tolerance
Proper sizing is crucial to avoid pressure sores and leaks.
Device Settings:
Continuous positive airway pressure (CPAP) is set as a fixed pressure (e.g., 5-12 cmH2O in neonates, 8-15 cmH2O in older children)
FiO2 is adjusted to achieve target SpO2 (e.g., 90-95%)
Flow rate is set to maintain the desired pressure and meet peak inspiratory demand
Humidification is essential to prevent mucosal drying.
Monitoring And Adjustment:
Close monitoring of respiratory rate, work of breathing, SpO2, EtCO2, and patient comfort is vital
Leaks should be minimized
Adjustments to CPAP level, FiO2, or flow may be needed based on patient response
Assess for signs of NIV failure (worsening distress, persistent hypoxemia/hypercapnia, increased work of breathing).
Bipap Setup And Management
Interface Selection:
Similar to CPAP, nasal or oronasal masks are used
Oronasal masks may provide better seal for higher pressures
Antifungal cream may be applied to areas of pressure to prevent skin breakdown.
Device Settings:
IPAP (Inspiratory Positive Airway Pressure): Higher pressure during inspiration (e.g., 10-25 cmH2O)
EPAP (Expiratory Positive Airway Pressure): Lower pressure during expiration, equivalent to CPAP (e.g., 5-10 cmH2O)
The pressure support (IPAP-EPAP) provides tidal volume support
FiO2 is adjusted as needed
Inspiratory Trigger and Expiratory Trigger sensitivity are set to synchronize with patient effort.
Monitoring And Adjustment:
Monitor respiratory rate, tidal volume, SpO2, EtCO2, and work of breathing
Tidal volume delivery is a key parameter
Adjust IPAP and EPAP to improve ventilation and oxygenation, reduce work of breathing, and maintain adequate tidal volumes (aiming for 4-8 mL/kg)
Monitor for air swallowing, gastric distension, and mask leak
Assess for signs of NIV failure.
Comparison And Selection Criteria
Indications For Cpap:
Primarily for oxygenation support with mild to moderate hypoxemia
Conditions like RDS, bronchiolitis, post-extubation support with minimal ventilatory failure
Patients who are able to spontaneously generate adequate tidal volumes.
Indications For Bipap:
When both oxygenation and ventilation support are needed
Hypercapnic respiratory failure, significant hypoventilation, impending respiratory arrest, severe asthma exacerbations with poor tidal volumes
Patients with neuromuscular weakness.
Transition And Weaning:
Patients on NIV can be weaned by gradually reducing pressures, FiO2, or ventilation support (for BiPAP)
Transition to invasive ventilation is considered if NIV fails to improve the patient's condition or worsens
Careful assessment for signs of improvement or deterioration guides decisions.
Complications And Management
Common Complications:
Mask discomfort and intolerance
Air leaks leading to ineffective therapy or dry eyes
Skin breakdown or pressure sores
Aerophagia leading to gastric distension, vomiting, and aspiration
Nasal congestion or rhinorrhea
Ocular irritation
Pneumothorax (rare).
Management Of Complications:
Optimize mask fit and interface type
Use adequate humidification
Consider sedation or analgesia if needed for tolerance
Monitor for gastric distension and decompress stomach if necessary
Frequent skin checks and barrier creams
If pneumothorax suspected, confirm with imaging and manage appropriately (chest tube insertion).
Signs Of Niv Failure:
Increasing work of breathing despite support
Worsening hypoxemia or hypercapnia
Paradoxical chest wall movement
Altered mental status
Hemodynamic instability
Persistent or worsening tachypnea
Decreased tidal volumes on BiPAP.
Key Points
Exam Focus:
Understand the core principles of CPAP and BiPAP
Differentiate indications for each
Recognize contraindications
Identify parameters to monitor and adjust
Know common complications and signs of NIV failure
Be familiar with pediatric age-specific considerations for NIV settings and interfaces.
Clinical Pearls:
Start with the lowest effective pressures and FiO2
Ensure good seal and comfort to maximize tolerance
Humidification is key
Closely monitor for signs of worsening or failure
Titrate therapy based on patient response, not just preset values
Consider sedation judiciously.
Common Mistakes:
Using inappropriate interface for age/condition
Inadequate mask seal leading to leaks
Failure to humidify the delivered gas
Over-reliance on SpO2 without assessing work of breathing or EtCO2
Delaying intubation when NIV fails
Incorrect trigger sensitivity settings on BiPAP.