Overview
Definition:
Pediatric acute respiratory failure (ARF) is a clinical syndrome characterized by the inability of the respiratory system to maintain adequate oxygenation (hypoxemia) or ventilation (hypercapnia), leading to impaired gas exchange and physiological derangement
It can be classified as Type 1 (hypoxemic) or Type 2 (hypercapnic).
Epidemiology:
ARF is a common reason for pediatric intensive care unit (PICU) admission, with an incidence varying by etiology
Common causes include pneumonia, bronchiolitis, asthma exacerbations, sepsis, and congenital heart disease
Outcomes are significantly influenced by the underlying cause and promptness of intervention.
Clinical Significance:
ARF represents a life-threatening condition requiring rapid assessment and intervention
Differentiating between the need for non-invasive ventilation (NIV) and endotracheal intubation is crucial for optimizing patient outcomes, minimizing complications, and improving resource utilization in pediatric critical care settings
This decision-making process is a core competency for pediatric residents and is frequently tested in DNB and NEET SS examinations.
Clinical Presentation
Symptoms:
Tachypnea
Retractions (subcostal, intercostal, suprasternal, accessory muscle use)
Nasal flaring
Grunting
Cyanosis (peripheral or central)
Altered mental status (irritability, lethargy)
Poor feeding
Vomiting
Cough
Wheezing
Stridor.
Signs:
Abnormal respiratory rate (tachypnea or bradypnea)
Tachycardia
Paradoxical breathing
Decreased air entry
Diffuse or localized wheezes or crackles
Pallor
Mottling
Signs of dehydration or shock.
Diagnostic Criteria:
No single universal criteria exist, but diagnosis is based on clinical assessment and objective measures
Key indicators include: PaO2 < 50 mmHg (or SaO2 < 90% on room air) indicating hypoxemia
PaCO2 > 50 mmHg with a pH < 7.35 indicating hypercapnia with respiratory acidosis
or clinical signs of severe respiratory distress refractory to initial conservative measures.
Diagnostic Approach
History Taking:
Onset and duration of symptoms
Presence of fever, cough, or coryza
History of prematurity, congenital heart disease, neuromuscular disorders, or previous respiratory issues
Exposure to sick contacts
Recent travel
Medication history and allergies
Feeding history
Birth history.
Physical Examination:
Assess work of breathing and oxygenation status
Vital signs (respiratory rate, heart rate, blood pressure, oxygen saturation, temperature)
Assess for cyanosis, retractions, accessory muscle use, nasal flaring, and grunting
Auscultate lung fields for breath sounds, wheezes, crackles, and air entry
Evaluate for signs of dehydration, sepsis, or cardiac compromise.
Investigations:
Arterial blood gas (ABG) analysis: Essential for assessing oxygenation, ventilation, and acid-base status
Complete blood count (CBC): To assess for infection and anemia
Chest X-ray: To identify pneumonia, atelectasis, pleural effusion, or structural abnormalities
Viral panel (e.g., RSV, influenza): Especially in infants and young children with bronchiolitis or pneumonia
Blood cultures: If sepsis is suspected
Electrolytes and renal function tests: To assess for metabolic derangements
Electrocardiogram (ECG) and echocardiogram: If cardiac pathology is suspected.
Differential Diagnosis:
Pneumonia (bacterial, viral, atypical)
Bronchiolitis
Asthma exacerbation
Sepsis with respiratory compromise
Congenital anomalies (e.g., choanal atresia, tracheomalacia)
Upper airway obstruction
Foreign body aspiration
Pneumothorax
Pulmonary edema
Neuromuscular weakness (e.g., Guillain-Barré syndrome, spinal muscular atrophy)
Metabolic disorders (e.g., inborn errors of metabolism).
Management
Initial Management:
Ensure patent airway and adequate ventilation
Administer supplemental oxygen to maintain target SpO2 (usually 92-96%)
Position the child comfortably, often in a semi-recumbent position
Provide reassurance and minimize distress
Secure intravenous (IV) access for fluid and medication administration.
Non Invasive Ventilation:
NIV, including CPAP (Continuous Positive Airway Pressure) and BiPAP (Bilevel Positive Airway Pressure), is a vital tool for managing mild to moderate ARF
Indications include moderate respiratory distress with hypoxemia or hypercapnia not improving with oxygen alone, but without impending respiratory arrest or contraindications
NIV improves oxygenation by recruiting alveoli, reduces work of breathing, and can help clear secretions.
Intubation And Mechanical Ventilation:
Indications for intubation include impending respiratory arrest, severe hypoxemia or hypercapnia refractory to NIV, hemodynamic instability, decreased level of consciousness, inability to protect airway, significant airway obstruction, or need for prolonged ventilation
Conventional mechanical ventilation (CMV) settings (tidal volume, respiratory rate, PEEP, FiO2) must be tailored to the child's age, weight, and underlying condition
Lung-protective strategies should be employed.
Supportive Care:
Fluid management: Maintain euvolemia
Nutrition: Provide adequate caloric intake, often via nasogastric or orogastric tube if intubated
Sedation and analgesia: Judicious use to reduce oxygen consumption and improve synchrony with mechanical ventilation
Fever control: Antipyretics as needed
Management of underlying cause: Antibiotics for bacterial pneumonia, bronchodilators for asthma/wheezing, diuretics for pulmonary edema.
Decision Making Niv Vs Intubation
Indications For Niv:
Moderate respiratory distress (e.g., RR > 40-50 in infants, >30 in older children) with persistent hypoxemia (SpO2 < 90-92% despite oxygen) or mild hypercapnia with compensated acidosis
Ability to cooperate and protect airway
Absence of significant secretions or vomiting
Intact neurological status
Presence of conditions like bronchiolitis, moderate asthma exacerbations, post-extubation support.
Contraindications For Niv:
Impending respiratory arrest, inability to protect airway (GCS < 8), severe encephalopathy, active vomiting, copious secretions, facial trauma or congenital anomalies affecting mask seal, hemodynamic instability, untreated pneumothorax.
Indications For Intubation:
Respiratory arrest
Severe hypoxemia (PaO2 < 40-50 mmHg or SpO2 < 85% refractory to NIV) or severe hypercapnia (PaCO2 > 60-70 mmHg with severe acidosis pH < 7.25) refractory to NIV
Worsening work of breathing despite adequate NIV support
Decreased level of consciousness or inability to protect airway
Hemodynamic instability
Need for surgical airway management or procedures requiring sedation and paralysis.
Monitoring During Niv:
Continuous monitoring of respiratory rate, heart rate, SpO2, and blood pressure
Assess work of breathing and comfort level
Monitor for signs of NIV failure: worsening gas exchange, increased work of breathing, altered mental status, need for higher ventilator support
Regular ABG checks to evaluate effectiveness.
Complications
Niv Related Complications:
Facial skin breakdown or pressure sores
Air leak or gastric distension due to poor mask seal
Discomfort or anxiety
Nosocomial pneumonia (increased risk with aspiration).
Intubation And Ventilation Related Complications:
Upper airway trauma (laryngeal or tracheal injury)
Vocal cord damage
Barotrauma/volutrauma (pneumothorax, pneumomediastinum)
Ventilator-associated pneumonia (VAP)
Subglottic stenosis
Tracheostomy complications
Oxygen toxicity
ARDS development or worsening.
Prevention Strategies:
For NIV: Optimize mask fit and interface
Regular skin care
Sedation if needed for tolerance
For intubation/ventilation: Use appropriate ETT size
Employ lung-protective ventilation strategies
Strict VAP prevention protocols (head elevation, oral care, sedation vacation)
Early mobilization when appropriate
Consider tracheostomy if prolonged ventilation is anticipated.
Prognosis
Factors Affecting Prognosis:
Underlying etiology of ARF
Severity of hypoxemia and hypercapnia
Presence of comorbidities (e.g., cardiac disease, neurological impairment)
Age of the child (infants and neonates have poorer outcomes)
Promptness and appropriateness of intervention (NIV vs
intubation)
Development of complications.
Outcomes:
With timely and appropriate management, many children with ARF, especially those managed with NIV, have favorable outcomes
However, severe ARF, particularly when associated with conditions like ARDS or sepsis, carries a significant mortality risk
Long-term sequelae can include chronic lung disease, neurodevelopmental deficits, and recurrent respiratory infections.
Follow Up:
Children who have experienced ARF, especially those requiring mechanical ventilation, require close follow-up
This may include pulmonology, cardiology, and developmental pediatric assessments
Pulmonary function tests and imaging may be performed as needed
Education for parents regarding home care and recognizing early signs of respiratory distress is crucial.
Key Points
Exam Focus:
Understand the specific criteria for initiating NIV versus intubation in pediatric ARF
Know the common etiologies and their management nuances
Recall potential complications of both NIV and mechanical ventilation
Differentiate between hypoxemic (Type 1) and hypercapnic (Type 2) ARF.
Clinical Pearls:
Always assess work of breathing first
A child with declining mental status and worsening work of breathing despite oxygen is a candidate for NIV or intubation
Continuous monitoring is key
reassess response to therapy frequently
Bronchiolitis in infants often responds well to NIV, while severe asthma may require early intubation
For neonates, specific considerations for airway management and ventilation are paramount.
Common Mistakes:
Delaying intervention due to uncertainty about NIV vs
intubation
Inadequate oxygenation or ventilation support
Using inappropriate ventilator settings for the child's size and condition
Failure to address the underlying etiology of ARF
Over-sedation leading to respiratory depression and dependence on mechanical ventilation.