Respiratory Failure

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Respiratory Failure - Defining Distress

  • Respiratory Failure (RF): Inability of respiratory system to maintain adequate oxygenation ($PaO_2$) or ventilation ($PaCO_2$).
  • Types:
    • Type I (Hypoxemic): $PaO_2$ < 60 mmHg (or $SpO_2$ < 90%) with normal/low $PaCO_2$.
      • Mechanisms: V/Q mismatch, shunt, diffusion impairment.
    • Type II (Hypercapnic): $PaCO_2$ > 50 mmHg (pH < 7.35 for acute).
      • Mechanism: Alveolar hypoventilation.
  • Respiratory Distress: Increased work of breathing (WOB).
    • Signs: Tachypnea, retractions, nasal flaring, grunting.
    • Accessory muscle use, head bobbing, paradoxical breathing.
  • Impending RF: Deterioration despite O2; fatigue, altered sensorium.

⭐ Grunting: expiratory sound (glottic closure) to maintain FRC & ↑ PEEP.

Respiratory Failure - Root Cause Roundup

  • Upper Airway Obstruction:
    • Croup, Epiglottitis
    • Foreign body aspiration
    • Laryngomalacia, Tracheomalacia
  • Lower Airway Disease:
    • Asthma (severe)
    • Bronchiolitis (RSV)
    • Pneumonia (viral/bacterial)
  • Lung Parenchymal Disease:
    • Acute Respiratory Distress Syndrome (ARDS)
    • Pulmonary edema
    • Aspiration pneumonitis
  • Neuromuscular Weakness:
    • Guillain-Barré syndrome
    • Spinal Muscular Atrophy (SMA)
    • Botulism
  • Central Drive Depression:
    • CNS infection/trauma
    • Drug overdose (opioids)
  • Chest Wall/Pleural:
    • Flail chest, Pneumothorax
    • Large pleural effusion
  • Cardiac:
    • Congenital heart disease (CHD)
    • Myocarditis

Causes of Acute Respiratory Failure in Children

⭐ Bronchiolitis, primarily due to Respiratory Syncytial Virus (RSV), is the most common cause of lower respiratory tract infection and subsequent respiratory failure in infants < 1 year old worldwide.

Respiratory Failure - Spotting the Signs

  • Early Recognition is Key: Observe for:

    • Increased Work of Breathing (WOB):
      • Tachypnea: Infants >60/min, Children >40/min.
      • Retractions: Suprasternal, intercostal, subcostal.
      • Nasal flaring, grunting (expiratory sound).
      • Head bobbing, accessory muscle use.
    • Inefficient Breathing:
      • ↓ Air entry, ↓ chest expansion.
      • Wheezing, crackles, stridor.
    • Systemic Effects (Hypoxia/Hypercapnia):
      • CNS: Agitation → lethargy, confusion, coma.
      • CVS: Tachycardia → bradycardia (late), hypertension → hypotension.
      • Skin: Pallor, cyanosis (central: SpO₂ < 90%).
  • Diagnostic Aids:

    • Pulse Oximetry: SpO₂ < 90% despite O₂ is alarming. Target >94%.
    • Arterial Blood Gas (ABG): Definitive.
      • Type I (Hypoxemic): PaO₂ < 60 mmHg (FiO₂ ≥ 0.6).
      • Type II (Hypercapnic): PaCO₂ > 50 mmHg & pH < 7.35.
    • Chest X-Ray: Identifies cause (pneumonia, ARDS).

Pediatric Respiratory Scoring Tool

⭐ Tripod position (child leans forward, supporting on arms) maximizes airway opening and indicates significant respiratory distress.

Respiratory Failure - Rescue & Relief

  • Oxygen Therapy:
    • Goal: SpO₂ > 92%.
    • Devices: Nasal cannula, Face mask, NRBM, HFNC (provides PEEP).
  • Non-Invasive Ventilation (NIV):
    • CPAP/BiPAP for ↑WOB. Contra: GCS < 10, facial trauma.
  • Invasive Mechanical Ventilation (MV):
    • Indications: Apnea, failed NIV, $P_aO_2/F_iO_2$ < 200.
    • Lung Protective: Vt 4-6 ml/kg (IBW), Pplat < 30 $cmH_2O$.
  • Adjuncts:
    • Bronchodilators, steroids, diuretics.
  • ECMO: Refractory hypoxemia/hypercapnia.

⭐ In pediatric ARDS, a key goal of PEEP is to improve oxygenation by recruiting alveoli and preventing atelectrauma.

High‑Yield Points - ⚡ Biggest Takeaways

  • Respiratory failure is the most common precursor to pediatric cardiac arrest.
  • Early recognition of tachypnea, retractions, grunting, and nasal flaring is crucial.
  • Impending failure signs include ↓ respiratory effort, cyanosis despite O2, and altered sensorium.
  • Differentiate Type I (Hypoxemic) with low PaO2/FiO2 and Type II (Hypercapnic) with high PaCO2.
  • Management priorities: ABC (Airway, Breathing, Circulation), oxygenation, and ventilatory support.
  • Common causes include pneumonia, bronchiolitis, and asthma exacerbations.
  • Consider PARDS in severe hypoxemia with bilateral infiltrates_._

Practice Questions: Respiratory Failure

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A 2-year-old male boy presenting with sudden severe dyspnea, what is the most common cause?

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Flashcards: Respiratory Failure

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According to the AHA 2020 guidelines for the Pediatric Basic and Advanced Life Support, it is reasonable to administer the initial dose of epinephrine within _____ minutes from the start of chest compressions

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According to the AHA 2020 guidelines for the Pediatric Basic and Advanced Life Support, it is reasonable to administer the initial dose of epinephrine within _____ minutes from the start of chest compressions

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