PARDS

• ARDS


  Acute heterogenous disease that causes an overwhelming pulmonary inflammation due to pulmonary (direct lung injury) and extrapulmonary (indirect lung injury) etiologies that leads to alveolar edema and hypoxemic respiratory failure

  
• PARDS


  Exclude patients with perinatal-related lung disease; the onset is within 7 days of known clinical insult
• Origin of pulmonary edema is due to respiratory failure not fully explained by cardiac failure or fluid overload

  
• Causes of acute respiratory failure

  • Pneumonia
  • Aspiration
  • Sepsis
  • Smoke inhalation
  • Multitrauma
  • Burns
  • Near drowning

  
• Mortality rate for pediatric patients about 60%; most common cause of death is due to multiorgan failure
• Chest imaging findings of new diffuse, bilateral alveolar infiltrates consistent with acute pulmonary parenchymal disease
• Mild ARDS


  Inflammatory syndrome that results in increased permeability of the pulmonary vasculature that causes hypoxemia and intrapulmonary shunting

  
• Moderate - severe ARDS

  Incorporates pulmonary edema and refractory hypoxemia
• Oxygen Index (OI)


  [(FiO2 X MAP X 100)/PaO2]
• Oxygen Saturation Index (OSI)


  [(FiO2 X MAP X 100)/SpO2]

  
• PaO2/FiO2 (P/F) ratio


  • Mild ARDS = P/F ratio <300 mmHg
  • Moderate ARDS = P/F ratio <200 mmHg
  • Severe ARDS = P/F ratio <100 mmHg
• NIV


  A CPAP of 5 cmH2O is set
• Measures of Oxygenation for PARDS

  • Mild OI 4 - 8
  • Mild OSI 5 - 7.5
  • Moderate OI 8 - 16
  • Moderate OSI 7.5 - 12.3
  • Severe OI >16
  • Severe OSI >12.3

  
• PARDS Management and Treatment

  • Non-invasive support: nCPAP, BiPAP, high flow O2 therapy (HFOT)
  • Severe hypoxemia and/or hypercapnea: intubation/ mechanical ventilation
  • AC-PCV with decelerating flow pattern; plateau pressure limited to 30-32 cmH2O; add moderately elevated PEEP (10 - 15cmH2O)
  • Permissive hypercapnea (TV <4-6ml/kg) to minimize lung injury with target pH minimum 7.25
• Other PARDS Management and Treatment

  • High Frequency Ventilation (HFV)
  • Prone positioning and ECMO - for severe PARDS
  • Inhaled Nitric Oxide (iNO) - for documented pulmonary HPN