ARDS

• Pathophysiology of ARDs

  • Injury/Exudative Phase:

  1. Damage to alveolar-capillary membrane causes increase capillary permeability leading to pulmonary edema
  2. Decreased lung compliance (stiff lungs)

  • Proliferation/Reparative

  1. Fibrin matrix forms progressive hypoxemia

  • Fibrotic phase

  1. Lungs become fibrotic, reduced functional residual capacity, narrowing airways
• Early clinical manifestations:

  • Difficulty breathing: dyspnea, tachypnea, cough, restlessness
  • Lung sounds: normal or fine, scattered crackles
  • ABG: mild hypoxemia, respiratory alkalosis
  • CXR: normal or scattered infiltrates
• Later manifestations of ARDs:

  • Tachycardia, diaphoresis, changes in mental status, cyanosis, and pallor increasing WOB
  • Lung sounds: diffuse crackles, coarse crackles
  • ABG: Hypoxemia despite increase FiO2
  • CXR: Bilateral extensive diffuse infiltrates
• Treatments of ARDs:

  • maintain airway
  • Optimize O2 delivery
  • Minimize oxygen demand
  • Treat the cause
  • Prevent complications
  • ECMO
• ECMO:

  • For patients with severe respiratory failure (hypoxemic and hypercapnic, bridge to transplant, tracheal airway injury) and high risk or mortality
  • Modification of cardiac bypass
  • Removing blood from patient
  • Infusing oxygen, removing CO2
  • Returning blood to patient
  • Collaborative care

  1. Closely monitor drain and return lines (large bore catheters): Major risk decannulation, infection, air embolism
  2. Systemic anticoagulation: Major risk bleeding
  3. C. Must have ECMO certified specialist continually at bedsides – this can be an RN that is trained
  4. Survival rates for ECMO 50-60%
• When a patient has been admitted with multiple rib fractures and a RR of 6 the primary problem is failure of ventilation.
• A patient has suffered form an acute MU and presents with a PaO2 of 55. The primary problem is failure of perfusion
• Failure of ventilation: Ineffective movement of air
• Respiratory failure: PaO2 <60 or PaCO2 >45 with pH </= 7.35
• Failure of oxygenation: O2 not passing from the lungs to the bloodstream effectively
• ARDS definition: Sudden and progressive respiratory failure
• ARDS characteristics: White out chest x-ray, increased PIP
• Goal of treatment for failure of ventilation: Effectively move air in and out of lungs