Acute Respiratory Distress Syndrome (ARDS)

Definition/Etiology:

• Definition
  • Most severe form of acute lung injury with a very high mortality rate. (30 -50%)
  • Characterized as noncardiogenic pulmonary edema and malfunction of the alveolar/capillary membrane.
• Etiology – anything that activates the immune system
  • Primary Causes
    • Sepsis – Systemic Inflammation
  • Secondary Causes
    • Covid-19
    • Pneumonia A
    • Acute Pancreatitis
    • Drug Overdose
    • Near Drowning

Pathophysiology:

• Inflammatory mediators not only go to the injured area of the body but to the alveoli and lung capillaries.
• Fluids shift from capillaries and flood alveoli -cannot make surfactant.
• Lack of surfactant = Lungs cannot expand
• Alveoli shrivel – becoming unusable
• Leads to atelectasis
• Three Phases BUT PCCN nurses focus on later stages/decompensated patients – early stages are rarely “caught”.

Noticing: Assessment & Recognizing Cues:

• FAST ONSET
• Subjective Cues
  • Fatigue
  • Dyspnea/Increased work of breathing
  • Decreased LOC
• Objective Cues
  • Vitals
    • Increased HR, decreased 02 Sat
    • Refractory Hypoxemia
  • Lung sounds
    • Diminished lung expansion
    • Wet Sounds
    • Productive Cough
    • Pink Frothy Sputum

Interpreting: Analyzing & Planning:

• Labs
  • CBC – R/O Sepsis
  • BNP: rule out cardiac causes
  • ABGs
    • P/F Ratio (PaO2 / FiO2)
      • <200
    • Refractory Hypoxemia
      • Arterial 02 doesn’t respond to applied Oxygen
      • Pa02 below 55 mm Hg
• Diagnostics
  • Chest X-ray → diffuse bilateral infiltrates
    • “White Out”
  • ECG – Tachycardias r/t hypoxia

Responding: Patient Interventions & Taking Action:

• ABCs + underlying cause
  • BiPap at minimum with probable VENT
  • Why? NEED PEEP? Pressure to keep open alveoli back up.
• Pharmacological Interventions
  • Depends on underlying cause
  • Sepsis?
    • Fluids + ABx + Pressors
  • Steroids
  • Paralytics & sedation for mechanical ventilation
• Non-Pharmacological
  • Prone positioning -Lets gas exchange happen where lung tissue is still good (Superior Anterior lobes)
• Adjunct Medical Therapy
  • Respiratory Therapist
  • Pulmonologist

Reflecting: Evaluating Patient Outcomes:

• Airway Breathing
  • Oral Care & HOB – prevent VAP
  • Improved P/F Ratio
  • Improved Pa02 on blood gasses
  • Improved CXR
  • Wean from BiPap or Vent
• Circulation
  • MAP > 65 (Perfusion)

Linchpins (Key Points):

• Notice – Refractory Hypoxemia
• Interpret – Blood Gases, P/F Ratio & CXR
• Respond – Proning & BiPaP/Vent
• Reflect – Pa02 improves WHILE weaning