What is the treatment approach for hemorrhagic Acute Respiratory Distress Syndrome (ARDS)?

Treatment of Hemorrhagic ARDS

The treatment of hemorrhagic ARDS requires a conservative fluid management strategy after resolution of shock, lung-protective ventilation, and consideration of extracorporeal support for refractory cases. 1

Initial Management

• Implement lung-protective ventilation with low tidal volumes (4-8 ml/kg predicted body weight) and limit plateau pressures (<30 cmH₂O) to prevent further lung injury 2, 3
• Ensure adequate tissue perfusion while avoiding fluid overload that can worsen pulmonary edema 1
• Monitor hemodynamic status using ultrasound evaluation of inferior vena cava, pulse pressure variation, and/or central venous pressure 1
• Target hemoglobin >8 g/dL in hemorrhagic ARDS to maintain adequate oxygen-carrying capacity 1

Fluid Management

• Apply a conservative fluid management strategy (FACTT-lite protocol) once shock has resolved, which has been shown to increase ventilator-free days 1
• Follow fluid management guidelines based on central venous pressure and urine output 1:
  • CVP >8 with urine output <0.5 mL/kg/h: administer furosemide
  • CVP 4-8 with urine output <0.5 mL/kg/h: give fluid bolus
  • CVP <4 with urine output <0.5 mL/kg/h: give fluid bolus 1
• Administer albumin in cases of sepsis-related ARDS or severely decreased serum albumin 1

Ventilation Strategy

• Set PEEP appropriately (≥12 cmH₂O in moderate to severe ARDS) to avoid lung derecruitment while preventing RV overload 1, 2
• Limit driving pressure to <18 cmH₂O to reduce risk of right ventricular failure 1
• Maintain PaCO₂ <48 mmHg to prevent pulmonary vasoconstriction 1
• Avoid high frequency oscillatory ventilation with high PEEP baseline 1
• Avoid vigorous spontaneous breathing which can worsen pulmonary hemorrhage 1

Positioning and Adjunctive Therapies

• Implement prone positioning for >12 hours daily in severe ARDS (PaO₂/FiO₂ <100 mmHg) 2, 3
• Consider neuromuscular blocking agents in early severe ARDS to improve ventilator synchrony 2, 3
• Use corticosteroids in selected cases with evidence of fibroproliferation 3
• Consider inhaled selective pulmonary vasodilators (nitric oxide 5-10 ppm or inhaled prostacyclin 20-30 ng/kg/min) for refractory hypoxemia and to improve RV function 1

Hemodynamic Support

• Use norepinephrine as the vasopressor of choice to support mean arterial pressure and improve RV function 1
• Monitor for acute cor pulmonale (occurs in 20-25% of ARDS cases) using echocardiography 1
• Consider levosimendan in cases of RV failure, though more data is needed before routine recommendation 1

Extracorporeal Support

• Consider venovenous ECMO (vvECMO) for severe ARDS with refractory hypoxemia (PaO₂/FiO₂ <70 mmHg for ≥3h or <100 mmHg for ≥6h) despite optimal conventional therapy 1
• Consider venoarterial ECMO (vaECMO) when ARDS is combined with severe cardiogenic shock 1
• Venovenous extracorporeal CO₂ removal (ECCO₂R) may be considered to facilitate lung-protective ventilation, though evidence is still limited 1, 4

Monitoring Requirements

• Perform regular echocardiography to assess RV function and detect acute cor pulmonale 2
• Monitor fluid balance carefully, as positive fluid balance is an independent predictor of poor outcomes in patients receiving ECMO 1
• Assess tissue perfusion through urine output, metabolic acidosis, and mixed venous oxygen saturation 1

Common Pitfalls to Avoid

• Excessive fluid administration worsening pulmonary edema and outcomes 2
• Delaying prone positioning in severe ARDS 2
• Underutilization of evidence-based strategies like lung-protective ventilation 2
• Using hydroxyethyl starch fluids in resuscitation 2
• Inappropriate ventilator settings causing right ventricular dysfunction 3