Haemorrhagic shock: low-dose arginine vasopressin reduces need for blood products

Takeaway

• For patients experiencing trauma-related haemorrhagic shock, low-dose supplementation with arginine vasopressin (AVP) leads to a reduced need for blood products and no more complications than placebo.
• Commentary:
  • “This finding refutes the dogma that pressor therapy should never be initiated in patients with hypotension or bleeding and that the answer is volume.”
  • Warns that targeting specific mean arterial pressure (MAP) may mean result is artifact.
  • Suggests deep venous thrombosis (DVT) finding is likely a statistical anomaly.

Why this matters

• Aggressive fluid resuscitation and transfusions in this setting can cause complications.

Key results

• AVP use vs placebo:
  • 1.00 L less blood product (95% CI, −2.03 to 0.00 L; P=.03).
  • Fewer DVTs: 20% vs 39% (P=.05).
• Similar lengths of stay, overall complications, mortality.
• On per-protocol analysis, AVP led to use of fewer blood products and fewer DVTs.

Study design

• Randomised, double-blind placebo-controlled AVERT Shock trial(n=100).
• Adults receiving ≥6 units of blood products were randomly assigned to receive bolus+infusion of AVP vs placebo.
• Study infusion and pressors titrated to maintain MAP at ≥65 mmHg.
• Outcomes: volume of transfused blood products within 48 hours.
• Funding: Supported by National Trauma Institute and Army awards to researchers.

Limitations

• Small, single-centre study.